Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric trains.Changing heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant ...Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric trains.Changing heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational height.This research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact forces.Specifically,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 train.From an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph extension.Combining the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph behaviour.The results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.展开更多
Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials.Rodents are the predominant animal model used in neurological re...Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials.Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans.As a result,functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models.Comparatively,large r,more clinically relevant models have not been as well studied.To achieve similar locomotor testing standardization in larger animals,the models must be accessible to a wide array of researchers.Non-human primates are the most relevant animal model fo r translational research,however ethical and financial barriers limit their accessibility.This review focuses on swine,sheep,and goats as large animal alternatives for transitional studies between rodents and non-human primates.The objective of this review is to compare motor testing and data collection methods used in swine,sheep,and goats to encourage testing standardization in these larger animal models.The PubMed database was analyzed by searching combinations of swine,sheep,and goats,neurologic injuries,and functional assessments.Findings were categorized by animal model,data collection method,and assessment design.Swine and sheep were used in the majority of the studies,while only two studies were found using goats.The functional assessments included open pen analysis,treadmill walking,and guided free walking.Data collection methods included subjective behavioral rating scales and objective tools such as pressure-sensitive mats and image-based analysis software.Overall,swine and sheep were well-suited for a variety of assessment designs,with treadmill walking and guided free walking offering the most consistency across multiple trials.Data collection methods varied,but image-based gait analysis software provided the most robust analysis.Future studies should be conducted to standardize functional testing methods after neurolo展开更多
Free convection of a viscous electrically conducting liquid past a vertical stretching surface is investigated in the presence of a transverse magnetic field.Natural convection is driven by both thermal and solutal bu...Free convection of a viscous electrically conducting liquid past a vertical stretching surface is investigated in the presence of a transverse magnetic field.Natural convection is driven by both thermal and solutal buoyancy.The original partial differential equations governing the problem are turned into a set of ordinary differential equations through a similar variables transformation.This alternate set of equations is solved through a Differential Transform Method(DTM)and the Pade approximation.The response of the considered physical system to the non-dimensional parameters accounting for the relative importance of different effects is assessed considering different situations.展开更多
In this article, we have considered the simultaneous influence of ohmic heating and chemical reaction on heat and mass transfer over a stretching sheet. The effects of applied magnetic field are also taken into consid...In this article, we have considered the simultaneous influence of ohmic heating and chemical reaction on heat and mass transfer over a stretching sheet. The effects of applied magnetic field are also taken into consideration while the induced magnetic field is not considered due to very small magnetics Reynolds number. The governing flow problem comprises of momentum, continuity, thermal energy and concentration equation which are transformed into highly nonlinear coupled ordinary differential equations by means of similarity transforms, which are then, solved numerically with the help of Successive Linearization method(SLM) and Chebyshev Spectral collocation method. Numerical values of skin friction coefficient, local Nusselt number, and Sherwood number are also taken into account with the help of tables. The physical influence of the involved parameters of flow velocity, temperature and concentration distribution is discussed and demonstrated graphically. The numerical comparison is also presented with the existing published results and found that the present results are in excellent agreement which also confirms the validity of the present methodology.展开更多
Acid doped Polyaniline(PANI)due to their increased electrical conductivity,are considered to be the most promising conducting filler materials.Hence,the present study,reports the synthesis of the PANI followed by acid...Acid doped Polyaniline(PANI)due to their increased electrical conductivity,are considered to be the most promising conducting filler materials.Hence,the present study,reports the synthesis of the PANI followed by acid doping,electrical conductivity and dielectric properties measurements of H2SO4;HCl and(Conc.HCl+NaNO2mixture)doped PANI.In order to know the effect of acetone washing on the electrical properties of acid doped PANI samples,the electrical properties of the non-acetone washed acid doped PANI samples are compared with that of their acetone washed counterparts.The PANI salt was prepared by conventional route using aniline hydrochloride and ammonium persulphate as an oxidant.PANI salt was subjected to 0.5M NaOH to form PANI base,which was further doped separately with H2SO4;HCl and(Conc.HCl+NaNO2mixture)respectively followed by acetone washing.A comparative electrical conductivity study between the acetone washed and unwashed PANI salt and H2SO4,HCl and Conc.HCl+NaNO2 mixture doped PANI were characterized by dielectric and impedance study.展开更多
