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
Direct electrolysis of seawater to produce green hydrogen is a more environmentally friendly process than freshwater electrolysis.The renewable energy sector exhibits tremendous interest in practical seawater electrol...Direct electrolysis of seawater to produce green hydrogen is a more environmentally friendly process than freshwater electrolysis.The renewable energy sector exhibits tremendous interest in practical seawater electrolysis techniques due to its substantial capacity to mitigate the need for freshwater consumption.With the low catalytic efficiency of the current seawater splitting process and the poor reliability of its operation,the process suffers from severe corrosion caused by chloride ions,as well as anodic competition between oxygen evolution and chlorine oxidation reactions.This review provides an overview of the latest electrocatalyst developments for promoting selectivity and stability in seawater electrolysis.Using the characterization and simulation results,as well as active machine learning,advanced electrocatalytic materials can be designed and developed,a research direction that will become increasingly important in the future.A variety of strategies are discussed in detail for designing advanced electrocatalysts in seawater electrolysis,including the surface protective layer,structural regulation by heteroatom doping and vacancies,porous structure,core-shell construction,and 3D hetero-structure construction to hinder chlorine evolution reactions.Finally,future perspectives and challenges for green hydrogen production from seawater electrolysis are also described.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
The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable...The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable sources,storage,and transport.The challenges,advantages,and uses of H_(2) energy are included at length.Moreover,apart from the sustainable production approaches,the approaches and current developments for combating the carbon dioxide(CO_(2))emissions from existing H_(2) production facilities are highlighted in terms of ca rbon capture,utilization,and storage(CCUS).Concisely,the review discusses current material and recent technological adva ncements in developing pilot projects and large-scale establishments for viable and rapidly emerging sou rce-ba sed H_(2) productio n.Moreover,the review also aims to provide an in-depthdiscussion and explore current developments based on the advantages of H_(2) energy in terms of its utilization,based on its high energy density,and its ability to be used as a feedstock and fuel.On the other hand,the challenges of H_(2) are also elabo rated.Next,the role of CCUS in a carbon-neutral economy and value chain for minimization of emissions from existing facilities is thoroughly deliberated,and the recent commercial-scale implementation of CCUS technologies is highlighted.Extending the utilization and recycling of captured CO_(2) emissions along with H_(2) to produce e-fuels in terms of current advances is detailed in this review.Fu rthermore,the most applicable,efficient,a nd develo ping approaches are discussed for physical and chemical H_(2) storage,considering recent la rge-scale implementations of liquid carriers and liquid organic hydrogen carriers as storage options.Lastly,the review elaborates on recent insights into advances in H_(2) transport infrastructure,including compressed and liquid H_(2) delivery via roads,ships,pipelines,and flight cargo.The review gives precise insights into the recent scenario through an elaborated conclusion of each discussion topic separately and a discussion of future perspectives.The current review will help researchers to fully understand the ongoing research advancements and challenges in the H_(2) value chain for formulating new solutions for sustainable H_(2) production,alo ng with focusing on suitable approaches for its storage and tra nsport to make the production and utilization of H_(2) applicable on a large scale.展开更多
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
We described ferromagnetic film and bilayer films composed of two ferromagnetic layers coupled through antiferromagnetic interfacial interaction by classical Heisenberg model and simulated their magnetization state,ma...We described ferromagnetic film and bilayer films composed of two ferromagnetic layers coupled through antiferromagnetic interfacial interaction by classical Heisenberg model and simulated their magnetization state,magnetic permeability,and Faraday effect at zero and finite temperature by using the Landau–Lifshitz–Gilbert(LLG)equation.The results indicate that in a microwave field with positive circular polarization,the ferromagnetic film has one resonance peak while the bilayer film has two resonance peaks.However,the resonance peak disappears in ferromagnetic film,and only one resonance peak emerges in bilayer film in the negative circularly polarized microwave field.When the microwave field’s frequency exceeds the film’s resonance frequency,the Faraday rotation angle of the ferromagnetic film is the greatest,and it decreases when the thickness of the two halves of the bilayer is reduced.When the microwave field’s frequency remains constant,the Faraday rotation angle fluctuates with temperature in the same manner as spontaneous magnetization does.When a DC magnetic field is applied in the direction of the anisotropic axis of the film,the Faraday rotation angle varies with the DC magnetic field and shows a similar shape of the hysteresis loop.展开更多
