There is considerable evidence from a wide range of sources,including written texts,preserved monuments,and natural plant medicines,that demonstrate the long history of humankind's search for medicinal substances ...There is considerable evidence from a wide range of sources,including written texts,preserved monuments,and natural plant medicines,that demonstrate the long history of humankind's search for medicinal substances in the natural world.The purpose of this article was to compare the performance of medicinal plant Thuja(T.)occidentalis in a variety of disease-relieving conditions.The current review draws on the work of nearly two hundred original research papers indexed in Google Scholar,ScienceDirect,and the NCBI Library.The authors gatherd all the accessible data on the therapeutic effects of T.occidentalis.Although there are no published randomized controlled trials of T.occidentalis alone so far,multiple clinical investigations have validated the therapeutic efficacy of a combination herbal medication including the extract of T.occidentalis and additional immune stimulants.T.occidentalis is a plant with great potential as it is widely used in both traditional homoeopathy and modern,evidence-based phytotherapy.In vitro and in vivo models have shown its immunopharmacological potential,including its immunostimulatory,anti-cancer,anti-bacterial,anti-fungal,and antiviral activities.More researches into these plants might be done to find out if any of them have the potential to be implemented as a novel drug to treat a wide range of conditions.展开更多
In the present work, for the first time on the basis ofpoly (vinyl alcohol) (PVA), 2- (4-dimethylaminostyryl)-l-ethylquinolinium iodide (quinaldine red (QR)) and trisodium (4E)-5-oxo- 1-(4-sulfonatophenyl...In the present work, for the first time on the basis ofpoly (vinyl alcohol) (PVA), 2- (4-dimethylaminostyryl)-l-ethylquinolinium iodide (quinaldine red (QR)) and trisodium (4E)-5-oxo- 1-(4-sulfonatophenyl)-4-[(4-sulfonatophenyl)hydrazono]-3 pyrazolecarboxylate (tartrazine (T)), thermostable polarizing film in a wide range of spectra (λmax=394-511 nm) with polarization efficiency (PE) = 98% in absorption maximum and stretching degree (Rs) = 3.5 was developed. The basic spectral-polarization parameters (polarization efficiency and transmittance) of oriented colored PVA-films were measured and discussed. During the work it was found that oriented PVA-films are the phenomenon of anisotropy of thermal conductivity (λ|/λ⊥). It is a very important parameter for the development of thermostable PVA-polarizing films. For the first time quantum-chemical calculations using density functional theory (DFT) approach for structural analysis and electronic spectrum of the QR were carried out via the B3LYP/dgdzvp and TDB3LYP/dgdzvp methods. Interpretation of absorption strips in visible region of spectrum was also reported. The excitation energies, electronic transitions and oscillator strengths for the studied structures have also been calculated (B3LYP/dgdzvp). The NBO analysis and Mulliken atomic charges of the QR were carried out.展开更多
The dependence of the directions of polarization of exciton emissions, fine structure splittings (FSS), and polarization anisotropy on the light- and heavy-hole (LH-HH) mixing in semiconductor quantum dots (QDs)...The dependence of the directions of polarization of exciton emissions, fine structure splittings (FSS), and polarization anisotropy on the light- and heavy-hole (LH-HH) mixing in semiconductor quantum dots (QDs) is investigated using a mesoscopic model. In general, all QDs have a four-fold exciton ground state. Two exciton states have directions of polarization in the growth-plane, while the other two are along the growth direction of the QD. The LH-HH mixing does affect the FSS and polarization anisotropy of bright exciton states in the growth-plane in the low symmetry QDs (e.g., C2v, CS, C1 ), while it has no effect on the FSS and polarization anisotropy in high symmetry QDs (e.g., C3V, D2d). When the hole ground state is pure HH or LH, the bright exciton states in the growth-plane are normal to each other. The LH-HH mixing affects the relative intensities and directions of bright exciton states in the growth-plane of the QD. The polarization anisotropy of exciton emissions in the growth-plane of the QD is independent of the phase angle of LH-HH mixing but strongly depends on the magnitude of LH-HH mixing in low symmetry QDs.展开更多
Genetically Modified Crops (GMCs) and Climate Change (CC) are the two most contentious ecological issues the world faces today. Application of transgenics in agriculture is most debated because of its direct and indir...Genetically Modified Crops (GMCs) and Climate Change (CC) are the two most contentious ecological issues the world faces today. Application of transgenics in agriculture is most debated because of its direct and indirect implications. The advertized benefits in the backdrop of the potentially harmful effects on health and environment make this an issue of greater concern. On the other hand, Climate Change is a problem of enormous scale and its after-effects even more grave. The impact of climate change on agriculture, though well researched, is still very uncertain. Further, the introduction and global embrace of a technology with unverified credentials may prove to be an ill-conceived and ill-timed act. The future of GMC technology in India will be both challenging as well as exciting. Therefore any decision on this front should be taken with scientific rigor and logic. Our aim is to explore this complex inter-relationship and provide impetus for further research.展开更多
