549 research outputs found

    A High Speed Particle Phase Discriminator (PPD-HS) for the classification of airborne particles, as tested in a continuous flow diffusion chamber

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    © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License.A new instrument, the High-speed Particle Phase Discriminator (PPD-HS), developed at the University of Hertfordshire, for sizing individual cloud hydrometeors and determining their phase is described herein. PPD-HS performs an in situ analysis of the spatial intensity distribution of near-forward scattered light for individual hydrometeors yielding shape properties. Discrimination of spherical and aspherical particles is based on an analysis of the symmetry of the recorded scattering patterns. Scattering patterns are collected onto two linear detector arrays, reducing the complete 2-D scattering pattern to scattered light intensities captured onto two linear, one-dimensional strips of light sensitive pixels. Using this reduced scattering information, we calculate symmetry indicators that are used for particle shape and ultimately phase analysis. This reduction of information allows for detection rates of a few hundred particles per second. Here, we present a comprehensive analysis of instrument performance using both spherical and aspherical particles generated in a well-controlled laboratory setting using a vibrating orifice aerosol generator (VOAG) and covering a size range of approximately 3-32 μm. We use supervised machine learning to train a random forest model on the VOAG data sets that can be used to classify any particles detected by PPD-HS. Classification results show that the PPD-HS can successfully discriminate between spherical and aspherical particles, with misclassification below 5% for diameters >3μm. This phase discrimination method is subsequently applied to classify simulated cloud particles produced in a continuous flow diffusion chamber setup. We report observations of small, near-spherical ice crystals at early stages of the ice nucleation experiments, where shape analysis fails to correctly determine the particle phase. Nevertheless, in the case of simultaneous presence of cloud droplets and ice crystals, the introduced particle shape indicators allow for a clear distinction between these two classes, independent of optical particle size. From our laboratory experiments we conclude that PPD-HS constitutes a powerful new instrument to size and discriminate the phase of cloud hydrometeors. The working principle of PPD-HS forms a basis for future instruments to study microphysical properties of atmospheric mixed-phase clouds that represent a major source of uncertainty in aerosol-indirect effect for future climate projections..Peer reviewe

    Анализ современных технологий заводнения при разработке нефтяных месторождений

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    Объектом исследования являются системы заводнения применяемые на месторождениях России Цель работы – анализ современных технологий заводнения при разработке нефтяных месторождений, а также обоснование применения технологий заводнения с целью увеличения темпов отбора, коэффициента нефтеизвлечения, технико-экономических показателей. В выпускной квалификационной работе приведены сведения о современных технологиях заводнения, применяемых на месторождениях России. Проведены расчеты экономической эффективности при внедрении нестационарного метода заводнения. Проанализирован процесс работы методов заводнения в условиях месторождений России. Бакалаврская работа выполнена в текстовом редакторе Microsoft Word, и Microsoft Excel.The object of the study are the waterflooding systems used in the fields of Russia The aim of the work is the analysis of modern flooding technologies in the development of oil fields, as well as the rationale for using flooding technologies to increase the rate of selection, the oil recovery factor, and the technical and economic indicators. In the final qualification work information on modern water flooding technologies used in the fields of Russia is given. Calculations of economic efficiency are implemented in the introduction of the non-stationary flooding method. The process of work of flooding methods in the conditions of Russian deposits is analyzed. Bachelor's work is executed in the text editor Microsoft Word, and Microsoft Excel

    Evelopment of the model of diagnosis of the risk of bankruptcy

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    The article presents an overview of foreign and domestic models for the diagnosis of bankruptcy risk, and gives a brief description of them. Also considered the development of our own model of bankruptcy risk diagnostics for Russian enterprise

    Исследование датчиков рН и удельной электрической проводимости фирмы WTW в системе автоматизированного контроля качества очистки сточных вод

