This study compares the Adomian Decomposition Method (ADM) and the Variational Iteration Method (VIM) for solving nonlinear differential equations in engineering. Differential equations are essential for modeling dyna...This study compares the Adomian Decomposition Method (ADM) and the Variational Iteration Method (VIM) for solving nonlinear differential equations in engineering. Differential equations are essential for modeling dynamic systems in various disciplines, including biological processes, heat transfer, and control systems. This study addresses first, second, and third-order nonlinear differential equations using Mathematica for data generation and graphing. The ADM, developed by George Adomian, uses Adomian polynomials to handle nonlinear terms, which can be computationally intensive. In contrast, VIM, developed by He, directly iterates the correction functional, providing a more straightforward and efficient approach. This study highlights VIM’s rapid convergence and effectiveness of VIM, particularly for nonlinear problems, where it simplifies calculations and offers direct solutions without polynomial derivation. The results demonstrate VIM’s superior efficiency and rapid convergence of VIM compared with ADM. The VIM’s minimal computational requirements make it practical for real-time applications and complex system modeling. Our findings align with those of previous research, confirming VIM’s efficiency of VIM in various engineering applications. This study emphasizes the importance of selecting appropriate methods based on specific problem requirements. While ADM is valuable for certain nonlinearities, VIM’s approach is ideal for many engineering scenarios. Future research should explore broader applications and hybrid methods to enhance the solution’s accuracy and efficiency. This comprehensive comparison provides valuable guidance for selecting effective numerical methods for differential equations in engineering.展开更多
Copper-zinc-nickel(Cu-Zn-Ni)ferrite nanoparticles are used for wastewater treatment technology.However,low degradation efficiency and stability are two main issues that make them unsuitable for actual production needs...Copper-zinc-nickel(Cu-Zn-Ni)ferrite nanoparticles are used for wastewater treatment technology.However,low degradation efficiency and stability are two main issues that make them unsuitable for actual production needs.In this paper,the citrate-nitrate auto-combustion method was applied for the formation of Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(x)Fe_(2-x)O_(4);(0≤x≤0.1;step 0.02)(CZNL)nanoferrites.Although the substitution process entails the replacement of a small ion with a larger one,the lattice constant and crystallite size does not exhibit a consistent incremental pattern.This behavior is justified and discussed.The size of all the CZNL ferrite nanoparticles is in the range of 8-12 nm,and the lattice constant is in the range of 8.6230 to 8.4865 nm.The morphological analysis conducted using field emission-scanning electron microscopy(FE-SEM)reveals that the CZNL exhibits agglomerated spherical morphology.The energy dispersive X-ray spectrameter(EDAX)analysis was employed to confirm the elemental composition of CZNL nanoferrites.Since the process entails the substitution of Fe^(3+)magnetic ions with nonmagnetic ions La^(3+),the magnetic parameters of CZNL nanoferrites show a general decreasing trend as predicted.At 20 K,saturation magnetization Ms shows an overall drop in its values from 59.302 emu/g at x=0.0-41.295 emu/g at x=0.1,the smallest value of 37.87 emu/g is recorded at x=0.06.the highest coercivity(H_(c)=125.9 Oe)and remanence(M_(r)=13.32 emu/g)are recorded for x=0.08 and x=0.04 nanoferrite,respectvely.The band gap of all the CZNL nanoferrites was determined using the Kubelka-Munk function and Tauc plot for direct permitted transitions.La doping modifies the band gap(within 1.86-1.75 eV),increases light absorption,induces efficient e/h separation and charge migration to Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(x)Fe_(2-x)O_(4)surfaces.The nanoferrite Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(0.06)Fe_(1.94)O_(4)achieves a degradation efficiency of 97.3%for methylene blue(MB)dye removal after just 60 min.After five recycling processes,the nanocatalyst Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(0.06)Fe_(1.94)O_(4)is degraded by 95.83%,resulting in a negligible1.51%decrease in photocatalytic activity efficiency.The new Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(0.06)Fe_(1.94)O_(4)has exceptional photocatalytic activity and remarkable stability,making it a promising candidate for applications in wastewater treatment.展开更多
