72 research outputs found
Dilatometer Based Liquefaction Potential of Sites in the Imperial Valley
The liquefaction potential of several sites in the Imperial Valley, south California, is evaluated on the basis of standard penetration, cone, and dilatometer test data. The performance of the soil deposits at these sites during past earthquakes has been documented in earlier studies. Since the dilatometer parameter Kd is expected to reflect factors (e.g. fabric, prestress, preshaking, aging) affecting liquefaction potential to a certain extent (Marchetti, 1982), this paper primarily focuses on this parameter as an index for evaluating liquefaction potential. A tentative boundary curve (in terms of stress ratio vs. Kd) for evaluating liquefaction potential that takes advantage of earlier boundaries is proposed. A promising index which combines dynamic and static dilatometer tests is also proposed
Effective Stress Analyses of Seismic Stability
The factors involved in performing effective stress analysis of seismic stability problems are examined. The advantages of using a stochastic model for pore pressure generation are discussed. A simplified analysis of a hypothetical case is outlined to illustrate the factors involved in performing effective stress stability analysis
ANALISIS PENGENDALIAN KUALITAS SIX SIGMA DENGAN METODE DEFINE, MEASURE, ANALYZE, IMPROVE, CONTROL (DMAIC) TERHADAP LINI Z PROSES PRODUKSI MOBIL KIJANG PADA PT. TOYOTA MOTOR MANUFACTURING INDONESIA
PT. Toyota Motor Manufacturing Indonesia (TMMI) sebagai salah satu
perusahaan otomotif terkemuka di Indonesia dengan salah satu produk
unggulannya yaitu mobil kijang berusaha meningkatkan kualitas produk yang
dihasilkannya. Salah satu program peningkatan kualitas yang dapat menjadi
pilihan dan telah terbukti keefektifannya adalah “Six-Sigma”, yaitu pada GE
Company dan Motorola.
Program peningkatan kualitas yang diusulkan pada penulisan skripsi
ini berfokus pada departemen produksi khususnya pada QE ( Quality
Engineering) dengen harapan hasil dari penerapan penelitian dengan metode
ini akan memberikan usulan yang berguna bagi perbaikan kualitas proses
produksi. Data-data masukan yang digunakan diperoleh selama berada di PT.
TMMI sejak bulan Agustus-September 2003, baik secara tertulis maupun
secara lisan.
Sesuai dengan prinsip Six Sigma yang berfokus pada pelanggan dan
berorientasi pada proses maka akan berpengaruh pada hasil akhir yang
diharapkan. Metode yang digunakan dalam proses pengolahan data adalah
DMAIC (Define, Measure, Analyze, Improve, Control). Proses pengolahan
data dimulai dari pendefinisian masalah yang akan dipecahkan, melakukan
pengukuran terhadap data, menganalisis hasil pengukuran data, memperbaiki
kesalahan produk yang didapatkan, dan kemudian mengendalikan usaha
perbaikan yang telah dilakukan.
Berdasarkan hasil penelitian, pada tahap define diketahui bahwa jenis
cacat terbesar pada lini produksi Z adalah bari. Pada tahap measure
diketahui data berdistribusi normal dengan CTQ sebanyak 21 buah dan
kinerja berada pada tingkat 4,7 sigma dengan nilai DPMO sebesar 732. Pada
tahap analyze diketahui indeks kapabilitas proses sebesar 0,984631, sumber
penyebab permasalahan terdapat pada faktor mesin, manusia, dan
lingkungan. Pada tahap improve ditetapkan suatu rencana tindakan terhadap
sumber-sumber dan akar penyebab dari masalah kualitas yang telah
teridentifikasi pada tahap-tahap sebelumnya. Pada tahap terakhir yaitu
control, usulan peningkatan kualitas didokumentasikan dan distandarisasikan
agar dapat disebarluaskan dengan menggunakan metode 5W -2H
Structural Collapse Behavior of Sands in Undrained Shear
Results from undrained torsional shear tests are presented and used to further examine the concepts of steady state and structural collapse in sands, with emphasis on the influence of the collapse mechanism on soil behavior at steady state. It is shown that the degree to which the material collapses is dependent on the loading conditions and the initial fabric of the sand. Consequently, the steady state position in the state diagram is also function of these parameters
Measurement and Analysis of Civil Engineering Vibrations
Man-made vibrations caused by construction activities, blasting, rail and vehicular traffic, and machinery can have an adverse impact on buildings and facilities, human occupants of buildings, and sensitive equipment housed within these facilities. Comparisons between vibrations are often difficult because of different methods used to measure, analyze, and interpret vibration data. To facilitate these comparisons, standard methods of selecting and mounting transducers, processing vibration data, and interpreting test results are reviewed. Specific measurement and analysis techniques and maximum allowable vibration criteria used for evaluating the influence of vibrations on humans, the potential for cosmetic damage to structures, and the impact on vibration-sensitive equipment are also summarized
Performance of Fill Soils During the Loma Prieta Earthquake
The results of high quality in situ test results obtained at Hunter\u27s Point Naval Station both before and after the Lorna Prieta earthquake are presented. The interpretation of these tests and the results of subsequent numerical ground motion analyses are validated by the observed response at that site during the event. Data show that densification of the loose fill soils occurred as a result of the seismic activity and corroborate the observed surface deformations
Trachynilysin mediates SNARE-dependent release of catecholamines from chromaffin cells via external and stored Ca2+
