1,015 research outputs found
PERANCANGAN KEBUTUHAN KAPASITOR BANK UNTUK PERBAIKAN FAKTOR DAYA PADA LINE MESS I DI PT. BUMI LAMONGAN SEJATI (WBL)
Abstrak Permasalahan pada line Mess I PT.Bumi Lamongan Sejati(WBL) adalah terdapat banyak beban-beban induktif yang muncul akibat banyaknya macam beban yang terpasang pada line ini, seperti beberapa alat permainan dan wahana yang berbeda-beda, keadaan tersebut membuat faktor dayanya menjadi rendah dan menurunnya tegangan pada daerah dekat beban sehingga trip tidak dapat dihindarkan pada line ini. Perhitungan besar daya reaktif dan kapasitas kapasitor bank yang sesuai dengan kebutuhan beban ini akan membantu meminimalisasikan faktor daya yang rendah yang akan berpengaruh pada optimalnya suplai tenaga listrik dan kenyamanan aktifitas operasional di line Mess I PT. Bumi Lamongan Sejati (WBL). Perancangan ini sangat penting untuk mengetahui perbaikan faktor daya pada sistem tenaga listrik di line Mess I PT. Bumi Lamongan Sejati (WBL).Dari hasil perhitungan,didapatkan besar kebutuhan kapasitas kapasitor banknya adalah 219,858 KVAR. Kata Kunci : Daya reaktif, faktor daya, kapasitor bank. Abstract The problem in Bumi Lamongan Sejati Limited Company Mess I line is the considerable inductive load that come up as the impact of many different load set in this line, such as some game devices and varying facilities, this condition lower its power factor and decline the strain in the area near the load so that trip cannot be avoided in this line. The calculation of reactive power consumption and the capacity of bank capacitor in accordance with the requirement of this load will help to minimize the low power factor which will impact on the optimization of the electricity supply and the comfort of operational activity in Bumi Lamongan Sejati Limited Company Mess I line. This design is very important to find out the improvement of power factor in the electricity system in Bumi Lamongan Sejati Limited Company Mess I line. From the calculation result, it was found that the required capacity of bank capacitor is 219,858 KVAR. Keywords: Reactive power, power factor, bank capacito
Analisis Manfaat dalam Proyek Pengerukan Studi Kasus: Alur Pelayaran Surabaya Timur
Pesisir pantai, penyeberangan laut, dan alur pelayaran memainkan peran penting dalam transportasi laut. Sebagian besar kargo yang diangkut adalah angkutan domestik dan internasional. Transportasi laut telah mendapatkan perhatian selama bertahun-tahun karena dinilai hemat energi dan bahan bakar, terdapat peningkatan minat dalam memperluas rute perdagangan melalui laut untuk pengiriman barang domestik. Karena draf berlayar kapal terkait langsung dengan tonase yang dimuat, kedalaman saluran yang diperlukan untuk memastikan kapasitas angkut yang memadai. Tantangan bagi para pengambil keputusan adalah untuk secara optimal mengalokasikan pengeluaran berupa biaya pengerukan alur pelayaran di seluruh jaringan alur pelayaran yang luas untuk memaksimalkan manfaat secara nasional. Penelitian ini bertujuan untuk mengidentifikasi konsep manfaat jika proyek pengerukan alur pelayaran dilakukan dengan menggunakan analisis deskriptif. Berdasarkan hasil analisis, manfaat pengerukan adalah meningkatkan keamanan dan keselamatan alur pelayaran, meningkatkan kelayakan transportasi laut, meningkatkan stabilitas pergerakan barang, meningkatkan konektivitas antar pelabuhan, meningkatkan pembangunan infrastruktur pelabuhan, meningkatkan dimensi kapal yang dapat memasuki pelabuhan, meningkatkan stabilitas kinerja pelabuhan, meningkatkan jumlah kapal yang dapat memasuki pelabuhan, menurunkan laju sedimentasi di saluran akses, mengurangi pergantian waktu kapal, meningkatkan efisiensi kinerja pelabuhan, menurunkan biaya pelabuhan, dan meningkatkan pendapatan operator pelabuhan
The Structure of the Oligomerization Domain of Lsr2 from Mycobacterium tuberculosis Reveals a Mechanism for Chromosome Organization and Protection
Lsr2 is a small DNA-binding protein present in mycobacteria and related actinobacteria that regulates gene expression and influences the organization of bacterial chromatin. Lsr2 is a dimer that binds to AT-rich regions of chromosomal DNA and physically protects DNA from damage by reactive oxygen intermediates (ROI). A recent structure of the C-terminal DNA-binding domain of Lsr2 provides a rationale for its interaction with the minor groove of DNA, its preference for AT-rich tracts, and its similarity to other bacterial nucleoid-associated DNA-binding domains. In contrast, the details of Lsr2 dimerization (and oligomerization) via its N-terminal domain, and the mechanism of Lsr2-mediated chromosomal cross-linking and protection is unknown. We have solved the structure of the N-terminal domain of Lsr2 (N-Lsr2) at 1.73 Å resolution using crystallographic ab initio approaches. The structure shows an intimate dimer of two ß-ß-a motifs with no close homologues in the structural databases. The organization of individual N-Lsr2 dimers in the crystal also reveals a mechanism for oligomerization. Proteolytic removal of three N-terminal residues from Lsr2 results in the formation of an anti-parallel β-sheet between neighboring molecules and the formation of linear chains