This work studied the magnetic,dielectric,and mechanical parameters of lanthanum doped cobalt-magnesium ferrite nanoparticles Co_(0.5)Mg_(0.5)La_(x)Fe_(2-x)O4(CMLF)prepared by citrate combustion route.Fourier transfor...This work studied the magnetic,dielectric,and mechanical parameters of lanthanum doped cobalt-magnesium ferrite nanoparticles Co_(0.5)Mg_(0.5)La_(x)Fe_(2-x)O4(CMLF)prepared by citrate combustion route.Fourier transform infrared spectroscopy(FTIR)spectra show lower band(v_(2))at 391-386 cm^(-1) and upper band(v_(1))at 572-570 cm^(-1),which demonstrate the cubic spinel structure formation for all CMLF nanoferrites.Magnetic parameters such as saturation magnetization,remanent magnetization,coer-civity,magnetic moment,anisotropy constant,and initial permittivity were investigated using a vibrating sample magnetometer(VSM).The sample Co_(0.5)Mg_(0.5)La_(0.03)Fe_(1.97)O4 has the optimal saturation magnetization of 47.78 emu/g,whereas the sample Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.85)O4 has a maximum coercivity of 1031 Oe.The dielectric constant,dielectric loss tangent,ac conductivity and impedance(Z)were also investigated with the addition of La ions.With La doping,the dielectric loss value decreases with 52%compared to the pristine sample,indicating it to be a potential candidate for high frequency appli-cations.The ac conductivity graphs exhibit adherence to Jonscher's single power law,indicating that the conduction process is primarily driven by the small polaron tunneling mechanism.Analytical investigation was conducted on the impedance spectroscopy and electric modulus for the CMLF nanoferrites.The nanoferrite Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.9)O_(4)has the optimum longitudinal modulus(4.60 GPa),shear modulus(0.85 GPa),Young's modulus(2.37 GPa),and bulk modulus(3.46 GPa)compared tothepristine sample.展开更多
Upgrading mechanical-dielectric features of ferrites through rare-earth yttrium(Y^(3+))doping provides feasibility to evolving high-frequency electronic devices.This paper reports the mechanical and dielectric propert...Upgrading mechanical-dielectric features of ferrites through rare-earth yttrium(Y^(3+))doping provides feasibility to evolving high-frequency electronic devices.This paper reports the mechanical and dielectric properties of Co_(0.5)Cu_(0.25)Zn_(0.25)Y_(x)Fe_(2-x)O_(4)ferrite nanoparticles labeled as CCZYF#0,CCZYF#1,CCZYF#2,CCZYF#3,CCZYF#4 and CCZYF#5 for x=0.0.0.02,0.04,0.06,0.08,and 0.1,respectively.The frequency and temperature dependence of dielectric parameters and co nductivity of all CCZYF nanoferrites are well discussed.The nanoferrite CCZYF#5 has the highest dielectric constant(enhancing ratio 170%)and the highest conductivity(enhancing ratio 7125.81%)compared with the undoped sample.Nyquist plots of all CCZYF nano ferrites manifest two arcs;the main reasons for the dielectric process are the grain boundaries and bulk grains.All impedance parameters were determined,which showed the effective role of Y^(3+)ions on their values.The nanoferrite CCZYF#5 has the highest grain boundaries capacitance(with enhancing ratio of 59.40%)and the highest grains capacitance(with enhancing ratio of 22.53%)with a relaxation time decrement efficiency of 62.51%.An ultrasonic flaw detector was utilized to determine the elastic moduli of all CCZYF nanoferrites.The nanoferrite CCZYF#5 has the highest longitudinal modulus(with enhancing ratio of 20.95%),the highest shear modulus(with enhancing ratio of48.72%),highest Young's modulus(with enhancing ratio of 88.47%),the highest bulk modulus(with enhancing ratio 13.27%)and the highest micro hardness(with enhancing ratio 77.77%).Hence,Y3+tuned Co-Cu-Zn nanoferrites possess new opportunities for high-frequency and storage applications.展开更多
This paper evaluates the skills of physical Parameterization schemes in simulating extreme rainfall events over Dar es Salaam Region, Tanzania using the Weather Research and Forecasting (WRF) model. The model skill is...This paper evaluates the skills of physical Parameterization schemes in simulating extreme rainfall events over Dar es Salaam Region, Tanzania using the Weather Research and Forecasting (WRF) model. The model skill is determined during the 21 December 2011 flooding event. Ten sensitivity experiments have been conducted using Cumulus, Convective and Planetary boundary layer schemes to find the best combination and optimize the WRF model for the study area for heavy rainfall events. Model simulation results were verified against observed data using standard statistical tests. The model simulations show encouraging and better statistical results with the combination of Kain-Fritsch cumulus parameterization scheme, Lin microphysics scheme and Asymmetric Convection Model 2 (ACM2) planetary boundary scheme than any other combinations of physical parameterization schemes over Dar es Salaam region.展开更多