Background There is insufficient evidence to provide recommendations for leisure-time physical activity among workers across various occupational physical activity levels.This study aimed to assess the association of ...Background There is insufficient evidence to provide recommendations for leisure-time physical activity among workers across various occupational physical activity levels.This study aimed to assess the association of leisure-time physical activity with cardiovascular and all-cause mortality across occupational physical activity levels.Methods This study utilized individual participant data from 21 cohort studies,comprising both published and unpublished data.Eligibility criteria included individual-level data on leisure-time and occupational physical activity(categorized as sedentary,low,moderate,and high)along with data on all-cause and/or cardiovascular mortality.A 2-stage individual participant data meta-analysis was conducted,with separate analysis of each study using Cox proportional hazards models(Stage 1).These results were combined using random-effects models(Stage 2).Results Higher leisure-time physical activity levels were associated with lower all-cause and cardiovascular mortality risk across most occupational physical activity levels,for both males and females.Among males with sedentary work,high compared to sedentary leisure-time physical activity was associated with lower all-cause(hazard ratios(HR)=0.77,95%confidence interval(95%CI):0.70-0.85)and cardiovascular mortality(HR=0.76,95%CI:0.66-0.87)risk.Among males with high levels of occupational physical activity,high compared to sedentary leisure-time physical activity was associated with lower all-cause(HR=0.84,95%CI:0.74-0.97)and cardiovascular mortality(HR=0.79,95%CI:0.60-1.04)risk,while HRs for low and moderate levels of leisure-time physical activity ranged between 0.87 and 0.97 and were not statistically significant.Among females,most effects were similar but more imprecise,especially in the higher occupational physical activity levels.Conclusion Higher levels of leisure-time physical activity were generally associated with lower mortality risks.However,results for workers with moderate and high occupational physical activity levels,especially women,were more imprecise.Our findings suggests that workers may benefit from engaging in high levels of leisure-time physical activity,irrespective of their level of occupational physical activity.展开更多
This research investigates the hydrothermal synthesis and annealing duration effects on nickel sulfide(NiS_(2) quantum dots(QDs)for catalytic decolorization of methylene blue(MB)dye and antimicrobial efficacy.QD size ...This research investigates the hydrothermal synthesis and annealing duration effects on nickel sulfide(NiS_(2) quantum dots(QDs)for catalytic decolorization of methylene blue(MB)dye and antimicrobial efficacy.QD size increased with longer annealing,reducing catalytic activity.UV–vis,XRD,TEM,and FTIR analyses probed optical structural,morphological,and vibrational features.XRD confirmed NiS2's anorthic structure,with crystallite size growing from 6.53 to 7.81 nm during extended annealing.UV–Vis exhibited a bathochromic shift,reflecting reduced band gap energy(Eg)in NiS_(2).TEM revealed NiS_(2)QD formation,with agglomerated QD average size increasing from 7.13 to 9.65 nm with prolonged annealing.Pure NiS_(2) showed significant MB decolorization(89.85%)in acidic conditions.Annealed NiS_(2) QDs demonstrated notable antibacterial activity,yielding a 6.15mm inhibition zone against Escherichia coli(E.coli)compared to Ciprofloxacin.First-principles computation supported a robust interaction between MB and NiS_(2),evidenced by obtained adsorption energies.This study highlights the nuanced relationship between annealing duration,structural changes,and functional properties in NiS_(2)QDs,emphasizing their potential applications in catalysis and antibacterial interventions.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 significance of the thermophysical properties of Tetra hybrid nanofluid in enhancing heat transmission in various applications like heat exchangers, automobiles, and solar storage cannot be overstated. These featu...The significance of the thermophysical properties of Tetra hybrid nanofluid in enhancing heat transmission in various applications like heat exchangers, automobiles, and solar storage cannot be overstated. These features can be tampered with when nanoparticles are been introduced into the base fluid to produce an improved heat carrier fluid for the system. This study investigates the impact of temperature-dependent properties on the movement of TiO2-SiO2-ZnO-Fe2O3/PAO Tetra hybrid nanofluid along a vertical porous surface with suction. The system of governing Partial Differential Equations (PDEs) was formulated and transformed into the system of coupled nonlinear third-order Ordinary Differential Equations (ODEs) by similarity techniques. The resulting ODEs were solved numerically using the shooting method and fourth order Runge-Kutta method with the aid of Maple 18.0 software. Using numerical and statistical methods, the study analyzes velocity, temperature profiles, skin friction coefficient, and Nusselt number. It was found that as the variable thermal conductivity parameter upsurges both the skin friction coefficient and Nusselt number intensify at the rate of 0.011697519 and 8.043581616 respectively. This study underscores the vital role of Tetra hybrid nanofluid’s thermophysical properties in improving heat transmission for diverse appli cations. By manipulating nanoparticles within the base fluid, the heat carrier fluid’s efficiency can be enhanced, critical for industries like automotive and enewable energy. These insights inform the design of more efficient heat exchange systems, advancing sustainability and performance in real-world scenarios.展开更多