Trachynilysin, a 159 kDa dimeric protein purified from stonefish (Synanceia trachynis) venom, dramatically increases spontaneous quantal transmitter release at the frog neuromuscular junction, depleting small clear synaptic vesicles, whilst not affecting large dense core vesicles. The basis of this insensitivity of large dense core vesicles exocytosis was examined using a fluorimetric assay to determine whether the toxin could elicit catecholamine release from bovine chromaffin cells. Unlike the case of the motor nerve endings, nanomolar concentrations of trachynilysin evoked sustained Soluble N-ethylmaleimide-sensitive fusion protein Attachment Protein REceptor-dependent exocytosis of large dense core vesicles, but only in the presence of extracellular Ca2+. However, this response to trachynilysin does not rely on Ca2+ influx through voltage-activated Ca2+ channels because the secretion was only slightly affected by blockers of L, N and P/Q types. Instead, trachynilysin elicited a localized increase in intracellular fluorescence monitored with fluo-3/AM, that precisely co-localized with the increase of fluorescence resulting from caffeine-induced release of Ca2+ from intracellular stores. Moreover, depletion of the latter stores inhibited trachynilysin-induced egocytosis. Thus, the observed requirement of external Ca2+ for stimulation of large dense core vesicles exocytosis from chromaffin cells implicates plasma membrane channels that signal efflux of Ca2+ from intracellular stores. This study also suggests that the bases of exocytosis of large dense core vesicles from motor nerve terminals and neuroendocrine cells are distinct
Replication of functional serotonin receptor type 3A and B variants in bipolar affective disorder: a European multicenter study
Serotonin type 3 receptors (5-HT3) are involved in learning, cognition and emotion, and have been implicated in various psychiatric phenotypes. However, their contribution to the pathomechanism of these disorders remains elusive. Three single nucleotide polymorphisms (SNPs) in the HTR3A and HTR3B genes (rs1062613, rs1176744 and rs3831455) have been associated with bipolar affective disorder (BPAD) in pilot studies, and all of them are of functional relevance. We performed a European multicenter study to confirm previous results and provide further evidence for the relevance of these SNPs to the etiology of neuropsychiatric disorders. This involved analysis of the distribution of the three SNPs among 1804 BPAD cases and 2407 healthy controls. A meta-analysis revealed a pooled odds ratio of 0.881 (P=0.009, 95% confidence intervals=0.802–0.968) for the non-synonymous functional SNP HTR3B p.Y129S (rs1176744), thereby confirming previous findings. In line with this, the three genome-wide association study samples BOMA (Bonn-Mannheim)-BPAD, WTCCC (Wellcome Trust Case Control Consortium)-BPAD and GAIN (Genetic Association Information Network)-BPAD, including >3500 patients and 5200 controls in total, showed an overrepresentation of the p.Y129 in patients. Remarkably, the meta-analysis revealed a P-value of 0.048 (OR=0.934, fixed effect model). We also performed expression analyses to gain further insights into the distribution of HTR3A and HTR3B mRNA in the human brain. HTR3A and HTR3B were detected in all investigated brain tissues with the exception of the cerebellum, and large differences in the A:B subunit ratio were observed. Interestingly, expression of the B subunit was most prominent in the brain stem, amygdalae and frontal cortex, regions of relevance to psychiatric disorders. In conclusion, the present study provides further evidence for the presence of impaired 5-HT3 receptor function in BPAD
Molecular and Electrophysiological Characterization of GFP-Expressing CA1 Interneurons in GAD65-GFP Mice
The use of transgenic mice in which subtypes of neurons are labeled with a fluorescent protein has greatly facilitated modern neuroscience research. GAD65-GFP mice, which have GABAergic interneurons labeled with GFP, are widely used in many research laboratories, although the properties of the labeled cells have not been studied in detail. Here we investigate these cells in the hippocampal area CA1 and show that they constitute ∼20% of interneurons in this area. The majority of them expresses either reelin (70±2%) or vasoactive intestinal peptide (VIP; 15±2%), while expression of parvalbumin and somatostatin is virtually absent. This strongly suggests they originate from the caudal, and not the medial, ganglionic eminence. GFP-labeled interneurons can be subdivided according to the (partially overlapping) expression of neuropeptide Y (42±3%), cholecystokinin (25±3%), calbindin (20±2%) or calretinin (20±2%). Most of these subtypes (with the exception of calretinin-expressing interneurons) target the dendrites of CA1 pyramidal cells. GFP-labeled interneurons mostly show delayed onset of firing around threshold, and regular firing with moderate frequency adaptation at more depolarized potentials
Molecular Characterization of a Novel Intracellular ADP-Ribosyl Cyclase
Background. ADP-ribosyl cyclases are remarkable enzymes capable of catalyzing multiple reactions including the synthesis of the novel and potent intracellular calcium mobilizing messengers, cyclic ADP-ribose and NAADP. Not all ADP-ribosyl cyclases however have been characterized at the molecular level. Moreover, those that have are located predominately at the outer cell surface and thus away from their cytosolic substrates. Methodology/Principal Findings. Here we report the molecular cloning of a novel expanded family of ADP-ribosyl cyclases from the sea urchin, an extensively used model organism for the study of inositol trisphosphate-independent calcium mobilization. We provide evidence that one of the isoforms (SpARC1) is a soluble protein that is targeted exclusively to the endoplasmic reticulum lumen when heterologously expressed. Catalytic activity of the recombinant protein was readily demonstrable in crude cell homogenates, even under conditions where luminal continuity was maintained. Conclusions/Significance. Our data reveal a new intracellular location for ADP-ribosyl cyclases and suggest that production of calcium mobilizing messengers may be compartmentalized
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