The medical health systems empowered by wireless body area networks(WBANs)are becoming a reliable technology with unmatched facilities for personalised health monitoring and managing real-time health issues.A WBAN is ...The medical health systems empowered by wireless body area networks(WBANs)are becoming a reliable technology with unmatched facilities for personalised health monitoring and managing real-time health issues.A WBAN is primarily composed of a miniature,and smart devices called sensors that are worn in,on,or around the human body.In recent years,research has been mainly centred towards the reduction of the energy consumption and stability of the network.The selection of the relay node is one of the foremost issues for balancing the energy consumption in WBAN.To overcome this issue,the authors propose a hybrid analytic hierarchy process-neutrosophic method for making the decision of the relay node selection,in which the analytic hierarchy process(AHP)technique calculates the weights for different criteria and forwards them to the neutrosophic technique which finds out the best alternative solution or choice which is closest to the ideal solution.A detailed analysis is carried out on multi-criteria decision-making techniques by comparing the proposed AHP-neutrosophic and AHP techniques taking into account various criteria and alternatives.The experimental outcomes of this research indicate a significant reduction in terms of energy consumption and enhanced overall network-stability.展开更多
Let H denote the class of complex-valued harmonic functions f defined in the open unit disc D and normalized by f(0)=fz(0)-1=0.In this paper,we define a new generalized subclass of H associated with the(p,q)-Ruschewey...Let H denote the class of complex-valued harmonic functions f defined in the open unit disc D and normalized by f(0)=fz(0)-1=0.In this paper,we define a new generalized subclass of H associated with the(p,q)-Ruscheweyh-type harmonic differential operator in D.We first obtain a sufficient coefficient condition that guarantees that a function f in H is sense-preserving harmonic univalent in D and belongs to the aforementioned class.Using this coefficient condition,we then examine ratios of partial sums of f in H.In all cases the results are sharp.In addition,the results so obtained generalize the related works of some authors,and many other new results are obtained.展开更多
The present work explores the propagation characteristics of high-power beams in weakly relativistic-ponderomotive thermal quantum plasma.A q-Gaussian laser beam is taken in the present investigation.The quasi-optics ...The present work explores the propagation characteristics of high-power beams in weakly relativistic-ponderomotive thermal quantum plasma.A q-Gaussian laser beam is taken in the present investigation.The quasi-optics equation obtained in the present study is solved through a well-established Wentzel–Kramers–Brillouin approximation and paraxial theory approach for obtaining the second-order differential equation describing the behavior of beam width of the laser beam.Further,a numerical simulation of this second-order differential equation is carried out for determining the behavior of the beam width with dimensionless distance for established laser–plasma parameters.The comparison of the present study is made with ordinary quantum plasma and classical relativistic plasma cases.展开更多
The influence of a self-focused beam on the stimulated Raman scattering(SRS)process in collisional plasma is explored.Here,collisional nonlinearity arises as a result of non-uniform heating,thereby causing carrier red...The influence of a self-focused beam on the stimulated Raman scattering(SRS)process in collisional plasma is explored.Here,collisional nonlinearity arises as a result of non-uniform heating,thereby causing carrier redistribution.The plasma density profile gets modified in a perpendicular direction to the main beam axis.This modified plasma density profile greatly affects the pump wave,electron plasma wave(EPW)and back-scattered wave.The well-known paraxial theory and Wentzel-Kramers-Brillouin approximation are used to derive second-order ordinary differential equations for the beam waists of the pump wave,EPW and the scattered wave.Further to this,the well-known fourth-order Runge-Kutta method is used to carry out numerical simulations of these equations.SRS back-reflectivity is found to increase due to the focusing of several waves involved in the process.展开更多