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    We demonstrate the suitability of microcavities based on circular grating resonators (CGRs) as fast switches. This type of optical resonator is characterized by a high quality factor and very small mode volume. The waveguide-coupled CGRs are fabricated with silicon-on-insulator technology compatible with standard complementary metal-oxide semiconductor (CMOS) processing. The linear optical properties of the CGRs are investigated by transmission spectroscopy. From 3D finite-difference time-domain simulations of isolated CGRs, we identify the measured resonances. We probe the spatial distribution and the parasitic losses of a resonant optical mode with scanning near-field optical microscopy. We observe fast all-optical switching within a few picoseconds by optically generating free charge carriers within the cavity. (C) 2009 Optical Society of Americ

    Photophysical properties of thin films and solid phase of switchable supermolecular anthracene-based rotaxanes

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    Polycrystalline powders and thin films of a novel rotaxane, methyl-exopyridine-anthracene rotaxane (EPAR-Me), and of the related thread and stoppers 10-[3,5-di (ter butyl)phenoxy]decyl-2-({2-[(9-anthrylcarbonyl) amino] acetyl}amino) acetate (ANTPEP), have been characterised by photoluminescence, absorption and photoluminescence excitation spectroscopy. A rather unusual, i.e. unstructured and largely red-shifted, photoluminescence spectral behaviour of the rotaxane has been found. Preliminary time resolved measurements indicate a fast energy transfer from the anthracene unit to different species the nature of which is still not assigned.

    Оптимизация процесса технического контроля

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    Объектом настоящего исследования является процесс технического контроля ПАО "ЗиО-Подольск". Предметом исследования являются теоретические и практические вопросы оптимизации технического контроля для улучшения производственной деятельности организации. Цель работы – оптимизация процесса технического контроля. В процессе работы проанализирован и структурирован материал по теме технического контроля. Исследован процесс "Оптимизация процесса оформления и учета актов о браке" предприятия, а также был предложен способ оптимизации данного процесса. Результатом работы является предложение по оптимизации процесса "Оформление и учет актов о браке".The object of this study is the process of technical control of ZiO-Podolsk PJSC. The subject of the study is the theoretical and practical issues of optimizing technical control to improve the production activities of the organization. The purpose of the work is to optimize the process of technical control. In the process, the material on the topic of technical control is analyzed and structured. The process "Optimization of the process of registration and registration of acts of marriage" of the enterprise was investigated, and a method for optimizing this process was also proposed. The result of the work is a proposal to optimize the process “Registration and registration of marriage certificates”

    Transcriptomic analysis of milk somatic cells in mastitis resistant and susceptible sheep upon challenge with Staphylococcus epidermidis and Staphylococcus aureus

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    <p>Abstract</p> <p>Background</p> <p>The existence of a genetic basis for host responses to bacterial intramammary infections has been widely documented, but the underlying mechanisms and the genes are still largely unknown. Previously, two divergent lines of sheep selected for high/low milk somatic cell scores have been shown to be respectively susceptible and resistant to intramammary infections by <it>Staphylococcus spp</it>. Transcriptional profiling with an 15K ovine-specific microarray of the milk somatic cells of susceptible and resistant sheep infected successively by <it>S. epidermidis </it>and <it>S. aureus </it>was performed in order to enhance our understanding of the molecular and cellular events associated with mastitis resistance.</p> <p>Results</p> <p>The bacteriological titre was lower in the resistant than in the susceptible animals in the 48 hours following inoculation, although milk somatic cell concentration was similar. Gene expression was analysed in milk somatic cells, mainly represented by neutrophils, collected 12 hours post-challenge. A high number of differentially expressed genes between the two challenges indicated that more T cells are recruited upon inoculation by <it>S. aureus </it>than <it>S. epidermidis</it>. A total of 52 genes were significantly differentially expressed between the resistant and susceptible animals. Further Gene Ontology analysis indicated that differentially expressed genes were associated with immune and inflammatory responses, leukocyte adhesion, cell migration, and signal transduction. Close biological relationships could be established between most genes using gene network analysis. Furthermore, gene expression suggests that the cell turn-over, as a consequence of apoptosis/granulopoiesis, may be enhanced in the resistant line when compared to the susceptible line.</p> <p>Conclusions</p> <p>Gene profiling in resistant and susceptible lines has provided good candidates for mapping the biological pathways and genes underlying genetically determined resistance and susceptibility towards <it>Staphylococcus </it>infections, and opens new fields for further investigation.</p
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