The current paper explores the behavior of the thermal radiation on the time-independent flow of mi-cropolar fluid past a vertical stretching surface with the interaction of a transverse magnetic field.The ef-fect of ...The current paper explores the behavior of the thermal radiation on the time-independent flow of mi-cropolar fluid past a vertical stretching surface with the interaction of a transverse magnetic field.The ef-fect of thermo-diffusion(Soret)along with the heat source is incorporated to enhance the thermal prop-erties.Also,the convective solutal condition is considered that affects the mass transfer phenomenon.The transformed equations are modeled using suitable similarity transformation.However,the complex cou-pled equations are handled mathematically employing the Runge-Kutta-Felhberg method.The behavior of characterizing parameters on the flow phenomena as well as the engineering coefficients are displayed via graphs and the validation of the current outcome is reported with the previously published results in particular cases.展开更多
A steady boundary layer flow over a porous flat plate has been considered in the present study.Mass transfer analysis with first order chemical reaction is also considered instead of heat transfer.The plate concentrat...A steady boundary layer flow over a porous flat plate has been considered in the present study.Mass transfer analysis with first order chemical reaction is also considered instead of heat transfer.The plate concentration is considered in the form of power law instead of taking constant.The goveming PDEs are transformed into ordinary differential equations using similarity transfomation and then these ODEs are solved by employing Runge-Kutta fourth order method associated with shooting technique.A parametric study of all involving parameters is obtained by the help of graphs.The major findings are:(i)the concentration of the fluid in its boundary layer decrease with increase in heavier species,the reaction rate parameter and the power law exponent;(ji)the rate of mass transfer increases with an increase in reaction rafe parameter and power-law exponent.展开更多
Among the family of ferrites, M-type hexaferrites has many industrial applications ranging from simple magnets to microwave devices. Improvement in magnetic and dielectric properties of ferrites is of continuous inter...Among the family of ferrites, M-type hexaferrites has many industrial applications ranging from simple magnets to microwave devices. Improvement in magnetic and dielectric properties of ferrites is of continuous interest. In this present work details study is done to observe the effect of co-doping of rare-earth (RE3+: Pr3+, Sm3+, and Gd3+) and aluminum in Sr0.82RE0.18Fe12-xAlxO19 (x = 0.0, 0.5, 1.0, 1.5, 2.0). The adopted samples were synthesized via autocombustion technique. Detailed synthesis, structural, magnetic, and electrical measurements of samples were performed to understand structural-magnetic-electrical property relationship. The Al3+ substitution for Fe3+ brings in a significant enhancement in coercivity but reduces magnetization due to the magnetic dilution effect. Additional coercivity enhancement was possible with RE3+ doping without affecting the magnetization of samples. Among all RE3+ doped samples, Pr3+ doped samples showed the highest Curie temperature, (Tc ~ 465℃), while Gd3+ doped samples showed little variation in dielectric properties in GHz frequency range. This makes RE3+ doped samples as an ideal candidate for high-frequency microwave applications. Pr3+ with oblate charge distribution (negative Stevens constant) was observed to substitute well into the lattice consequently bringing in desired improvements in physical properties of Sr0.82RE0.18Fe12-xAlxO19 ferrite.展开更多
“Sight can be acquired, Vision cannot”. Orind Refractories Limited （ORIND）, China was formed with this rare vision. At a time when the world was testing the tepid waters of China; Mr. Ravin Jhunjhunwala, Chairman ...“Sight can be acquired, Vision cannot”. Orind Refractories Limited （ORIND）, China was formed with this rare vision. At a time when the world was testing the tepid waters of China; Mr. Ravin Jhunjhunwala, Chairman of ORIND and the management of ORIND India had looked over the Great Wall to begin a journey of success. Incorported on 18th August 1994 with an initial investment of USD 5 million,展开更多
The ballistic range has long been employed in a variety of engineering fields such as high-velocity impact engineering, projectile aerodynamics and aeroballistics, since it can create an extremely high-pressure state ...The ballistic range has long been employed in a variety of engineering fields such as high-velocity impact engineering, projectile aerodynamics and aeroballistics, since it can create an extremely high-pressure state in very short time. Since the operation of the ballistic range includes many complicated phenomena, each process should be understood in detail for the performance enhancement of the device. One of the main processes which have significant influence on the device performance is the compression process of the driver gas. Most of the studies available in this field hardly discuss this phenomenon in detail and thus lack a proper understanding of its effect on the whole system performance. In the present study, a computational analysis has been made to investigate the fluid dynamic aspects of the compression process in the pump tube of a ballistic range and to assess how it affects the performance of the ballistic range. The results obtained are validated with the available experimental data. In order to evaluate the system performance, several performance parameters are defined. Effect of a shock tube added in between the pump tube and launch tube on the performance of the ballistic range is also studied analytically. Performance of the ballistic range could be significantly improved by the proper selection of the pump tube and high-pressure tube parameters and the addition of the shock tube.展开更多
Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the potential utilization of coal in the thermal industries. The primary objective of t...Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the potential utilization of coal in the thermal industries. The primary objective of this work is to analyze the quality of Indian Coals and obtain their mineral species-specific information at different depths. The samples were obtained from Talcher Coalfield, Odisha, India. Coal from four seam sections in the Talcher coalfield, India are mainly high ash coal （〉50 %） and volatile matter deceases along with the seam depth. XRD results show that the major mineral phases present in the coal are quartz and kaolinite. Siderite, illite, and anatase were found in minor quantities. It has been observed that the clay minerals （kaolinite, silimanite, illite） decompose at higher temperature and traces of dolomite, mullite, hematite etc. are formed during the process of combustion. Among the four seams （M2, M12, M24 and M43） studied, ash of M43 has high A1203%, TIO2% and K20% content and low SIO2%, CaO% and MgO% content. High acid- to-base ratios contributed to high ash fusion temperatures （IDT 〉 1500 ℃） and low slagging potential of the coals studied. Relatively low fouling index （〈0.3） was estimated for all the coal seams studied. Furthermore, thermodynamic modeling software, FactSage, have been used to envision the mineral phase transformations that take place between 800 and 1500℃ during coal combustion.展开更多
The present study investigates the influence of La<sup>3+</sup> and Pr<sup>3+</sup> doping on the structural, magnetic properties, and hyperfine fields of Sr<sub>0.7</sub>RE<sub&...The present study investigates the influence of La<sup>3+</sup> and Pr<sup>3+</sup> doping on the structural, magnetic properties, and hyperfine fields of Sr<sub>0.7</sub>RE<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub>, (RE: La<sup>3+</sup> and Pr<sup>3+</sup>, <em>x</em> = 0.0 - 0.8) hexaferrite compounds prepared via auto-combustion technique. The XRD analysis shows a linear decrease in a and c lattice and unit cell volume contraction with the content <em>x</em>. The room temperature magnetic study shows that for the Pr<sup>3+</sup> doped Sr<sub>0.7</sub>Pr<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (Pr<sup>3+</sup>-SrM), the magnetization value monotonically decreases while for La<sup>3+</sup> doped Sr<sub>0.7</sub>La<sub>0.3</sub>Fe<sub>12-2x</sub>Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (La<sup>3+</sup>-SrM) magnetization value shows a noticeable increase in magnetization value with <em>x</em>. The coercivity of the Pr<sup>3+</sup>-SrM compound was observed to decrease while that of the La<sup>3+</sup>-SrM compound showed a marked 40% increase at <em>x</em> = 0.2 (~5829 Oe) in comparison to undoped SrFe<sub>12</sub>O<sub>19</sub> (~3918 Oe). A difference in Curie temperature was also observed, with Tc ~ 525<span style="white-space:nowrap;">°</span>C at <em>x</em> = 0.4 for Pr<sup>3+</sup>-SrM and Tc = 505<span style="white-space:nowrap;">°</span>C for <em>x</em> = 0.4 for La<sup>3+</sup>-SrM compound. The observed differences in magnetic properties have been explained on the basis of the site occupancy of Co<sup>2+</sup> and Al<sup>3+</sup> in the presence of rare-earth ions. The presence of non-magnetic rare-earth ion, La<sup>3+</sup>, improved saturation magnetization, and coercivity and deemed suitable replacement for Sr<sup>2+</sup>. The hyperfine parameters namely quadrupole shift showed a decrease with the La3<sup>+</sup> or Pr<sup>3+</sup> doping independent of (Co<sup>2+</sup>-Al<sup>3+</sup>) ions doping. Overall, the Mossbauer 展开更多
Understory vegetation controls, in a significant way, the regeneration of overstory trees, carbon sequestration and nutrient retention in tropical forests. Development and organization of understory vegetation depend ...Understory vegetation controls, in a significant way, the regeneration of overstory trees, carbon sequestration and nutrient retention in tropical forests. Development and organization of understory vegetation depend on climate, edaphic and biotic factors which are not well correlated with plant community structures. This study aimed to explore the relationships between understory vegetation and abiotic factors in natural and planted forest ecosystems. A non-metric multidimensional scaling(NMS) ordination technique was applied to represent forest understory vegetation among five forest communities, i.e., a dry miscellaneous forest(DMF), a sal mixed forest(SMF), a teak plantation(TP), a low-land miscellaneous forest(LMF) and a savanna area(SAV) of the Katerniaghat Wildlife Sanctuary, located in northern India. Microclimatic variables, such as photosynthetically active radiation(PAR), air temperature(AT), soil temperature(ST), ambient atmospheric CO 2 concentration, absolute air humidity(AH), physical and chemical soil properties as well as biological properties were measured. Understory species were assessed via 100 random quadrats(5 m × 5 m) in each of the five forests in which a total of 75 species were recorded encompassing 67 genera from 37 families, consisting of 32 shrubs and 43 plant saplings. DMF was the most dense forest with 34,068 understory individuals per ha of different species, whereas the lowest understory population(13,900 per ha) was observed in the savanna. Ordination and correlation revealed that microclimate factors are most important in their effect compared to edaphic factors, on the development of understory vegetation in the various forest communities in the north of India.展开更多
