The emergence of smart grids in India is propelled by an intricate interaction of market dynamics,regulatory structures,and stakeholder obligations.This study analyzes the primary factors that are driving the widespre...The emergence of smart grids in India is propelled by an intricate interaction of market dynamics,regulatory structures,and stakeholder obligations.This study analyzes the primary factors that are driving the widespread use of smart grid technologies and outlines the specific roles and obligations of different stakeholders,such as government entities,utility companies,technology suppliers,and consumers.Government activities and regulations are crucial in facilitating the implementation of smart grid technology by offering financial incentives,regulatory assistance,and strategic guidance.Utility firms have the responsibility of implementing and integrating smart grid infrastructure,with an emphasis on improving the dependability of the grid,minimizing losses in transmission and distribution,and integrating renewable energy sources.Technology companies offer the essential hardware and software solutions,which stimulate creativity and enhance efficiency.Consumers actively engage in the energy ecosystem by participating in demand response,implementing energy saving measures,and adopting distributed energy resources like solar panels and electric vehicles.This study examines the difficulties and possibilities in India’s smart grid industry,highlighting the importance of cooperation among stakeholders to build a strong,effective,and environmentally friendly energy future.展开更多
The shape characterization and spatial distribution of aggregate,mastic and air void phases for asphalt mixture were analyzed.Three air void percentage asphalt mixtures,4%,7% and 8%,respectively,were cut into cross se...The shape characterization and spatial distribution of aggregate,mastic and air void phases for asphalt mixture were analyzed.Three air void percentage asphalt mixtures,4%,7% and 8%,respectively,were cut into cross sections and polished.X-ray scanning microscope was used to capture aggregate,mastic,air void phase by the image.The average of polygon diameter was chosen as a threshold to determine which aggregates would be retained on a given sieve.The aggregate morphological image from scanned image was utilized by digital image processing method to calculate the gradation of aggregate and simulate the real gradation.Analysis result shows that the air void of asphalt mixture has influence on the correlation between calculation gradation and actual gradation.When comparing 4.75 mm sieve size of 4%,7% and 8% air void asphalt mixtures,7% air void asphalt mixture has 55% higher than actual size gradation,8% air void asphalt mixture has 8% higher than actual size gradation,and 4% air void asphalt mixture has 3.71% lower than actual size gradation.4% air void asphalt mixture has the best correlation between calculation gradation and actual gradation comparing to other specimens.The air void percentage of asphalt mixture has no obvious influence on the air void orientation,and three asphalt mixtures show the similar air orientation along the same direction.展开更多
Catalyst-coated membranes(CCMs)have gained popularity among membrane electrode assembly(MEA)fabricators for their abilities and advantages compared with those of other methods,such as catalyst-coated substrates(CCSs)....Catalyst-coated membranes(CCMs)have gained popularity among membrane electrode assembly(MEA)fabricators for their abilities and advantages compared with those of other methods,such as catalyst-coated substrates(CCSs).CCMs show a profound new analysis for reducing platinum(Pt)catalyst loading.In addition,they increase the total number of reactions that occur on the MEA because of their active area amplification,which leads to an improved catalyst-utilization efficiency rate.Moreover,several characteristics are involved in the MEA fabrication methods.Material-manufacturing effects with regard to catalyst inks and analysis of the overall performance of MEAs prepared by the CCM and CCS methods are deliberated.This deliberation emphasizes the practical approaches in minimizing performance deterioration during the fabrication of MEAs using the CCM method and converses the commercialization of the CCM fabrication method toward developing an end product.Novel research is required for MEA fabrication using the CCM methods to ensure that the fuel cell performance is improved.Therefore,this review is focusing on the pros and cons of both distinguished methods,that is,CCM and CCS fabrication,for better comparison.展开更多
The aim of this work is to investigate microstructure,corrosion resistance characteristics and nanohardness of the oxide layer on AZ91 Mg alloy by applying different voltage with KMnO4 contained solution.There are lot...The aim of this work is to investigate microstructure,corrosion resistance characteristics and nanohardness of the oxide layer on AZ91 Mg alloy by applying different voltage with KMnO4 contained solution.There are lots of closed pores that are filled with another oxide compound compared with the typical surface morphology with pore coated until 350 V of coating voltage.The thickness of oxide layer increases with increasing coating voltage.The oxide layer formed on AZ91 Mg alloy in electrolyte with potassium permanganate consists of MgO and Mn2O3.Corrosion potential of the oxide layer on AZ91 Mg alloy obtained at different plasma electrolytic oxidation(PEO) reaction stages increases with increasing coating voltage.The corrosion resistance of AZ91 Mg alloy depends on the existence of the manganese oxide in the oxide layer.The inner barrier layer composed of the MgO and Mn2O3 may serve as diffusion barrier to enhance the corrosion resistance and may partially explain the excellent anti-corrosion performance in corrosion test.Nanohardness values increase with increasing coating voltage.The increase in the nanohardness may be due to the effect of manganese oxide in the oxide layer on AZ91 Mg alloy coated from electrolyte containing KMnO4.展开更多
