Study on Gas Leakage Detection and Pressure Difference Identification by Asymmetric Differential Pressure Method

As the most common actuator in the pneumatic system, the excellent air tightness of the tank is the key to meet the use requirements of automatic equipment. This paper introduces the common air tightness detection contents, and models the inflation and detection process of the differential pressure method. In order to break away from the restriction on the detection efficiency caused by the asynchronous temperature recovery of the two chambers in the asymmetric differential pressure method, the differential calculation of directly detected pressure difference is replaced by the pressure difference substitute formula. The influence of various parameters in the fitting formula is analyzed by simulation, and the effectiveness of this method is verified by experiments.

Effects of Different Types of Incubators on Embryo Development and Clinical Outcomes

Main differences of incubators are humidity, temperature and gas control ways, which play important roles in regulating the steady state of culture media. In this study, we compared the effects of different types of incubators (air jacket incubators and water jacket incubators) on embryo development and clinical outcomes in human assisted reproduction. We found that temperature recovery time in air jacket incubators was significantly shorter than that in water jacket incubators. Although the O2 recovering time was also significantly shorter in air jacket incubators as compared with the water jacket incubator, no significant differences were observed in CO2 recovering time between two groups, which was also verified by pH recovering time of culture media. Besides, the temperature of culture medium in the dish covered with oil recovered more quickly in the air jacket incubators. However, there were no significant differences observed in the fertilization rate, Day 3 high-quality embryo rate, blastocyst rate, good blastocyst rate and clinical outcomes between two groups. These results indicate that the microenvironment, especially the temperature, in air jacket incubator recover faster than that in water jacket incubators, however, there were no significant differences in embryo development and clinical outcomes between two types of incubators.

The Evolution of Thermal Conductivity and Pore Structure for Coal under Liquid Nitrogen Soaking

An experimental system for liquid nitrogen soaking and real-time temperature measurement was designed and implemented to investigate the characteristics of temperature field changes in coal under liquid nitrogen soaking. Then, the heat conduction law of the coal in the process of liquid nitrogen soaking and room temperature recovery for dry and water-saturated coal were examined. The microstructure characteristics of the coal before and after liquid nitrogen soaking were analyzed with nuclear magnetic resonance (NMR) technology. The results showed that, during the liquid nitrogen cold soaking process, the heat transfer law of the dry and water-saturated coal samples exhibited a notable three-stage distribution. For the room temperature recovery process, the dry and water-saturated coal samples exhibited rapid heating characteristics, and the cooling rate gradually decreased to zero. NMR test results indicated that the liquid nitrogen soaking increased the number of micro and small pores in the coal. Thermal stress analysis revealed that the thermal stress generated by the dry coal was larger than that produced by the saturated coal, and the damage was primarily caused by thermal stress. However, the permeability of the saturated coal was better than that of the dry coal. The damage on the saturated coal was caused by the volume expansion of pores and fissures caused by water-ice phase transition.

Efficacy of Hydroxychloroquine in Patients with COVID-19 (Chen et al., 2020): Moderate Evidence for a Treatment Effect on Pneumonia

A recent randomized clinical trial assessed the efficacy of hydroxychloroquine (HCQ) in the treatment of patients with common coronavirus disease-19 (COVID-19). 1 The results showed that “the body temperature recovery time and the cough remission time were significantly shortened in the HCQ treatment group. Besides, a larger proportion of patients with improved pneumonia in the HCQ treatment group (80.6%, 25 of 31) compared with the control group (54.8%, 17 of 31).” A Bayesian reanalysis of the pneumonia data provides support for the hypothesis that HCQ improves pneumonia in patients with COVID-19. However, the degree of this support is moderate. In line with the authors’ conclusion, more data are needed to draw definite conclusions.

Estimation of Temperature Recovery Distance and the Influence of Heat Pump Discharge on Fluvial Ecosystems

Temperature differences between the atmosphere and river water allow rivers to be used as a hydrothermal energy source. River-water heat pump systems are a relatively non-invasive renewable energy source; however, effluent discharged from the heat pump can cause downstream temperature changes which may impact sensitive fluvial ecosystems. The temperature change associated with heat pump discharge in a river reach was examined using the heat transfer equation in a previous study, but not using models. There were also no studies on the impact of temperature change due to heat pump discharge on river ecosystem elements such as endangered fishes. Therefore, in this study, the water temperature recovery distance of effluent was estimated for a river section in the Han River Basin, Korea, using the heat transfer equation and the Environmental Fluid Dynamic Code (EFDC) model. The water temperature recovery distance was estimated to be 9.7 km using the heat transfer equation and 5 km using the EFDC model in summer. It was also estimated to be 4.5 km using the heat transfer equation and 6.7 km using the EFDC model in winter. Results showed that the water temperature recovery distance results estimated by the heat transfer equation had greater variation than the EFDC model. The water temperature recovery distance could also be used as an objective indicator to decide the reuse of downstream river water. Furthermore, as the river system was found to support an endangered fish species that is sensitive to water environment changes, care should be taken to exclude the habitats of protected species affected by water temperatures within water temperature recovery distance.