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
Lithium-sulfur batteries have been developing in recent years and appear to offer an alternative to existing commercial batteries that can potentially replace them in the future.With their exceptional theoretical ener...Lithium-sulfur batteries have been developing in recent years and appear to offer an alternative to existing commercial batteries that can potentially replace them in the future.With their exceptional theoretical energy density,lower production costs,and affordable and environmentally friendly abundant raw materials,lithium-sulfur batteries have shown the ability to defeat counterparts in the race for rechargeable energy devices currently being developed.The lithium-sulfur batteries display extraordinary features,but they suffer from sulfur's non-conductivity,the shuttle effect that results from polysulfide dissolution,volumetric sulfur changes during charging,and dendrites at the anode,resulting in a decline in capacity and a short battery life.As a result of rigorous and innovative engineering designs,lithium-sulfur batteries have been developed to overcome their drawbacks and utilize their entire potential during the past decade.This review will pay particular attention to porous carbon-based matrix materials,especially graphene-based nanocomposites that are most commonly used in producing sulfur cathodes.We provide an in-depth perspective on the structural merits of graphene materials,the detailed mechanism by which they interact with sulfur,and essential strategies for designing high-performance cathodes for lithium-sulfur batteries.Finally,we discuss the significant challenges and prospects for developing lithium-sulfur batteries with high energy density and long cycle lives for the next-generation electric vehicles.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
In this study,Cu_(0.25)Ni_(0.5)Zn_(0.25)Fe_(2-x)Nd_(x)O_(4)(0.000≤x≤0.100,andΔx=0.025)spinel ferrites were synthesized using the auto-combustion method to investigate the influence of neodymium(Nd^(3+))substitution...In this study,Cu_(0.25)Ni_(0.5)Zn_(0.25)Fe_(2-x)Nd_(x)O_(4)(0.000≤x≤0.100,andΔx=0.025)spinel ferrites were synthesized using the auto-combustion method to investigate the influence of neodymium(Nd^(3+))substitution on their structural,optical,dielectric,and magnetic properties.X-ray diffraction result confirms the formation of a face-centered cubic spinel structure,with the average crystallite size decreasing from 39 to 15 nm as Nd^(3+)concentration increases.Fourier transform infrared spectroscopy reveals characteristic absorption bands,affirming the spinel structure.Dielectric measurements over a broad frequency range show a higher dielectric constant and lower dielectric loss,indicating potential suitability for energy-efficient electronic applications.Magnetic analysis using a vibrating sample magnetometer demonstrates soft magnetic behavior,with saturation magnetization decreasing from82.69 to 66.80 emu/g and a tunable ratio(0.0221-0.0068)of remnant magnetization to saturation magnetization depending on Nd^(3+)content.In situ ultrasonic studies provides phase transition temperature(Curie temperature,T_(c))values ranging from 516 to 489 K,highlighting thermal stability and magnetic phase transition behavior.Furthermore,reflection loss measurements in the X-band frequency range(8-12 GHz)confirm the excellent electromagnetic interference shielding and radar absorption capabilities of Cu_(0.25)Ni_(0.5)Zn_(0.25)Fe_(2-x)Nd_(x)O_(4)spinel ferrites.These findings underscore the potential of Nd^(3+)-doped Cu-Ni-Zn spinel ferrites for advanced technological applications,including electronic devices,thermal sensors,and electromagnetic wave absorbers.展开更多
Spinels are an emerging class of advanced technological materials for spintronic,energy harvesting,and water-splitting applications.In this work,we explored the electronic,magnetic,optical,and transport properties of ...Spinels are an emerging class of advanced technological materials for spintronic,energy harvesting,and water-splitting applications.In this work,we explored the electronic,magnetic,optical,and transport properties of CaCe_(2)(S/Se)_(4)by density functional theory based on the Wien2k code.The energy released during optimization in ferromagnetic and antiferromagnetic states confirms that the ferromagnetic state is stable,which is further verified by negative formation energy.Heisenberg model and density of states report the Curie temperature and spin polarization.Half metallic ferromagnetism(HMF)regarding hybridization,crystal fields,exchange ene rgies,and double exchange mechanisms is discussed.The transfer of magnetic moments from Ce to Ca and S/Se and interstitial sites ensure the role of spin of electrons rather than clustering.Mo reover,the optical prope rties are addressed by dielectric constants,absorption,refraction,and optical loss.The first absorption peaks exist in infrared zone;others fall in visible to ultraviolet zones.The spin-up(↑)and spin-down(↓)channel thermoelectric factors combine and report the performance by conductivities,Seebeck coefficient,and power factor.Therefore,the studied materials'optical and thermoelectric behaviours will allow researchers to realize them for technological applications.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