Tungsten inert gas(TIG) welding is the most commonly used joining process for aluminum alloy for AA6061 and AA7075 which are highly demanded in the aerospace engineering and the automobile sector, but there are some d...Tungsten inert gas(TIG) welding is the most commonly used joining process for aluminum alloy for AA6061 and AA7075 which are highly demanded in the aerospace engineering and the automobile sector, but there are some defects occur during TIG welding like micro-crack, coarse grain structure, and porosity. To improve these defects, the TIG welded joint is processed using friction stir processing(FSP).This paper presents the effect of friction stir processing on TIG welding with filler ER4043 and ER 5356 for dissimilar aluminum alloy AA6061 and AA7075. The mechanical characterization, finite element formulation and mathematical equations of heat transfer of TIG + FSP welded joints are investigated using ANSYS Fluent software by adjusting process parameters of FSP. The results show that the maximum compressive residual stress 73 MPa was obtained at the fusion zone(FZ) of the TIG weldment with filler ER4043, whereas minimum compressive residual stress 37 MPa was obtained at stir zone(SZ) of the TIG+ FSP with filler 5356. The maximum heat flux 5.33 × 106 W/m2 and temperature 515C have observed at tool rotation 1600 rpm with a feed rate of 63 mm/min. These results give a satisfactory measure of confidence in the fidelity of the simulation。展开更多
Nowadays,the recompression supercritical carbon dioxide(R-SCO_(2))cycle has emerged as a promising option for power conversion systems because of its boundless potential to tackle energy and environmental issues.In th...Nowadays,the recompression supercritical carbon dioxide(R-SCO_(2))cycle has emerged as a promising option for power conversion systems because of its boundless potential to tackle energy and environmental issues.In this study,we examined the performance of the solar parabolic trough collector(SPTC)integrated combined cogeneration system for the purpose of power generation as well as recovery of waste exhaust heat from the R-SCO_(2) cycle with the help of the organic Rankine cycle(ORC).An exergy and energy analysis was performed for a combined recompression cycle(R-SCO_(2)-ORC)by varying the input variables such as intensity of solar irradiation(Gb),pressure at the inlet of SCO_(2) turbine(P_(5)),mass flow rate of SCO_(2)()&mSCO_(2) inlet temperature of SCO_(2) turbine(T5),inlet temperature of main compressor(T_(9))and effectiveness of the high-and low-temperature recuperator( HTR and LTR).Eight organic working fluids were considered for the ORC:R123,R290,isobutane,R1234yf,R1234ze,toluene,isopentane and cyclohexane.The study revealed that R123-based R-SCO_(2)-ORC demonstrates the highest thermal and exergy efficiency:~73.4 and 40.89%at G_(b)=0.5 kW/m^(2);78.8 and 43.9%at P_(5)=14 MPa;63.86 and 35.57%at T5=650 K;74.84 and 41.69%at&mSCO 7kg s;2=/85.83 and 47.82%at T_(9)=300 K;84.57 and 47.11%at HTR 65;=0.85.06 and 47.38%at LTR 65,=0.respectively.Alternatively,R290 showed the minimum value of exergy and thermal efficiency.As can be seen,the maximum amount of exergy destruction or exergy loss occurs in a solar collector field,~58.25%of the total exergy destruction rate(i.e.6703 kW)and 18.99%of the solar inlet exergy(i.e.20562 kJ).Moreover,R123 has the highest net work output,~4594 kJ at T5=650 K and 6176 kJ at T_(9)=300 K.展开更多
The extraction and separation of zinc, manganese, cobalt and nickel from nickel laterite bacteria leach liquor were carried out using sodium salts of TOPS-99 and Cyanex 272 in kerosene. The unwanted metal ions were re...The extraction and separation of zinc, manganese, cobalt and nickel from nickel laterite bacteria leach liquor were carried out using sodium salts of TOPS-99 and Cyanex 272 in kerosene. The unwanted metal ions were removed by precipitation method and solvent extraction was used to extract/separate Zn, Mn, Co and Ni. The nickel laterite leach liquor which was obtained from bioleaching of chromite overburden samples contained 3.72 g/L Fe, 2.08 g/L Al, 0.44 g/L Ni, 0.02 g/L Co, 0.13 g/L Mn, 0.14 g/L Zn and 0.22 g/L Cr. From this leach liquor, 100% Fe, 96.98% Al and 70.42% Cr were removed by precipitation with Ca CO_3 at pH 4.4 followed by precipitation of remaining Al and Cr with 50% ammonia at p H 5.4. After precipitation, the extraction of Zn from the Fe, Al and Cr free leach liquor was carried out with 0.1 mol/L TOPS-99 followed by Mn extraction with 0.04 mol/L Na TOPS-99. The yields of Zn and Mn were 97.77% and 95.63%, respectively. After Mn extraction, cobalt was removed from the leach liquor using 0.0125 mol/L Na Cyanex 272 and finally nickel extraction was carried out using 0.12 mol/L Na TOPS-99 with 99.84% yield. The stripping of loaded organic（LO） phases were achieved with dilute H_2SO_4.展开更多
The work presents the synthesis and characterization of amidated pectin(AP) based polymer electrolyte membranes(PEM) crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform in...The work presents the synthesis and characterization of amidated pectin(AP) based polymer electrolyte membranes(PEM) crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA) and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(Y_M and K_N) are calcu...展开更多
Addressing social issues is very crucial for government and thus government is primarily expected to create an enabling environment for raising awareness and stimulating public debate for the existing social challenge...Addressing social issues is very crucial for government and thus government is primarily expected to create an enabling environment for raising awareness and stimulating public debate for the existing social challenges and issues.Indian government is proactive to encourage legal mandates in various dimensions enabling responsible business practices.What organizations do with their money is being increasingly caught on the public radar leading to bringing ethical issues to the forefront.The paper is an effort to understand how financial responsible effort is playing out in the state-owned enterprises(SOEs),and also the effort towards handling corporate social responsibility(CSR)across SOEs in India.The paper elaborates whether ethical financing is a form of social responsibility in organizations and elaborates the status of responsible financing of SOEs in India.The paper also discusses the practices encouraging ethical financing in SOEs in India.展开更多
