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At high altitude and low pressure, the changes of inlet and exhaust pressure and the combustion environment in the cylinder lead to the deterioration of physicochemical characteristics and combustion in the cylinder of the coal-based mixed fuel. In this research, based on the plateau environment simulation test platform, the combustion characteristics, dynamic performance and fuel economy of the turbocharged diesel engine burned at different simulated altitudes (0 m, 1500 m, 2500 m, 3500 m and 4500 m) were studied. The results revealed that as altitude increased, the coal-based composite fuel caused the diesel engine's in-cylinder pressure, pressure rise rate, and instantaneous heat release rate to gradually decrease, the flameout period to gradually extend, and the center of gravity of combustion to gradually delay. At low engine speed, the average effective pressure cycle variation rate increased significantly. The coal-based complex fuel diesel engine has increased in-cylinder pressure, torque, and effective thermal efficiency, as well as peak instantaneous heat release rate at high altitude, when compared to diesel combustion. It also causes a reduction in the maximum pressure rise rate, a forward shift in the combustion center of gravity, a reduction in the average effective pressure cycle rate of change, and a shortening of the stall period. [ABSTRACT FROM AUTHOR]

Understanding the influence of environmental boundary parameters on the through-flow characteristics of two-stage supercharged centrifugal compressors is the key to maximizing the power recovery potential of diesel engines at high altitudes. In this paper, the influence of the compressor through-flow characteristics on the full-load thermal cycle performance of a diesel engine under variable altitude is studied by means of tests and simulation. The results show that with the increase in altitude, the range of stable work flow decreases, and the pressure ratio of the plugging point changes greatly with altitude. The efficiency of the compressor with the same mass flow point decreases, and the highest efficiency point moves in the direction of the small flow range. With the goal of maximizing the torque of the diesel engine under full load and low speed, the key geometric parameters of the variable-altitude through-flow characteristics of the two-stage supercharged compressor were optimized as follows: at the altitudes of 0 m, 2500 m, and 5500 m, the diesel engine torque increased by 5.89%, 3.78%, and 2.18%, respectively. Based on the optimization method of the compressor through-flow design, a new direction is provided to break through the research on the independent limitation of the diesel engine thermal cycle performance optimization and compressor flow control. [ABSTRACT FROM AUTHOR]

The twin variable geometry turbocharger (VGT) System, through efficient use of exhaust energy, maximizes internal combustion engine (ICE) power, reduces exhaust emissions and improves reliability. However, the internal flow characteristics of the twin-VGT system are greatly affected by the environment. To ensure that the two-stage adjustable supercharged internal combustion engine is efficient in all geographical environments and under all operating conditions, it is necessary to conduct in-depth research on the internal flow characteristics of high- and low-pressure turbines. In this paper, an experimental system of the flow characteristics of a double variable-geometry turbocharging (twin-VGT) system is designed and developed. A two-stage variable turbine flow characteristic test was carried out, focusing on the relationship between the initial rotational velocity of high variable-geometry turbocharging (HVGT) and blade opening in low variable-geometry turbocharging (LVGT). The effects of high- and low-pressure variable-geometry turbocharger (VGT) blade opening on available exhaust energy, expansion ratio distribution, blade velocity ratio, compressor power consumption and isentropic efficiency were studied. The results show that when the available energy of exhaust gas is constant, with the increase in HVGT turbine speed, when the LVGT blade opening decreases by 10%, the low-pressure turbine expansion ratio increases by about 0.23. [ABSTRACT FROM AUTHOR]

A variable geometry turbocharger in series with a variable geometry turbocharger (Twin-VGT) system was designed to improve engine power at high altitudes. The influence of altitudes on the performance of the Twin-VGT system was investigated in the perspective of available exhaust energy. The interaction between exhaust flow characteristics of Twin-VGT and openings of Twin-VGT vanes was theoretically analyzed at different altitudes. Meanwhile, a model of a diesel engine matched with the Twin-VGT system was built to study the matching performance of the Twin-VGT system with engine at different altitudes. The optimal opening maps of both high-pressure and low-pressure VGT vanes at high altitudes were obtained to achieve the maximum engine power. The results showed that the optimal openings of high-pressure and low-pressure VGT vanes decreased with increase in altitudes. The operating points of the two-stage compressors located at the high efficiency region and the compressor efficiency region both exceeded 62% at different altitudes. The global expansion ratio increased with increase in altitudes and reached 4.9 at 5500 m. Compared with the VGT in series with a fixed geometry turbocharger on testing bed, exhaust energy of Twin-VGT turbines at low speeds was utilized reasonably and global pressure ratio increased by 0.69–0.94, while brake-specific fuel consumption decreased by 11.24–33.62% under low speeds above altitudes of 2500 m. [ABSTRACT FROM AUTHOR]

Dupilumab is approved for multiple type 2 inflammatory diseases. In the treatment procedure, the changes of IgE levels need further analysis. We evaluated the changes of IgE levels through meta-analysis, aiming to provide a more comprehensive result. Databases were searched to select eligible publications. After being included, study quality was assessed. The standardized mean difference (SMD) was used as an evaluation. Seven studies were included. At week 4, the level of IgE did not decrease significantly, with SMD = −0.12 (95%CI: −0.31, 0.07) (P > 0.05). At week 8, 12, 16, 24, and 52, the level of IgE decreased significantly, which was SMD = −0.26 (95%CI: −0.48, −0.03); −0.25 (95%CI: −0.32, −0.18); −0.49 (95%CI: −0.65, −0.33); −0.30 (95%CI: −0.38, −0.22); −0.40 (95%CI: −0.48, −0.32) (P < 0.05). In AD studies, with the increase of IgE levels, due to the decrease in the total dose of dupilumab, the efficacy index showed a decreasing trend. Levels of IgE can be significantly decreased in patients with dupilumab treatment. In AD patients, the efficacy was related to total dose; for patients with high IgE levels, efficacy may be better with the dose increased. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Modern Laboratory Medicine is the property of Journal of Modern Laboratory Medicine Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Modern Laboratory Medicine is the property of Journal of Modern Laboratory Medicine Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The PIV technique was applied to study the turbulent characteristics of the spays through the swirl injector and the double-jet holes injector which belong to the typical spray models called liquid-film spray and cylindrical spray respectively. The Spatial Turbulent Intensity (short for "I") and the Turbulent Integral Length Scale (short for "ILS" ) were used as parameters to analyze the turbulent characteristics of the two typical sprays. The result indicated that in the whole spray process, the distributions of I-values for the two kinds of sprays were diffuser than the distributions of speed-values, and the I-values were mainly distributed on the regions of the upside, downside and the root side of the spray flow fields. With the spray is continuing the I-value of the spray flow field, the L-value of the spray flow fields became higher and its distributions mainly concentrated in the regions of the non-front for the swirl spray and the non-front, non-central line for the double-jet spray. In order to simulate the ILS distribution more convenient, the ILS-value of every point of the spray flow field was decomposed into 4 components, Lxx, Lyx, Lxy, Lyy. Begining with the injectors spraying, at the time of 1. 5ms and 4ms, the Lxx-value of the swirl spray was higher than the double- jet spray and was also higher than the 3 other components at the same time; the local values of the Lxx reached the scales of 6mm (1.5ms) and 7mm(4ms) . At the time of 8ms, the distributions of all components for the swirl spray were diffuser than the double-jet spray; at the same time, the distributions including values and integralities of Lyx and Lxy were completely contrary. In the whole spay process, the distributions of Lyx for the two sprays were obviously lower and less integrated than the 3 other components respectively. [ABSTRACT FROM AUTHOR]