Transdermal drug delivery （TDD） can effectively bypass the first-pass effect. In this paper, ultrasound-facilitated TDD on fresh porcine skin was studied under various acoustic parameters, including frequency, ampli...Transdermal drug delivery （TDD） can effectively bypass the first-pass effect. In this paper, ultrasound-facilitated TDD on fresh porcine skin was studied under various acoustic parameters, including frequency, amplitude, and exposure time. The delivery of yellow-green fluorescent nanoparticles and high molecular weight hyaluronic acid （HA） in the skin samples was observed by laser confocal microscopy and ultraviolet spectrometry, respectively. The results showed that, with the application of ultrasound exposures, the permeability of the skin to these markers （e.g., their penetration depth and concentration） could be raised above its passive diffusion permeability. Moreover, ultrasound-facilitated TDD was also tested with/without the presence of ultrasound contrast agents （UCAs）. When the ultrasound was applied without UCAs, low ultrasound frequency will give a better drug delivery effect than high frequency, but the penetration depth was less likely to exceed 200 p.m. However, with the help of the ultrasound-induced microbubble cavitation effect, both the penetration depth and concentration in the skin were significantly enhanced even more. The best ultrasound-facilitated TDD could be achieved with a drug penetration depth of over 600 p.m, and the penetration concentrations of fluorescent nanoparticles and HA increased up to about 4-5 folds. In order to get better understanding of ultrasound-facilitated TDD, scanning electron microscopy was used to examine the surface morphology of skin samples, which showed that the skin structure changed greatly under the treatment of ultrasound and UCA. The present work suggests that, for TDD applications （e.g., nanoparticle drug carriers, transdermal patches and cosmetics）, protocols and methods presented in this paper are potentially useful.展开更多
Recently, a semi-solid metal processing has been acknowledged as a cost-effective technique to be able to manufacture high quality product for the transportation industry. In this study a hypo-eutectic Al alloy was fa...Recently, a semi-solid metal processing has been acknowledged as a cost-effective technique to be able to manufacture high quality product for the transportation industry. In this study a hypo-eutectic Al alloy was fabricated by means of an electromagnetic stirrer in continuous casting process and the microstructural change during solidification due to a fluid flow by electromagnetic stirring was examined. Due to the forced fluid flow during solidification a dendritic phase of primary α phase of Al alloy was turned into a globular phase, which can make the Al alloy get a thixotropic behavior in the semi-solid region. In order to establish the quantitative relationship between microstructure and the process parameters, the morphology shape, a silicon distribution and a size of primary α phase were observed according to casting speed in continuous casting machine. The primary α phase was turned into the degenerate dendrites approaching a spherical configuration with increasing casting speed. The fine-grained and equiaxed microstructure appeared at higher casting speed. A segregation behavior of Si element was declined with increasing casting speed and a very uniform distribution of Si element was observed on the billet at a casting speed of 600 mm·min-1. A thickness of the solidifying shell of the billet was shortened with increasing the casting speed.展开更多
The design and development of a timer based revolution per minute(RPM)measurement system were described in this paper.The rotating shaft of a dc motor was used to measure the RPM and timer integrated circuit(IC)555 wa...The design and development of a timer based revolution per minute(RPM)measurement system were described in this paper.The rotating shaft of a dc motor was used to measure the RPM and timer integrated circuit(IC)555 was used in astable mode.The frequency of timer output waveform measured by a digital storage oscilloscope(DSO)is almost linearly proportional to the RPM of rotating shaft,and the RPM also linearly varies with the change of the external input voltage level.Hence the linear relationship between the frequency of timer output waveform and the RPM can be obtained.The main advantages of this developed system are linear input-output relationship,small size,easy to carry and cost effective.展开更多
