Geochemical Characteristics of Hydrothermal Volatiles From Southeast China and Their Implications on the Tectonic Structure Controlling Heat Convection

Hot springs and igneous rocks are present widely in southeast China, influenced by the subduction of the Western Pacific and Philippine Sea Plates. This study reports on new data of chemical compositions and He–Ne–C isotopes for gas samples from representative hot springs and wells in the Guangdong and Fujian provinces to identify the origin of hydrothermal volatiles and provide insight into geothermal tectonic affinities. The primary hydrothermal volatile component from southeast China is atmospheric N2, with a volumetric percentage of 82.19%–98.29%. It indicates medium-low temperature geothermal systems where geothermal fluids suffered a shallow circulation in closed fracture systems. Low CO2 and CH4 contents and their depleted δ13C values confirmed the small number of deep-derived components in the study area. However, spatially discernible geochemical characteristics imply enhanced hydrothermal fluid convection in the adjacent area of the two provinces, including the Fengshun, Zhangzhou, Longyan, and Sanming geothermal fields. Specifically, the He–Ne isotopes from this area exhibit mantle He contribution of more than 10% and mantle heat flow accounts for more than half of the total heat flow. Moreover, according to the thermal background calculations, the highest heat flow value of 77.7 mW/m2 is indicated for the Zhangzhou geothermal area and the lowest value of 54.7 mW/m2 is indicated for the Maoming geothermal area. Given the epicenter distributions and the corresponding earthquake magnitudes, the NE-trending faults are heat-control tectonic structures and their intersections with the NW-trending faults provided expedite channels for geothermal fluids rising to the surface. Therefore, the preferred development potential of geothermal resources can be expected in the adjacent area of the two provinces where two sets of active faults crossed. This study provides critical information on understanding the geothermal distribution controlled by the tectonic structure in southeast China.

Characterization of Volatile Component Changes in Peas under Different Treatments by GC-IMS and GC-MS

Volatile profiles of peas under 9 kinds of different treatments including native, washing, blanching, precooling, freezing, steaming, boiling, frying, and freeze-drying were characterized by GC-IMS and GC-MS. The differences of volatile compounds in different peas were observed from the characteristic fingerprints by GC-IMS. The Venn diagram found that the common flavor substances codetected by GC-IMS and GC-MS were n-hexanal, nonanal, 1-octene-3-ol, benzaldehyde, 6-methyl-5-hepten-2-one, trans-2-octenal, and 2-ethyl-3,5-dimethylpyrazine, which were speculated to be the key flavor substances of peas. The cluster analysis of the heat map conducted towards the differences of volatile components in peas under different treatments; the results indicated that peas could be mainly divided into four groups, which was consistent with the above conclusion of GC-IMS. Eight sensory descriptors were used to evaluate the aroma notes: sweet flowers, fat fragrance, waxy aldehydes, mushroom hay, roasted potato with nuts, vegetable-like bean, spicy dry tar, and bitter almond from the sensory analysis, and the sensory analysis also showed good agreement with the results of GC-IMS and GC-MS. The results indicated that the volatile compounds of peas under different treatments could be visualized and identified quickly via GC-IMS, and the samples could be clearly classified based on the difference of volatile compounds. Practical Application. In the study, fingerprints coupled with cluster analysis were a visualized method for the identification of volatile compounds. Meanwhile, a new method, the Venn diagram with OAV, was used to identify the key-aroma of products. Finally, a rapid method is established to classify products by GC-IMS. In future practical applications, GC-IMS can be used to classify products from different origins and different manufacturers. Similarly, it can identify fake and inferior products and whether the products have deteriorated. In addition, this research will provide a new strategy to find the relationship between flavor compounds and various processed technology towards different cereals.