of N-Lsr2. Oligomerization can be artificially induced using low concentrations of trypsin and the arrangement of N-Lsr2 into long chains is observed in both monoclinic and hexagonal crystallographic space groups. In solution, oligomerization of N-Lsr2 is also observed following treatment with trypsin. A change in chromosomal topology after the addition of trypsin to full-length Lsr2-DNA complexes and protection of DNA towards DNAse digestion can be observed using electron microscopy and electrophoresis. These results suggest a mechanism for oligomerization of Lsr2 via protease-activation leading to chromosome compaction and protection, and concomitant down-regulation of large numbers of genes. This mechanism is likely to be relevant under conditions of stress where cellular proteases are known to be upregulated
Analyzing Falling Weight Deflectometer Data on Curled and Warped Concrete Slabs
Falling weight deflectometer testing (FWD) is a non-destructive testing method for pavements, which involves measuring the response of a pavement to a a falling weight. For jointed plain concrete pavements (JPCP), the response of the pavement to the FWD load can be used to backcalculate the pavement layer properties, estimate the performance of the joints, and detect voids. Temperature and moisture gradients in the concrete layer of JPCPs induce curvature in the slab, altering the support conditions of the slab throughout the day. This change in support condition can have a significant effect on FWD testing results.
A combination of computational analyses, interpretation of field trials, and statistical analysis was used to evaluate the effect of slab curvature when interpreting FWD data. It was determined that backcalculation of the modulus of subgrade reaction (k-value), is sensitive to slab curvature, if the equivalent linear temperature gradient (ELTG) in the slab is less than 0.5 °F/in especially. for pavements with stiff supporting layers. A backcalculation procedure was developed to backcalculate the modulus of subgrade reaction using FWD testing when positive temperature gradients are present. The measured load transfer efficiency (LTE) for doweled JPCP slabs was found to be at a minimum when the slab is approximately flat and increase as a positive or negative temperature gradient develops. The measured differential deflection for doweled slabs was found to be at a maximum when the slab is approximately flat or with a negative temperature gradient, depending on the condition of the dowels. A void detection model for doweled JPCP pavements was developed using LASSO logistic regression, which outperforms currently available void detection techniques. Finally, a temperature prediction model was developed, which predicts the pavement temperature profile as a function of the weather conditions. The developed models are all packaged in the University of Pittsburgh FWD Analysis of Concretes Slabs (PITT-FACS) web tool, so that they can easily be used by practitioners
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A major T cell antigen of Mycobacterium leprae is a 10-kD heat-shock cognate protein.
Several mycobacterial antigens, identified by monoclonal antibodies and patient sera, have been found to be homologous to stress or heat-shock proteins (hsp) defined in Escherichia coli and yeast. A major antigen recognized by most Mycobacterium leprae-reactive human T cell lines and cell wall-reactive T cell clones is a 10-kD protein that has now been cloned and sequenced. The predicted amino acid sequence of this protein is 44% homologous to the hsp 10 (GroES) of E. coli. The purified native and recombinant 10-kD protein was found to be a stronger stimulator of peripheral blood T cell proliferation than other native and recombinant M. leprae proteins tested. The degree of reactivity paralleled the response to intact M. leprae throughout the spectrum of leprosy. Limiting-dilution analysis of peripheral blood lymphocytes from a patient contact and a tuberculoid patient indicated that approximately one third of M. leprae-reactive T cell precursors responded to the 10-kD antigen. T cell lines derived from lepromin skin tests were strongly responsive to the 10-kD protein. T cell clones reactive to both the purified native and recombinant 10-kD antigens recognized M. leprae-specific epitopes as well as epitopes crossreactive with the cognate antigen of M. tuberculosis. Further, the purified hsp 10 elicited strong delayed-type hypersensitivity reactions in guinea pigs sensitized to M. leprae. The strong T cell responses against the M. leprae 10-kD protein suggest a role for this heat-shock cognate protein in the protective/resistant responses to infection
Whole genome sequencing of Mycobacterium tuberculosis reveals slow growth and low mutation rates during latent infections in humans