Polysaccharide production from tea flower(TFPS) was carried out using supercritical fluid extraction(SFE).Response surface methodology(RSM),based on a five level,four variable small central composite design,was employ...Polysaccharide production from tea flower(TFPS) was carried out using supercritical fluid extraction(SFE).Response surface methodology(RSM),based on a five level,four variable small central composite design,was employed to obtain the best possible combination of extraction time,pressure,temperature and ethanol content of modifier for maximum production.The optimum conditions were as follows:extraction time of 170 min,pressure of45 MPa,temperature of 75 ℃,and 50% aqueous ethanol solution as modifier.Under these conditions,the experimental yield was 6.56 ± 0.37%,which was similar to the value predicted by the model.Monosaccharide composition of TFPS was fucose,rhamnose,arabinose,xylose,galactose,glucose,mannose,fructose,ribose,galacturonic acid and glucuronic acid in a molar percent of 31.69,0.21,0.49,1.29,35.82,0.97,1.63,18.34,7.88,1.06 and 0.63.Compared to other extraction methods,SFE could achieve higher yield and gain more types of monosaccharide.展开更多
The effects of lntcr-ckxttxxk insertion on the performance of a hollow--electrode plasma torch have been investigated by numerical analysis.Simulation results revealed that when inter-dcctrodes arc inserted,the arc vo...The effects of lntcr-ckxttxxk insertion on the performance of a hollow--electrode plasma torch have been investigated by numerical analysis.Simulation results revealed that when inter-dcctrodes arc inserted,the arc voltages and plasma powers increase due to the increase in the arc length.In addition,it was predicted that thermal efficiency can be improved with the increase in plasma power by injecting plasma gases through the gaps between inter-electrodes.These unique effects of inter-electrode insertion arc a result of the plasma temperatures adjusting themselves to increase arc voltages when the arc column is contracted radially by increasing gas-flow rate or decreasing inter-electrcxk diameter.展开更多
In this paper, we propose a novelmethod based on the plate theory to simultaneously predict retention times and peak shapes under gradient elutions and different flow rates by reversed-phase high-performance liquid ch...In this paper, we propose a novelmethod based on the plate theory to simultaneously predict retention times and peak shapes under gradient elutions and different flow rates by reversed-phase high-performance liquid chromatography. The proposed method yielded excellent retention prediction results in experiments with 16 common sulfonamides under 18 gradient conditions and four different flow rates, including 0.7, 1.0, 1.3, and 1.5 mL/min. The mean absolute deviation was 0.70%, which indicates accurate prediction. Moreover, the proposed method predicts the change wellin peak shapes caused by the expansion or compression ofpeaks under different gradient conditions.展开更多
The time evolution of populations of the ground state hyperfine Zeeman levels of ^(87)Rb atoms is analyzed using the Runge-Kutta method for the case that a rubidium beam is optically pumped,under different conditions ...The time evolution of populations of the ground state hyperfine Zeeman levels of ^(87)Rb atoms is analyzed using the Runge-Kutta method for the case that a rubidium beam is optically pumped,under different conditions of polarization,with a weak monochromatic laser and an ^(87)R lamp.On the base of the results above,the least estimated laser and ^(87)R lamp power for the best population inversion is obtained,aiding further investigations.展开更多
The influence of different factors on the plasma chemical reactions is widely studied today. However, insufficient consideration is given to the research of paramagnetic phenomena which takes place in plasma systems. ...The influence of different factors on the plasma chemical reactions is widely studied today. However, insufficient consideration is given to the research of paramagnetic phenomena which takes place in plasma systems. The results of modeling the process of redistribution carbon isotopes between different phases while oxidizing it in high-frequency low-temperature plasma in an external magnetic field are shown in the article. The equilibrium concentrations of components involved in the oxidation process in a plasma system are defined. A principle possibility of isotope-selective plasma chemical reactions in a magnetic field was experimentally determined. The increase of concentration of 13C in the gas phase up to 1.3 times relative to natural abundance was obtained. It was found that the content of the carbon heavy isotope in the gas phase depends on the magnetic field action area. The best results were achieved with the combination of magnetic field impact area and the priority area of the appearance of plasma chemical reactions products.展开更多
Adequate regional groundwater assessment studies are essential for the correct groundwater management by policy/decision makers;increased use of groundwater resources and drought have led to concern about the future a...Adequate regional groundwater assessment studies are essential for the correct groundwater management by policy/decision makers;increased use of groundwater resources and drought have led to concern about the future availability of groundwater to meet domestic,agricultural,industrial,and environmental needs.Deep understanding of spatial and temporal water table dynamics together with transport processes is required.This paper gathers historical geological,hidrological and chemical information for quantitative and qualitative as well as spatial and temporal evolution of groundwater for Aguanaval and Chupaderos aquifers,both surrounding Calera aquifer in Mexico.Historical databases were employed to determine temporal trends of water levels and values were projected for years 2010,2030 and 2050.Potential recharge sites were also identified through water level-topography correlation.The water quality analysis was completed by obtaining,through geostatistics,spatial distributions for bicarbonate,chloride,sulfate,total dissolved solids,temperature,and sodium,employing databases generated in recent sampling campaigns.This analysis provided additional elements to help understand the functioning of groundwater in studied aquifers.Finally,results were compared with permissible values established in the Mexican norm.展开更多