This study examined the interconnectedness and volatility correlation between cryptocurrency and traditional financial markets in the five largest African countries,addressing concerns about potential spillover effect...This study examined the interconnectedness and volatility correlation between cryptocurrency and traditional financial markets in the five largest African countries,addressing concerns about potential spillover effects,especially the high volatility and lack of regulation in the cryptocurrency market.The study employed both diagonal BEKK-GARCH and DCC-GARCH to analyze the existence of spillover effects and correlation between both markets.A daily time series dataset from January 1,2017,to December 31,2021,was employed to analyze the contagion effect.Our findings reveal a significant spillover effect from cryptocurrency to the African traditional financial market;however,the percentage spillover effect is still low but growing.Specifically,evidence is insufficient to suggest a spillover effect from cryptocurrency to Egypt and Morocco’s financial markets,at least in the short run.Evidence in South Africa,Nigeria,and Kenya indicates a moderate but growing spillover effect from cryptocurrency to the financial market.Similarly,we found no evidence of a spillover effect from the African financial market to the cryptocurrency market.The conditional correlation result from the DCC-GARCH revealed a positive low to moderate correlation between cryptocurrency volatility and the African financial market.Specifically,the DCC-GARCH revealed a greater integration in both markets,especially in the long run.The findings have policy implications for financial regulators concerning the dynamics of both markets and for investors interested in portfolio diversification within the two markets.展开更多
U-Pb ages of detrital zircons were newly dated for 4 Archean sandstones from the Pilbara craton in Australia, Wyoming craton in North America, and Kaapvaal craton in Africa. By using the present results with previousl...U-Pb ages of detrital zircons were newly dated for 4 Archean sandstones from the Pilbara craton in Australia, Wyoming craton in North America, and Kaapvaal craton in Africa. By using the present results with previously published data, we compiled the age spectra of detrital zircons for 2.9, 2.6, 2.3,1.0, and0.6 Ga sandstones and modern river sands in order to document the secular change in age structure of continental crusts through time. The results demonstrated the following episodes in the history of continental crust：（1） low growth rate of the continents due to the short cycle in production/destruction of granitic crust during the Neoarchean to Paleoproterozoic（2.9-23 Ga）,（2） net increase in volume of the continents during Paleo-to Mesoproterozoic（2.3-1.0 Ga）, and（3） net decrease in volume of the continents during the Neoproterozoic and Phanerozoic（after 1.0 Ga）. In the Archean and Paleoproterozoic, the embryonic continents were smaller than the modern continents, probably owing to the relatively rapid production and destruction of continental crust. This is indeed reflected in the heterogeneous crustal age structure of modern continents that usually have relatively small amount of Archean crusts with respect to the post-Archean ones. During the Mesoproterozoic, plural continents amalgamated into larger ones comparable to modern continental blocks in size. Relatively older crusts were preserved in continental interiors, whereas younger crusts were accreted along continental peripheries.In addition to continental arc magmatism, the direct accretion of intra-oceanic island arc around continental peripheries also became important for net continental growth. Since 1.0 Ga, total volume of continents has decreased, and this appears consistent with on-going phenomena along modern active arc-trench system with dominant tectonic erosion and/or arc subduction. Subduction of a huge amount of granitic crusts into the mantle through time is suggested, and this requires re-consideration of the mantle composition and heterogeneity.展开更多
Formulation in terms of hypersingular integral equations for the interaction between straight and curved cracks in plane elasticity is obtained using the complex variable functions method. The curved length coordinate...Formulation in terms of hypersingular integral equations for the interaction between straight and curved cracks in plane elasticity is obtained using the complex variable functions method. The curved length coordinate method and a suitable numerical scheme are used to solve such integrals numerically for the unknown function, which are later used to find the stress intensity factor, SIF.展开更多
In this paper, silver nanoparticles （AgNPs） and AgNPs/reduced graphene oxide （RGO） nanocomposites were prepared using lemon juice under microwave irradiation （MWI） and UV light irradiation. AgNPs with face-cente...In this paper, silver nanoparticles （AgNPs） and AgNPs/reduced graphene oxide （RGO） nanocomposites were prepared using lemon juice under microwave irradiation （MWI） and UV light irradiation. AgNPs with face-centered cubic structure RGO peaks were observed by X-ray diffraction. The UV-Vis spectrum showed modifications in the absorption peaks of the AgNPs with the concentration of the precursor solution and irradiation time, and the optimized condition was obtained for 20 min MWI and 60 s of UV light. Raman analysis confirmed the presence of RGO as D and G bands in the spectrum. Transmission electron microscopy analyses confirmed that the AgNPs of size ranging from 3 to 8 nm were anchored onto the RGO sheets. The antibacterial properties of the AgNPs/RGO nanocomposites were investigated using gram-negative bacteria. The results revealed that AgNPs/RGO nanocomposites consisting of approximately 5 wt% AgNPs can achieve antibacterial performance similar to that of neat AgNPS. This method can be useful for the applications of AgNPs-based nanocomposites, where minute amount of silver will be utilized.展开更多