Recent advances in technology provide countless innovative solutions and applications for supporting children with autism in educational learning and personal development. This result is an increasingly recognized nee...Recent advances in technology provide countless innovative solutions and applications for supporting children with autism in educational learning and personal development. This result is an increasingly recognized need to deal with new and unexpected risks and issues such as social exclusion. Diverse advanced technologies were aimed to support learning activity from different perspectives with multiple strategies. However, despite the significant amount of work and explored technology, several common risks pop up due to user’s vulnerability to diverse risks such as negative screen effects. Accordingly, there is still plenty of room for improvement in this regard. To address these vulnerabilities and gaps, this paper aims at identifying issues and challenges improving the technology applied for Autism Spectrum Disorders and autistics dedicated applications. It put forward requirements and design decisions supporting safe autistic dedicated interaction with regards to ISO31000 risk management process.展开更多
Climate change is impacting on climate dependent activities such as Avocado farming in Tanzania. The extent of the impact of climate change in agriculture depends on the level of vulnerability or exposure of farmers t...Climate change is impacting on climate dependent activities such as Avocado farming in Tanzania. The extent of the impact of climate change in agriculture depends on the level of vulnerability or exposure of farmers to these impacts. This study addresses gender vulnerabilities to Avocado smallholder farmers to climate change in the Southern Highlands regions of Tanzania where the temperature and rainfall stresses are relevant using the Livelihood Vulnerability Index (LVI) and tested for significant difference in their vulnerability levels by applying independent two sample student’s t-test based on gender by using a sample of 104 Avocado smallholder farming. The results in this study revealed that both male and female avocado farmers were vulnerable to the effects of climate change and variability, but the vulnerabilities varied with gender. Female small holder farmers were more vulnerable to socio-demographic profile, livelihood strategies, social network, water and food major components of the LVI, whereas were more vulnerable to social network and health. The vulnerability indices revealed that female small holder farmers were more sensitive to the impact of climate change and variability. It was also found that female small holder farmers have the least adaptive capacities. In all, female small holder farmers are more vulnerable to climate change and variability than male. There is a need for better gender-sensitive approaches to adaptation planning and implementation to ensure that both men and women have equal opportunities to benefit from adaptation options in agriculture.展开更多
The generation of hydrogen peroxide(H_(2)O_(2)),a compound with diverse applications,via the two-electron(2e^(-))oxygen reduction reaction(ORR)has garnered extensive attention in both laboratory research and industria...The generation of hydrogen peroxide(H_(2)O_(2)),a compound with diverse applications,via the two-electron(2e^(-))oxygen reduction reaction(ORR)has garnered extensive attention in both laboratory research and industrial settings.The integration of non-noble metals such as Co,Fe,Ni,Zn,Mn,Mo,or Bi into nitrogen-doped carbon(M-N-C)matrices with defined structures and active metal center sites has emerged as a promising approach for fabricating electrocatalysts for the ORR.This review uncovers the latest advancements in the development of noble metal-free single-atom electrocatalysts(M-N-C SAECs)and electrochemical reactors aimed at enhancing and stabilizing H_(2)O_(2)production from the 2e^(-)ORR.Firstly,the review explores the basics of the ORR for H_(2)O_(2)production and the impact of electrochemical conditions.Subsequently,the synthesis strategies and characterization methods of various M-N-C SAECs are examined in depth.In addition,the structural attributes of both conventional and altered M-N-C SAECs are meticulously investigated,and the importance of engineering and optimizing reactors to elevate H_(2)O_(2)yields is highlighted.This review identifies the challenges and technological hurdles in bridging the gap between laboratory-scale research and practical,real-world applications.展开更多