In the present work,nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation.Nonlinear differential equations for the beam width parameters of semi-major ax...In the present work,nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation.Nonlinear differential equations for the beam width parameters of semi-major axis and semi-minor axis of elliptical laser beam have been set up and solved numerically to study the variation of beam width parameters with normalized distance of propagation.Effects of variation in absorption coefficient and plasma density on the beam width parameters are also analyzed.It is observed from the analysis that extent of self-focusing of beam increases with increase/decrease in plasma density/absorption coefficient.展开更多
Background:In the northern hemisphere,the north face of the mountains has a high diversity of species which is attributed to the moist and shady conditions at the north face.Other environmental variables may also infl...Background:In the northern hemisphere,the north face of the mountains has a high diversity of species which is attributed to the moist and shady conditions at the north face.Other environmental variables may also influence the species diversity on the northern faces of the mountain and therefore needs to be studied in detail.The northern slopes represent three different sub-slopes—north,north east,and north west.During the current investigation of Pir-Panjal and Dauladhar ranges in Bhadarwah valley,fine-scale studies on the relationship between vegetation and four variables(soil pH,moisture content,electrical conductivity,and steepness)were conducted.The study determined the role of these variables on the vegetation of three different sub-slopes.The sampling was done at the confluence of two communities(forest and grassland)at three sites on the northern sub-slopes of the lesser stratum in western Himalayan.Results:The result revealed that rich herbaceous diversity prevails on the lesser Himalayan stratum(Bhadarwah valley).As many as 65.8%species differ from site to site,whereas species commonality among the sites is minimum.The role of environmental variables on the species composition at different sub-slopes of the north mountain face is deduced through canonical correspondence analysis(CCA).Conclusions:The availability of solar light increases air and soil temperature on the north east–facing slope.All the environmental variables(soil pH,moisture,electrical conductivity,and mountain steepness)are insignificant at pure north face for the species composition.Therefore,it can be concluded that some other environmental variables may influence the species composition which are needed to be further investigated.展开更多
This paper presents an investigation of weakly relativistic ponderomotive effects on self-focusing during interaction of high power elliptical laser beam with plasma. The nonlinear differential equations for the beam ...This paper presents an investigation of weakly relativistic ponderomotive effects on self-focusing during interaction of high power elliptical laser beam with plasma. The nonlinear differential equations for the beam width parameters of elliptical laser beam have set up by using Wentzal–Krammers–Brillouin(WKB) and paraxial approximations. These equations have been solved numerically by using fourth order Runge–Kutta method to study the variation of these beam width parameters against normalized distance of propagation. Effects of variation in laser beam intensity,plasma density and electron temperature on the beam width parameters are also analyzed.展开更多
The purpose of this study is to explore the second harmonic generation(SHG)of a high power Cosh-Gaussian beam in cold collisionless plasma.The ponderomotive force causes carrier redistribution from high field to low f...The purpose of this study is to explore the second harmonic generation(SHG)of a high power Cosh-Gaussian beam in cold collisionless plasma.The ponderomotive force causes carrier redistribution from high field to low field region in presence of a Cosh-Gaussian beam thereby producing density gradients in the transverse direction.The density gradients so produced the results in electron plasma wave(EPW)generation at the frequency of the input beam.The EPW interacts with the input beam resulting in the production of 2nd harmonics.WKB and paraxial approximations are employed for obtaining the 2nd order differential equation describing the behavior of the beam’s spot size against normalized distance.The impact of well-established laser-plasma parameters on the behavior of the beam’s spot size and SHG yield are also analyzed.The focusing behavior of the beam and SHG yield is enhanced with an increase in the density of plasma,the radius of the beam and the decentred parameter,and with a decrease in the intensity of the beam.The results of the current problem are really helpful for complete information of laser-plasma interaction physics.展开更多