A high percentage of failure in pump elements originates from fatigue.This study focuses on the discharge section behavior,made of ductile iron,under dynamic load.An experimental protocol is established to collect the...A high percentage of failure in pump elements originates from fatigue.This study focuses on the discharge section behavior,made of ductile iron,under dynamic load.An experimental protocol is established to collect the strain under pressurization and depressurization tests at specific locations.These experimental results are used to formulate the ultimate pressure expression function of the strain and the lateral surface of the discharge section and to validate finite element modeling.Fe-Safe is then used to assess the fatigue life cycle using different types of fatigue criteria(Coffin-Manson,Morrow,Goodman,and Soderberg).When the pressure is under 3000 PSI,pumps have an unlimited service life of 107 cycles,regardless of the criterion.However,for a pressure of 3555 PSI,only the Morrow criterion denotes a significant decrease in fatigue life cycles,as it considers the average stress.The topological optimization is then applied to the most critical pump model(with the lowest fatigue life cycle)to increase its fatigue life.Using the solid isotropic material with a penalization approach,the Abaqus Topology OptimizationModule is employed.The goal is to reduce the strain energy density while keeping the volume within bounds.According to the findings,a 5%volume reduction causes the strain energy density to decrease from 1.06 to 0.66106 J/m^(3).According to Morrow,the fatigue life cycle at 3,555 PSI is 782,425 longer than the initial 309,742 cycles.展开更多
The aim of this study is to enhance the recycled PVC （polyvinyl chloride） related material property by formulation technology and develop the recycling product processing technology furthermore develop the chemical ...The aim of this study is to enhance the recycled PVC （polyvinyl chloride） related material property by formulation technology and develop the recycling product processing technology furthermore develop the chemical recycling technology for last stage of PVC wastes. The formulation technology is composed of pre-treatment （crushing, separation etc.） and post-treatment （material ratio, additives, stabilizer etc.） to enhance the recyclate property. The formulation for recycled PVC by application basis and processing technology is applied to produce the structural product for civil and construction application such as pipe fittings and water drainage cap for environmental waterway. Also chemical recycling technology for end life PVC scrap which causes environmental pollution by incineration or landfill is studied for producing hydrocarbon and hydrogen chloride for VCM.展开更多
A novel and simple fluorescent molecular sensor,1-pyrenecarboxaldehyde thiosemicarbazone（Hpytsc）,was synthesized.Its higher sensitivity and selectivity to mercury（Ⅱ） ion were studied through absorption and emissi...A novel and simple fluorescent molecular sensor,1-pyrenecarboxaldehyde thiosemicarbazone（Hpytsc）,was synthesized.Its higher sensitivity and selectivity to mercury（Ⅱ） ion were studied through absorption and emission channels.The UV-vis spectra show that the increasing mercury（Ⅱ） ion concentrations result in the decreasing absorption intensity.The fluorescence monomer emission of Hpytsc is enhanced upon binding mercury（Ⅱ） ion,which should be due to the 1：1 complex formation between Hpytsc and metal ion.展开更多
Modification of the commercial polymer electrolyte membrane （PEM） Nation 117 by γ-ray irradiation to produce an improved proton exchange membrane for direct methanol fuel cells （DMFCs） was described. The Nation 1...Modification of the commercial polymer electrolyte membrane （PEM） Nation 117 by γ-ray irradiation to produce an improved proton exchange membrane for direct methanol fuel cells （DMFCs） was described. The Nation 117 membrane was exposed under γ-ray irradiation circumstance with the irradiation doses from 103 to 105 Gy. Subsequently the properties of the membrane itself, in terms of swelling ratio, water uptake rate, proton conductivity and methanol permeability, together with the performance of its membrane electrode assembly （MEA） in DMFC were analyzed and contrasted with the untreated material. When the Nation 117 membrane was exposed under γ-ray irradiation circumstance, the degradation and crosslinking reactions occurred at the same time. Specific scopes of the γ-ray irradiation dose may cause the membrane crosslinking, thus reduce the membrane swelling ratio and decrease the methanol crossover. By reducing the membrane swelling ratio and methanol permeation, the single DMFC with the modified Nation 117 membrane produced reasonable power density performance as high as 32 W/m2 under 2 mol/L methanol solution at room temperature.展开更多