基金support of RSSB to this work via the project RSSB/COF-UOH-49 is greatly appreciated.The authors also acknowledge the support by FCT,through IDMEC,under LAETA,project UIDB/50022/2020.
文摘Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric trains.Changing heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational height.This research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact forces.Specifically,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 train.From an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph extension.Combining the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph behaviour.The results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.
文摘Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials.Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans.As a result,functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models.Comparatively,large r,more clinically relevant models have not been as well studied.To achieve similar locomotor testing standardization in larger animals,the models must be accessible to a wide array of researchers.Non-human primates are the most relevant animal model fo r translational research,however ethical and financial barriers limit their accessibility.This review focuses on swine,sheep,and goats as large animal alternatives for transitional studies between rodents and non-human primates.The objective of this review is to compare motor testing and data collection methods used in swine,sheep,and goats to encourage testing standardization in these larger animal models.The PubMed database was analyzed by searching combinations of swine,sheep,and goats,neurologic injuries,and functional assessments.Findings were categorized by animal model,data collection method,and assessment design.Swine and sheep were used in the majority of the studies,while only two studies were found using goats.The functional assessments included open pen analysis,treadmill walking,and guided free walking.Data collection methods included subjective behavioral rating scales and objective tools such as pressure-sensitive mats and image-based analysis software.Overall,swine and sheep were well-suited for a variety of assessment designs,with treadmill walking and guided free walking offering the most consistency across multiple trials.Data collection methods varied,but image-based gait analysis software provided the most robust analysis.Future studies should be conducted to standardize functional testing methods after neurolo
文摘Free convection of a viscous electrically conducting liquid past a vertical stretching surface is investigated in the presence of a transverse magnetic field.Natural convection is driven by both thermal and solutal buoyancy.The original partial differential equations governing the problem are turned into a set of ordinary differential equations through a similar variables transformation.This alternate set of equations is solved through a Differential Transform Method(DTM)and the Pade approximation.The response of the considered physical system to the non-dimensional parameters accounting for the relative importance of different effects is assessed considering different situations.
文摘In this article, we have considered the simultaneous influence of ohmic heating and chemical reaction on heat and mass transfer over a stretching sheet. The effects of applied magnetic field are also taken into consideration while the induced magnetic field is not considered due to very small magnetics Reynolds number. The governing flow problem comprises of momentum, continuity, thermal energy and concentration equation which are transformed into highly nonlinear coupled ordinary differential equations by means of similarity transforms, which are then, solved numerically with the help of Successive Linearization method(SLM) and Chebyshev Spectral collocation method. Numerical values of skin friction coefficient, local Nusselt number, and Sherwood number are also taken into account with the help of tables. The physical influence of the involved parameters of flow velocity, temperature and concentration distribution is discussed and demonstrated graphically. The numerical comparison is also presented with the existing published results and found that the present results are in excellent agreement which also confirms the validity of the present methodology.
文摘Acid doped Polyaniline(PANI)due to their increased electrical conductivity,are considered to be the most promising conducting filler materials.Hence,the present study,reports the synthesis of the PANI followed by acid doping,electrical conductivity and dielectric properties measurements of H2SO4;HCl and(Conc.HCl+NaNO2mixture)doped PANI.In order to know the effect of acetone washing on the electrical properties of acid doped PANI samples,the electrical properties of the non-acetone washed acid doped PANI samples are compared with that of their acetone washed counterparts.The PANI salt was prepared by conventional route using aniline hydrochloride and ammonium persulphate as an oxidant.PANI salt was subjected to 0.5M NaOH to form PANI base,which was further doped separately with H2SO4;HCl and(Conc.HCl+NaNO2mixture)respectively followed by acetone washing.A comparative electrical conductivity study between the acetone washed and unwashed PANI salt and H2SO4,HCl and Conc.HCl+NaNO2 mixture doped PANI were characterized by dielectric and impedance study.
