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Due to pollution discharge and climate change, hypoxia is becoming more prevalent in water bodies such as lakes, rivers, and oceans. It leads to black blooms in lakes, black and odors in rivers, and dead zones in the oceans. Iron sulfide, especially amorphous mackinawite, is the main blackening substance. In this paper, the physical characteristics and detection methods of mackinawite were used to determine how to detect it in hypoxic water bodies. The population and metabolism of key microorganisms during mackinawite generation were analyzed to provide a reference for studying related microorganisms during the blackening process. Finally, the influence of macromolecular organic matter and microorganisms on the stable suspension of mackinawite was determined, and the existing patterns of mackinawite during the blackening process of hypoxic waters were illustrated. The generation of amorphous mackinawite and its stable suspension in a supernatant are two indispensable factors during the blackening process. The clarification of substance characteristics and key action processes are conducive to the accurate and targeted control of the blackening process and promote the restoration of the sustainable self-purification ability of water bodies. [ABSTRACT FROM AUTHOR]

A high-efficiency propeller can enable a long mission duration for autonomous underwater vehicles (AUVs). In this study, a new method with OpenProp coupled with computational fluid dynamics was developed to design a propeller for an Explorer100 AUV. The towed system simulation of the AUV was used to measure the nominal wake, and a self-propulsion simulation was used to measure the effective wake at the disc plane just in front of a propeller. Two propellers referring to the nominal wake (propeller 1) and effective wake (propeller 2) were designed with OpenProp and appended with the AUV for self-propulsion simulations, respectively. Through the numerical simulation of the AUV self-propulsion tests, the cruising velocity of AUV was obtained. The flow characteristics of the self-propulsion in pressure and velocity contours were also analyzed. The propeller designed with an effective wake improved the thrust, velocity, and efficiency by approximately 11.3%, 6.7%, and 2.5%, respectively, as compared with those with a nominal wake. The cruising velocity of the final designed propeller for the Explorer100 AUV improved by 21.8%, as compared to that of the original propeller from the AUV free-running tests. [ABSTRACT FROM AUTHOR]

Designing a material with the advantage of adsorption–enrichment and photocatalysis degradation has great practical significance in water treatment. BiPO4, as a promising photocatalyst for environmental purification, still suffers from small specific surface area and relative low photocatalytic activity. Herein, BiPO4–SiO2 hybrid hydrogels were successfully fabricated by facile two-step methods. BiPO4 nanorods are uniformly compounded with SiO2 spheres, and the specific surface area of BiPO4 is enhanced by 2.3 times after forming a network structure. 90% BiPO4–SiO2 hybrid hydrogel presents the highest photocatalytic degradation activities, which is 3.4 times that of pure BiPO4. The total organic carbon removal ability of BiPO4 is also enhanced by 1.1 times after constructing a hybrid hydrogel. The pollutant removal enhancement of BiPO4–SiO2 hybrid hydrogel can be attributed to the synergistic effect of adsorption–enrichment and photocatalytic degradation. Our results may provide a promising way to greatly enhance the pollutant removal performance of BiPO4, which may promote the industrial application of BiPO4. [ABSTRACT FROM AUTHOR]

Background and Objective: Azilsartan medoxomil (AZL-M) is an angiotensin II receptor blocker approved to treat hypertension. After oral dosing, AZL-M is quickly hydrolyzed to azilsartan (AZL). The aims of this study were to assess the effects of age, sex, and race on the pharmacokinetics of AZL-M in healthy subjects, as well as safety and tolerability.Methods: Sixty-one healthy adults were enrolled in this phase I, single-blind, randomized placebo-controlled study (placebo control was for assessment of safety/tolerability only). Subjects were stratified by age (18-45 vs. 65-85 years), sex, and race (black vs. white) and given oral AZL-M 60 mg (3 × 20 mg capsules) or placebo as a single dose (Day 1) and consecutive daily doses (Days 4-8) (6:2 ratio for AZL-M:placebo per group). Pharmacokinetics were evaluated (AZL-M patients only) on Days 1-3 and 8-9 and safety/tolerability was monitored.Results: Age, sex, and race had no clinically meaningful effect on AZL exposures after single or multiple dosing. Pharmacokinetic parameters remained similar between Days 1 and 8 for each age, sex, and race subgroup. The frequency of adverse events was similar for AZL-M (32%) and placebo (29%). No discontinuations or serious adverse events occurred.Conclusions: Based on these pharmacokinetic and safety/tolerability findings, no AZL-M dose adjustments are required based on age, sex, or race (black/white). [ABSTRACT FROM AUTHOR]

