Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,ma...Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.展开更多
The unavailability of wasted energy due to the irreversibility in the process is called the entropy generation.An irreversible process is a process in which the entropy of the system is increased.The second law of the...The unavailability of wasted energy due to the irreversibility in the process is called the entropy generation.An irreversible process is a process in which the entropy of the system is increased.The second law of thermodynamics is used to define whether the given system is reversible or irreversible.Here,our focus is how to reduce the entropy of the system and maximize the capability of the system.There are many methods for maximizing the capacity of heat transport.The constant pressure gradient or motion of the wall can be used to increase the heat transfer rate and minimize the entropy.The objective of this study is to analyze the heat and mass transfer of an Eyring-Powell fluid in a porous channel.For this,we choose two different fluid models,namely,the plane and generalized Couette flows.The flow is generated in the channel due to a pressure gradient or with the moving of the upper lid.The present analysis shows the effects of the fluid parameters on the velocity,the temperature,the entropy generation,and the Bejan number.The nonlinear boundary value problem of the flow problem is solved with the help of the regular perturbation method.To validate the perturbation solution,a numerical solution is also obtained with the help of the built-in command NDSolve of MATHEMATICA 11.0.The velocity profile shows the shear thickening behavior via first-order Eyring-Powell parameters.It is also observed that the profile of the Bejan number has a decreasing trend against the Brinkman number.Whenηi→0(i=1,2,3),the Eyring-Powell fluid is transformed into a Newtonian fluid.展开更多
This article reports the simultaneous properties of variable conductivity and chemical reaction in stagnation point flow of magneto Maxwell nanofluid.The Buongiorno’s theory has been established to picture the induce...This article reports the simultaneous properties of variable conductivity and chemical reaction in stagnation point flow of magneto Maxwell nanofluid.The Buongiorno’s theory has been established to picture the inducement of Brownian and thermophrotic diffusions effects.Additionally,the aspect of heat sink/source is reported.The homotopic analysis method(HAM)has been worked out for the solution of nonlinear ODEs.The behavior of inferential variables on the velocity,temperature,concentration and local Nusselt number for Maxwell nanofluid are sketched and discussed.The attained outcomes specify that both the temperature and concentration of Maxwell fluid display analogous behavior,while the depiction of Brownian motion is quite conflicting on both temperature and concentration fields.It is further noted that the influence of variable thermal conductivity on temperature field is similar to that of Brownian motion parameter.Moreover,for the confirmation of our study comparison tables are reported.展开更多
Application of biochar to agricultural soils is mostly used to improve soil fertility.Experimental treatments were comprised of two factors:i)drought at two level,i.e.,80%and 40%water holding capacity(WHC)which was ma...Application of biochar to agricultural soils is mostly used to improve soil fertility.Experimental treatments were comprised of two factors:i)drought at two level,i.e.,80%and 40%water holding capacity(WHC)which was maintained on gravimetric basis ii)three levels of biochar i.e.,control,2 t ha^(-1) and 4 t ha^(-1) added to soil.Experimentation was done to examine potential of biochar application to enhance the growth attributes,water relations,photosynthetic pigments and antioxidants activities in maize(Zea mays L.)seedlings.Results of study revealed that biochar application increased the growth qualities(total seedlings biomass,dry weight of shoot and root,shoot length and root length).In addition;contents of photosynthetic pigments(chlorophyll a,b,a+b and a/b),water relation(relative water contents,turgor potential,osmotic potential and water potential)were improved significantly due to addition of biochar.Addition of 4 t ha^(-1) biochar led to significant rise activity of enzymatic antioxidant catalase(CAT),superoxide dismutase(SOD)and peroxidase(POD)in leaf of maize seedling sunder drought as well as well watered circumstances.However,biochar applied at the rate 4 t ha^(-1) improved the all the physiological and biochemical attributes in maize seedlings under drought.From the results it was concluded that biochar application is an efficient way to alleviate adverse effect of drought stress on maize.In drought prone areas,long term impacts of biochar on production of maize and properties of soil could be recommended as upcoming shove.展开更多
Zn1-xCrxO （x = 0.00, 0.01, 0.03, 0.05, 0.07, and 0.09） nanoparticles were synthesized, by an auto-com- bustion method. Structural, optical, and magnetic characteristics of Cr-doped ZnO samples calcined at 600 ℃ hav...Zn1-xCrxO （x = 0.00, 0.01, 0.03, 0.05, 0.07, and 0.09） nanoparticles were synthesized, by an auto-com- bustion method. Structural, optical, and magnetic characteristics of Cr-doped ZnO samples calcined at 600 ℃ have been analyzed by using X-ray diffraction （XRD）, field emission scanning electron microscope （FESEM）, UV-Vis spectroscopy and vibrating sample magnetometer （VSM）. The XRD data confirmed the hexagonal wurtzite structure of pure and Cr-doped ZnO nanoparticles. The calculated values of grain size using Scherrer＇s formula are in the range of 30.7-9.2 nm. The morphology of nanopowders has been observed by FESEM, and EDS results con- firmed a systematic increase of Cr content in the samples and clearly indicate with no impurity element. The band gaps, computed by UV-Vis spectroscopy, are in the range of 2.83-2.35 eV for different doping concentrations. By analyzing VSM data, significantly enhanced room temperature ferromagnetism is identified in Cr-doped ZnO samples. The value of magnetization is a 12 times increased of the value reported by Daun et al. （2010）. Room temperature ferromagnetism of the nanoparticles is of vital prominence for spintronics applications.展开更多
基金supported by the Deanship of Scienti c Research at King Saud University for funding under Research Group(No.RG1440-021).