A lossy mode resonance(LMR)-supported fiber optic sensor in which a uniform fiber core is placed among two identical tapered regions, is investigated numerically. Indium tin oxide(ITO)and aluminum-doped zinc oxide(AZO...A lossy mode resonance(LMR)-supported fiber optic sensor in which a uniform fiber core is placed among two identical tapered regions, is investigated numerically. Indium tin oxide(ITO)and aluminum-doped zinc oxide(AZO) are considered as LMR active materials used to excite several lossy modes and gold and silver are used as surface plasmon resonance(SPR) active materials. In this probe design, a central uniform core coated with ITO/AZO is the active sensing region, whereas tapered regions are meant for bringing the incident angle close to the critical angle. The sensitivity of the present fiber optic bio-sensor is evaluated for first two LMRs utilizing both ITO and AZO separately, along with its variation with the taper ratio(TR). For ITO, the maximum sensitivity values are observed to be 18.425 μm RIU^(-1)(refractive index unit)and 0.825 μm RIU^(-1), corresponding to the first and second LMRs, respectively, at a TR of 1.6 and for AZO, equivalent values are 0.79 μm RIU^(-1) and 0.35 μm RIU^(-1), respectively, at a TR of2.0. The results illustrate that the first LMR is more sensitive than the second LMR and the ITOcoated probe possesses greater sensitivity than the AZO-coated probe for both LMRs. Similarly,for the fiber optic SPR sensor, the maximum value of sensitivity is 5.6425 μm RIU^(-1), in the case of gold and 5.0615 μm RIU^(-1) in the case of silver, at a TR of 1.6. Hence, the result shows that the sensor with the present fiber optic probe design has around a 3-fold enhancement in sensitivity compared with conventional SPR sensors. This study will have applications in many sensing schemes where the requirement of large sensitivity is vital.展开更多
The Reynolds number of molten metal flowing mold cavity causes bulk turbulence and is the main cause of defects like shrinkage porosity and sand erosion.Machined housings with shrinkage porosity at critical bearing bo...The Reynolds number of molten metal flowing mold cavity causes bulk turbulence and is the main cause of defects like shrinkage porosity and sand erosion.Machined housings with shrinkage porosity at critical bearing bores and surface made the casting useless.In old gating casting areas of perimeters 290mm and 264mm of transmission housing,Reynolds numbers were observed as 16307 and 13806,respectively using simulation software.Data were collected from experiments to change casting area perimeters from 785mm and 785mm along with the addition of overlap area.New Reynolds numbers at two locations were observed as 3705 and 3393,respectively.Molten metal pressure,velocity and temperature results were related for final shrinkage results of the components on full production.The purpose of the study is to reduce shrinkage and porosity defects in green sand casting part using MAGMAS simulation software.High outcome was the reduction of casting machining rejection in transmission housing casting from 5.8%0.7%with savings of approximately 0.13 million USD over the period of 14 months.Implications of this work include casting defects study and reduction in different grades and weight range.展开更多
Due to their unique activation modes,small organic molecule catalysts(organocatalysts)have proved their potential in facilitating the remote functionalizations of unsaturated acceptors with extended conjugation.The or...Due to their unique activation modes,small organic molecule catalysts(organocatalysts)have proved their potential in facilitating the remote functionalizations of unsaturated acceptors with extended conjugation.The organocatalytic 1,6-addition reaction involving the attack of nucleophiles on the δ-carbon of the α,β,γ,δ-unsaturated acceptors has emerged as an excellent strategy to create a stereocenter at the δ-site with high regio-and stereo-control.Organocatalysis has also opened the window for developing complex domino reactions involving the 1,6-addition step.Tremendous advancement has been accomplished in the organocatalytic asymmetric 1,6-addition and related domino reactions for the stereocontrolled synthesis of complex molecular structures bearing multiple stereocenters.This review article summarizes the significant advancement in stereoselective domino reactions involving 1,6-addition as a critical step.展开更多
文摘There is considerable evidence from a wide range of sources,including written texts,preserved monuments,and natural plant medicines,that demonstrate the long history of humankind's search for medicinal substances in the natural world.The purpose of this article was to compare the performance of medicinal plant Thuja(T.)occidentalis in a variety of disease-relieving conditions.The current review draws on the work of nearly two hundred original research papers indexed in Google Scholar,ScienceDirect,and the NCBI Library.The authors gatherd all the accessible data on the therapeutic effects of T.occidentalis.Although there are no published randomized controlled trials of T.occidentalis alone so far,multiple clinical investigations have validated the therapeutic efficacy of a combination herbal medication including the extract of T.occidentalis and additional immune stimulants.T.occidentalis is a plant with great potential as it is widely used in both traditional homoeopathy and modern,evidence-based phytotherapy.In vitro and in vivo models have shown its immunopharmacological potential,including its immunostimulatory,anti-cancer,anti-bacterial,anti-fungal,and antiviral activities.More researches into these plants might be done to find out if any of them have the potential to be implemented as a novel drug to treat a wide range of conditions.