The existing investigations on thermal comfort mostly focus on the thermal environment conditions, especially of the air-flow field and the temperature distributions in vehicle cabin. Less attention appears to direct to the thermal comfort or thermal sensation of occupants, even to the relationship between thermal conditions and thermal sensation. In this paper, a series of experiments were designed and conducted for understanding the non-uniform conditions and the occupant's thermal responses in vehicle cabin during the heating period. To accurately assess the transient temperature distribution in cabin in common daily condition, the air temperature at a number of positions is measured in a full size vehicle cabin under natural winter environment in South China by using a discrete thermocouples network. The occupant body is divided into nine segments, the skin temperature at each segment and the occupant's local thermal sensation at the head, body, upper limb and lower limb are monitored continuously. The skin temperature is observed by using a discrete thermocouples network, and the local thermal sensation is evaluated by using a seven-point thermal comfort survey questionnaire proposed by American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc(ASHRAE) Standard. The relationship between the skin temperature and the thermal sensation is discussed and regressed by statistics method. The results show that the interior air temperature is highly non-uniform over the vehicle cabin. The locations where the occupants sit have a significant effect on the occupant's thermal responses, including the skin temperature and the thermal sensation. The skin temperature and thermal sensation are quite different between body segments due to the effect of non-uniform conditions, clothing resistance, and the human thermal regulating system. A quantitative relationship between the thermal sensation and the skin temperature at each body segment of occupant in real life traffic is presented. The investigation result indicates that the skin temperature is a robust index to evaluate the thermal sensation. Applying the skin temperature to designing and controlling parameters of the heating, ventilation and air conditioning(HVAC) system may benefit the thermal comfort and reducing energy consumption. [ABSTRACT FROM AUTHOR]

A numerical simulation of combined natural convection and radiation in a square enclosure heated by a centric circular cylinder and filled with absorbing-emitting medium is presented. The ideal gas law and the discrete ordinates method are used to model the density changes due to temperature differences and the radiation heat transfer correspondingly. The influence of Rayleigh number, optical thickness and temperature difference on flow and temperature fields along with the natural convection, radiation and total Nusselt number at the source surfaces is studied. The results reveal that the radiation heat transfer as well as the optical thickness of the fluid has a distinct effect on the fluid flow phenomena, especially at high Rayleigh number. The heat transfer and so the Nusselt number decreases with increase in optical thickness, while increases greatly with increase in temperature difference. The variation in radiation heat transfer with optical thickness and temperature difference is much more obvious as comparison with convection heat transfer. [ABSTRACT FROM AUTHOR]

Solid-state fermentation with Yarrowia lipolytica was applied to palm kernels (PK) with the aim to modulate the aroma of palm kernel oil (PKO) obtained after kernel roasting. The results showed that, the metabolic activities of Y. lipolityca brought about significant changes to the volatile profile of obtained PKO either by providing thermal reaction reactants or by directly contributing aroma compounds. After fermentation, a decreased content in glucose (60%) while an elevated amount (7-fold) in free amino acids was found in PK, which further impacted the formation of volatile compounds by influencing the Maillard reaction and Strecker degradation during roasting. More Strecker aldehydes and N-heterocyclic compounds were formed in PKO derived from fermented PK especially after intensified roasting. In addition, the catabolism of Y. lipolytica imparted some distinct volatile compounds such as 2-phenylethanol to the obtained PKO. However, the lipase excreted by Y. lipolytica hydrolysed PK lipids and released 5-fold more free fatty acids in fermented PKO, relative to the blank and control PKO, which likely contributed to the off-flavor. On the basis of all volatile categories, principal component analysis (PCA) clearly separated the fermented PKO from the blank and control PKO, with light roasted, fermented PKO being correlated with acids, alcohols and aliphatic aldehydes; medium and dark roasted, fermented PKO tending to be dominated by pyrroles, pyrazines and furanones, which is in correspondence with sensory changes of PKO. This study demonstrated that combining fermentation with roasting could provide a novel way to modulate the volatile composition and aroma of PKO. [ABSTRACT FROM AUTHOR]