Persuasive technology is the use of computers,devices or applications to change a person's attitudes or behavior.Persuasibility design within the system life-cycle is a nascent area of research which is different ...Persuasive technology is the use of computers,devices or applications to change a person's attitudes or behavior.Persuasibility design within the system life-cycle is a nascent area of research which is different from design in the traditional method.This paper focuses on the research of persuasibility design and its assessment in the system life-cycle.A life-cycle oriented systemic general theory is developed in this paper to evaluate persuasibility design.Persuasibility assessment is considered as a part of persuasibility design.Its procedure and method are explored and analyzed based on the system life-cycle in this paper.A possible research direction is to create more explicit and detailed persuasion design and assessment methods which can be used not only in personal computer persuasive application,but also many other electric devices that are designed for persuasion purposes.展开更多
The study examines the impact of variability in rainfall characteristics on maize yield in a tropical setting. The study design involves the collection and analyses of data on rainfall characteristics and maize yield ...The study examines the impact of variability in rainfall characteristics on maize yield in a tropical setting. The study design involves the collection and analyses of data on rainfall characteristics and maize yield at Gboko LGA in Benue State, Nigeria. The methodology adopted is the use of archival data on rainfall and maize yield for 30 years, collected from the Agro-Meteorological Unit and Farm Department of Akperan Orshi College of Agriculture, Yandev (AOCAY). The data was analyzed using mean, correlation and regression analysis to establish cause and effect relationship between rainfall characteristics and maize yield at the study area. The result of the correlation analysis showed that rain days and rainfall amount had strong positive relationship (r = 0.747 and r = 0.599, respectively) with maize yield. It was also observed that the rainfall characteristics jointly contributed 67.4% in explaining the variations in the yield of maize per hectare. The study concludes with the development of a model for predicting maize yield in Gboko LGA. The study also recommended the application of irrigation technology, use of appropriate management practices that ensured moisture conservation and improved crop species with shorter growing periods/less moisture consumption as adaptive measures to the changing rainfall pattern within the study area.展开更多
This paper reports on the assessment of the quality and quantity of castor oil from castor seeds collected from different regions in Tanzania. The castor seeds from Arusha, Dar es Salaam, Dodoma, Iringa, Kagera and Mo...This paper reports on the assessment of the quality and quantity of castor oil from castor seeds collected from different regions in Tanzania. The castor seeds from Arusha, Dar es Salaam, Dodoma, Iringa, Kagera and Morogoro regions in Tanzania were extracted by Soxhlet method using n-hexane and the oil yields were determined. The yields were 52.78%, 49.95%, 47.89%, 44.23%, 43.71% and 43.69% for Dodoma, Arusha, Iringa, Morogoro, Kagera and Dar es Salaam respectively. The physico-chemical parameters that were determined were refractive index (1.468 - 1.473), pH 5.7- 6.3, viscosity (0.943 - 0.954), specific gravity (165.50 - 187.46 mg KOH/g Oil), saponification value (76.68 - 80 mg KOH/g Oil), iodine value (76.68 - 80.12 g I2/100 g Oil), acid value (0.44 - 1.97 mg NaOH/g Oil), free fatty acid (0.22 - 0.99) and peroxide value (10.79 - 13.73). Fatty acid profile of castor oil was analysed using Shimadzu GCMS and ricinoleic acid ranged from 83.5% to 92.3% of the total fatty acids in the castor oils.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 investigative study is focused on the impact of wavelet on traditional forecasting time-series models,which significantly shows the usage of wavelet algorithms.Wavelet Decomposition(WD)algorithm has been combined...This investigative study is focused on the impact of wavelet on traditional forecasting time-series models,which significantly shows the usage of wavelet algorithms.Wavelet Decomposition(WD)algorithm has been combined with various traditional forecasting time-series models,such as Least Square Support Vector Machine(LSSVM),Artificial Neural Network(ANN)and Multivariate Adaptive Regression Splines(MARS)and their effects are examined in terms of the statistical estimations.The WD has been used as a mathematical application in traditional forecast modelling to collect periodically measured parameters,which has yielded tremendous constructive outcomes.Further,it is observed that the wavelet combined models are classy compared to the various time series models in terms of performance basis.Therefore,combining wavelet forecasting models has yielded much better results.展开更多
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.