Very little is known about the growth and mutation rates of Mycobacterium tuberculosis during latent infection in humans. However, studies in rhesus macaques have suggested that latent infections have mutation rates that are higher than that observed during active tuberculosis disease. Elevated mutation rates are presumed risk factors for the development of drug resistance. Therefore, the investigation of mutation rates during human latency is of high importance. We performed whole genome mutation analysis of M. tuberculosis isolates from a multi-decade tuberculosis outbreak of the New Zealand Rangipo strain. We used epidemiological and phylogenetic analysis to identify four cases of tuberculosis acquired from the same index case. Two of the tuberculosis cases occurred within two years of exposure and were classified as recently transmitted tuberculosis. Two other cases occurred more than 20 years after exposure and were classified as reactivation of latent M. tuberculosis infections. Mutation rates were compared between the two recently transmitted pairs versus the two latent pairs. Mean mutation rates assuming 20 hour generation times were 5.5X10⁻¹⁰ mutations/bp/generation for recently transmitted tuberculosis and 7.3X10⁻¹¹ mutations/bp/generation for latent tuberculosis. Generation time versus mutation rate curves were also significantly higher for recently transmitted tuberculosis across all replication rates (p = 0.006). Assuming identical replication and mutation rates among all isolates in the final two years before disease reactivation, the u20hr mutation rate attributable to the remaining latent period was 1.6×10⁻¹¹ mutations/bp/generation, or approximately 30 fold less than that calculated during the two years immediately before disease. Mutations attributable to oxidative stress as might be caused by bacterial exposure to the host immune system were not increased in latent infections. In conclusion, we did not find any evidence to suggest elevated mutation rates during tuberculosis latency in humans, unlike the situation in rhesus macaques
Pengaruh Store Atmosphere terhadap Proses Keputusan Pembelian pada Kopi Ireng Bandung
Dewasa ini kopi merupakan hal yang sangat trend oleh masyarakat dengan itu bisnis toko kopi di Indonesia telah berkembang dengan pesat. Di Bandung sendiri sedikitnya sudah ada sepuluh toko kopi recomended yang masuk didalam website www.pergidulu.com. Dalam hal ini, perlu dilakukan retensi pelanggan untuk mempertahankan pelanggan salah satunya dengan menyajikan store atmosphere. Dalam penelitian ini mencoba mengukur pengaruh store atmosphere terhadap proses keputusan pembelian di Kopi Ireng Bandung. Penelitian ini menggunakan pendekatan kuantitatif dimana jumlah populasi yang dijadikan sampel sebanyak 100 orang dengan metode non-probability sampling dengan metode convenience sampling. Data dalam penelitian ini didapatkan melalui penyebaran kuesioner dan dianalisis menggunakan analisis regresi linier berganda. Hasil penelitian menunjukkan bahwa pengaruh store atmosphere secara simultan sebesar 39,6% dalam mempengaruhi proses keputusan pembelian dan sisanya 60,4% dipengaruhi oleh faktor lain diluar penelitian ini. Secara parsial sub variabel exterior tidak berpengaruh signifikan terhadap proses keputusan pembelian. Sedangkan sub variabel general interior, store layout, dan interior display berpengaruh signifikan terhadap proses keputusan pembelian
PERANCANGAN KEBUTUHAN KAPASITOR BANK UNTUK PERBAIKAN FAKTOR DAYA PADA LINE MESS I DI PT. BUMI LAMONGAN SEJATI (WBL)
Abstrak Permasalahan pada line Mess I PT.Bumi Lamongan Sejati(WBL) adalah terdapat banyak beban-beban induktif yang muncul akibat banyaknya macam beban yang terpasang pada line ini, seperti beberapa alat permainan dan wahana yang berbeda-beda, keadaan tersebut membuat faktor dayanya menjadi rendah dan menurunnya tegangan pada daerah dekat beban sehingga trip tidak dapat dihindarkan pada line ini. Perhitungan besar daya reaktif dan kapasitas kapasitor bank yang sesuai dengan kebutuhan beban ini akan membantu meminimalisasikan faktor daya yang rendah yang akan berpengaruh pada optimalnya suplai tenaga listrik dan kenyamanan aktifitas operasional di line Mess I PT. Bumi Lamongan Sejati (WBL). Perancangan ini sangat penting untuk mengetahui perbaikan faktor daya pada sistem tenaga listrik di line Mess I PT. Bumi Lamongan Sejati (WBL).Dari hasil perhitungan,didapatkan besar kebutuhan kapasitas kapasitor banknya adalah 219,858 KVAR. Kata Kunci : Daya reaktif, faktor daya, kapasitor bank. Abstract The problem in Bumi Lamongan Sejati Limited Company Mess I line is the considerable inductive load that come up as the impact of many different load set in this line, such as some game devices and varying facilities, this condition lower its power factor and decline the strain in the area near the load so that trip cannot be avoided in this line. The calculation of reactive power consumption and the capacity of bank capacitor in accordance with the requirement of this load will help to minimize the low power factor which will impact on the optimization of the electricity supply and the comfort of operational activity in Bumi Lamongan Sejati Limited Company Mess I line. This design is very important to find out the improvement of power factor in the electricity system in Bumi Lamongan Sejati Limited Company Mess I line. From the calculation result, it was found that the required capacity of bank capacitor is 219,858 KVAR. Keywords: Reactive power, power factor, bank capacito
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