The present work explores the application of La_(0.5)Sr_(0.5)Co_(0.95)Nb_(0.05)O_(3-δ)(LSCNO)perovskite as electrode material for the symmetric solid oxide fuel *** solid oxide fuel cells of thin-film LSCNO electrode...
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The present work explores the application of La_(0.5)Sr_(0.5)Co_(0.95)Nb_(0.05)O_(3-δ)(LSCNO)perovskite as electrode material for the symmetric solid oxide fuel *** solid oxide fuel cells of thin-film LSCNO electrodes were prepared to study the oxygen reduction reaction at intermediate *** Rietveld refinement of syn-thesized material shows a hexagonal structure with the R-3c space group of the prepared perovskite *** parameter and fractional coordinates were utilized to calculate the oxygen ion diffusion coefficient for molecular dynamic *** 973 K,the oxygen ion diffusion of LSCNO was 1.407×10^(-8)cm^(2)s^(-1) higher by order of one magnitude than that of the La_(0.5)Sr_(0.5)Co_(0.95)Nb_(0.05)O_(3-δ)(7.751×10^(-9)cm^(2)^(-1)).The results suggest that the Nb doping provide the structural stability which improves oxygen anion *** enhanced structural stability was analysed by the thermal expansion coefficient calculated experimentally and from molecular dynamics ***,the density functional theory calculation revealed the role of Nb dopant for oxygen vacancy formation energy at Sr-0 and La-O planes is lower than the undoped *** understand the rate-limiting process for sluggish oxygen diffusion kinetics,80 nm and 40 nm thin films were fabricated using radio frequency magnetron sputtering on gadolinium doped ceria electrolyte *** impedance was observed to increase with an increasing thickness,suggesting the bulk diffusion as a rate-limiting step for oxygen ion *** electrochemical performance was analysed for the thin-flm symmetric solid oxide fuel cell,which achieved a peak power density of 390 mW cm^(-2) at 1.02 V in the presence of H_(2) fuel on the anode side and air on the cathode side.
An efficient method for the synthesis of 14-alkyl or aryl 14H-dibenzo[a,j]xanthene derivatives by the reaction of β-naphthol,and aldehydes in the presence of a catalytic amount of bismuth(Ⅲ) chloride(BiCl_3) und...
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An efficient method for the synthesis of 14-alkyl or aryl 14H-dibenzo[a,j]xanthene derivatives by the reaction of β-naphthol,and aldehydes in the presence of a catalytic amount of bismuth(Ⅲ) chloride(BiCl_3) under solvent-free conditions at 110℃is *** and aromatic aldehydes were used in the reaction and in all cases the desired products were synthesized *** reaction was studied under different temperatures;the maximum yield was obtained in a short reaction period at 110℃.The method offers the advantages of high yields,short reaction times,simplicity and easy workup compared to the conventional method of syntheses.
Based on the principle of 3D particle flow code,a numerical landslide run-out model is presented to simulate the failure process of the Zhenggang landslide(in southwestern China) under the effect of water after a *** ...
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Based on the principle of 3D particle flow code,a numerical landslide run-out model is presented to simulate the failure process of the Zhenggang landslide(in southwestern China) under the effect of water after a *** relationship between the micro-mechanical parameters and the macro-shear strength of the grain material is determined through numerical *** the rainfall effect is considered in numerical simulations and rain-induced sliding processes are performed,which help us to discuss the mechanism of deformation and failure of this landslide together with field *** shows the Zhenggang landslide would most likely be activated in Zone I and would gain momentum in Zone *** order to prevent the potential disaster,a tailing dam is advised to be designed about 175 m downstream from the current landslide boundary of Zone *** by field observations,the presented landslide model can reflect the failure mechanism after *** can also provide a method to predict the potential disaster and draft disaster prevention measures.
AIM:To compare the effects of yellow(577 nm)subthreshold micropulse laser(SML)and intravitreal(IV)anti-vascular endothelial growth factor(VEGF)treatment in patients with diabetic macular edema(DME)with relatively bett...