In this work,the concepts of particle swarm optimization-based method,named non-Gaussian improved particle swarm optimization for minimizing the cost of energy(COE)of wind turbines(WTs)on high-altitude sites are intro...In this work,the concepts of particle swarm optimization-based method,named non-Gaussian improved particle swarm optimization for minimizing the cost of energy(COE)of wind turbines(WTs)on high-altitude sites are introduced.Since the COE depends on site specification constants and initialized parameters of wind turbine,the focus was on the design optimization of rotor radius,hub height and rated power.Based on literature,the COE is converted to the Saudi Arabia context.Thus,the constrained wind turbine optimization problem is developed.Then,non-Gaussian improved particle swarm optimization is provided and compared with the conventional particle swarm optimization for solving the optimization design in wind turbine efficiency under different altitudes ranging from 2500 to 4000 m.The results show that as altitude rises,the optimal rotor radius grows,but the optimal hub height and rated power drop,resulting in an increase in COE.Further,the non-Gaussian method display a faster convergence compared to the classical particle swarm optimization.These findings will be useful as a reference for wind turbine design at high altitudes.Thus,it could be employed to optimize the initialized parameter of wind turbine for the planned and largest wind farm in Saudi Arabia in Dumat Al-Jandal selected site.展开更多
文摘The emergence of smart grids in India is propelled by an intricate interaction of market dynamics,regulatory structures,and stakeholder obligations.This study analyzes the primary factors that are driving the widespread use of smart grid technologies and outlines the specific roles and obligations of different stakeholders,such as government entities,utility companies,technology suppliers,and consumers.Government activities and regulations are crucial in facilitating the implementation of smart grid technology by offering financial incentives,regulatory assistance,and strategic guidance.Utility firms have the responsibility of implementing and integrating smart grid infrastructure,with an emphasis on improving the dependability of the grid,minimizing losses in transmission and distribution,and integrating renewable energy sources.Technology companies offer the essential hardware and software solutions,which stimulate creativity and enhance efficiency.Consumers actively engage in the energy ecosystem by participating in demand response,implementing energy saving measures,and adopting distributed energy resources like solar panels and electric vehicles.This study examines the difficulties and possibilities in India’s smart grid industry,highlighting the importance of cooperation among stakeholders to build a strong,effective,and environmentally friendly energy future.
基金National Natural Science Foundation of China(51250110077)
文摘The shape characterization and spatial distribution of aggregate,mastic and air void phases for asphalt mixture were analyzed.Three air void percentage asphalt mixtures,4%,7% and 8%,respectively,were cut into cross sections and polished.X-ray scanning microscope was used to capture aggregate,mastic,air void phase by the image.The average of polygon diameter was chosen as a threshold to determine which aggregates would be retained on a given sieve.The aggregate morphological image from scanned image was utilized by digital image processing method to calculate the gradation of aggregate and simulate the real gradation.Analysis result shows that the air void of asphalt mixture has influence on the correlation between calculation gradation and actual gradation.When comparing 4.75 mm sieve size of 4%,7% and 8% air void asphalt mixtures,7% air void asphalt mixture has 55% higher than actual size gradation,8% air void asphalt mixture has 8% higher than actual size gradation,and 4% air void asphalt mixture has 3.71% lower than actual size gradation.4% air void asphalt mixture has the best correlation between calculation gradation and actual gradation comparing to other specimens.The air void percentage of asphalt mixture has no obvious influence on the air void orientation,and three asphalt mixtures show the similar air orientation along the same direction.
基金The authors acknowledge the financial support provided by the Ministry of Higher Education,Malaysia through the research grants LRGS/2013/UKM-UKM/TP-01 and UKM GUP-2016-044.9.0.
文摘Catalyst-coated membranes(CCMs)have gained popularity among membrane electrode assembly(MEA)fabricators for their abilities and advantages compared with those of other methods,such as catalyst-coated substrates(CCSs).CCMs show a profound new analysis for reducing platinum(Pt)catalyst loading.In addition,they increase the total number of reactions that occur on the MEA because of their active area amplification,which leads to an improved catalyst-utilization efficiency rate.Moreover,several characteristics are involved in the MEA fabrication methods.Material-manufacturing effects with regard to catalyst inks and analysis of the overall performance of MEAs prepared by the CCM and CCS methods are deliberated.This deliberation emphasizes the practical approaches in minimizing performance deterioration during the fabrication of MEAs using the CCM method and converses the commercialization of the CCM fabrication method toward developing an end product.Novel research is required for MEA fabrication using the CCM methods to ensure that the fuel cell performance is improved.Therefore,this review is focusing on the pros and cons of both distinguished methods,that is,CCM and CCS fabrication,for better comparison.
