Oxygen transfer presents a serious challenge in the application of liquid lead as a nuclear coolant in advanced reactors. To mitigate corrosion by liquid lead in contact with steel, carefully controlling the oxygen co...Oxygen transfer presents a serious challenge in the application of liquid lead as a nuclear coolant in advanced reactors. To mitigate corrosion by liquid lead in contact with steel, carefully controlling the oxygen concentration has been used as an effective way. Oxygen needs to mix in liquid lead uniformly and quickly. To enhance oxygen transport in liquid lead, nanoparticles are added to the liquid metal. In the current study, a lattice Boltzmann method is applied to investigate natural convection of copper/lead and aluminum oxide/lead in two-dimensional simplified container. Two thermal boundary cases are evaluated in order to check the effect of different natural convection flow patterns on oxygen transport. Some useful information are obtained such as improvement in natural convection and reduction in oxygen equilibrium time.展开更多
Thermal management is essential in our body as it affects various bodily functions,ranging from thermal discomfort to serious organ failures,as an example of the worst-case scenario.There have been extensive studies a...Thermal management is essential in our body as it affects various bodily functions,ranging from thermal discomfort to serious organ failures,as an example of the worst-case scenario.There have been extensive studies about wearable materials and devices that augment thermoregulatory functionalities in our body,employing diverse materials and systematic approaches to attaining thermal homeostasis.This paper reviews the recent progress of functional materials and devices that contribute to thermoregulatory wearables,particularly emphasizing the strategic methodology to regulate body temperature.There exist several methods to promote personal thermal management in a wearable form.For instance,we can impede heat transfer using a thermally insulating material with extremely low thermal conductivity or directly cool and heat the skin surface.Thus,we classify many studies into two branches,passive and active thermal management modes,which are further subdivided into specific strategies.Apart from discussing the strategies and their mechanisms,we also identify the weaknesses of each strategy and scrutinize its potential direction that studies should follow to make substantial contributions to future thermal regulatory wearable industries.展开更多
It is of great significance to study the relationship between the excited state intramolecular proton transfer(ESIPT)properties and antioxidant activities of compounds in the field of life sciences.In this work,two no...It is of great significance to study the relationship between the excited state intramolecular proton transfer(ESIPT)properties and antioxidant activities of compounds in the field of life sciences.In this work,two novel compounds 5HF-OMe and 5HF-NH2 are designed through introducing a methoxy-and amino-group into the structure of 5-hydroxyflavone(5HF)respectively.The relationship between the ESIPT reaction and antioxidant activities of the three compounds is studied via the density functional theory(DFT)and time-dependent DFT(TD-DFT)methods.The calculated potential energy curves suggest that the rate of ESIPT reaction will gradually slow down from 5HF to 5HF-OMe and 5HF-NH2.In addition,the antioxidant activities of the three compounds gradually enhance from 5HF to 5HF-OMe and 5HF-NH2,which can be seen from the calculated energy gaps and ionization potential values.Interestingly,the above results imply that the rate of ESIPT reaction has a negative relationship with the antioxidant activities of the compounds,i.e.,the slower rate of ESIPT reaction will reflect the higher antioxidant activity of the compound,which will provide valuable reference for detecting the antioxidant activity of compound via the photophysical method.展开更多
Drying characteristics in terms of diffusivity were studied for mushrooms and different vegetables in a fluidized bed dryer. Drying characteristics with falling rate regime were computed for all the sampi^z. Effective...Drying characteristics in terms of diffusivity were studied for mushrooms and different vegetables in a fluidized bed dryer. Drying characteristics with falling rate regime were computed for all the sampi^z. Effective diffusivity of each sample was calculated. Mass transfer coefficients were determined. Mass transfer kinetics for drying of different samples was also found out. Correlations for the diffusivity of samples were developed by relating the experimentally observed data with the different system parame- ters on the basis of regression analysis. The developed correlations for effective moisture diffusivity of the samples are validated by artificial neural network (ANN) modeling. Finally calculated values of diffusivity obtained through both the methods are compared with the experimentally measured values which show a very good approximation thereby indicating the wide applicability of the developed correlations for industrial uses.展开更多
基金the financial support from the office of Vice-President for Research at University of Nevada-Las Vegas
文摘Oxygen transfer presents a serious challenge in the application of liquid lead as a nuclear coolant in advanced reactors. To mitigate corrosion by liquid lead in contact with steel, carefully controlling the oxygen concentration has been used as an effective way. Oxygen needs to mix in liquid lead uniformly and quickly. To enhance oxygen transport in liquid lead, nanoparticles are added to the liquid metal. In the current study, a lattice Boltzmann method is applied to investigate natural convection of copper/lead and aluminum oxide/lead in two-dimensional simplified container. Two thermal boundary cases are evaluated in order to check the effect of different natural convection flow patterns on oxygen transport. Some useful information are obtained such as improvement in natural convection and reduction in oxygen equilibrium time.