基金part of a research project, PIF 726175Alfaisal University and its Office of Research & Innovation for their continuous support throughout this study。
文摘Direct electrolysis of seawater to produce green hydrogen is a more environmentally friendly process than freshwater electrolysis.The renewable energy sector exhibits tremendous interest in practical seawater electrolysis techniques due to its substantial capacity to mitigate the need for freshwater consumption.With the low catalytic efficiency of the current seawater splitting process and the poor reliability of its operation,the process suffers from severe corrosion caused by chloride ions,as well as anodic competition between oxygen evolution and chlorine oxidation reactions.This review provides an overview of the latest electrocatalyst developments for promoting selectivity and stability in seawater electrolysis.Using the characterization and simulation results,as well as active machine learning,advanced electrocatalytic materials can be designed and developed,a research direction that will become increasingly important in the future.A variety of strategies are discussed in detail for designing advanced electrocatalysts in seawater electrolysis,including the surface protective layer,structural regulation by heteroatom doping and vacancies,porous structure,core-shell construction,and 3D hetero-structure construction to hinder chlorine evolution reactions.Finally,future perspectives and challenges for green hydrogen production from seawater electrolysis are also described.
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.
基金part of a research project PIF Alfa HI initiative 726174Alfaisal University and its Office of Research&Innovation for their continuous support throughout this study。
文摘The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable sources,storage,and transport.The challenges,advantages,and uses of H_(2) energy are included at length.Moreover,apart from the sustainable production approaches,the approaches and current developments for combating the carbon dioxide(CO_(2))emissions from existing H_(2) production facilities are highlighted in terms of ca rbon capture,utilization,and storage(CCUS).Concisely,the review discusses current material and recent technological adva ncements in developing pilot projects and large-scale establishments for viable and rapidly emerging sou rce-ba sed H_(2) productio n.Moreover,the review also aims to provide an in-depthdiscussion and explore current developments based on the advantages of H_(2) energy in terms of its utilization,based on its high energy density,and its ability to be used as a feedstock and fuel.On the other hand,the challenges of H_(2) are also elabo rated.Next,the role of CCUS in a carbon-neutral economy and value chain for minimization of emissions from existing facilities is thoroughly deliberated,and the recent commercial-scale implementation of CCUS technologies is highlighted.Extending the utilization and recycling of captured CO_(2) emissions along with H_(2) to produce e-fuels in terms of current advances is detailed in this review.Fu rthermore,the most applicable,efficient,a nd develo ping approaches are discussed for physical and chemical H_(2) storage,considering recent la rge-scale implementations of liquid carriers and liquid organic hydrogen carriers as storage options.Lastly,the review elaborates on recent insights into advances in H_(2) transport infrastructure,including compressed and liquid H_(2) delivery via roads,ships,pipelines,and flight cargo.The review gives precise insights into the recent scenario through an elaborated conclusion of each discussion topic separately and a discussion of future perspectives.The current review will help researchers to fully understand the ongoing research advancements and challenges in the H_(2) value chain for formulating new solutions for sustainable H_(2) production,alo ng with focusing on suitable approaches for its storage and tra nsport to make the production and utilization of H_(2) applicable on a large scale.
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.
基金the Research Program of Shenyang Institute of Science and Technology(Grant No.ZD-2024-05).
文摘We described ferromagnetic film and bilayer films composed of two ferromagnetic layers coupled through antiferromagnetic interfacial interaction by classical Heisenberg model and simulated their magnetization state,magnetic permeability,and Faraday effect at zero and finite temperature by using the Landau–Lifshitz–Gilbert(LLG)equation.The results indicate that in a microwave field with positive circular polarization,the ferromagnetic film has one resonance peak while the bilayer film has two resonance peaks.However,the resonance peak disappears in ferromagnetic film,and only one resonance peak emerges in bilayer film in the negative circularly polarized microwave field.When the microwave field’s frequency exceeds the film’s resonance frequency,the Faraday rotation angle of the ferromagnetic film is the greatest,and it decreases when the thickness of the two halves of the bilayer is reduced.When the microwave field’s frequency remains constant,the Faraday rotation angle fluctuates with temperature in the same manner as spontaneous magnetization does.When a DC magnetic field is applied in the direction of the anisotropic axis of the film,the Faraday rotation angle varies with the DC magnetic field and shows a similar shape of the hysteresis loop.