This study undertakes a multimodal framing analysis of the Obidient movement in Nigeria,with a view to exposing how Internet memes are deployed to advertise Peter Obi,the presidential candidate of the Labour Party(LP)...This study undertakes a multimodal framing analysis of the Obidient movement in Nigeria,with a view to exposing how Internet memes are deployed to advertise Peter Obi,the presidential candidate of the Labour Party(LP)in Nigeria's 2023 election.Forty memes were purposively sampled from Nigerian WhatsApp platforms and data were analysed qualitatively using aspects of Kress and van Leeuwen(2006.Reading images:The grammar of visual design,2nd edn.London:Routledge)grammar of visual design and Kuypers(2002.Press bias and politics:How the media frame controversial issues.Westport,CT:Praeger,2009.Framing analysis.In Kuypers Jim(ed.),Rhetorical criticism:Perspectives in action,181-204.London:Lexington Books)rhetorical framing analysis.The findings reveal that the meme producers employed contextual variables such as labels,metaphors,visuals,salience and keywords to frame Peter Obi,the Obidient movement and the LP as a valid alternative in the presidential election.The study also shows the deployment of semiotic concepts such as salience,social distance,attitude and framing to positively represent the Obidient movement and Obi.The study concludes that the text producers deploy memes to portray the Obidients and the Labour Party presidential candidate as victims of an incredible electoral process,and that the memes are created to reveal broader socio-cultural realities,especially the predominance of religious and ethnic politics in the Nigerian context.展开更多
In this paper, I consider two species feeding on limiting substrate in a chemostat taking into account some possible effects of each species on the other one. System of differential equations is proposed as model of t...In this paper, I consider two species feeding on limiting substrate in a chemostat taking into account some possible effects of each species on the other one. System of differential equations is proposed as model of these effects with general inter-specific density-dependent growth rates. Three cases were considered. The first one for a mutual inhibitory relationship where it is proved that at most one species can survive which confirms the competitive exclusion principle. Initial concentrations of species have great importance in determination of which species is the winner. The second one for a food web relationship where it is proved that under general assumptions on the dilution rate, both species persist for any initial conditions. Finally, a third case dealing with an obligate mutualistic relationship was discussed. It is proved that initial condition has a great importance in determination of persistence or extinction of both species.展开更多
This paper explores the communicative acts deployed in covid-19 vaccination-related pictorials circulated on digital media platforms.Seven internet images were purposively sampled with a view to exploring their commun...This paper explores the communicative acts deployed in covid-19 vaccination-related pictorials circulated on digital media platforms.Seven internet images were purposively sampled with a view to exploring their communicative functions as well as their generic structure.The data,which were culled from the websites of the World Health Organisation,Centre for Disease Control,Pan American Health Organisation and Facebook,were subjected to qualitative analysis.The study deployed van Leeuwen’s Multimodal Discourse Analysis and Yuen’s Generic Structure Potential as theoretical anchor.The multimodal communicative acts are deployed for instructive,illustrative,informative,persuasive,inviting and advisory purposes.Categories such as Lead,Emblem,Announcement and Enhancer are compulsory in the data while Display,Tag and Call-and-Visit Information are non-compulsory elements.This can be catalogued as:‘Lead^(Display)^Emblem^(Announcement)^(Enhancer)^(Tag)^(Call-and-Visit Information)’.The study contends that the various semiotic resources deployed in the internet-circulated covid-19 images are used not only for informative and other communicative purposes but also to evoke attitudinal change towards and encourage widespread acceptance of the covid-19 vaccines.展开更多