基金supported by the National Academy of Sciences of Belarus
文摘In the present work, for the first time on the basis ofpoly (vinyl alcohol) (PVA), 2- (4-dimethylaminostyryl)-l-ethylquinolinium iodide (quinaldine red (QR)) and trisodium (4E)-5-oxo- 1-(4-sulfonatophenyl)-4-[(4-sulfonatophenyl)hydrazono]-3 pyrazolecarboxylate (tartrazine (T)), thermostable polarizing film in a wide range of spectra (λmax=394-511 nm) with polarization efficiency (PE) = 98% in absorption maximum and stretching degree (Rs) = 3.5 was developed. The basic spectral-polarization parameters (polarization efficiency and transmittance) of oriented colored PVA-films were measured and discussed. During the work it was found that oriented PVA-films are the phenomenon of anisotropy of thermal conductivity (λ|/λ⊥). It is a very important parameter for the development of thermostable PVA-polarizing films. For the first time quantum-chemical calculations using density functional theory (DFT) approach for structural analysis and electronic spectrum of the QR were carried out via the B3LYP/dgdzvp and TDB3LYP/dgdzvp methods. Interpretation of absorption strips in visible region of spectrum was also reported. The excitation energies, electronic transitions and oscillator strengths for the studied structures have also been calculated (B3LYP/dgdzvp). The NBO analysis and Mulliken atomic charges of the QR were carried out.
文摘The dependence of the directions of polarization of exciton emissions, fine structure splittings (FSS), and polarization anisotropy on the light- and heavy-hole (LH-HH) mixing in semiconductor quantum dots (QDs) is investigated using a mesoscopic model. In general, all QDs have a four-fold exciton ground state. Two exciton states have directions of polarization in the growth-plane, while the other two are along the growth direction of the QD. The LH-HH mixing does affect the FSS and polarization anisotropy of bright exciton states in the growth-plane in the low symmetry QDs (e.g., C2v, CS, C1 ), while it has no effect on the FSS and polarization anisotropy in high symmetry QDs (e.g., C3V, D2d). When the hole ground state is pure HH or LH, the bright exciton states in the growth-plane are normal to each other. The LH-HH mixing affects the relative intensities and directions of bright exciton states in the growth-plane of the QD. The polarization anisotropy of exciton emissions in the growth-plane of the QD is independent of the phase angle of LH-HH mixing but strongly depends on the magnitude of LH-HH mixing in low symmetry QDs.
文摘Genetically Modified Crops (GMCs) and Climate Change (CC) are the two most contentious ecological issues the world faces today. Application of transgenics in agriculture is most debated because of its direct and indirect implications. The advertized benefits in the backdrop of the potentially harmful effects on health and environment make this an issue of greater concern. On the other hand, Climate Change is a problem of enormous scale and its after-effects even more grave. The impact of climate change on agriculture, though well researched, is still very uncertain. Further, the introduction and global embrace of a technology with unverified credentials may prove to be an ill-conceived and ill-timed act. The future of GMC technology in India will be both challenging as well as exciting. Therefore any decision on this front should be taken with scientific rigor and logic. Our aim is to explore this complex inter-relationship and provide impetus for further research.
文摘The medical health systems empowered by wireless body area networks(WBANs)are becoming a reliable technology with unmatched facilities for personalised health monitoring and managing real-time health issues.A WBAN is primarily composed of a miniature,and smart devices called sensors that are worn in,on,or around the human body.In recent years,research has been mainly centred towards the reduction of the energy consumption and stability of the network.The selection of the relay node is one of the foremost issues for balancing the energy consumption in WBAN.To overcome this issue,the authors propose a hybrid analytic hierarchy process-neutrosophic method for making the decision of the relay node selection,in which the analytic hierarchy process(AHP)technique calculates the weights for different criteria and forwards them to the neutrosophic technique which finds out the best alternative solution or choice which is closest to the ideal solution.A detailed analysis is carried out on multi-criteria decision-making techniques by comparing the proposed AHP-neutrosophic and AHP techniques taking into account various criteria and alternatives.The experimental outcomes of this research indicate a significant reduction in terms of energy consumption and enhanced overall network-stability.