基金supported by the National Research Foundation of Korea(NRF)Grant funded through Basic Science Research Program(2021M3H4A1A02050237).
文摘Thermal management is essential in our body as it affects various bodily functions,ranging from thermal discomfort to serious organ failures,as an example of the worst-case scenario.There have been extensive studies about wearable materials and devices that augment thermoregulatory functionalities in our body,employing diverse materials and systematic approaches to attaining thermal homeostasis.This paper reviews the recent progress of functional materials and devices that contribute to thermoregulatory wearables,particularly emphasizing the strategic methodology to regulate body temperature.There exist several methods to promote personal thermal management in a wearable form.For instance,we can impede heat transfer using a thermally insulating material with extremely low thermal conductivity or directly cool and heat the skin surface.Thus,we classify many studies into two branches,passive and active thermal management modes,which are further subdivided into specific strategies.Apart from discussing the strategies and their mechanisms,we also identify the weaknesses of each strategy and scrutinize its potential direction that studies should follow to make substantial contributions to future thermal regulatory wearable industries.
基金Project supported by the National Basic Research Program of China(Grant No.2019YFA0307701)the National Natural Science Foundation of China(Grant No.11874180)the Science and Technology Development Project of Jilin Province of China(Grant No.20190103101JH).
文摘It is of great significance to study the relationship between the excited state intramolecular proton transfer(ESIPT)properties and antioxidant activities of compounds in the field of life sciences.In this work,two novel compounds 5HF-OMe and 5HF-NH2 are designed through introducing a methoxy-and amino-group into the structure of 5-hydroxyflavone(5HF)respectively.The relationship between the ESIPT reaction and antioxidant activities of the three compounds is studied via the density functional theory(DFT)and time-dependent DFT(TD-DFT)methods.The calculated potential energy curves suggest that the rate of ESIPT reaction will gradually slow down from 5HF to 5HF-OMe and 5HF-NH2.In addition,the antioxidant activities of the three compounds gradually enhance from 5HF to 5HF-OMe and 5HF-NH2,which can be seen from the calculated energy gaps and ionization potential values.Interestingly,the above results imply that the rate of ESIPT reaction has a negative relationship with the antioxidant activities of the compounds,i.e.,the slower rate of ESIPT reaction will reflect the higher antioxidant activity of the compound,which will provide valuable reference for detecting the antioxidant activity of compound via the photophysical method.
文摘Drying characteristics in terms of diffusivity were studied for mushrooms and different vegetables in a fluidized bed dryer. Drying characteristics with falling rate regime were computed for all the sampi^z. Effective diffusivity of each sample was calculated. Mass transfer coefficients were determined. Mass transfer kinetics for drying of different samples was also found out. Correlations for the diffusivity of samples were developed by relating the experimentally observed data with the different system parame- ters on the basis of regression analysis. The developed correlations for effective moisture diffusivity of the samples are validated by artificial neural network (ANN) modeling. Finally calculated values of diffusivity obtained through both the methods are compared with the experimentally measured values which show a very good approximation thereby indicating the wide applicability of the developed correlations for industrial uses.