文摘This study compares the Adomian Decomposition Method (ADM) and the Variational Iteration Method (VIM) for solving nonlinear differential equations in engineering. Differential equations are essential for modeling dynamic systems in various disciplines, including biological processes, heat transfer, and control systems. This study addresses first, second, and third-order nonlinear differential equations using Mathematica for data generation and graphing. The ADM, developed by George Adomian, uses Adomian polynomials to handle nonlinear terms, which can be computationally intensive. In contrast, VIM, developed by He, directly iterates the correction functional, providing a more straightforward and efficient approach. This study highlights VIM’s rapid convergence and effectiveness of VIM, particularly for nonlinear problems, where it simplifies calculations and offers direct solutions without polynomial derivation. The results demonstrate VIM’s superior efficiency and rapid convergence of VIM compared with ADM. The VIM’s minimal computational requirements make it practical for real-time applications and complex system modeling. Our findings align with those of previous research, confirming VIM’s efficiency of VIM in various engineering applications. This study emphasizes the importance of selecting appropriate methods based on specific problem requirements. While ADM is valuable for certain nonlinearities, VIM’s approach is ideal for many engineering scenarios. Future research should explore broader applications and hybrid methods to enhance the solution’s accuracy and efficiency. This comprehensive comparison provides valuable guidance for selecting effective numerical methods for differential equations in engineering.
文摘Copper-zinc-nickel(Cu-Zn-Ni)ferrite nanoparticles are used for wastewater treatment technology.However,low degradation efficiency and stability are two main issues that make them unsuitable for actual production needs.In this paper,the citrate-nitrate auto-combustion method was applied for the formation of Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(x)Fe_(2-x)O_(4);(0≤x≤0.1;step 0.02)(CZNL)nanoferrites.Although the substitution process entails the replacement of a small ion with a larger one,the lattice constant and crystallite size does not exhibit a consistent incremental pattern.This behavior is justified and discussed.The size of all the CZNL ferrite nanoparticles is in the range of 8-12 nm,and the lattice constant is in the range of 8.6230 to 8.4865 nm.The morphological analysis conducted using field emission-scanning electron microscopy(FE-SEM)reveals that the CZNL exhibits agglomerated spherical morphology.The energy dispersive X-ray spectrameter(EDAX)analysis was employed to confirm the elemental composition of CZNL nanoferrites.Since the process entails the substitution of Fe^(3+)magnetic ions with nonmagnetic ions La^(3+),the magnetic parameters of CZNL nanoferrites show a general decreasing trend as predicted.At 20 K,saturation magnetization Ms shows an overall drop in its values from 59.302 emu/g at x=0.0-41.295 emu/g at x=0.1,the smallest value of 37.87 emu/g is recorded at x=0.06.the highest coercivity(H_(c)=125.9 Oe)and remanence(M_(r)=13.32 emu/g)are recorded for x=0.08 and x=0.04 nanoferrite,respectvely.The band gap of all the CZNL nanoferrites was determined using the Kubelka-Munk function and Tauc plot for direct permitted transitions.La doping modifies the band gap(within 1.86-1.75 eV),increases light absorption,induces efficient e/h separation and charge migration to Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(x)Fe_(2-x)O_(4)surfaces.The nanoferrite Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(0.06)Fe_(1.94)O_(4)achieves a degradation efficiency of 97.3%for methylene blue(MB)dye removal after just 60 min.After five recycling processes,the nanocatalyst Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(0.06)Fe_(1.94)O_(4)is degraded by 95.83%,resulting in a negligible1.51%decrease in photocatalytic activity efficiency.The new Cu_(0.5)Zn_(0.25)Ni_(0.25)La_(0.06)Fe_(1.94)O_(4)has exceptional photocatalytic activity and remarkable stability,making it a promising candidate for applications in wastewater treatment.