基金The Trùndelag Health Study (HUNT) is a collaboration between HUNT Research Centre (Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology), Trùndelag County Council, Central Norway Regional Health Authority, and the Norwegian Institute of Public HealthThe coordination of European Prospective Investigation into Cancer and Nutrition - Spain study (EPIC) is financially supported by the International Agency for Research on Cancer (IARC)+7 种基金by the Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, which has additional infrastructure support provided by the NIHR Imperial Biomedical Research Centre (BRC)supported by Health Research Fund (FIS) - Instituto de Salud Carlos III (ISCIII), Regional Governments of Andaluc 1a, Asturias, Basque Country, Murcia and Navarra, and the Catalan Institute of Oncology - ICO (Spain)funded by The Netherlands Organisation for Health Research and DevelopmentZon Mw (Grant No.: 531-00141-3)Funding for the SHIP study has been provided by the Federal Ministry for Education and Research (BMBFidentification codes 01 ZZ96030, 01 ZZ0103, and 01 ZZ0701)support from the Swedish Research Council (2018-02527 and 2019-00193)financed by the Helmholtz Zentrum München - German Research Center for Environmental Health, which is funded by the German Federal Ministry of Education and Research (BMBF) and by the State of Bavaria.
文摘Background There is insufficient evidence to provide recommendations for leisure-time physical activity among workers across various occupational physical activity levels.This study aimed to assess the association of leisure-time physical activity with cardiovascular and all-cause mortality across occupational physical activity levels.Methods This study utilized individual participant data from 21 cohort studies,comprising both published and unpublished data.Eligibility criteria included individual-level data on leisure-time and occupational physical activity(categorized as sedentary,low,moderate,and high)along with data on all-cause and/or cardiovascular mortality.A 2-stage individual participant data meta-analysis was conducted,with separate analysis of each study using Cox proportional hazards models(Stage 1).These results were combined using random-effects models(Stage 2).Results Higher leisure-time physical activity levels were associated with lower all-cause and cardiovascular mortality risk across most occupational physical activity levels,for both males and females.Among males with sedentary work,high compared to sedentary leisure-time physical activity was associated with lower all-cause(hazard ratios(HR)=0.77,95%confidence interval(95%CI):0.70-0.85)and cardiovascular mortality(HR=0.76,95%CI:0.66-0.87)risk.Among males with high levels of occupational physical activity,high compared to sedentary leisure-time physical activity was associated with lower all-cause(HR=0.84,95%CI:0.74-0.97)and cardiovascular mortality(HR=0.79,95%CI:0.60-1.04)risk,while HRs for low and moderate levels of leisure-time physical activity ranged between 0.87 and 0.97 and were not statistically significant.Among females,most effects were similar but more imprecise,especially in the higher occupational physical activity levels.Conclusion Higher levels of leisure-time physical activity were generally associated with lower mortality risks.However,results for workers with moderate and high occupational physical activity levels,especially women,were more imprecise.Our findings suggests that workers may benefit from engaging in high levels of leisure-time physical activity,irrespective of their level of occupational physical activity.
基金The authors thank the Deanship of Scientific Research at King Khalid University for funding this work through a large group Research Project under grant number(R.G.P.2/123/44).The author MBK would like to thank Prince Sultan University for their support.
文摘This research investigates the hydrothermal synthesis and annealing duration effects on nickel sulfide(NiS_(2) quantum dots(QDs)for catalytic decolorization of methylene blue(MB)dye and antimicrobial efficacy.QD size increased with longer annealing,reducing catalytic activity.UV–vis,XRD,TEM,and FTIR analyses probed optical structural,morphological,and vibrational features.XRD confirmed NiS2's anorthic structure,with crystallite size growing from 6.53 to 7.81 nm during extended annealing.UV–Vis exhibited a bathochromic shift,reflecting reduced band gap energy(Eg)in NiS_(2).TEM revealed NiS_(2)QD formation,with agglomerated QD average size increasing from 7.13 to 9.65 nm with prolonged annealing.Pure NiS_(2) showed significant MB decolorization(89.85%)in acidic conditions.Annealed NiS_(2) QDs demonstrated notable antibacterial activity,yielding a 6.15mm inhibition zone against Escherichia coli(E.coli)compared to Ciprofloxacin.First-principles computation supported a robust interaction between MB and NiS_(2),evidenced by obtained adsorption energies.This study highlights the nuanced relationship between annealing duration,structural changes,and functional properties in NiS_(2)QDs,emphasizing their potential applications in catalysis and antibacterial interventions.
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.