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AIM:To compare the effects of yellow(577 nm)subthreshold micropulse laser(SML)and intravitreal(IV)anti-vascular endothelial growth factor(VEGF)treatment in patients with diabetic macular edema(DME)with relatively better visual acuity[best corrected visual acuity(BCVA)≤0.15 log MAR].METHODS:The medical records of 76 eyes of 47 patients underwent IV(0.5 mg)anti-VEGF injection or SML for the DME with relatively better BCVA were *** IV group received three consecutive monthly IV anti-VEGF injections,then were retreated as *** laser treatment group was treated at baseline and 3 mo,and then retreated at 6 and 9 mo if *** participants were followed up for one *** mean BCVA and mean central macular thickness(CMT)values changes over the follow-up were ***:Twenty-four and 23 patients were assigned to the SML and IV subgroups,*** mean number of treatments was 3.64±0.76 in SML group and 5.85±1.38 in IV group(P<0.05).The subgroups were similar with regard to the mean BCVA score at baseline and at the 1st and 3rd months,but the score of SML group was better than that of IV group at the 6th,9th,and 12th months(P<0.05).The decrease in the mean CMT values from baseline values was higher in SML group at the 6th,9th,and 12th months(P<0.05).CONCLUSION:Yellow SML treatment is superior to IV anti-VEGF injection in DME patients with relatively better BCVA for increasing visual acuity and decreasing CMT at 6,9,and 12 *** can be a good alternative first-line therapy for DME with BCVA≤0.15 log MAR.
This study examines the issues in development of pharmacokinetic single compartment model for systems that obey free radical copolymerization kinetics. Copolymer composition as a function of reactivity ratios of comon...
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This study examines the issues in development of pharmacokinetic single compartment model for systems that obey free radical copolymerization kinetics. Copolymer composition as a function of reactivity ratios of comonomers for well mixed case was derived. For some cases, such as DEF-AN, diethyl fumarate and acrylonitrile system multiplicity in composition were found. The analysis is extended to n monomers. State space model expressions are used and the QSSA assumption is stated in state space equation form. Conditions when damped oscillations can be expected are noted. In addition to multiplicity in product composition, an account of reactivity ratios and other instances of multi- plicity were found during the pharmacodynamics of the free radical polymerization reactions. A careful study of initiated case, thermal case, 1 CSTR and 2 CSTRS was undertaken and results were presented. Numerical integration techniques were employed on the desktop computer. Steady state and transient state conversion for initiated case and thermal case for 1 CSTR and 2 CSTRs were calculated and plotted in Figures 7-9 and 12. No multiplicity was found in the thermal case for 1 CSTR in the dynamics of transient monomer conversion. Multiplicity was found in the initiated case for 1 CSTR in the dynamics of transient conversion of monomer. The multiplicity was found in the second CSTR for the case of 2 CSTRs in series. No multiplicity was found in the case of initiator decay.
This study deals with the optimization of best working conditions in molten melt for the production of hydrogen(H2) *** research has been carried out on how electrochemical process occurs through steam splitting via m...
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This study deals with the optimization of best working conditions in molten melt for the production of hydrogen(H2) *** research has been carried out on how electrochemical process occurs through steam splitting via molten hydroxide.54 combinations of cathode,anode,temperature and voltage have been investigated for the optimization of best working conditions with molten hydroxide for hydrogen gas *** these electrochemical investigations were carried out at 225 to 300℃ temperature and 1.5 to 2.5 V applied voltage *** current efficiency of 90.5,80.0 and 68.6% has been achieved using stainless steel anodic cell with nickel,stainless steel and platinum working cathode *** nickel cathode,an increase in the current directly affected the hydrogen gas flow rate at *** can be hypothesized from the noted results that increase in current is directly proportional to operating temperature and applied *** values were noted when the applied voltages increased from 1.5 to 2.5 V at 300℃,the flow rate of hydrogen gas increased from 1.5 to 11.3 cm^(3) min^(-1),1.0 to 13 cm^(3) min^(-1) in case of electrolysis@stainless steel and@graphite anode *** is observed that the current efficiency of stainless steel anodic cell was higher than the graphite anodic ***,steam splitting with the help of molten salts has shown an encouraging alternate to current methodology for H2 fuel production.
Robotics has emerged as a collegiate course about 20 years ago at Stanford University, Stanford, CA. From the first IRB6, the electrically powered robot in 1974, the industry has grown over a 30-year period. A leading...