文摘This work studied the magnetic,dielectric,and mechanical parameters of lanthanum doped cobalt-magnesium ferrite nanoparticles Co_(0.5)Mg_(0.5)La_(x)Fe_(2-x)O4(CMLF)prepared by citrate combustion route.Fourier transform infrared spectroscopy(FTIR)spectra show lower band(v_(2))at 391-386 cm^(-1) and upper band(v_(1))at 572-570 cm^(-1),which demonstrate the cubic spinel structure formation for all CMLF nanoferrites.Magnetic parameters such as saturation magnetization,remanent magnetization,coer-civity,magnetic moment,anisotropy constant,and initial permittivity were investigated using a vibrating sample magnetometer(VSM).The sample Co_(0.5)Mg_(0.5)La_(0.03)Fe_(1.97)O4 has the optimal saturation magnetization of 47.78 emu/g,whereas the sample Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.85)O4 has a maximum coercivity of 1031 Oe.The dielectric constant,dielectric loss tangent,ac conductivity and impedance(Z)were also investigated with the addition of La ions.With La doping,the dielectric loss value decreases with 52%compared to the pristine sample,indicating it to be a potential candidate for high frequency appli-cations.The ac conductivity graphs exhibit adherence to Jonscher's single power law,indicating that the conduction process is primarily driven by the small polaron tunneling mechanism.Analytical investigation was conducted on the impedance spectroscopy and electric modulus for the CMLF nanoferrites.The nanoferrite Co_(0.5)Mg_(0.5)La_(0.15)Fe_(1.9)O_(4)has the optimum longitudinal modulus(4.60 GPa),shear modulus(0.85 GPa),Young's modulus(2.37 GPa),and bulk modulus(3.46 GPa)compared tothepristine sample.
文摘Upgrading mechanical-dielectric features of ferrites through rare-earth yttrium(Y^(3+))doping provides feasibility to evolving high-frequency electronic devices.This paper reports the mechanical and dielectric properties of Co_(0.5)Cu_(0.25)Zn_(0.25)Y_(x)Fe_(2-x)O_(4)ferrite nanoparticles labeled as CCZYF#0,CCZYF#1,CCZYF#2,CCZYF#3,CCZYF#4 and CCZYF#5 for x=0.0.0.02,0.04,0.06,0.08,and 0.1,respectively.The frequency and temperature dependence of dielectric parameters and co nductivity of all CCZYF nanoferrites are well discussed.The nanoferrite CCZYF#5 has the highest dielectric constant(enhancing ratio 170%)and the highest conductivity(enhancing ratio 7125.81%)compared with the undoped sample.Nyquist plots of all CCZYF nano ferrites manifest two arcs;the main reasons for the dielectric process are the grain boundaries and bulk grains.All impedance parameters were determined,which showed the effective role of Y^(3+)ions on their values.The nanoferrite CCZYF#5 has the highest grain boundaries capacitance(with enhancing ratio of 59.40%)and the highest grains capacitance(with enhancing ratio of 22.53%)with a relaxation time decrement efficiency of 62.51%.An ultrasonic flaw detector was utilized to determine the elastic moduli of all CCZYF nanoferrites.The nanoferrite CCZYF#5 has the highest longitudinal modulus(with enhancing ratio of 20.95%),the highest shear modulus(with enhancing ratio of48.72%),highest Young's modulus(with enhancing ratio of 88.47%),the highest bulk modulus(with enhancing ratio 13.27%)and the highest micro hardness(with enhancing ratio 77.77%).Hence,Y3+tuned Co-Cu-Zn nanoferrites possess new opportunities for high-frequency and storage applications.