文摘The significance of the thermophysical properties of Tetra hybrid nanofluid in enhancing heat transmission in various applications like heat exchangers, automobiles, and solar storage cannot be overstated. These features can be tampered with when nanoparticles are been introduced into the base fluid to produce an improved heat carrier fluid for the system. This study investigates the impact of temperature-dependent properties on the movement of TiO2-SiO2-ZnO-Fe2O3/PAO Tetra hybrid nanofluid along a vertical porous surface with suction. The system of governing Partial Differential Equations (PDEs) was formulated and transformed into the system of coupled nonlinear third-order Ordinary Differential Equations (ODEs) by similarity techniques. The resulting ODEs were solved numerically using the shooting method and fourth order Runge-Kutta method with the aid of Maple 18.0 software. Using numerical and statistical methods, the study analyzes velocity, temperature profiles, skin friction coefficient, and Nusselt number. It was found that as the variable thermal conductivity parameter upsurges both the skin friction coefficient and Nusselt number intensify at the rate of 0.011697519 and 8.043581616 respectively. This study underscores the vital role of Tetra hybrid nanofluid’s thermophysical properties in improving heat transmission for diverse appli cations. By manipulating nanoparticles within the base fluid, the heat carrier fluid’s efficiency can be enhanced, critical for industries like automotive and enewable energy. These insights inform the design of more efficient heat exchange systems, advancing sustainability and performance in real-world scenarios.
文摘This study examined the interconnectedness and volatility correlation between cryptocurrency and traditional financial markets in the five largest African countries,addressing concerns about potential spillover effects,especially the high volatility and lack of regulation in the cryptocurrency market.The study employed both diagonal BEKK-GARCH and DCC-GARCH to analyze the existence of spillover effects and correlation between both markets.A daily time series dataset from January 1,2017,to December 31,2021,was employed to analyze the contagion effect.Our findings reveal a significant spillover effect from cryptocurrency to the African traditional financial market;however,the percentage spillover effect is still low but growing.Specifically,evidence is insufficient to suggest a spillover effect from cryptocurrency to Egypt and Morocco’s financial markets,at least in the short run.Evidence in South Africa,Nigeria,and Kenya indicates a moderate but growing spillover effect from cryptocurrency to the financial market.Similarly,we found no evidence of a spillover effect from the African financial market to the cryptocurrency market.The conditional correlation result from the DCC-GARCH revealed a positive low to moderate correlation between cryptocurrency volatility and the African financial market.Specifically,the DCC-GARCH revealed a greater integration in both markets,especially in the long run.The findings have policy implications for financial regulators concerning the dynamics of both markets and for investors interested in portfolio diversification within the two markets.
基金supported by Japan Society of Promotion of Science (JSPS KAKENHI Grants-in-Aid for Scientific Research Grant Nos. 23224012, 26106002, and 26106005) from the Japanese Ministry of Education, Science, Sports, Technology, and Culture
文摘U-Pb ages of detrital zircons were newly dated for 4 Archean sandstones from the Pilbara craton in Australia, Wyoming craton in North America, and Kaapvaal craton in Africa. By using the present results with previously published data, we compiled the age spectra of detrital zircons for 2.9, 2.6, 2.3,1.0, and0.6 Ga sandstones and modern river sands in order to document the secular change in age structure of continental crusts through time. The results demonstrated the following episodes in the history of continental crust：（1） low growth rate of the continents due to the short cycle in production/destruction of granitic crust during the Neoarchean to Paleoproterozoic（2.9-23 Ga）,（2） net increase in volume of the continents during Paleo-to Mesoproterozoic（2.3-1.0 Ga）, and（3） net decrease in volume of the continents during the Neoproterozoic and Phanerozoic（after 1.0 Ga）. In the Archean and Paleoproterozoic, the embryonic continents were smaller than the modern continents, probably owing to the relatively rapid production and destruction of continental crust. This is indeed reflected in the heterogeneous crustal age structure of modern continents that usually have relatively small amount of Archean crusts with respect to the post-Archean ones. During the Mesoproterozoic, plural continents amalgamated into larger ones comparable to modern continental blocks in size. Relatively older crusts were preserved in continental interiors, whereas younger crusts were accreted along continental peripheries.In addition to continental arc magmatism, the direct accretion of intra-oceanic island arc around continental peripheries also became important for net continental growth. Since 1.0 Ga, total volume of continents has decreased, and this appears consistent with on-going phenomena along modern active arc-trench system with dominant tectonic erosion and/or arc subduction. Subduction of a huge amount of granitic crusts into the mantle through time is suggested, and this requires re-consideration of the mantle composition and heterogeneity.
基金Ministry of Science,Technology and Innovation(MOSTI),Malaysia for the Science Fund,Vot No.5450657
文摘Formulation in terms of hypersingular integral equations for the interaction between straight and curved cracks in plane elasticity is obtained using the complex variable functions method. The curved length coordinate method and a suitable numerical scheme are used to solve such integrals numerically for the unknown function, which are later used to find the stress intensity factor, SIF.
