Электроснабжение установки перекачки нефти п. Пионерный ОАО «Томскнефть»

РЕФЕРАТ Выпускная квалификационная работа 149 с., 23 рис., 32 табл., 29 источников, 6 прил. Ключевые слова: нефтепровод, насос, электрооборудование, схема электроснабжения, линия, сеть, электроприемник, нагрузка, оборудование, защита, ток, напряжение, мощность. Объектом исследования является электрическая часть УПН п. Пионерный ОАО «Томскенефть». Цель работы – проектирование схемы электроснабжения предприятия, выбор оборудования. В процессе исследования проводился сбор исходных данных в ходе производственной практики на объекте исследования. В результате была спроектирована схема электроснабжения от подстанции энергосистемы, до конечного электроприемника. Были выбраны кабели и провода, коммутационное оборудование, были сделаны необходимые проверки. Также результатом работы сталESSAY Final qualifying work 149 p., 23 fig., 32 tab., 29 sources, 6 adj. Keywords: oil, pump, electrical equipment, power supply circuit, line, network, power-consuming equipment, load equipment, protection, current, voltage, power. The object of research is the electrical part of UPN claim. Pionerny of "Tomskeneft". The purpose of work - designing enterprise power scheme, the choice of equipment. The study was conducted to collect baseline data in the course of practical training on the subject of the study. As a result, power supply circuit has been designed from the substation grid, appliance, to the end. Were selected cables and wires, switching equipment, the necessary checks have been made. It is also the result of the work became an economic calculation of capital costs for the con

Measurement of the spin temperature of optically cooled nuclei and GaAs hyperfine constants in GaAs/AlGaAs quantum dots

Deep cooling of electron and nuclear spins is equivalent to achieving polarization degrees close to 100% and is a key requirement in solid state quantum information technologies. While polarization of individual nuclear spins in diamond and SiC reaches 99% and beyond, it has been limited to 60-65% for the nuclei in quantum dots. Theoretical models have attributed this limit to formation of coherent "dark" nuclear spin states but experimental verification is lacking, especially due to the poor accuracy of polarization degree measurements. Here we measure the nuclear polarization in GaAs/AlGaAs quantum dots with high accuracy using a new approach enabled by manipulation of the nuclear spin states with radiofrequency pulses. Polarizations up to 80% are observed - the highest reported so far for optical cooling in quantum dots. This value is still not limited by nuclear coherence effects. Instead we find that optically cooled nuclei are well described within a classical spin temperature framework. Our findings unlock a route for further progress towards quantum dot electron spin qubits where deep cooling of the mesoscopic nuclear spin ensemble is used to achieve long qubit coherence. Moreover, GaAs hyperfine material constants are measured here experimentally for the first time

Index assignment for multiple description repair in distributed storage systems

Distributed storage systems have been receiving increasing attention lately due to the developments in cloud and grid computing. Furthermore, a major part of the stored information comprises of multimedia, whose content can be communicated even with a lossy (non-perfect) reconstruction. In this context, Multiple Description Lattice Quantizers (MDLQ) can be employed to encode such sources for distributed storage and store them across distributed nodes. Their inherent properties yield that having access to all nodes gives perfect reconstruction of the source, while the reconstruction quality decreases gracefully with fewer available nodes. If a set of nodes fails, lossy repair techniques could be applied to reconstruct the failed nodes from the available ones. This problem has mostly been studied with the lossless (perfect) reconstruction assumption. In this work, a general model, Multiple Description Lattice Quantizer with Repairs (MDLQR), is introduced that encompasses the lossy repair problem for distributed storage applications. New performance measures and repair techniques are introduced for MDLQR, and a non-trivial identity is derived, which is related to other results in the literature. This enables us to find the optimal encoder for a certain repair technique used in the MDLQR. Furthermore, simulation results are used to evaluate the performance of the different repair techniques. © 2014 IEEE

Comprehensive non-targeted molecular characterization of organic aerosols in the Amazon rainforest

