191 research outputs found

    Exploration of hidden structure and prediction of gas anomaly area based on gas control projects

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    The investigation of hidden structures and the prediction of gas abnormal area form the foundation of gas disaster prevention engineering. In accordance with the laws and regulations governing coal mining in our country, a gas pumping project must be implemented prior to mining coal seams with a gas hazard. Typically, geologic anomaly area represent gas hazard zones, where the combination of tectonic stress field and mining-induced stress field can disturb coal bodies and pressurize gas. To accurately locate geologic anomaly areas and evaluate their gas disaster potential, a gas geologic anomaly survey method has been proposed based on gas extraction projects. This method uses drilling parameters and records to calculate the coordinates of the control points of the coal seam roof and bottom, and then utilizes two-dimensional projection diagrams and three-dimensional stress field models to survey and forecast small, hidden geological structures (such as small faults, folds, and locally abnormal coal thicknesses). By analyzing the additional stress field surrounding small geological structures, gas disaster potential can be dynamically predicted. The application of this method enables the detailed investigation of geological anomalies and reveals the general pattern of gas geological evolution at coal mining worksites. The research results provide a scientific basis for the optimal design and effective implementation of disaster prevention and control measures for coal seams with high gas content or at risk of gas outbursts

    Energy metabolism and maternal-fetal tolerance working in decidualization

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    One pivotal aspect of early pregnancy is decidualization. The decidualization process includes two components: the differentiation of endometrial stromal cells to decidual stromal cells (DSCs), as well as the recruitment and education of decidual immune cells (DICs). At the maternal-fetal interface, stromal cells undergo morphological and phenotypic changes and interact with trophoblasts and DICs to provide an appropriate decidual bed and tolerogenic immune environment to maintain the survival of the semi-allogeneic fetus without causing immunological rejection. Despite classic endocrine mechanism by 17 β-estradiol and progesterone, metabolic regulations do take part in this process according to recent studies. And based on our previous research in maternal-fetal crosstalk, in this review, we elaborate mechanisms of decidualization, with a special focus on DSC profiles from aspects of metabolism and maternal-fetal tolerance to provide some new insights into endometrial decidualization in early pregnancy

    Associations between Children's Physical Activity and Neighborhood Environments Using GIS: A Secondary Analysis from a Systematic Scoping Review.

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    Regular participation in physical activity is essential for children's physical, mental, and cognitive health. Neighborhood environments may be especially important for children who are more likely to spend time in the environment proximal to home. This article provides an update of evidence for associations between children's physical activity behaviors and objectively assessed environmental characteristics derived using geographical information system (GIS)-based approaches. A systematic scoping review yielded 36 relevant articles of varying study quality. Most studies were conducted in the USA. Findings highlight the need for neighborhoods that are well connected, have higher population densities, and have a variety of destinations in the proximal neighborhood to support children's physical activity behaviors. A shorter distance to school and safe traffic environments were significant factors in supporting children's active travel behaviors. Areas for improvement in the field include the consideration of neighborhood self-selection bias, including more diverse population groups, ground-truthing GIS databases, utilising data-driven approaches to derive environmental indices, and improving the temporal alignment of GIS datasets with behavioral outcomes

    Experimental Investigations on the Inner Flow Behavior of Centrifugal Pumps under Inlet Air-Water Two-Phase Conditions

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    Centrifugal pumps are widely used and are known to be sensitive to inlet air-water two-phase flow conditions. The pump performance degradation mainly depends on the changes in the two-phase flow behavior inside the pump. In the present paper, experimental overall pump performance tests were performed for two different rotational speeds and several inlet air void fractions (αi) up to pump shut-off condition. Visualizations were also performed on the flow patterns of a whole impeller passage and the volute tongue area to physically understand pump performance degradation. The results showed that liquid flow modification does not follow head modification as described by affinity laws, which are only valid for homogeneous bubbly flow regimes. Three-dimensional effects were more pronounced when inlet void fraction increased up to 3%. Bubbly flow with low mean velocities were observed close to the volute tongue for all αi, and returned back to the impeller blade passages. The starting point of pump break down was related to a strong inward reverse flow that occurred in the vicinity of the shroud gap between the impeller and volute tongue area

    Green Mass Production of Pure Nanodrugs via an Ice-Template-Assisted Strategy

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    To make nanomedicine potentially applicable in a clinical setting, several methods have been developed to synthesize pure nanodrugs (PNDs) without using any additional inert carriers. In this work, we report a novel green, low-cost, and scalable ice-template-assisted approach which shows several unique characteristics. First, the whole process only requires adding a drug solution into an ice template and subsequent melting (or freeze-drying), allowing easy industrial mass production with low capital investment. Second, the production yield is much higher than that of the traditional reprecipitation approach. The yield of Curcumin (Cur) PNDs is over two orders (∼140 times) magnitude higher than that obtained in a typical reprecipitation preparation. By adjusting simple processing parameters, PNDs with different sizes (∼20–200 nm) can be controllably obtained. Finally, the present approach can be easily applicable for a wide range of hydrophobic therapeutic drugs without any structural modification
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