基金supported by a grant from the Center of Advanced Materials Processing(CAMP) of the 21st Centry Froniter R&D Program Funded by the Ministry of Knowledge Economy(MKE),Koreasupported by the Korea Science and Engineering Foundation (No.2009-0079807)
文摘The aim of this work is to investigate microstructure,corrosion resistance characteristics and nanohardness of the oxide layer on AZ91 Mg alloy by applying different voltage with KMnO4 contained solution.There are lots of closed pores that are filled with another oxide compound compared with the typical surface morphology with pore coated until 350 V of coating voltage.The thickness of oxide layer increases with increasing coating voltage.The oxide layer formed on AZ91 Mg alloy in electrolyte with potassium permanganate consists of MgO and Mn2O3.Corrosion potential of the oxide layer on AZ91 Mg alloy obtained at different plasma electrolytic oxidation(PEO) reaction stages increases with increasing coating voltage.The corrosion resistance of AZ91 Mg alloy depends on the existence of the manganese oxide in the oxide layer.The inner barrier layer composed of the MgO and Mn2O3 may serve as diffusion barrier to enhance the corrosion resistance and may partially explain the excellent anti-corrosion performance in corrosion test.Nanohardness values increase with increasing coating voltage.The increase in the nanohardness may be due to the effect of manganese oxide in the oxide layer on AZ91 Mg alloy coated from electrolyte containing KMnO4.
基金Project partially supported by the National Natural Science Foundation of China(Grant Nos.81127901,81227004,81473692,81673995,11374155,11574156,11274170,11274176,11474001,11474161,11474166,and 11674173)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK2011812)+1 种基金the Fundamental Research Funds for the Central Universitiesthe National High-Tech Research and Development Program of China(Grant No.2012AA022702)
文摘Transdermal drug delivery （TDD） can effectively bypass the first-pass effect. In this paper, ultrasound-facilitated TDD on fresh porcine skin was studied under various acoustic parameters, including frequency, amplitude, and exposure time. The delivery of yellow-green fluorescent nanoparticles and high molecular weight hyaluronic acid （HA） in the skin samples was observed by laser confocal microscopy and ultraviolet spectrometry, respectively. The results showed that, with the application of ultrasound exposures, the permeability of the skin to these markers （e.g., their penetration depth and concentration） could be raised above its passive diffusion permeability. Moreover, ultrasound-facilitated TDD was also tested with/without the presence of ultrasound contrast agents （UCAs）. When the ultrasound was applied without UCAs, low ultrasound frequency will give a better drug delivery effect than high frequency, but the penetration depth was less likely to exceed 200 p.m. However, with the help of the ultrasound-induced microbubble cavitation effect, both the penetration depth and concentration in the skin were significantly enhanced even more. The best ultrasound-facilitated TDD could be achieved with a drug penetration depth of over 600 p.m, and the penetration concentrations of fluorescent nanoparticles and HA increased up to about 4-5 folds. In order to get better understanding of ultrasound-facilitated TDD, scanning electron microscopy was used to examine the surface morphology of skin samples, which showed that the skin structure changed greatly under the treatment of ultrasound and UCA. The present work suggests that, for TDD applications （e.g., nanoparticle drug carriers, transdermal patches and cosmetics）, protocols and methods presented in this paper are potentially useful.
基金This work was financiallysupported bythe KISTProgram(No.2E19470)and by the Components&Materials Technology Development Program of Ministry of Commerce,Industry and Energy of Korea.
文摘Recently, a semi-solid metal processing has been acknowledged as a cost-effective technique to be able to manufacture high quality product for the transportation industry. In this study a hypo-eutectic Al alloy was fabricated by means of an electromagnetic stirrer in continuous casting process and the microstructural change during solidification due to a fluid flow by electromagnetic stirring was examined. Due to the forced fluid flow during solidification a dendritic phase of primary α phase of Al alloy was turned into a globular phase, which can make the Al alloy get a thixotropic behavior in the semi-solid region. In order to establish the quantitative relationship between microstructure and the process parameters, the morphology shape, a silicon distribution and a size of primary α phase were observed according to casting speed in continuous casting machine. The primary α phase was turned into the degenerate dendrites approaching a spherical configuration with increasing casting speed. The fine-grained and equiaxed microstructure appeared at higher casting speed. A segregation behavior of Si element was declined with increasing casting speed and a very uniform distribution of Si element was observed on the billet at a casting speed of 600 mm·min-1. A thickness of the solidifying shell of the billet was shortened with increasing the casting speed.
文摘The design and development of a timer based revolution per minute(RPM)measurement system were described in this paper.The rotating shaft of a dc motor was used to measure the RPM and timer integrated circuit(IC)555 was used in astable mode.The frequency of timer output waveform measured by a digital storage oscilloscope(DSO)is almost linearly proportional to the RPM of rotating shaft,and the RPM also linearly varies with the change of the external input voltage level.Hence the linear relationship between the frequency of timer output waveform and the RPM can be obtained.The main advantages of this developed system are linear input-output relationship,small size,easy to carry and cost effective.
