Analisis Pengujian Pemutus Tenaga Bay Kedungombo 2 Dalam Pemeliharaan Dua Tahunan Di Gardu Induk Purwodadi

Gardu induk merupakan bagian dari sistem transmisi tenaga listrik yang berfungsi untuk menurunkan tegangan. Salah satu bagian peralatan listriknya adalah pemutus tenaga (PMT). Fungsi utama PMT adalah saklar mekanis yang mampu mengalirkan dan memutus arus beban dalam keadaan normal maupun dalam keadaan abnormal/gangguan sesuai dengan nilai ratingnya. Untuk tetap menjaga keandalan PMT perlu dilakukan pemeliharaan secara berkala. Pemeliharaan PMT dilakukan dengan melakukan pengujian terhadap tahanan isolasi, tahanan kontak, tahanan pentanahan dan uji keserempakan kontak PMT. Penelitian ini bertujuan untuk mengetahui pengaruh pemeliharaan PMT terhadap kelayakan PMT tersebut. Penelitian ini dilakukan dengan membandingkan data hasil pemeliharaan PMT dalam beberapa periode pemeliharaan terakhir. Penelitian ini dilakukan pada PMT bay Kedungombo 2 di gardu induk Purwodadi. Pada pemutus tenaga bay Kedungombo 2 di gardu induk Purwodadi memiliki nilai tahanan isolasi berbeda-beda. Nilai kemampuan isolasi bay Kedungombo 2 di gardu induk Purwodadi terkecil dalam 3 periode pemeliharaan terakhir adalah 2.900 MΩ/kV, nilai tersebut masih memenuhi standar yaitu ≥ 1 MΩ/kV. Nilai tahanan pentanahan PMT bay Kedungombo 2 di gardu induk Purwodadi terbesar dalam 3 periode pemeliharaan yaitu 0,11 Ω, nilai tersebut masih memenuhi standar yaitu ≤ 1 Ohm. Pada pengujian keserempakan kontak PMT nilainnya berbeda-beda dalam setiap periode pemeliharaan, waktu kerja kontak masih berada dalam batas yang diijinkan yaitu di bawah 120 mili detik. Pada tahun 2014 selisih waktu keserempakan kontak pada saat open lebih sedikit daripada close sebesar 6,45 ms. Pada tahun 2016 selisih waktu keserempakan kontak pada saat open lebih banyak daripada close sebesar 2 ms. Pada tahun 2018 selisih waktu keserempakan kontak pada saat open lebih sedikit daripada close sebesar 1 ms. Kata Kunci : pemutus tenaga, pengujian tahanan isolasi, tahanan kontak, tahanan pentanahan, keserempakan konta

Population growth and reproductive potential of five important fishes from the freshwater bodies of Bangladesh

Population growth (length-weight relationship), and reproductive potential (e.g. fecundity, and sex-ratio) of five important fish species (‘mola’: Amblypharyngodon mola, ‘puti’: Puntius sophore, ‘tengra’: Mystus vittatus, ‘shing’: Heteropneustes fossilis and ‘taki’: Channa punctatus) collected from two important fresh water bodies (namely Hilna beel and Beel Kumari beel) Rajshahi, Bangladesh, were studied. Population growth pattern by length-weight relationship (W=aLb ) for the species differed, and exhibited positive allometric growth (P. sophore in Hilna beel), isometric growth (A. mola and C. punctatus in Hilna beel) and negative allometric growth (M. vittatus & H. fossilis in Hilna beel and A. mola, P. sophore, M. vittatus, C. punctatus and H. fossilis in Beel Kumari beel). The results denoted that fecundity of mature females followed a non-linear relationship (F=aLb ) with total length and exhibited positive allometric growth (b>3) with some exception (A. mola in Hilna beel and M. vittatus in Beel Kumari beel). Fecundity of mature females also increased with total body weight and ovary weight following a linear relationship (F=a+bW). Differences in values of sexratios with seasons for all species in this study may have resulted from different environmental factors as well as breeding seasons. The findings of this study would be useful in imposing adequate regulations for the conservation of these fascinating fishes in the fresh water bodies of Bangladesh

Adaptive performance of garlic varieties under high Ganges River floodplain soil (calcareous) of Bangladesh

Any variety needs to evaluate at different locations, along with variable soils for asses their yield potentiality after its releasing. Thus, an experiment was conducted at Multi Location Testing (MLT) site, Kushtia Sadar Upazila, under High Ganges River Floodplain (AEZ-11) in Bangladesh, during three consecutive Rabi seasons of 2013-2014 to 2015-2016. The objective of this study was to evaluate the performances of garlic varieties and economic profitability of these varieties at farmer’s field. There were three garlic varieties, namely BARI Rashun-1, BARI Rashun-2 and a local cultivar, which were evaluated at six dispersed locations as replications. Results observed that the highest yield (8.34-9.80 t ha-1) was obtained from BARI Rashun-1, which was followed by BARI Rashun-2 (7.43-9.48 t ha-1) and the local one (7.12-9.15 t ha-1). BARI Rashun-1 produced 3-12% higher yield over BARI Rashun-2 and 7-20% over the local cultivar, respectively in three consecutive years. Correlation analysis showed that there were positive and significant correlation among bulb yields with bulb length and individual bulb weight. Regarding the functional relationship, the traits like crop duration, plant population, plant height, bulb length, bulb width, individual bulb weight had positive contribution on the bulb yield. It was dependent on those traits, and accounted for 12, 36, 0.05, 45, 41 and 55% of the total bulb yield variation, respectively. The highest gross return (Tk. 3, 63,700 ha-1) and gross margin (Tk. 2,19,425 ha-1) were obtained from BARI Rashun-1. As such, this variety performed as the best, in respect of higher bulb yield potential, as well as the highest economic return among the tested varieties, which was followed by BARI Rashun-2. Therefore, the result of this study could be helpful for improving bulb production of garlic under High Ganges River Floodplain soil (calcareous soils) in Bangladesh