文摘Let H denote the class of complex-valued harmonic functions f defined in the open unit disc D and normalized by f(0)=fz(0)-1=0.In this paper,we define a new generalized subclass of H associated with the(p,q)-Ruscheweyh-type harmonic differential operator in D.We first obtain a sufficient coefficient condition that guarantees that a function f in H is sense-preserving harmonic univalent in D and belongs to the aforementioned class.Using this coefficient condition,we then examine ratios of partial sums of f in H.In all cases the results are sharp.In addition,the results so obtained generalize the related works of some authors,and many other new results are obtained.
文摘The present work explores the propagation characteristics of high-power beams in weakly relativistic-ponderomotive thermal quantum plasma.A q-Gaussian laser beam is taken in the present investigation.The quasi-optics equation obtained in the present study is solved through a well-established Wentzel–Kramers–Brillouin approximation and paraxial theory approach for obtaining the second-order differential equation describing the behavior of beam width of the laser beam.Further,a numerical simulation of this second-order differential equation is carried out for determining the behavior of the beam width with dimensionless distance for established laser–plasma parameters.The comparison of the present study is made with ordinary quantum plasma and classical relativistic plasma cases.
文摘The influence of a self-focused beam on the stimulated Raman scattering(SRS)process in collisional plasma is explored.Here,collisional nonlinearity arises as a result of non-uniform heating,thereby causing carrier redistribution.The plasma density profile gets modified in a perpendicular direction to the main beam axis.This modified plasma density profile greatly affects the pump wave,electron plasma wave(EPW)and back-scattered wave.The well-known paraxial theory and Wentzel-Kramers-Brillouin approximation are used to derive second-order ordinary differential equations for the beam waists of the pump wave,EPW and the scattered wave.Further to this,the well-known fourth-order Runge-Kutta method is used to carry out numerical simulations of these equations.SRS back-reflectivity is found to increase due to the focusing of several waves involved in the process.
文摘In the present work,nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation.Nonlinear differential equations for the beam width parameters of semi-major axis and semi-minor axis of elliptical laser beam have been set up and solved numerically to study the variation of beam width parameters with normalized distance of propagation.Effects of variation in absorption coefficient and plasma density on the beam width parameters are also analyzed.It is observed from the analysis that extent of self-focusing of beam increases with increase/decrease in plasma density/absorption coefficient.
文摘Background:In the northern hemisphere,the north face of the mountains has a high diversity of species which is attributed to the moist and shady conditions at the north face.Other environmental variables may also influence the species diversity on the northern faces of the mountain and therefore needs to be studied in detail.The northern slopes represent three different sub-slopes—north,north east,and north west.During the current investigation of Pir-Panjal and Dauladhar ranges in Bhadarwah valley,fine-scale studies on the relationship between vegetation and four variables(soil pH,moisture content,electrical conductivity,and steepness)were conducted.The study determined the role of these variables on the vegetation of three different sub-slopes.The sampling was done at the confluence of two communities(forest and grassland)at three sites on the northern sub-slopes of the lesser stratum in western Himalayan.Results:The result revealed that rich herbaceous diversity prevails on the lesser Himalayan stratum(Bhadarwah valley).As many as 65.8%species differ from site to site,whereas species commonality among the sites is minimum.The role of environmental variables on the species composition at different sub-slopes of the north mountain face is deduced through canonical correspondence analysis(CCA).Conclusions:The availability of solar light increases air and soil temperature on the north east–facing slope.All the environmental variables(soil pH,moisture,electrical conductivity,and mountain steepness)are insignificant at pure north face for the species composition.Therefore,it can be concluded that some other environmental variables may influence the species composition which are needed to be further investigated.
文摘This paper presents an investigation of weakly relativistic ponderomotive effects on self-focusing during interaction of high power elliptical laser beam with plasma. The nonlinear differential equations for the beam width parameters of elliptical laser beam have set up by using Wentzal–Krammers–Brillouin(WKB) and paraxial approximations. These equations have been solved numerically by using fourth order Runge–Kutta method to study the variation of these beam width parameters against normalized distance of propagation. Effects of variation in laser beam intensity,plasma density and electron temperature on the beam width parameters are also analyzed.