基金supported by a key research grant "The application and Utilization of Tea (Camellia sinensis) Flowers" from the 2013 Zhejiang Province
文摘Polysaccharide production from tea flower(TFPS) was carried out using supercritical fluid extraction(SFE).Response surface methodology(RSM),based on a five level,four variable small central composite design,was employed to obtain the best possible combination of extraction time,pressure,temperature and ethanol content of modifier for maximum production.The optimum conditions were as follows:extraction time of 170 min,pressure of45 MPa,temperature of 75 ℃,and 50% aqueous ethanol solution as modifier.Under these conditions,the experimental yield was 6.56 ± 0.37%,which was similar to the value predicted by the model.Monosaccharide composition of TFPS was fucose,rhamnose,arabinose,xylose,galactose,glucose,mannose,fructose,ribose,galacturonic acid and glucuronic acid in a molar percent of 31.69,0.21,0.49,1.29,35.82,0.97,1.63,18.34,7.88,1.06 and 0.63.Compared to other extraction methods,SFE could achieve higher yield and gain more types of monosaccharide.
文摘The effects of lntcr-ckxttxxk insertion on the performance of a hollow--electrode plasma torch have been investigated by numerical analysis.Simulation results revealed that when inter-dcctrodes arc inserted,the arc voltages and plasma powers increase due to the increase in the arc length.In addition,it was predicted that thermal efficiency can be improved with the increase in plasma power by injecting plasma gases through the gaps between inter-electrodes.These unique effects of inter-electrode insertion arc a result of the plasma temperatures adjusting themselves to increase arc voltages when the arc column is contracted radially by increasing gas-flow rate or decreasing inter-electrcxk diameter.
基金supported by the National Nature Science Foundation of China (No. 51406109)
文摘In this paper, we propose a novelmethod based on the plate theory to simultaneously predict retention times and peak shapes under gradient elutions and different flow rates by reversed-phase high-performance liquid chromatography. The proposed method yielded excellent retention prediction results in experiments with 16 common sulfonamides under 18 gradient conditions and four different flow rates, including 0.7, 1.0, 1.3, and 1.5 mL/min. The mean absolute deviation was 0.70%, which indicates accurate prediction. Moreover, the proposed method predicts the change wellin peak shapes caused by the expansion or compression ofpeaks under different gradient conditions.
基金Supported by the National Natural Science Foundation of China under Grant No 11174015the Fundamental Research Funds for the Central Universities.
文摘The time evolution of populations of the ground state hyperfine Zeeman levels of ^(87)Rb atoms is analyzed using the Runge-Kutta method for the case that a rubidium beam is optically pumped,under different conditions of polarization,with a weak monochromatic laser and an ^(87)R lamp.On the base of the results above,the least estimated laser and ^(87)R lamp power for the best population inversion is obtained,aiding further investigations.
文摘The influence of different factors on the plasma chemical reactions is widely studied today. However, insufficient consideration is given to the research of paramagnetic phenomena which takes place in plasma systems. The results of modeling the process of redistribution carbon isotopes between different phases while oxidizing it in high-frequency low-temperature plasma in an external magnetic field are shown in the article. The equilibrium concentrations of components involved in the oxidation process in a plasma system are defined. A principle possibility of isotope-selective plasma chemical reactions in a magnetic field was experimentally determined. The increase of concentration of 13C in the gas phase up to 1.3 times relative to natural abundance was obtained. It was found that the content of the carbon heavy isotope in the gas phase depends on the magnetic field action area. The best results were achieved with the combination of magnetic field impact area and the priority area of the appearance of plasma chemical reactions products.
文摘Adequate regional groundwater assessment studies are essential for the correct groundwater management by policy/decision makers;increased use of groundwater resources and drought have led to concern about the future availability of groundwater to meet domestic,agricultural,industrial,and environmental needs.Deep understanding of spatial and temporal water table dynamics together with transport processes is required.This paper gathers historical geological,hidrological and chemical information for quantitative and qualitative as well as spatial and temporal evolution of groundwater for Aguanaval and Chupaderos aquifers,both surrounding Calera aquifer in Mexico.Historical databases were employed to determine temporal trends of water levels and values were projected for years 2010,2030 and 2050.Potential recharge sites were also identified through water level-topography correlation.The water quality analysis was completed by obtaining,through geostatistics,spatial distributions for bicarbonate,chloride,sulfate,total dissolved solids,temperature,and sodium,employing databases generated in recent sampling campaigns.This analysis provided additional elements to help understand the functioning of groundwater in studied aquifers.Finally,results were compared with permissible values established in the Mexican norm.
基金The authors extend their appreciation to the Researchers Supporting Project number(RSPD2023R698),King Saud University,Riyadh,Saudi Arabia for funding this research work.
