Статистическая модель оценки веса газовых баллонов

Объектом исследования: выборка фактического веса пустого баллона, выборка наполненного газом баллона и выборка веса газа. Цель работы: определить количество баллонов для взвешивания, чтобы определить средний вес газа в баллонах в выборке. В процессе исследования проводилась оценка распределения вероятностей на основе выборочных данных для определения веса газа в баллоне и проверка гипотезы о параметрах нормального распределения. В результате исследования сделан вывод о том, к какому типу распределения подчиняется выборка веса газа в баллонах и определено количество взвешиваний баллонов.The object of research: sample of actual weight of empty gas bottle, sample of filled gas bottle and sample of gas weight. Purpose of research: to quantify gas bottles for weighing in order to determine the average weight of the gas in the gas bottles in the sample. During the research the evaluation of probability distribution, based on the sample data for weighing gas in the gas bottle, was applied; proving of hypothesis concerning parameters of the normal distribution was carried out. As the result of the research comes the conclusion concerning the type of distribution which the sample of gas weight in gas bottles submitted to; the number of weighings of gas bottles was determined

A Trigger Enzyme in Mycoplasma pneumoniae: Impact of the Glycerophosphodiesterase GlpQ on Virulence and Gene Expression

Mycoplasma pneumoniae is a causative agent of atypical pneumonia. The formation of hydrogen peroxide, a product of glycerol metabolism, is essential for host cell cytotoxicity. Phosphatidylcholine is the major carbon source available on lung epithelia, and its utilization requires the cleavage of deacylated phospholipids to glycerol-3-phosphate and choline. M. pneumoniae possesses two potential glycerophosphodiesterases, MPN420 (GlpQ) and MPN566. In this work, the function of these proteins was analyzed by biochemical, genetic, and physiological studies. The results indicate that only GlpQ is an active glycerophosphodiesterase. MPN566 has no enzymatic activity as glycerophosphodiesterase and the inactivation of the gene did not result in any detectable phenotype. Inactivation of the glpQ gene resulted in reduced growth in medium with glucose as the carbon source, in loss of hydrogen peroxide production when phosphatidylcholine was present, and in a complete loss of cytotoxicity towards HeLa cells. All these phenotypes were reverted upon complementation of the mutant. Moreover, the glpQ mutant strain exhibited a reduced gliding velocity. A comparison of the proteomes of the wild type strain and the glpQ mutant revealed that this enzyme is also implicated in the control of gene expression. Several proteins were present in higher or lower amounts in the mutant. This apparent regulation by GlpQ is exerted at the level of transcription as determined by mRNA slot blot analyses. All genes subject to GlpQ-dependent control have a conserved potential cis-acting element upstream of the coding region. This element overlaps the promoter in the case of the genes that are repressed in a GlpQ-dependent manner and it is located upstream of the promoter for GlpQ-activated genes. We may suggest that GlpQ acts as a trigger enzyme that measures the availability of its product glycerol-3-phosphate and uses this information to differentially control gene expression

Time resolution of a photomultiplier readout system for space application

The performance of a readout system for the synchrotron radiation detector (SRD) is studied. The detector is proposed as part of the Alpha Magnetic Spectrometer experiment, an experiment to fly on the International Space Station (ISS) beginning of 2005. The SRD is designed to detect the synchrotron radiation from electrons and positrons (TeV energy range) produced in the earth's magnetic field. For the planned array of scintillators and photomultipliers a readout system is chosen, which is compact, space qualified and has a low- power consumption. The low-power chip APV, originally designed for the CMS experiment at LHC (CERN), is foreseen for the readout. To overcome the diffuse background from photons and charged particles the SRD readout must have a time resolution better than 10 ns. The intrinsic time resolution (sigma from Gauss fit) of the APV25-S0 was found to be 0.46 +or- 0.01 and 0.68 +or-0.02 ns for the APVM. whereas the time resolution of the photomultiplier-APV readout system was measured to be 2.73 +or- 0.10 ns for the APV25-S0 and 2.90 +or- 0.21 ns for the APVM. The investigated timing capabilities of the photomultiplier-APV readout system show that the APV chip is suitable for the SRD readout

Measurements with an MSGC Hodoscope Using the PreMux128 Frontend Chip

We report on the performance of a hodoscope containing 3 large area micro strip gas chambers ( MSGCs). The results of the measurements in a test beam experiment and with cosmics rays are presented. As counting gas Ar/Propan ( 60/40) and Ar/DME ( 50/50) provided by a closed gas system that recycles and purifies the gas was used. The detectors were equipped with the PreMux128 chip, a multiplexer chip using double correlated sampling for signal processing. The influence of this method for the operation with MSGCs is discussed

Geiger-mode avalanche photodiodes as photodetectors in Cherenkov astronomy

The progress in the development of Geiger-mode avalanche photodiodes (G-APD) has resulted in devices which show great promise for Imaging Atmospheric Cherenkov Telescopes (IACT). In the course of the First G-APD Camera Test (FACT) project with the purpose to construct a G-APD based camera, their characteristics are analysed and measured in detail. The angle dependence of the photon detection efficiency was measured and found to be flat. The effects of saturation and cross-talk on the reconstruction of the number of detected photons was studied. Since these effects are of a statistical nature, the reconstructed number is limited in its precision. For small numbers of photons, crosstalk is the limiting factor. For photon numbers comparable to or higher than the number of cells of the G-APD, the main limitation is the saturation

CMS : the TriDAS Project Technical Design Report; v.1, the Trigger Systems

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