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Robotics has emerged as a collegiate course about 20 years ago at Stanford University, Stanford, CA. From the first IRB6, the electrically powered robot in 1974, the industry has grown over a 30-year period. A leading supplier of robots has put out over 100,000 robots by year 2001. Robot capable of handling 500 kg load was introduced in 2001, IRB 7000. A number of advances have been made in nanostructuring. About 40 different nanostructuring methods were reviewed recently [1]. Nanobots can be developed that effect cures of disorders that are difficult to treat. Principles from photodynamic therapy, fullerene chemistry, nanostructuring, X-rays, computers, pharmacokinetics and robotics are applied in a design of nanorobot for treatment of Alzheimer’s disease. The curcuma longa that has shown curative effects in rats’ brain with Alzheimer’s is complexed with fullerenes. The drug is inactive when caged. It is infused intrathecally into the cerebrospinal system. Irradiation of the hypothalamous and other areas of the brain where Alzheimer’s disease is prevalent lead to breakage of fullerenes and availability of the drug with the diseased cells. Due to better mass transfer, better cure is affected. The other plausible reactions such as addition polymerization of fullerene, polycurcumin formation and other hydrolysis reactions are modeled along with the drug action under the Denbigh scheme of reactions. The fractional yield of drug-curcumin interaction is a function of intensity of radiation, frequency of radiation, patient demographics, age, gender, and other disorders etc. Chromophore in curcumin is used as a sensor and computer imaging and feedback control design can result in more bioavailability for curcumin therapeutic action to cure Alzheimer’s disease. This study examines the principles used in the design, the strategy of the design of the nanorobot drug delivery system with a specific target and pharamacokinetic formulation of the associated competing parallel rea
The development of agriculture is one of the most transformative changes in the history of *** the most common changes occurring during plant domestication are reductions in seed dispersal and changes in *** there are...
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The development of agriculture is one of the most transformative changes in the history of *** the most common changes occurring during plant domestication are reductions in seed dispersal and changes in *** there are archaeological records of these processes,the advancement of genomics offers a tool to achieve greater insight into the process of converting wild plants into crops(Smýkal et al.,2018).This involved and resulted in a set of specific phenotypic changes referred to collectively as the domestication ***,less obvious domestication-related modifications have also been identified,including changes in plant *** processes are often *** example,among visible changes,selection for visual appearance such as pigmentation is governed by modulation of specific metabolic *** genomic tools,the improvement of analytical methods provides the opportunity to reveal metabolomic changes involved in plant domestication.
There are reports in the literature on the discovery of novel materials that were observed to shrink upon heating. Treatment of these materials in the same manner as the materials with positive coefficient of thermal ...
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There are reports in the literature on the discovery of novel materials that were observed to shrink upon heating. Treatment of these materials in the same manner as the materials with positive coefficient of thermal expansion can lead to the misinterpretation of the laws of thermodynamics. This is because volume expansivity is usually defined at constant pressure. Negative values for volume expansivity can be shown using Maxwell’s reciprocity relations to lead to negative values for absolute temperature for ideal gas. For real systems, using Helmholz free energy analysis at equilibrium an expression for the volume expansivity was derived. It can be seen that this expression would be always positive for real physical changes, either heating or cooling. Isentropic volume expansivity is proposed as better suited for analysis of materials with negative thermal expansion, NTE and composites used in space such as Hubble telescope and Chandra telescope with zero coefficient of thermal expansion. This kind of a switch from isobaric to isentropic has precedence in the history of development of speed of sound.
The integration of Michaelis-Menten kinetics results in a trancedental equation. The results are not in a form that is readily usable. A more usable form of the model solutions is developed. This was accomplished by u...
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The integration of Michaelis-Menten kinetics results in a trancedental equation. The results are not in a form that is readily usable. A more usable form of the model solutions is developed. This was accomplished by using Taylor series expansion of dimensionless concentration u in terms of its derivatives. The infinite series expression for dimensionless concentration is given. It can be seen that for times t < , the Taylor series expression evaluated near the origin up to the third derivative is a reasonable representation of the integrated solution. More terms in the Taylor series expression can be added to suit the application. It can vary with the apparent volume, dosage, enzyme concentration, Michaelis constant and the desired accuracy level needed. The single compartment model solution was obtained by the method of Laplace transform. It can be seen from Figure 2 that the dimensionless drug concentration in the compartment goes through a maxima. The curve is convex throughout the absorption and elimination processes. The drug gets completely depleted after a said time. The curve is asymmetrical with a right skew. The systems under absorption with elimination that obey the kinetics that can be represented by a set of reactions in circle were considered. A system of simple reactions in circle was taken into account. The concentration profile of the reactants were obtained by the method of Laplace transforms. The conditions when subcritical damped oscillations can be expected are derived. A model was developed for cases when absorption kinetics exhibit subcritical damped oscillations. The solution was developed by the method of Laplace transforms. The solution for dimensionless concentration of the drug in single compartment for different values of rate constants and dimensionless frequency are shown in Figures 6-9. The drug profile reaches a maximum and drops to zero concen-tration after a said time. The fluctuations in concentration depends on the dimensionless
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