文摘The current paper explores the behavior of the thermal radiation on the time-independent flow of mi-cropolar fluid past a vertical stretching surface with the interaction of a transverse magnetic field.The ef-fect of thermo-diffusion(Soret)along with the heat source is incorporated to enhance the thermal prop-erties.Also,the convective solutal condition is considered that affects the mass transfer phenomenon.The transformed equations are modeled using suitable similarity transformation.However,the complex cou-pled equations are handled mathematically employing the Runge-Kutta-Felhberg method.The behavior of characterizing parameters on the flow phenomena as well as the engineering coefficients are displayed via graphs and the validation of the current outcome is reported with the previously published results in particular cases.
文摘A steady boundary layer flow over a porous flat plate has been considered in the present study.Mass transfer analysis with first order chemical reaction is also considered instead of heat transfer.The plate concentration is considered in the form of power law instead of taking constant.The goveming PDEs are transformed into ordinary differential equations using similarity transfomation and then these ODEs are solved by employing Runge-Kutta fourth order method associated with shooting technique.A parametric study of all involving parameters is obtained by the help of graphs.The major findings are:(i)the concentration of the fluid in its boundary layer decrease with increase in heavier species,the reaction rate parameter and the power law exponent;(ji)the rate of mass transfer increases with an increase in reaction rafe parameter and power-law exponent.
文摘Among the family of ferrites, M-type hexaferrites has many industrial applications ranging from simple magnets to microwave devices. Improvement in magnetic and dielectric properties of ferrites is of continuous interest. In this present work details study is done to observe the effect of co-doping of rare-earth (RE3+: Pr3+, Sm3+, and Gd3+) and aluminum in Sr0.82RE0.18Fe12-xAlxO19 (x = 0.0, 0.5, 1.0, 1.5, 2.0). The adopted samples were synthesized via autocombustion technique. Detailed synthesis, structural, magnetic, and electrical measurements of samples were performed to understand structural-magnetic-electrical property relationship. The Al3+ substitution for Fe3+ brings in a significant enhancement in coercivity but reduces magnetization due to the magnetic dilution effect. Additional coercivity enhancement was possible with RE3+ doping without affecting the magnetization of samples. Among all RE3+ doped samples, Pr3+ doped samples showed the highest Curie temperature, (Tc ~ 465℃), while Gd3+ doped samples showed little variation in dielectric properties in GHz frequency range. This makes RE3+ doped samples as an ideal candidate for high-frequency microwave applications. Pr3+ with oblate charge distribution (negative Stevens constant) was observed to substitute well into the lattice consequently bringing in desired improvements in physical properties of Sr0.82RE0.18Fe12-xAlxO19 ferrite.
文摘“Sight can be acquired, Vision cannot”. Orind Refractories Limited （ORIND）, China was formed with this rare vision. At a time when the world was testing the tepid waters of China; Mr. Ravin Jhunjhunwala, Chairman of ORIND and the management of ORIND India had looked over the Great Wall to begin a journey of success. Incorported on 18th August 1994 with an initial investment of USD 5 million,
文摘The ballistic range has long been employed in a variety of engineering fields such as high-velocity impact engineering, projectile aerodynamics and aeroballistics, since it can create an extremely high-pressure state in very short time. Since the operation of the ballistic range includes many complicated phenomena, each process should be understood in detail for the performance enhancement of the device. One of the main processes which have significant influence on the device performance is the compression process of the driver gas. Most of the studies available in this field hardly discuss this phenomenon in detail and thus lack a proper understanding of its effect on the whole system performance. In the present study, a computational analysis has been made to investigate the fluid dynamic aspects of the compression process in the pump tube of a ballistic range and to assess how it affects the performance of the ballistic range. The results obtained are validated with the available experimental data. In order to evaluate the system performance, several performance parameters are defined. Effect of a shock tube added in between the pump tube and launch tube on the performance of the ballistic range is also studied analytically. Performance of the ballistic range could be significantly improved by the proper selection of the pump tube and high-pressure tube parameters and the addition of the shock tube.
