486 research outputs found
Evaluation of amine emissions from the post-combustion CO2 capture pilot plant
AbstractIn this work, we evaluated amine emissions from 10ton-CO2/day scale pilot plant in Mikawa Power Plant of Sigma Power Co. Ltd. within TS-1 solvent. Firstly, we investigated that how sampling gas flow rate affects measured value of amine concentration in flue gas by using on-line sampling method with PTR-MS analyzer. It was found that the error from an iso-kinetic sampling rises sharply for lower sampling velocities and in the range of higher sample stream velocities, however the error is lower. Secondly, we compared between beginning of operation and 2,800hours operation in terms of amine emissions at Mikawa pilot plant under one set of conditions. At beginning of operation, there were no degraded amines in TS-1 solution. Thus, there were no amine emissions of degraded amines. However, at 2,800hours operating, in addition to TS-1 emissions, some quantity of emissions of degraded amines were detected even though degraded amines were much less than TS-1 main amine in TS-1 solution. Toshiba improved operating conditions such as plant system, water wash system to reduce the amount of amine emissions. As a result, the latest tests showed lower emissions of less than 1 ppm(v/v) at 2,800hours operation. A concentration of degraded amine [D] in TS-1 solution at 2,800hours operation, which was nearly detection limit, was lower than other degraded amines. Nevertheless, degraded amine [D] accounted for the greater part of amine emissions after water wash was improved. This result suggested that it is crucial to reduce the volatility of emitted degraded amines in order to improve performance of suppression amine emissions further. Then, finally we evaluated effect of addition acid to reduce the volatility of degraded amine [D]. The results in diluted aqueous amines at 40°C showed that effectiveness of acid for reducing amine volatility is in the order: sulfuric acid > oxalic acid carbonic acid produced by 10%CO2 > boric acid
MHD Simulation of The Inner Galaxy with Radiative Cooling and Heating
We investigate the role of magnetic field on the gas dynamics in the Galactic
bulge region by three dimensional simulations with radiative cooling and
heating. While high-temperature corona with is formed in the
halo regions, the temperature near the Galactic plane is following the thermal equilibrium curve determined by the radiative cooling
and heating. Although the thermal energy of the interstellar gas is lost by
radiative cooling, the saturation level of the magnetic field strength does not
significantly depend on the radiative cooling and heating. The magnetic field
strength is amplified to on average, and reaches several
hundred locally. We find the formation of magnetically dominated
regions at mid-latitudes in the case with the radiative cooling and heating,
which is not seen in the case without radiative effect. The vertical thickness
of the mid-latitude regions is at the radial location of
from the Galactic center, which is comparable to the
observed vertical distribution of neutral atomic gas. When we take the average
of different components of energy density integrated over the Galactic bulge
region, the magnetic energy is comparable to the thermal energy. We conclude
that the magnetic field plays a substantial role in controlling the dynamical
and thermal properties of the Galactic bulge region.Comment: Submitted to ApJ; 21 pages, 18 figures 3 tables. Comment are welcom
Diabetic Cardiovascular Disease Induced by Oxidative Stress.
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality among patients with diabetes mellitus (DM). DM can lead to multiple cardiovascular complications, including coronary artery disease (CAD), cardiac hypertrophy, and heart failure (HF). HF represents one of the most common causes of death in patients with DM and results from DM-induced CAD and diabetic cardiomyopathy. Oxidative stress is closely associated with the pathogenesis of DM and results from overproduction of reactive oxygen species (ROS). ROS overproduction is associated with hyperglycemia and metabolic disorders, such as impaired antioxidant function in conjunction with impaired antioxidant activity. Long-term exposure to oxidative stress in DM induces chronic inflammation and fibrosis in a range of tissues, leading to formation and progression of disease states in these tissues. Indeed, markers for oxidative stress are overexpressed in patients with DM, suggesting that increased ROS may be primarily responsible for the development of diabetic complications. Therefore, an understanding of the pathophysiological mechanisms mediated by oxidative stress is crucial to the prevention and treatment of diabetes-induced CVD. The current review focuses on the relationship between diabetes-induced CVD and oxidative stress, while highlighting the latest insights into this relationship from findings on diabetic heart and vascular disease
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