Analysis of advanced IGCC economic indicators

In this paper, the influence presence of a shift reactor and a CO2 removal unit (CCS) from syngas (pre-combustion technology) on the thermal efficiency of a combined-cycle plant with in-cycle gasification of solid fuel (IGCC) is considered. The literature sources on the effect of CCS on the thermal efficiency of three oxygen IGCC are analyzed. The calculated influence of the degree of integration of CCS in the demonstration IGCC scheme on the composition of the combusted gas fuel is presented. The principle of shift-reactor operation is given. Various types of catalysts used in the shift reactor are considered. The influence of CCS on the economic and environmental indicators of IGCC is analyzed. The analysis of air IGCC schemes with CCS node and without it is carried out.В данной работе рассматривается влияние наличия shift-реактора и узла удаления СО2 (CCS) из синтез-газа (технология pre-combustion) на термический КПД перспективной парогазовой установки с внутрицикловой газификацией твёрдого топлива (ПГУ-ВЦГ). Проведен анализ литературных источников по влиянию CCS на термический КПД трёх кислородных ПГУ-ВЦГ. Представлено расчетное влияние степени интеграции CCS в схему демонстрационной ПГУ-ВЦГ на состав сжигаемого газового топлива. Приводится принцип работы shift-реактора. Рассматриваются различные типы катализаторов, используемых в shift-реакторе. Проанализировано влияние CCS на экономические и экологические показатели ПГУ-ВЦГ. Проведен анализ схем перспективной воздушной ПГУ-ВЦГ с узлом CCS и без него

Josephson Vortex States in Intermediate Fields

Motivated by recent resistance data in high $T_c$ superconductors in fields {\it parallel} to the CuO layers, we address two issues on the Josephson-vortex phase diagram, the appearances of structural transitions on the observed first order transition (FOT) curve in intermediate fields and of a lower critical point of the FOT line. It is found that some rotated pinned solids are more stable than the ordinary rhombic pinned solids with vacant interlayer spacings and that, due to the vertical portion in higher fields of the FOT line, the FOT tends to be destroyed by creating a lower critical point.Comment: 12 pages, 3 figures. To appear in J.Phys.Soc.Jpn. 71, No.2 (February, 2002

Rapid dissipation of magnetic fields due to Hall current

We propose a mechanism for the fast dissipation of magnetic fields which is effective in a stratified medium where ion motions can be neglected. In such a medium, the field is frozen into the electrons and Hall currents prevail. Although Hall currents conserve magnetic energy, in the presence of density gradients, they are able to create current sheets which can be the sites for efficient dissipation of magnetic fields. We recover the frequency, $\omega_{MH}$, for Hall oscillations modified by the presence of density gradients. We show that these oscillations can lead to the exchange of energy between different components of the field. We calculate the time evolution and show that magnetic fields can dissipate on a timescale of order $1/\omega_{MH}$. This mechanism can play an important role for magnetic dissipation in systems with very steep density gradients where the ions are static such as those found in the solid crust of neutron stars.Comment: 9 pages, changed fig.

ANALYSIS OF METHODS OF SYNTHESIS GAS STEAM CORRECTION FOR GAS TURBINES

Using as example the thermochemical conversion of Kuzbass coal, the possibility of increasing the hydrogen yield due to the addition of water vapor is considered. It was found that the potential for increasing the yield of hydrogen during autothermal conversion is 13.6%. When the gasifying agents are heated up to 900 °C, the conversion regime shifts from α = 0.43 to 0.32. Calculated hydrogen content is 18.8%, CO - 34,1%, N2 - 47,1 zero content of H2O and CO2.Исследование выполнено в Уральском федеральном университете за счет гранта Российского научного фонда (проект №14-19-00524)

Development of low-temperature thermochemical conversion reactors for coal power engineering

The main principles applied in developing a technology for low-temperature thermochemical conversion of brown coals to obtain fuel gas and semicoke intended for being fired in two-fuel power installations are considered on the basis of a set of experimental and calculated investigations. The obtained results are compared with the experimental data obtained using other methods and with the results of previous industrial tests. © 2013 Pleiades Publishing, Inc

Flow Induced Organization and Memory of a Vortex Lattice

We report on experiments probing the evolution of a vortex state in response to a driving current in 2H-NbSe$_2$ crystals. By following the vortex motion with fast transport measurements we find that the current enables the system to reorganize and access new configurations. During this process the system exhibits a long-term memory: if the current is turned off the vortices freeze in place remembering their prior motion. When the current is restored the motion resumes where it stopped. The experiments provide evidence for a dynamically driven structural change of the vortex lattice and a corresponding dynamic phase diagram that contains a previously unknown regime where the critical current can be either $increased$ or $decreased$ by applying an appropriate driving current.Comment: 5 pages, 4figure

Anal cancer with large metastases into the perirectal fat: differential diagnosis and treatment policy

Selected squamous-cell anal carcinoma (SCAC) patients are initially presented with large pararectal lymph node metastases.The aim of this study was to investigate safety, efficacy and long-term outcome of chemoradiotherapy in this patient group.Materials and methods. SCAC patients, initially referred with gastrointestinal stromal tumors, rectal cancer diagnosis or patients with regional metastatic lymph nodes more than twice the size of the primary tumour were included in this retrospective analysis. Previous treatment, diagnostic and clinical mistakes of primary care specialists, short- and long-term outcome of chemoradiotherapy were analyzed.Results. 6 patients were included. Primary tumour size varied between 0.5 and 6.5 cm (median – 1.7 cm), metastatic lymph node size varied between 4.2 and 7.4 cm (median – 6.4 cm). All patients received radical doses of chemoradiation. All patients developed grade 3 toxicities, 2 patients developed grade 4 toxicities. Median followup was 15.5 months. 5 out of 6 patients had persistent complete clinical response. 1 patient died of disease progression (incomplete response and metachronous distant metastases).Conclusion. SCAC patients with large regional lymph node metastases have equal prognosis with the rest of the patient group of adequate treatment was carried out

Роль ПЭТ/КТ с 18F-фтордезоксиглюкозой в выявлении прогрессирования колоректального рака у асимптоматических пациентов с повышенным уровнем раково-эмбрионального антигена (обзор литературы)

Positron emission tomography-computed tomography (PET/CT) with 18F-fluorodeoxyglucose in colorectal cancer is a highly sensitive imaging technique that detects malignant foci characterized by increased glucose metabolism. Currently, an increasing number of studies indicate the added value of PET/CT for the diagnosis and preoperative restaging of recurrent colorectal cancer. A special problem is a group of patients suffering from colorectal cancer, with negative or ambiguous results of radiology methods, but with an elevated level of сarcinoembryonic antigen. Many studies confirm the opinion that early use of PET/CT with 18F- fluorodeoxyglucose may have predictive value in the treatment of such patients.Совмещенная с компьютерной томографией позитронно-эмиссионная томография (ПЭТ/КТ) с использованием 18F-фтор-дезоксиглюкозы при колоректальном раке представляет собой высокочувствительный метод визуализации, позволяющий выявлять злокачественные очаги, характеризующиеся повышенным метаболизмом глюкозы. В настоящее время все большее количество исследований показывают дополнительную ценность ПЭТ/КТ для диагностики прогрессирования колоректального рака. Особую проблему представляет группа пациентов, страдающих колоректальным раком, с отрицательными или неоднозначными результатами лучевых методов диагностики, но с повышенным уровнем раково-эмбрионального антигена. Многие исследования подтверждают мнение о том, что раннее использование ПЭТ/КТ с 18F-фтордезоксиглюкозой может иметь прогностическую ценность в лечении таких пациентов