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This study explores the problem of maximizing the sum rate in uplink multi-user Multiple-Input Multiple-Output (MIMO) using Rate-Splitting Multiple Access (RSMA) systems. The investigation revolves around the scenario where the Users (UEs) are single-antenna nodes transmitting data to a multi-antenna Base Station (BS) through the RSMA technique. The optimization process encompasses determining parameters such as UEs’ transmit powers, decoding order, and detection vector at the BS. An approach based on Deep Reinforcement Learning (DRL) is introduced to address this challenge. This DRL framework involves an action-refined stage and applies a Deep Deterministic Policy Gradient (DDPG)-based strategy. Simulation outcomes effectively demonstrate the convergence of the proposed DRL framework, where it converges after approximately 1,800 episodes. Also, the results prove the superior performance of the proposed method when compared to established benchmark strategies, where it is up to 45% and 86% higher than the local search and random schemes, respectively.

The ever-growing concerns about global warming and the rapid depletion of fossil fuels have triggered a rising interest in the research for cleaner, more efficient, and cost-effective energy generation. Organic Rankine cycle systems have immense potential to become a strong alternative to conventional methods of energy generation. However, such systems' efficiency is limited by the performance of the incorporated gas expanders or prime movers. Conventional gas expanders often utilize ports or cam-operated valves. Ported expanders offer limited efficiency and controllability and produce high emissions, causing a large amount of heated and compressed gas to be wasted. Cam-operated valves, in contrast, increase expansion performance compared to ported expanders; however, they have no variability and adaptability to changes in system parameters such as gas pressure, temperature, dryness fraction, and load variation, to name a few. On a positive note, this issue can be addressed by adopting a variable timing and fast-operating, control valve with an accurate and adaptive control mechanism at the expander inlet. A properly designed and controlled valve can greatly improve the system performance of gas expanders and pave the way for an efficient low-cost alternative energy generation. This manuscript provides a comparative review of recent progress on the design, modeling, optimization, and control aspects of valves for gas expanders. A clear pathway on the scope of further development is also drawn based on the present state of the art. [ABSTRACT FROM AUTHOR]

Organic Rankine Cycle (ORC)–based small-scale power plants are becoming a promising instrument in the recent drive to utilize renewable sources and reduce carbon emissions. But the effectiveness of such systems is limited by the low efficiency of gas expanders, which are the main part of an ORC system. Limaçon-based expansion machines with a fast inlet control valve have great prospects as they could potentially offer efficiencies over 50%. However, the lack of a highly reliable and significantly fast control valve is hindering its possible application. In this paper, a push–pull solenoid valve is optimized using a stochastic optimization technique to provide a fast response. The optimization yields about 56–58% improvement in overall valve response. A performance comparison of the initial and optimized valves applied to a limaçon expander thermodynamic model is also presented. Additionally, the sensitivity of the valve towards a changing inlet pressure and expander rotor velocity is analyzed to better understand the effectiveness of the valve and provide clues to overall performance improvement. [ABSTRACT FROM AUTHOR]

Renewable energy-based compact energy-generation systems based on the organic Rankine cycle (ORC) can be employed to meet the ever-growing thirst for affordable and clean energy. The overall performance and effectiveness of ORC systems are constrained by the low efficiency of the gas expander, specifically the positive displacement expander, which is responsible for energy conversion from the working fluid. This low-efficiency scenario can be significantly improved by employing a control valve to regulate and restrict the flow of the working fluid into the expander. A control valve can effectively curve the loss of costly compressed and energized working fluids by allowing them to expand in the expander chamber before discharging through the outlet port. They can thus be used to regulate the amount of energy yield and output power. In this work, two direct drive rotary valves (DDRVs) operated by a stepper motor (SM-DDRV) and rotary solenoid (RS-DDRV) are suggested, and the behavior of the valves is examined. The effect of friction and temperature on the valve response is also studied. Additionally, the effect of inlet control valves on the overall system performance of the limaçon expander is assessed. Thermodynamic properties such as the isentropic efficiency and filling factor are also computed. The effect of leakage due to valve response delay is analyzed at different inlet pressures. The performance indices are compared to the expander performance without any inlet valve. The SM-DDRV setup results in a 14.86% increase in isentropic efficiency and a 220% increase in the filling factor, whereas the RS-DDRV performs moderately with a 2.58% increase in isentropic efficiency and an 80% increase in the filling factor compared to a ported expander. The SM-DDRV provides better performance indices compared to the RS-DDRV and without valve setups. However, the performance of the limaçon expander with the SM-DDRV is sensitive to the inlet pressure and degrades at higher pressure. Overall, the valves proposed in this work present key insights into improving the performance characteristics of gas expanders of ORC systems. [ABSTRACT FROM AUTHOR]

Recently, Vietnam has reformed the laws and drew up the targets on protection the patients’ rights. Among the important purposes of these works are to raise the number of well-protected patients’ rights. As a territory of Vietnam, Mekong Delta has also been imposed to follow the determined trend of Vietnam. However, in practice, as it has its own particularities, Mekong Delta may breach the common expectations. Hence, to answer for the doubt of the real situation of actual status the patients have been protected in the collected provinces in Mekong, the author conducted research. In 2016, the research was conducted in the selected provinces that have similar characteristics such as Can Tho, Vinh Long, Soc Trang, and Kien Giang to present the status of patients’ rights protection. Based on the results, it is clear that some problems still remain. The results provide reasonable evidence to look for future solutions to the obstacles that hinder the selected provinces as well as Mekong Delta from developing

XPO5 codes for the nuclear transport factor exportin-5, which is a membrane-bound protein. This gene is responsible for the transport of pre-miRNA from the nucleus to the cytoplasmic compartments, thereby adjusting the whole miRNA expression level. The reduction of the miRNA levels was recorded when XPO5 was knocked down. rs11077 is found in the 3′UTR region of XPO5, and this SNP might affect mRNA stability and be associated with the altered expression of XPO5. This leads to the universal suppression of miRNA expression profiles, thereby mediating the HCC survival. HCC patients bearing C/C and A/C genotypes of rs11077 had a survival rate of 60% after 3 years; and this rate was reduced to 24.7% with HCC patients bearing the A/A genotype. In this study, we constructed a molecular assay based on a real-time PCR HRM technique for rs11077 genotyping. We successfully designed the primer pair for the real-time PCR HRM of rs11077. We also found the optimal concentration of MgCl2 to arrive at a clear differentiation of the three genotypes of rs11077. Thereafter, we characterised the analytical specificity and the precisions of the molecular assay. The SNP genotyping results were compared between the real-time PCR HRM and nucleotide sequencing. Finally, we evaluated the molecular assay on 123 human blood samples. The rs11077 genotyping assay in this study could be used for the prognosis of HCC patients.