The Amazon rainforest plays a crucial role in the global climate system, hydrological cycle, and earth's energy balance. As one of the planet's least industrialized regions, it allows investigation of organic aerosol formation and constituents under almost pristine conditions. Nevertheless, human activities are known to affect this ecosystem – especially during the dry season. In this study, ambient aerosol samples collected at the Amazon Tall Tower Observatory (ATTO) during two dry and two wet seasons were characterized by high-resolution mass spectrometry (HR-MS). Comprehensive non-targeted data evaluation was applied to identify thousands of molecular formulae. Most were found to be associated with oxidation products of isoprene and monoterpenes, highlighting the predominance of biogenic secondary organic aerosols (SOA) at ATTO. The chemical composition exhibited distinct seasonal patterns with more processed organic compounds during the dry season, which can be explained by an increase of later-generation oxidation products due to reduced wet deposition and enhanced long-range transport. Mono- and polycyclic heteroaromatic components from biomass burning (BB) sources were enhanced during the dry seasons and the second wet season. The wet season was generally characterized by less oxidized compounds, associated with freshly formed SOA particles. Height-resolved measurements showed the forest canopy to be the main source for biogenic emissions with higher concentrations of early terpene oxidation products lower down. Overall, our results provide new insights into the molecular characteristics and seasonality of organic particulate matter at ATTO, helping to constrain the sources and interactions of aerosols, clouds, and precipitation in the Amazon rainforest

Frequent rainfall-induced new particle formation within the canopy in the Amazon rainforest

Atmospheric aerosol particles are essential for forming clouds and precipitation, thereby influencing Earth’s energy budget, water cycle and climate on regional and global scales. However, the origin of aerosol particles over the Amazon rainforest during the wet season is poorly understood. Earlier studies showed new particle formation in the outflow of deep convective clouds and suggested a downward flux of aerosol particles during precipitation events. Here we use comprehensive aerosol, trace gas and meteorological data from the Amazon Tall Tower Observatory to show that rainfall regularly induces bursts of nanoparticles in the nucleation size range. This can be attributed to rain-related scavenging of larger particles and a corresponding reduction of the condensation sink, along with an ozone injection into the forest canopy, which could increase the oxidation of biogenic volatile organic compounds, especially terpenes, and enhance new particle formation. During and after rainfall, the nucleation particle concentrations directly above the canopy are greater than those higher up. This gradient persists throughout the wet season for the nucleation size range, indicating continuous particle formation within the canopy, a net upward flux of newly formed particles and a paradigm shift in understanding aerosol–cloud–precipitation interactions in the Amazon. Particle bursts provide a plausible explanation for the formation of cloud condensation nuclei, leading to the local formation of green-ocean clouds and precipitation. Our findings suggest that an interplay of a rain-related reduction in the condensation sink, primary emissions of gases, mainly terpenes, and particles from the forest canopy, and convective cloud processing determines the population of cloud condensation nuclei in pristine rainforest air

Molecular control of HIV-1 postintegration latency: implications for the development of new therapeutic strategies

The persistence of HIV-1 latent reservoirs represents a major barrier to virus eradication in infected patients under HAART since interruption of the treatment inevitably leads to a rebound of plasma viremia. Latency establishes early after infection notably (but not only) in resting memory CD4+ T cells and involves numerous host and viral trans-acting proteins, as well as processes such as transcriptional interference, RNA silencing, epigenetic modifications and chromatin organization. In order to eliminate latent reservoirs, new strategies are envisaged and consist of reactivating HIV-1 transcription in latently-infected cells, while maintaining HAART in order to prevent de novo infection. The difficulty lies in the fact that a single residual latently-infected cell can in theory rekindle the infection. Here, we review our current understanding of the molecular mechanisms involved in the establishment and maintenance of HIV-1 latency and in the transcriptional reactivation from latency. We highlight the potential of new therapeutic strategies based on this understanding of latency. Combinations of various compounds used simultaneously allow for the targeting of transcriptional repression at multiple levels and can facilitate the escape from latency and the clearance of viral reservoirs. We describe the current advantages and limitations of immune T-cell activators, inducers of the NF-κB signaling pathway, and inhibitors of deacetylases and histone- and DNA- methyltransferases, used alone or in combinations. While a solution will not be achieved by tomorrow, the battle against HIV-1 latent reservoirs is well- underway

Transcellular transport of calcium and inorganic phosphate in the small intestinal epithelium

Transport mechanisms involved in the small intestinal handling of inorganic phosphate and calcium have been studied by different in vitro methods during the last few years. In concordance with studies on intact epithelial preparations, studies with brush-border and basal-lateral membrane vesicles isolated from the small intestinal epithelial cell revealed that transcellular calcium and inorganic phosphate fluxes are coupled to transcellular sodium flux, i.e., secondary active via coupling to the primary active sodium flux. A sodium-coupled mechanism in the brush-border membrane leads to cellular accumulation of inorganic phosphate. A sodium-coupled mechanism leads to extrusion of calcium from the cell into the serosal interstitium. A primary active transport mediated by the Ca-ATPase and located in the basal-lateral membrane also exists for calcium. Regulation of transcellular phosphate and calcium flux proceeds via altered influx rates at the luminal cell pole