Applying Concepts and Tools in Demography for Estimating, Analyzing, and Forecasting Forced Migration

Among demographic events (birth, death, and migration), migration is notably the most volatile component to forecast accurately. Accounting for forced migration is even more challenging given the difficulty in collecting forced migration data. Knowledge of trends and patterns of forced migration and its future trajectory is, however, highly relevant for policy planning for migrant sending and receiving areas. This paper aims to review existing methodological tools to estimate and forecast migration in demography and explore how they can be applied to the study of forced migration. It presents steps towards estimation of forced migration and future assessments, which comprise: (1) migration flows estimation methods using both traditional and nontraditional data; (2) empirical analysis of drivers of migration and migration patterns; and (3) forecasting migration based on multidimensional population projections and scenarios approach. The paper then discusses how these demographic methods and tools can be applied to estimate and forecast forced migration.

Atmospheres of lava exoplanets. Where and what to look for.

<p>Strongly irradiated rocky planets will have sufficiently high surface temperatures to sustain dayside magma lakes and oceans that will outgas low-pressure days-side silicate atmospheres. The surface magma will preferentially outgas its most volatile components and eventually equilibrate itself with the formed atmosphere. However, the volatile constituents may be depleted due to transport and condensation to the cooler night side or escape to space. If the atmospheric evolution is slower than the surface-interior exchange, the melt composition will remain coupled with the planet's interior. In such a case the atmospheric component will be continuously replenished. If atmospheric evolution is fast, the magma pool will lose its volatile component and the atmospheric composition will be irreversibly changed. We employ numerical models of outgassing, atmospheric chemistry, and radiative transfer to model the possible observable emission features of evolving magma atmospheres for all confirmed rocky lava worlds. . Our results highlight the best possible observable features in the atmospheres of hot rocky exoplanets that may give insight in their interior and atmospheric evolution. We also propose a set of ideal targets for JWST and ARIEL missions.<br><br><br></p>

Systematic heat transfer measurements in highly viscous binary fluids

Investigations of flow boiling in highly viscous fluids show that heat transfer mechanisms in such fluids are different from those in fluids of low viscosity like refrigerants or water. To gain a better understanding, a modified standard apparatus was developed; it was specifically designed for fluids of high viscosity up to 1000 Pa∙s and enables heat transfer measurements with a single horizontal test tube over a wide range of heat fluxes. Here, we present measurements of the heat transfer coefficient at pool boiling conditions in highly viscous binary mixtures of three different polydimethylsiloxanes (PDMS) and n-pentane, which is the volatile component in the mixture. Systematic measurements were carried out to investigate pool boiling in mixtures with a focus on the temperature, the viscosity of the non-volatile component and the fraction of the volatile component on the heat transfer coefficient. Furthermore, copper test tubes with polished and sanded surfaces were used to evaluate the influence of the surface structure on the heat transfer coefficient. The results show that viscosity and composition of the mixture have the strongest effect on the heat transfer coefficient in highly viscous mixtures, whereby the viscosity of the mixture depends on the base viscosity of the used PDMS, on the concentration of n-pentane in the mixture, and on the temperature. For nucleate boiling, the influence of the surface structure of the test tube is less pronounced than observed in boiling experiments with pure fluids of low viscosity, but the relative enhancement of the heat transfer coefficient is still significant. In particular for mixtures with high concentrations of the volatile component and at high pool temperature, heat transfer coefficients increase with heat flux until they reach a maximum. At further increased heat fluxes the heat transfer coefficients decrease again. Observed temperature differences between heating surface and pool are much larger than for boiling fluids with low viscosity. Temperature differences up to 137 K (for a mixture containing 5% n-pentane by mass at a heat flux of 13.6 kW/m2) were measured.

Determination of the working temperature of the MOS sensors used for the detection of ethanol and methanol

In this work, some peruvian red wines were analyzed using gas chromatography coupled to mass spectrometry (GC-MS) and it was determined that ethanol was the major volatile component present in the aroma (12 % in volume). followed by methanol (2-3 % in volume). Some MOS sensors based on SnO2 doped with Pd and Pt were prepared by precipitation with metallic charges from 0.1 to 0.5% and were tested with the same Peruvian wines. The stability and reproducibility of the sensing signal was analyzed at different working temperatures (200, 220, 240, 260 and 280 °C). The best working temperature at which the highest intensity of the response signal of the sensors was obtained at 260 ⁰C. In most of the cases studied, the sensing signal of the sensors was in general repetitive and stable, maintaining its amplitude and shape during long periods of the analysis. However, at the temperature of 280 ° C the signal loses intensity and in contact with methanol the signal is distorted.