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
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
Grain boundary activity in nanocrystalline Al under an indenter is studied by using a multiscale method. It is found that grain boundaries and twin boundaries can be transformed into each other by emitting and absorbi...Grain boundary activity in nanocrystalline Al under an indenter is studied by using a multiscale method. It is found that grain boundaries and twin boundaries can be transformed into each other by emitting and absorbing dislocations. The transition processes might result in grain coarsening and refinement events. Dislocation reflection generated by a piece of stable grain boundary is also observed, because of the complex local atomic structure within the nanocrystalline Al. This implies that nanocrystalline metals might improve their internal structural stability with the help of some special local grain boundaries.展开更多
The effects of stacking fault energy,unstable stacking fault energy,and unstable twinning fault energy on the fracture behavior of nanocrystalline Ni are studied via quasicontinuum simulations.Two semi-empirical poten...The effects of stacking fault energy,unstable stacking fault energy,and unstable twinning fault energy on the fracture behavior of nanocrystalline Ni are studied via quasicontinuum simulations.Two semi-empirical potentials for Ni are used to vary the values of these generalized planar fault energies.When the above three energies are reduced,a brittle-to-ductile transition of the fracture behavior is observed.In the model with higher generalized planar fault energies,a nanocrack proceeds along a grain boundary,while in the model with lower energies,the tip of the nanocrack becomes blunt.A greater twinning tendency is also observed in the more ductile model.These results indicate that the fracture toughness of nanocrystalline face-centered-cubic metals and alloys might be efficiently improved by controlling the generalized planar fault energies.展开更多
Climate change has become a serious global challenge. Developing countries are the worst affected due to poor response mechanism to associated disasters. This study examined the application of the indigenous knowledge...Climate change has become a serious global challenge. Developing countries are the worst affected due to poor response mechanism to associated disasters. This study examined the application of the indigenous knowledge (IK) methods to predict the changes in seasonal rainfall. The study used data collected through individual interviews using a structured questionnaire. The study found vegetation changes (i.e. shading off leaves, excessive branching);changes in animal behavior (i.e. eating soil, restlessness), and other atmospheric indicators (i.e. changes in wind, color of stars and moon, earthquake, migrating of birds, swarming of bees, cold windy mornings and warm nights) being used to observe and monitor the changes in rainfall over the season. The study recommends a more detailed study to validate the IK and integrate it with the scientific knowledge so as to reduce local farmers’ vulnerability, increase resilience and strengthen their adaptive capacity to cope with climate change effects.展开更多
The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas,Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots..This is done for the purpose of findin...The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas,Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots..This is done for the purpose of finding a replacement for conventional insecticides which has been found to be harmful to man.The seed oil was applied topically at the rate of 0.1,0.2,0.3 and 0.4 mL per insect.There were a total of 20 insects per Petri-dish.There were four replicates per treatment.Insect mortality was recorded on 12 hourly basis for 48 hours.The results of insects treated with all dosage rates of C.nucifera showed a significantly higher mortality when compared with the control.In the case ofH.annus,insect mortality ranged from 40-100,70-100,60-100 and 80-100%and for J.curcas the result ranged from 0.0-100,40-100,80-100 and 80-100%for rates of 0.1,0.2,0.3 and 0.4 mL,respectively,from 12 hrs to 48 hrs post application.The control experiment remained at 0%level throughout the period of the experiments.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.
基金funded by the Alfaisal University grant number 726174.