文摘The purpose of this study is to explore the second harmonic generation(SHG)of a high power Cosh-Gaussian beam in cold collisionless plasma.The ponderomotive force causes carrier redistribution from high field to low field region in presence of a Cosh-Gaussian beam thereby producing density gradients in the transverse direction.The density gradients so produced the results in electron plasma wave(EPW)generation at the frequency of the input beam.The EPW interacts with the input beam resulting in the production of 2nd harmonics.WKB and paraxial approximations are employed for obtaining the 2nd order differential equation describing the behavior of the beam’s spot size against normalized distance.The impact of well-established laser-plasma parameters on the behavior of the beam’s spot size and SHG yield are also analyzed.The focusing behavior of the beam and SHG yield is enhanced with an increase in the density of plasma,the radius of the beam and the decentred parameter,and with a decrease in the intensity of the beam.The results of the current problem are really helpful for complete information of laser-plasma interaction physics.
基金the Department of Science and Technology (DST),INDIA for providing the INSPIRE fellowship (Registration No.-IF170543)。
文摘A lossy mode resonance(LMR)-supported fiber optic sensor in which a uniform fiber core is placed among two identical tapered regions, is investigated numerically. Indium tin oxide(ITO)and aluminum-doped zinc oxide(AZO) are considered as LMR active materials used to excite several lossy modes and gold and silver are used as surface plasmon resonance(SPR) active materials. In this probe design, a central uniform core coated with ITO/AZO is the active sensing region, whereas tapered regions are meant for bringing the incident angle close to the critical angle. The sensitivity of the present fiber optic bio-sensor is evaluated for first two LMRs utilizing both ITO and AZO separately, along with its variation with the taper ratio(TR). For ITO, the maximum sensitivity values are observed to be 18.425 μm RIU^(-1)(refractive index unit)and 0.825 μm RIU^(-1), corresponding to the first and second LMRs, respectively, at a TR of 1.6 and for AZO, equivalent values are 0.79 μm RIU^(-1) and 0.35 μm RIU^(-1), respectively, at a TR of2.0. The results illustrate that the first LMR is more sensitive than the second LMR and the ITOcoated probe possesses greater sensitivity than the AZO-coated probe for both LMRs. Similarly,for the fiber optic SPR sensor, the maximum value of sensitivity is 5.6425 μm RIU^(-1), in the case of gold and 5.0615 μm RIU^(-1) in the case of silver, at a TR of 1.6. Hence, the result shows that the sensor with the present fiber optic probe design has around a 3-fold enhancement in sensitivity compared with conventional SPR sensors. This study will have applications in many sensing schemes where the requirement of large sensitivity is vital.
文摘The Reynolds number of molten metal flowing mold cavity causes bulk turbulence and is the main cause of defects like shrinkage porosity and sand erosion.Machined housings with shrinkage porosity at critical bearing bores and surface made the casting useless.In old gating casting areas of perimeters 290mm and 264mm of transmission housing,Reynolds numbers were observed as 16307 and 13806,respectively using simulation software.Data were collected from experiments to change casting area perimeters from 785mm and 785mm along with the addition of overlap area.New Reynolds numbers at two locations were observed as 3705 and 3393,respectively.Molten metal pressure,velocity and temperature results were related for final shrinkage results of the components on full production.The purpose of the study is to reduce shrinkage and porosity defects in green sand casting part using MAGMAS simulation software.High outcome was the reduction of casting machining rejection in transmission housing casting from 5.8%0.7%with savings of approximately 0.13 million USD over the period of 14 months.Implications of this work include casting defects study and reduction in different grades and weight range.
基金financial support from the Council of Scientific and Industrial Research(CSIR),India(File No.:02(0422)/21/EMR-Ⅱ)the Indian Institute of Technology Jammu for providing Seed Grant(File No.:SG0002)to establish the independent research groupthe Indian Institute of Technology Jammu for the fellowships.
文摘Due to their unique activation modes,small organic molecule catalysts(organocatalysts)have proved their potential in facilitating the remote functionalizations of unsaturated acceptors with extended conjugation.The organocatalytic 1,6-addition reaction involving the attack of nucleophiles on the δ-carbon of the α,β,γ,δ-unsaturated acceptors has emerged as an excellent strategy to create a stereocenter at the δ-site with high regio-and stereo-control.Organocatalysis has also opened the window for developing complex domino reactions involving the 1,6-addition step.Tremendous advancement has been accomplished in the organocatalytic asymmetric 1,6-addition and related domino reactions for the stereocontrolled synthesis of complex molecular structures bearing multiple stereocenters.This review article summarizes the significant advancement in stereoselective domino reactions involving 1,6-addition as a critical step.