基金supported by the Internal Research Grant,Alfaisal University(IRG 2014,No.4050101011410)
文摘In this paper, silver nanoparticles （AgNPs） and AgNPs/reduced graphene oxide （RGO） nanocomposites were prepared using lemon juice under microwave irradiation （MWI） and UV light irradiation. AgNPs with face-centered cubic structure RGO peaks were observed by X-ray diffraction. The UV-Vis spectrum showed modifications in the absorption peaks of the AgNPs with the concentration of the precursor solution and irradiation time, and the optimized condition was obtained for 20 min MWI and 60 s of UV light. Raman analysis confirmed the presence of RGO as D and G bands in the spectrum. Transmission electron microscopy analyses confirmed that the AgNPs of size ranging from 3 to 8 nm were anchored onto the RGO sheets. The antibacterial properties of the AgNPs/RGO nanocomposites were investigated using gram-negative bacteria. The results revealed that AgNPs/RGO nanocomposites consisting of approximately 5 wt% AgNPs can achieve antibacterial performance similar to that of neat AgNPS. This method can be useful for the applications of AgNPs-based nanocomposites, where minute amount of silver will be utilized.
文摘Persuasive technology is the use of computers,devices or applications to change a person's attitudes or behavior.Persuasibility design within the system life-cycle is a nascent area of research which is different from design in the traditional method.This paper focuses on the research of persuasibility design and its assessment in the system life-cycle.A life-cycle oriented systemic general theory is developed in this paper to evaluate persuasibility design.Persuasibility assessment is considered as a part of persuasibility design.Its procedure and method are explored and analyzed based on the system life-cycle in this paper.A possible research direction is to create more explicit and detailed persuasion design and assessment methods which can be used not only in personal computer persuasive application,but also many other electric devices that are designed for persuasion purposes.
文摘The study examines the impact of variability in rainfall characteristics on maize yield in a tropical setting. The study design involves the collection and analyses of data on rainfall characteristics and maize yield at Gboko LGA in Benue State, Nigeria. The methodology adopted is the use of archival data on rainfall and maize yield for 30 years, collected from the Agro-Meteorological Unit and Farm Department of Akperan Orshi College of Agriculture, Yandev (AOCAY). The data was analyzed using mean, correlation and regression analysis to establish cause and effect relationship between rainfall characteristics and maize yield at the study area. The result of the correlation analysis showed that rain days and rainfall amount had strong positive relationship (r = 0.747 and r = 0.599, respectively) with maize yield. It was also observed that the rainfall characteristics jointly contributed 67.4% in explaining the variations in the yield of maize per hectare. The study concludes with the development of a model for predicting maize yield in Gboko LGA. The study also recommended the application of irrigation technology, use of appropriate management practices that ensured moisture conservation and improved crop species with shorter growing periods/less moisture consumption as adaptive measures to the changing rainfall pattern within the study area.
文摘This paper reports on the assessment of the quality and quantity of castor oil from castor seeds collected from different regions in Tanzania. The castor seeds from Arusha, Dar es Salaam, Dodoma, Iringa, Kagera and Morogoro regions in Tanzania were extracted by Soxhlet method using n-hexane and the oil yields were determined. The yields were 52.78%, 49.95%, 47.89%, 44.23%, 43.71% and 43.69% for Dodoma, Arusha, Iringa, Morogoro, Kagera and Dar es Salaam respectively. The physico-chemical parameters that were determined were refractive index (1.468 - 1.473), pH 5.7- 6.3, viscosity (0.943 - 0.954), specific gravity (165.50 - 187.46 mg KOH/g Oil), saponification value (76.68 - 80 mg KOH/g Oil), iodine value (76.68 - 80.12 g I2/100 g Oil), acid value (0.44 - 1.97 mg NaOH/g Oil), free fatty acid (0.22 - 0.99) and peroxide value (10.79 - 13.73). Fatty acid profile of castor oil was analysed using Shimadzu GCMS and ricinoleic acid ranged from 83.5% to 92.3% of the total fatty acids in the castor oils.
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 investigative study is focused on the impact of wavelet on traditional forecasting time-series models,which significantly shows the usage of wavelet algorithms.Wavelet Decomposition(WD)algorithm has been combined with various traditional forecasting time-series models,such as Least Square Support Vector Machine(LSSVM),Artificial Neural Network(ANN)and Multivariate Adaptive Regression Splines(MARS)and their effects are examined in terms of the statistical estimations.The WD has been used as a mathematical application in traditional forecast modelling to collect periodically measured parameters,which has yielded tremendous constructive outcomes.Further,it is observed that the wavelet combined models are classy compared to the various time series models in terms of performance basis.Therefore,combining wavelet forecasting models has yielded much better results.