文摘Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the potential utilization of coal in the thermal industries. The primary objective of this work is to analyze the quality of Indian Coals and obtain their mineral species-specific information at different depths. The samples were obtained from Talcher Coalfield, Odisha, India. Coal from four seam sections in the Talcher coalfield, India are mainly high ash coal （〉50 %） and volatile matter deceases along with the seam depth. XRD results show that the major mineral phases present in the coal are quartz and kaolinite. Siderite, illite, and anatase were found in minor quantities. It has been observed that the clay minerals （kaolinite, silimanite, illite） decompose at higher temperature and traces of dolomite, mullite, hematite etc. are formed during the process of combustion. Among the four seams （M2, M12, M24 and M43） studied, ash of M43 has high A1203%, TIO2% and K20% content and low SIO2%, CaO% and MgO% content. High acid- to-base ratios contributed to high ash fusion temperatures （IDT 〉 1500 ℃） and low slagging potential of the coals studied. Relatively low fouling index （〈0.3） was estimated for all the coal seams studied. Furthermore, thermodynamic modeling software, FactSage, have been used to envision the mineral phase transformations that take place between 800 and 1500℃ during coal combustion.
文摘The present study investigates the influence of La<sup>3+</sup> and Pr<sup>3+</sup> doping on the structural, magnetic properties, and hyperfine fields of Sr<sub>0.7</sub>RE<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub>, (RE: La<sup>3+</sup> and Pr<sup>3+</sup>, <em>x</em> = 0.0 - 0.8) hexaferrite compounds prepared via auto-combustion technique. The XRD analysis shows a linear decrease in a and c lattice and unit cell volume contraction with the content <em>x</em>. The room temperature magnetic study shows that for the Pr<sup>3+</sup> doped Sr<sub>0.7</sub>Pr<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (Pr<sup>3+</sup>-SrM), the magnetization value monotonically decreases while for La<sup>3+</sup> doped Sr<sub>0.7</sub>La<sub>0.3</sub>Fe<sub>12-2x</sub>Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (La<sup>3+</sup>-SrM) magnetization value shows a noticeable increase in magnetization value with <em>x</em>. The coercivity of the Pr<sup>3+</sup>-SrM compound was observed to decrease while that of the La<sup>3+</sup>-SrM compound showed a marked 40% increase at <em>x</em> = 0.2 (~5829 Oe) in comparison to undoped SrFe<sub>12</sub>O<sub>19</sub> (~3918 Oe). A difference in Curie temperature was also observed, with Tc ~ 525<span style="white-space:nowrap;">°</span>C at <em>x</em> = 0.4 for Pr<sup>3+</sup>-SrM and Tc = 505<span style="white-space:nowrap;">°</span>C for <em>x</em> = 0.4 for La<sup>3+</sup>-SrM compound. The observed differences in magnetic properties have been explained on the basis of the site occupancy of Co<sup>2+</sup> and Al<sup>3+</sup> in the presence of rare-earth ions. The presence of non-magnetic rare-earth ion, La<sup>3+</sup>, improved saturation magnetization, and coercivity and deemed suitable replacement for Sr<sup>2+</sup>. The hyperfine parameters namely quadrupole shift showed a decrease with the La3<sup>+</sup> or Pr<sup>3+</sup> doping independent of (Co<sup>2+</sup>-Al<sup>3+</sup>) ions doping. Overall, the Mossbauer
基金the support of CSIR funding under budget head NWP-020
文摘Understory vegetation controls, in a significant way, the regeneration of overstory trees, carbon sequestration and nutrient retention in tropical forests. Development and organization of understory vegetation depend on climate, edaphic and biotic factors which are not well correlated with plant community structures. This study aimed to explore the relationships between understory vegetation and abiotic factors in natural and planted forest ecosystems. A non-metric multidimensional scaling(NMS) ordination technique was applied to represent forest understory vegetation among five forest communities, i.e., a dry miscellaneous forest(DMF), a sal mixed forest(SMF), a teak plantation(TP), a low-land miscellaneous forest(LMF) and a savanna area(SAV) of the Katerniaghat Wildlife Sanctuary, located in northern India. Microclimatic variables, such as photosynthetically active radiation(PAR), air temperature(AT), soil temperature(ST), ambient atmospheric CO 2 concentration, absolute air humidity(AH), physical and chemical soil properties as well as biological properties were measured. Understory species were assessed via 100 random quadrats(5 m × 5 m) in each of the five forests in which a total of 75 species were recorded encompassing 67 genera from 37 families, consisting of 32 shrubs and 43 plant saplings. DMF was the most dense forest with 34,068 understory individuals per ha of different species, whereas the lowest understory population(13,900 per ha) was observed in the savanna. Ordination and correlation revealed that microclimate factors are most important in their effect compared to edaphic factors, on the development of understory vegetation in the various forest communities in the north of India.