文摘Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.
基金Project supported by the National Natural Science Foundation of China(Nos.11971142,11871202,61673169,11701176,11626101,and 11601485)。
文摘The unavailability of wasted energy due to the irreversibility in the process is called the entropy generation.An irreversible process is a process in which the entropy of the system is increased.The second law of thermodynamics is used to define whether the given system is reversible or irreversible.Here,our focus is how to reduce the entropy of the system and maximize the capability of the system.There are many methods for maximizing the capacity of heat transport.The constant pressure gradient or motion of the wall can be used to increase the heat transfer rate and minimize the entropy.The objective of this study is to analyze the heat and mass transfer of an Eyring-Powell fluid in a porous channel.For this,we choose two different fluid models,namely,the plane and generalized Couette flows.The flow is generated in the channel due to a pressure gradient or with the moving of the upper lid.The present analysis shows the effects of the fluid parameters on the velocity,the temperature,the entropy generation,and the Bejan number.The nonlinear boundary value problem of the flow problem is solved with the help of the regular perturbation method.To validate the perturbation solution,a numerical solution is also obtained with the help of the built-in command NDSolve of MATHEMATICA 11.0.The velocity profile shows the shear thickening behavior via first-order Eyring-Powell parameters.It is also observed that the profile of the Bejan number has a decreasing trend against the Brinkman number.Whenηi→0(i=1,2,3),the Eyring-Powell fluid is transformed into a Newtonian fluid.
基金the Deanship of Scientific Research at King Khalid University for funding this work through Research Groups Program under Grant number (R.G. P2. /26/40)
文摘This article reports the simultaneous properties of variable conductivity and chemical reaction in stagnation point flow of magneto Maxwell nanofluid.The Buongiorno’s theory has been established to picture the inducement of Brownian and thermophrotic diffusions effects.Additionally,the aspect of heat sink/source is reported.The homotopic analysis method(HAM)has been worked out for the solution of nonlinear ODEs.The behavior of inferential variables on the velocity,temperature,concentration and local Nusselt number for Maxwell nanofluid are sketched and discussed.The attained outcomes specify that both the temperature and concentration of Maxwell fluid display analogous behavior,while the depiction of Brownian motion is quite conflicting on both temperature and concentration fields.It is further noted that the influence of variable thermal conductivity on temperature field is similar to that of Brownian motion parameter.Moreover,for the confirmation of our study comparison tables are reported.
文摘Application of biochar to agricultural soils is mostly used to improve soil fertility.Experimental treatments were comprised of two factors:i)drought at two level,i.e.,80%and 40%water holding capacity(WHC)which was maintained on gravimetric basis ii)three levels of biochar i.e.,control,2 t ha^(-1) and 4 t ha^(-1) added to soil.Experimentation was done to examine potential of biochar application to enhance the growth attributes,water relations,photosynthetic pigments and antioxidants activities in maize(Zea mays L.)seedlings.Results of study revealed that biochar application increased the growth qualities(total seedlings biomass,dry weight of shoot and root,shoot length and root length).In addition;contents of photosynthetic pigments(chlorophyll a,b,a+b and a/b),water relation(relative water contents,turgor potential,osmotic potential and water potential)were improved significantly due to addition of biochar.Addition of 4 t ha^(-1) biochar led to significant rise activity of enzymatic antioxidant catalase(CAT),superoxide dismutase(SOD)and peroxidase(POD)in leaf of maize seedling sunder drought as well as well watered circumstances.However,biochar applied at the rate 4 t ha^(-1) improved the all the physiological and biochemical attributes in maize seedlings under drought.From the results it was concluded that biochar application is an efficient way to alleviate adverse effect of drought stress on maize.In drought prone areas,long term impacts of biochar on production of maize and properties of soil could be recommended as upcoming shove.
基金Project supported by the Office of Research,Innovation,and Commercialization(ORIC),MUST Mirpur(AJK)
文摘Zn1-xCrxO （x = 0.00, 0.01, 0.03, 0.05, 0.07, and 0.09） nanoparticles were synthesized, by an auto-com- bustion method. Structural, optical, and magnetic characteristics of Cr-doped ZnO samples calcined at 600 ℃ have been analyzed by using X-ray diffraction （XRD）, field emission scanning electron microscope （FESEM）, UV-Vis spectroscopy and vibrating sample magnetometer （VSM）. The XRD data confirmed the hexagonal wurtzite structure of pure and Cr-doped ZnO nanoparticles. The calculated values of grain size using Scherrer＇s formula are in the range of 30.7-9.2 nm. The morphology of nanopowders has been observed by FESEM, and EDS results con- firmed a systematic increase of Cr content in the samples and clearly indicate with no impurity element. The band gaps, computed by UV-Vis spectroscopy, are in the range of 2.83-2.35 eV for different doping concentrations. By analyzing VSM data, significantly enhanced room temperature ferromagnetism is identified in Cr-doped ZnO samples. The value of magnetization is a 12 times increased of the value reported by Daun et al. （2010）. Room temperature ferromagnetism of the nanoparticles is of vital prominence for spintronics applications.