Transesterifikasi Minyak Biji Buta-Buta menjadi Biodiesel pada Katalis Heterogen Kalsium Oksida (CaO)

Penelitian ini menggunakan katalis padat CaO untuk reaksi transesterifikasi minyak biji buta-buta menjadi biodiesel. Minyak biji buta-buta diekstraksi menggunakan alat press. Katalis CaO disiapkan dari cangkang kerang dengan cara dipijar pada suhu 850 oC. Sampel katalis dikarakterisasi dengan metode scanning electron microscopy (SEM) dan x-ray diffractometer (XRD). Katalis cangkang kerang memiliki ukuran partikel antara 200-2000 nm. Hal ini karena pemanasan cangkang pada 850 oC menyebabkan terjadi aglomerasi. Dari rekaman XRD teridentifikasi bahwa katalis didominasi oleh senyawa CaO dan terdapat sedikit CaCO3. Reaksi transesterifikasi dilangsungkan dalam reaktor batch dengan variasi suhu (55 oC, 60 oC, 65oC, dan 70oC), rasio metanol terhadap minyak: 3:1, 6:1, 9:1, 12:1, dan 15:1. Reaksi dilangsungkan selama 3 jam dan katalis didispersi 6 % berat dari minyak. Perolehan metil ester maksimum dicapai 96,7% pada kondisi reaksi, yaitu: molar metanol:minyak 12:1 dan suhu reaksi 65 oC. Karakteristik biodiesel hasil penelitian ini memenuhi sifat-sifat bahan bakar berkualitas tinggi sesuai dengan standar SNI dan ASTM. Proses transesterifikasi minyak biji buta-buta dan metanol menggunakan CaO sebagai katalis basa heterogen layak diaplikasikan secara komersial untuk produksi biodiesel dalam skala industri

Quintessential Maldacena-Maoz Cosmologies

Maldacena and Maoz have proposed a new approach to holographic cosmology based on Euclidean manifolds with disconnected boundaries. This approach appears, however, to be in conflict with the known geometric results [the Witten-Yau theorem and its extensions] on spaces with boundaries of non-negative scalar curvature. We show precisely how the Maldacena-Maoz approach evades these theorems. We also exhibit Maldacena-Maoz cosmologies with [cosmologically] more natural matter content, namely quintessence instead of Yang-Mills fields, thereby demonstrating that these cosmologies do not depend on a special choice of matter to split the Euclidean boundary. We conclude that if our Universe is fundamentally anti-de Sitter-like [with the current acceleration being only temporary], then this may force us to confront the holography of spaces with a connected bulk but a disconnected boundary.Comment: Much improved exposition, exponent in Cai-Galloway theorem fixed, axionic interpretation of scalar explained, JHEP version. 33 pages, 3 eps figure

Deep tubewell microbial water quality and access in arsenic mitigation programs in rural Bangladesh

The objective of this paper is to determine whether deep tubewells installed through arsenic mitigation efforts in rural Bangladesh provide better drinking water microbial quality compared to shallow tubewells. We conducted a stratified random cross-sectional survey of 484 households to assess microbial contamination of deep tubewell water at source and at point of use (POU) compared to shallow tubewell water using the Compartment Bag Test. In addition, we measured storage time, distance, travel time and ownership status among both sets of users to assess deep tubewell efficacy and under what conditions they offer poorer or better water quality. Differences in tubewell characteristics were compared using non-parametric Mann-Whitney U tests and two-proportion Z-tests. Prevalence ratios of microbial contamination stratified by water quality, storage time and distance to tubewells and ownership were estimated using unadjusted Mantel-Haenszel tests. There was no significant difference in microbial contamination between shallow and deep tubewells at source. The presence of POU water microbial contamination in storage containers in deep tubewell households was 1.11 times the prevalence in shallow tubewell storage containers (95% CI = 0.97–1.27). Deep tubewell users stored water longer and walked significantly farther to obtain water compared to shallow tubewell users. Among deep tubewell households, those residing farther away from the source were 1.24 times as likely to drink contaminated water from storage containers compared to those located nearby (95% CI = 1.04–1.48). Our findings suggest that deep tubewells have comparable water quality to shallow tubewells at source, but increasing distance from the household exacerbates risk of microbial contamination at POU

Search for Anomalous Couplings in the Higgs Sector at LEP

Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H -> Z\gamma and H -> WW^(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, db, Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H -> gamma gamma and H -> Z gamma decay rates

Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02