文摘Tungsten inert gas(TIG) welding is the most commonly used joining process for aluminum alloy for AA6061 and AA7075 which are highly demanded in the aerospace engineering and the automobile sector, but there are some defects occur during TIG welding like micro-crack, coarse grain structure, and porosity. To improve these defects, the TIG welded joint is processed using friction stir processing(FSP).This paper presents the effect of friction stir processing on TIG welding with filler ER4043 and ER 5356 for dissimilar aluminum alloy AA6061 and AA7075. The mechanical characterization, finite element formulation and mathematical equations of heat transfer of TIG + FSP welded joints are investigated using ANSYS Fluent software by adjusting process parameters of FSP. The results show that the maximum compressive residual stress 73 MPa was obtained at the fusion zone(FZ) of the TIG weldment with filler ER4043, whereas minimum compressive residual stress 37 MPa was obtained at stir zone(SZ) of the TIG+ FSP with filler 5356. The maximum heat flux 5.33 × 106 W/m2 and temperature 515C have observed at tool rotation 1600 rpm with a feed rate of 63 mm/min. These results give a satisfactory measure of confidence in the fidelity of the simulation。
文摘Nowadays,the recompression supercritical carbon dioxide(R-SCO_(2))cycle has emerged as a promising option for power conversion systems because of its boundless potential to tackle energy and environmental issues.In this study,we examined the performance of the solar parabolic trough collector(SPTC)integrated combined cogeneration system for the purpose of power generation as well as recovery of waste exhaust heat from the R-SCO_(2) cycle with the help of the organic Rankine cycle(ORC).An exergy and energy analysis was performed for a combined recompression cycle(R-SCO_(2)-ORC)by varying the input variables such as intensity of solar irradiation(Gb),pressure at the inlet of SCO_(2) turbine(P_(5)),mass flow rate of SCO_(2)()&mSCO_(2) inlet temperature of SCO_(2) turbine(T5),inlet temperature of main compressor(T_(9))and effectiveness of the high-and low-temperature recuperator( HTR and LTR).Eight organic working fluids were considered for the ORC:R123,R290,isobutane,R1234yf,R1234ze,toluene,isopentane and cyclohexane.The study revealed that R123-based R-SCO_(2)-ORC demonstrates the highest thermal and exergy efficiency:~73.4 and 40.89%at G_(b)=0.5 kW/m^(2);78.8 and 43.9%at P_(5)=14 MPa;63.86 and 35.57%at T5=650 K;74.84 and 41.69%at&mSCO 7kg s;2=/85.83 and 47.82%at T_(9)=300 K;84.57 and 47.11%at HTR 65;=0.85.06 and 47.38%at LTR 65,=0.respectively.Alternatively,R290 showed the minimum value of exergy and thermal efficiency.As can be seen,the maximum amount of exergy destruction or exergy loss occurs in a solar collector field,~58.25%of the total exergy destruction rate(i.e.6703 kW)and 18.99%of the solar inlet exergy(i.e.20562 kJ).Moreover,R123 has the highest net work output,~4594 kJ at T5=650 K and 6176 kJ at T_(9)=300 K.
文摘The extraction and separation of zinc, manganese, cobalt and nickel from nickel laterite bacteria leach liquor were carried out using sodium salts of TOPS-99 and Cyanex 272 in kerosene. The unwanted metal ions were removed by precipitation method and solvent extraction was used to extract/separate Zn, Mn, Co and Ni. The nickel laterite leach liquor which was obtained from bioleaching of chromite overburden samples contained 3.72 g/L Fe, 2.08 g/L Al, 0.44 g/L Ni, 0.02 g/L Co, 0.13 g/L Mn, 0.14 g/L Zn and 0.22 g/L Cr. From this leach liquor, 100% Fe, 96.98% Al and 70.42% Cr were removed by precipitation with Ca CO_3 at pH 4.4 followed by precipitation of remaining Al and Cr with 50% ammonia at p H 5.4. After precipitation, the extraction of Zn from the Fe, Al and Cr free leach liquor was carried out with 0.1 mol/L TOPS-99 followed by Mn extraction with 0.04 mol/L Na TOPS-99. The yields of Zn and Mn were 97.77% and 95.63%, respectively. After Mn extraction, cobalt was removed from the leach liquor using 0.0125 mol/L Na Cyanex 272 and finally nickel extraction was carried out using 0.12 mol/L Na TOPS-99 with 99.84% yield. The stripping of loaded organic（LO） phases were achieved with dilute H_2SO_4.
文摘The work presents the synthesis and characterization of amidated pectin(AP) based polymer electrolyte membranes(PEM) crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA) and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(Y_M and K_N) are calcu...
文摘Addressing social issues is very crucial for government and thus government is primarily expected to create an enabling environment for raising awareness and stimulating public debate for the existing social challenges and issues.Indian government is proactive to encourage legal mandates in various dimensions enabling responsible business practices.What organizations do with their money is being increasingly caught on the public radar leading to bringing ethical issues to the forefront.The paper is an effort to understand how financial responsible effort is playing out in the state-owned enterprises(SOEs),and also the effort towards handling corporate social responsibility(CSR)across SOEs in India.The paper elaborates whether ethical financing is a form of social responsibility in organizations and elaborates the status of responsible financing of SOEs in India.The paper also discusses the practices encouraging ethical financing in SOEs in India.