Combustion Characteristics and Kinetic Analysis of Biomass Pellet Fuel Using Thermogravimetric Analysis

Biomass pellet fuel is one of the development directions of renewable energy. The purpose of the article is to study the combustion characteristics of five kinds of biomass pellet fuel that can be used as biomass fuel and analyze their combustion kinetics. The thermogravimetric method (TG method) was used to analyze the combustion characteristics of five kinds of biomass pellet fuel and to calculate the index S of comprehensive combustion characteristic. The Arrhenius equation and the Coats–Redfern method were used to analyze the combustion kinetics of five kinds of biomass pellet fuel. The activation energy and pre-exponential factor were obtained according to different temperature ranges. Conclusions are as follows: The pyrolysis of five kinds of biomass pellet fuel mainly includes three stages: (1) water evaporation stage, (2) volatile component combustion stage, (3) fixed carbon oxidation stage. The TG curves of five kinds of biomass pellet fuel are roughly the same at the same heating rate. The peaks of thermal weight loss rate and maximum degradation rate are both in the high temperature range. The differential thermal gravity(DTG) curves of five kinds of biomass pellet fuel have an obvious peak. The peak temperature of the largest peak in the DTG curves is 280–310 °C. The first-order reaction equation is used to obtain the kinetic parameters in stages. The correlation coefficients are bigger than the value of 0.92. The fitting results are in good agreement with the experimental results. The activation energy of each sample is basically the same in each stage. The value in the volatile matter combustion stage is 56–542kJ/mol, and the activation energy of the carbon layer slowly increases rapidly. The five kinds of biomass pellet fuels have good combustion characteristics and kinetic characteristics, and they can be promoted and applied as biomass pellet fuels in the future.

The Key Target and Molecular Mechanism of the Volatile Component of Scutellaria baicalensis Georgi in Acute Lung Injury Based on Network Pharmacology

Ethnopharmacological relevance:Scutellaria baicalensis georgi is one of the most widely studied TCMs; its effects in ALI have been studied in a large number of experiments, and the efficacy of volatile oil from TCM remains to be studied.Aim: The volatile component of Scutellaria baicalensis georgi was selected to act on the key target of acute lung injury and was preliminarily studied for its specific molecular mechanism.Methods: The volatile active substances of Scutellaria baicalensis georgi were extracted by GC–MS, and the active ingredients related with the occurrence and development of acute lung injury were searched and matched by the TCMSP database. The pharmacologic data and analysis platform of TCM were used to retrieve and screen for the volatile active components and the possible therapeutic targets of Scutellaria baicalensis georgi. In addition, acute lung injury was searched in the disease target database to identify the corresponding disease target proteins, thereby establishing a protein–protein interaction network. Finally, the effects of wogonin on the apoptotic and inflammatory factors in the acute lung injury cell model were analyzed experimentally.Results: We identified 100 candidate targets and successfully constructed a complex target network. The targets identified by the above gene enrichment analysis played important roles in the autoimmune disease cell cycle apoptosis and related signaling pathways. The KEGG pathway analysis showed that most of the target genes were involved in the inflammatory response regulation of the TRP, PI3K-Akt, and IL-17 signaling pathways. The participation of wogonin in the specific regulatory pathways of PI3K-Akt signaling and IL-17 signaling was verified through experiments. In the lung-injured cell model, the results showed that wogonin inhibited the apoptosis of injured lung cells by inhibiting the expression of BAD gene and the activation of cleaved caspase-3 gene while increasing Bcl-2 expression. In addition, wogonin inhibited the expression of the abovementioned inflammatory factors and further inhibited the inflammatory response in the lung injury cells.Conclusion: The results of pharmacological network analysis can predict and explain the regulation mechanism of multi-target and multi-pathway of TCM components. This study identified the potential target and important pathway of wogonin in regulating acute lung injury. At the same time, the accuracy of network pharmacological prediction is also preliminarily verified by molecular biology experiment.