文摘This paper evaluates the skills of physical Parameterization schemes in simulating extreme rainfall events over Dar es Salaam Region, Tanzania using the Weather Research and Forecasting (WRF) model. The model skill is determined during the 21 December 2011 flooding event. Ten sensitivity experiments have been conducted using Cumulus, Convective and Planetary boundary layer schemes to find the best combination and optimize the WRF model for the study area for heavy rainfall events. Model simulation results were verified against observed data using standard statistical tests. The model simulations show encouraging and better statistical results with the combination of Kain-Fritsch cumulus parameterization scheme, Lin microphysics scheme and Asymmetric Convection Model 2 (ACM2) planetary boundary scheme than any other combinations of physical parameterization schemes over Dar es Salaam region.
文摘Recent advances in technology provide countless innovative solutions and applications for supporting children with autism in educational learning and personal development. This result is an increasingly recognized need to deal with new and unexpected risks and issues such as social exclusion. Diverse advanced technologies were aimed to support learning activity from different perspectives with multiple strategies. However, despite the significant amount of work and explored technology, several common risks pop up due to user’s vulnerability to diverse risks such as negative screen effects. Accordingly, there is still plenty of room for improvement in this regard. To address these vulnerabilities and gaps, this paper aims at identifying issues and challenges improving the technology applied for Autism Spectrum Disorders and autistics dedicated applications. It put forward requirements and design decisions supporting safe autistic dedicated interaction with regards to ISO31000 risk management process.
文摘Climate change is impacting on climate dependent activities such as Avocado farming in Tanzania. The extent of the impact of climate change in agriculture depends on the level of vulnerability or exposure of farmers to these impacts. This study addresses gender vulnerabilities to Avocado smallholder farmers to climate change in the Southern Highlands regions of Tanzania where the temperature and rainfall stresses are relevant using the Livelihood Vulnerability Index (LVI) and tested for significant difference in their vulnerability levels by applying independent two sample student’s t-test based on gender by using a sample of 104 Avocado smallholder farming. The results in this study revealed that both male and female avocado farmers were vulnerable to the effects of climate change and variability, but the vulnerabilities varied with gender. Female small holder farmers were more vulnerable to socio-demographic profile, livelihood strategies, social network, water and food major components of the LVI, whereas were more vulnerable to social network and health. The vulnerability indices revealed that female small holder farmers were more sensitive to the impact of climate change and variability. It was also found that female small holder farmers have the least adaptive capacities. In all, female small holder farmers are more vulnerable to climate change and variability than male. There is a need for better gender-sensitive approaches to adaptation planning and implementation to ensure that both men and women have equal opportunities to benefit from adaptation options in agriculture.
基金support provided by the National key research and development program of China-Key technologies and system for intelligent control of water supply network(2022YFC3203800)the Science and Technology Plan Project of Beijing City(Z231100006623001)+2 种基金the National Natural Science Foundation of China(52270083)the Fundamental Research Funds for the Central Universities(531119200298)the Special Research Fund of Natural Science(Special Post)of Guizhou University[grant number:(2023)43].