文摘A high percentage of failure in pump elements originates from fatigue.This study focuses on the discharge section behavior,made of ductile iron,under dynamic load.An experimental protocol is established to collect the strain under pressurization and depressurization tests at specific locations.These experimental results are used to formulate the ultimate pressure expression function of the strain and the lateral surface of the discharge section and to validate finite element modeling.Fe-Safe is then used to assess the fatigue life cycle using different types of fatigue criteria(Coffin-Manson,Morrow,Goodman,and Soderberg).When the pressure is under 3000 PSI,pumps have an unlimited service life of 107 cycles,regardless of the criterion.However,for a pressure of 3555 PSI,only the Morrow criterion denotes a significant decrease in fatigue life cycles,as it considers the average stress.The topological optimization is then applied to the most critical pump model(with the lowest fatigue life cycle)to increase its fatigue life.Using the solid isotropic material with a penalization approach,the Abaqus Topology OptimizationModule is employed.The goal is to reduce the strain energy density while keeping the volume within bounds.According to the findings,a 5%volume reduction causes the strain energy density to decrease from 1.06 to 0.66106 J/m^(3).According to Morrow,the fatigue life cycle at 3,555 PSI is 782,425 longer than the initial 309,742 cycles.
文摘The aim of this study is to enhance the recycled PVC （polyvinyl chloride） related material property by formulation technology and develop the recycling product processing technology furthermore develop the chemical recycling technology for last stage of PVC wastes. The formulation technology is composed of pre-treatment （crushing, separation etc.） and post-treatment （material ratio, additives, stabilizer etc.） to enhance the recyclate property. The formulation for recycled PVC by application basis and processing technology is applied to produce the structural product for civil and construction application such as pipe fittings and water drainage cap for environmental waterway. Also chemical recycling technology for end life PVC scrap which causes environmental pollution by incineration or landfill is studied for producing hydrocarbon and hydrogen chloride for VCM.
基金financed by the Graduate Innovation Foundation of Logistic Engineering University(Chongqing, China)
文摘A novel and simple fluorescent molecular sensor,1-pyrenecarboxaldehyde thiosemicarbazone（Hpytsc）,was synthesized.Its higher sensitivity and selectivity to mercury（Ⅱ） ion were studied through absorption and emission channels.The UV-vis spectra show that the increasing mercury（Ⅱ） ion concentrations result in the decreasing absorption intensity.The fluorescence monomer emission of Hpytsc is enhanced upon binding mercury（Ⅱ） ion,which should be due to the 1：1 complex formation between Hpytsc and metal ion.
基金the National Natural Science Foundation of China(No.21106060)the China Postdoctoral Science Fundation(No.2012M511950)the Yunnan Province Natural Science Foundation(Nos.2010ZC015 and 2010ZC037)
文摘Modification of the commercial polymer electrolyte membrane （PEM） Nation 117 by γ-ray irradiation to produce an improved proton exchange membrane for direct methanol fuel cells （DMFCs） was described. The Nation 117 membrane was exposed under γ-ray irradiation circumstance with the irradiation doses from 103 to 105 Gy. Subsequently the properties of the membrane itself, in terms of swelling ratio, water uptake rate, proton conductivity and methanol permeability, together with the performance of its membrane electrode assembly （MEA） in DMFC were analyzed and contrasted with the untreated material. When the Nation 117 membrane was exposed under γ-ray irradiation circumstance, the degradation and crosslinking reactions occurred at the same time. Specific scopes of the γ-ray irradiation dose may cause the membrane crosslinking, thus reduce the membrane swelling ratio and decrease the methanol crossover. By reducing the membrane swelling ratio and methanol permeation, the single DMFC with the modified Nation 117 membrane produced reasonable power density performance as high as 32 W/m2 under 2 mol/L methanol solution at room temperature.
基金The authors extend their appreciation to the Researchers Supporting Project number(RSP2022R515)King Saud University,Riyadh,Saudi Arabia for funding this research work。
文摘In this work,the concepts of particle swarm optimization-based method,named non-Gaussian improved particle swarm optimization for minimizing the cost of energy(COE)of wind turbines(WTs)on high-altitude sites are introduced.Since the COE depends on site specification constants and initialized parameters of wind turbine,the focus was on the design optimization of rotor radius,hub height and rated power.Based on literature,the COE is converted to the Saudi Arabia context.Thus,the constrained wind turbine optimization problem is developed.Then,non-Gaussian improved particle swarm optimization is provided and compared with the conventional particle swarm optimization for solving the optimization design in wind turbine efficiency under different altitudes ranging from 2500 to 4000 m.The results show that as altitude rises,the optimal rotor radius grows,but the optimal hub height and rated power drop,resulting in an increase in COE.Further,the non-Gaussian method display a faster convergence compared to the classical particle swarm optimization.These findings will be useful as a reference for wind turbine design at high altitudes.Thus,it could be employed to optimize the initialized parameter of wind turbine for the planned and largest wind farm in Saudi Arabia in Dumat Al-Jandal selected site.
