Модернизация ректификационной колонны разделения пропан-пропиленовой фракции

Объектом проектирования является ректификационная колонна непрерывного действия для разделения пропан пропиленовой фракции, а также конденсатора-холодильника для конденсации пропилена. Целью работы является расчет ректификационной колонны и конденсатора-холодильника. В ходе расчета колонны был составлен материальный баланс колонны, рассчитано оптимальное флегмовое число и оптимальное значение числа теоретических тарелок. Так же был выполнен конструктивно-механический расчет. Входе которого определили исполнительную марку стали ректификационной колонны, условия прочности и устойчивости, найдены значения толщины стенки цилиндрической обечайки, эллиптических днища и крышки. Произведен расчет штуцеров и фланцев. В технологическом расчете теплообменника был составлен тепловой баланс. РассчитаныThe design object is a continuous distillation column for the separation of propane propylene fraction, as well as a condenser-cooler for condensation of propylene. The aim of the work is to calculate the distillation column and condenser-refrigerator. During the calculation of the column, the material balance of the column was compiled, the optimal reflux ratio and the optimal value of the number of theoretical plates were calculated. A structural and mechanical calculation was also performed. The inlet of which the executive grade of the distillation column was determined, the strength and stability conditions, the wall thickness of the cylindrical shell, elliptical bottom and cover were found. Calculation of fittings and flanges. In the technological calculation of the heat exchanger,

Assessment of the physical characteristics and stormwater effluent quality of permeable pavement systems containing recycled materials

This paper evaluates the physical characteristics of two recycled materials and the pollutant removal efficiencies of four 0.2 m2 tanked permeable pavement rigs in the laboratory, that contained either natural aggregates or these recycled materials in the sub-base. The selected recycled materials were Crushed Concrete Aggregates (CCA) and Cement-bounded Expanded Polystyrene beads (C-EPS) whilst the natural aggregates were basalt and quartzite. Natural stormwater runoff was used as influent. Effluent was collected for analysis after 7–10 mins of discharge. Influent and effluent were analysed for pH, Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), Electroconductivity (EC), turbidity, Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Nitrate-Nitrogen (NO3-N), reactive phosphorous (PO43-) and sulphates (SO42-). Both CCA and C-EPS had suitable physical properties for use as sub-base materials in PPS. However, C-EPS is recommended for use in pavements with light to no traffic because of its relatively low compressive strength. In terms of pollutant removal efficiencies, significant differences (p 0.05) were found with respect to TSS, turbidity, COD and NO3-N. Effluent from rigs containing CCA and C-EPS saw significant increases in pH, EC and TDS measurements whilst improvements in DO, TSS, turbidity, COD, PO43- and SO42- were observed. All mean values except pH were, however, within the Maximum Permissible Levels (MPLs) of water pollutants discharged into the environment according to the Trinidad and Tobago Environmental Management Authority (EMA) or the United States Environmental Protection Agency (US EPA). In this regard, the CCA and C-EPS performed satisfactorily as sub-base materials in the permeable pavement rigs. It is noted, however, that further analysis is recommended through leaching tests on the recycled materials

Управление системой электрохимической защиты магистрального газопровода в условиях вечной мерзлоты

Объектом исследования подсистема коррозионного мониторинга электрохимической зашиты магистрального газопровода. Цель работы – проанализировать управление системой электрохимической зашиты магистрального газопровода в условиях вечной мерзлоты. В результате анализа установлено, что ПКМ-ТСТ-КонтКорр удовлетворяет требованиям системы управления техническим состоянием и целостностью площадных объектов организации.The object of study is the subsystem of corrosion monitoring of electrochemical protection of the main gas pipeline. The purpose of the work is to analyze the management of the system of electrochemical protection of the main gas pipeline in permafrost conditions. As a result of the analysis, it was established that PKM-TST-KontKorr satisfies the requirements of the system for managing the technical condition and integrity of the organization’s area facilities

Measurement of Z0 decays to hadrons, and a precise determination of the number of neutrino species

We have made a precise measurement of the cross section for e+e--->Z0-->hadrons with the L3 detector at LEP, covering the range from 88.28 to 95.04 GeV. From a fit to the Z0 mass, total width, and the hadronic cross section to be MZ0=91.160 +/- 0.024 (experiment) +/-0.030(LEP) GeV, [Gamma]Z0=2.539+/-0.054 GeV, and [sigma]h(MZ0)=29.5+/-0.7 nb. We also used the fit to the Z0 peak cross section and the width todetermine [Gamma]invisible=0.548+/-0.029 GeV, which corresponds to 3.29+/-0.17 species of light neutrinos. The possibility of four or more neutrino flavors is thus ruled out at the 4[sigma] confidence level.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28683/3/0000500.pd

A measurement of the Z0 leptonic partial widths and the vector and axial vector coupling constants

We have measured the partial widths of the Z0 into lepton pairs, and the forward-backward charge asymmetry for the process e+e--->[mu]+[mu]- using the L3 detector at LEP. We obtain an average [Gamma]ll of 83.0+/-2.1+/-1.1 MeV.From this result and the asymmetry measurement, we extract the values of the vector and axial vector couplings of the Z0 to leptons: grmv=-0.066-0.027+0.046 and grmA= -0.495-0.007+0.007.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28666/3/0000483.pd