文摘The generation of hydrogen peroxide(H_(2)O_(2)),a compound with diverse applications,via the two-electron(2e^(-))oxygen reduction reaction(ORR)has garnered extensive attention in both laboratory research and industrial settings.The integration of non-noble metals such as Co,Fe,Ni,Zn,Mn,Mo,or Bi into nitrogen-doped carbon(M-N-C)matrices with defined structures and active metal center sites has emerged as a promising approach for fabricating electrocatalysts for the ORR.This review uncovers the latest advancements in the development of noble metal-free single-atom electrocatalysts(M-N-C SAECs)and electrochemical reactors aimed at enhancing and stabilizing H_(2)O_(2)production from the 2e^(-)ORR.Firstly,the review explores the basics of the ORR for H_(2)O_(2)production and the impact of electrochemical conditions.Subsequently,the synthesis strategies and characterization methods of various M-N-C SAECs are examined in depth.In addition,the structural attributes of both conventional and altered M-N-C SAECs are meticulously investigated,and the importance of engineering and optimizing reactors to elevate H_(2)O_(2)yields is highlighted.This review identifies the challenges and technological hurdles in bridging the gap between laboratory-scale research and practical,real-world applications.
文摘This study undertakes a multimodal framing analysis of the Obidient movement in Nigeria,with a view to exposing how Internet memes are deployed to advertise Peter Obi,the presidential candidate of the Labour Party(LP)in Nigeria's 2023 election.Forty memes were purposively sampled from Nigerian WhatsApp platforms and data were analysed qualitatively using aspects of Kress and van Leeuwen(2006.Reading images:The grammar of visual design,2nd edn.London:Routledge)grammar of visual design and Kuypers(2002.Press bias and politics:How the media frame controversial issues.Westport,CT:Praeger,2009.Framing analysis.In Kuypers Jim(ed.),Rhetorical criticism:Perspectives in action,181-204.London:Lexington Books)rhetorical framing analysis.The findings reveal that the meme producers employed contextual variables such as labels,metaphors,visuals,salience and keywords to frame Peter Obi,the Obidient movement and the LP as a valid alternative in the presidential election.The study also shows the deployment of semiotic concepts such as salience,social distance,attitude and framing to positively represent the Obidient movement and Obi.The study concludes that the text producers deploy memes to portray the Obidients and the Labour Party presidential candidate as victims of an incredible electoral process,and that the memes are created to reveal broader socio-cultural realities,especially the predominance of religious and ethnic politics in the Nigerian context.
文摘In this paper, I consider two species feeding on limiting substrate in a chemostat taking into account some possible effects of each species on the other one. System of differential equations is proposed as model of these effects with general inter-specific density-dependent growth rates. Three cases were considered. The first one for a mutual inhibitory relationship where it is proved that at most one species can survive which confirms the competitive exclusion principle. Initial concentrations of species have great importance in determination of which species is the winner. The second one for a food web relationship where it is proved that under general assumptions on the dilution rate, both species persist for any initial conditions. Finally, a third case dealing with an obligate mutualistic relationship was discussed. It is proved that initial condition has a great importance in determination of persistence or extinction of both species.
文摘This paper explores the communicative acts deployed in covid-19 vaccination-related pictorials circulated on digital media platforms.Seven internet images were purposively sampled with a view to exploring their communicative functions as well as their generic structure.The data,which were culled from the websites of the World Health Organisation,Centre for Disease Control,Pan American Health Organisation and Facebook,were subjected to qualitative analysis.The study deployed van Leeuwen’s Multimodal Discourse Analysis and Yuen’s Generic Structure Potential as theoretical anchor.The multimodal communicative acts are deployed for instructive,illustrative,informative,persuasive,inviting and advisory purposes.Categories such as Lead,Emblem,Announcement and Enhancer are compulsory in the data while Display,Tag and Call-and-Visit Information are non-compulsory elements.This can be catalogued as:‘Lead^(Display)^Emblem^(Announcement)^(Enhancer)^(Tag)^(Call-and-Visit Information)’.The study contends that the various semiotic resources deployed in the internet-circulated covid-19 images are used not only for informative and other communicative purposes but also to evoke attitudinal change towards and encourage widespread acceptance of the covid-19 vaccines.