文摘Lithium-sulfur batteries have been developing in recent years and appear to offer an alternative to existing commercial batteries that can potentially replace them in the future.With their exceptional theoretical energy density,lower production costs,and affordable and environmentally friendly abundant raw materials,lithium-sulfur batteries have shown the ability to defeat counterparts in the race for rechargeable energy devices currently being developed.The lithium-sulfur batteries display extraordinary features,but they suffer from sulfur's non-conductivity,the shuttle effect that results from polysulfide dissolution,volumetric sulfur changes during charging,and dendrites at the anode,resulting in a decline in capacity and a short battery life.As a result of rigorous and innovative engineering designs,lithium-sulfur batteries have been developed to overcome their drawbacks and utilize their entire potential during the past decade.This review will pay particular attention to porous carbon-based matrix materials,especially graphene-based nanocomposites that are most commonly used in producing sulfur cathodes.We provide an in-depth perspective on the structural merits of graphene materials,the detailed mechanism by which they interact with sulfur,and essential strategies for designing high-performance cathodes for lithium-sulfur batteries.Finally,we discuss the significant challenges and prospects for developing lithium-sulfur batteries with high energy density and long cycle lives for the next-generation electric vehicles.
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Princess Nourah bint Abdulrahman University Researchers Supporting Project(No.PNURSP2025R479)。
文摘In this study,Cu_(0.25)Ni_(0.5)Zn_(0.25)Fe_(2-x)Nd_(x)O_(4)(0.000≤x≤0.100,andΔx=0.025)spinel ferrites were synthesized using the auto-combustion method to investigate the influence of neodymium(Nd^(3+))substitution on their structural,optical,dielectric,and magnetic properties.X-ray diffraction result confirms the formation of a face-centered cubic spinel structure,with the average crystallite size decreasing from 39 to 15 nm as Nd^(3+)concentration increases.Fourier transform infrared spectroscopy reveals characteristic absorption bands,affirming the spinel structure.Dielectric measurements over a broad frequency range show a higher dielectric constant and lower dielectric loss,indicating potential suitability for energy-efficient electronic applications.Magnetic analysis using a vibrating sample magnetometer demonstrates soft magnetic behavior,with saturation magnetization decreasing from82.69 to 66.80 emu/g and a tunable ratio(0.0221-0.0068)of remnant magnetization to saturation magnetization depending on Nd^(3+)content.In situ ultrasonic studies provides phase transition temperature(Curie temperature,T_(c))values ranging from 516 to 489 K,highlighting thermal stability and magnetic phase transition behavior.Furthermore,reflection loss measurements in the X-band frequency range(8-12 GHz)confirm the excellent electromagnetic interference shielding and radar absorption capabilities of Cu_(0.25)Ni_(0.5)Zn_(0.25)Fe_(2-x)Nd_(x)O_(4)spinel ferrites.These findings underscore the potential of Nd^(3+)-doped Cu-Ni-Zn spinel ferrites for advanced technological applications,including electronic devices,thermal sensors,and electromagnetic wave absorbers.
基金the Deanship of Research and Graduate Studies at King Khalid University,Saudi Arabia for funding this work through Large Research Project under grant number RGP2/630/45。
文摘Spinels are an emerging class of advanced technological materials for spintronic,energy harvesting,and water-splitting applications.In this work,we explored the electronic,magnetic,optical,and transport properties of CaCe_(2)(S/Se)_(4)by density functional theory based on the Wien2k code.The energy released during optimization in ferromagnetic and antiferromagnetic states confirms that the ferromagnetic state is stable,which is further verified by negative formation energy.Heisenberg model and density of states report the Curie temperature and spin polarization.Half metallic ferromagnetism(HMF)regarding hybridization,crystal fields,exchange ene rgies,and double exchange mechanisms is discussed.The transfer of magnetic moments from Ce to Ca and S/Se and interstitial sites ensure the role of spin of electrons rather than clustering.Mo reover,the optical prope rties are addressed by dielectric constants,absorption,refraction,and optical loss.The first absorption peaks exist in infrared zone;others fall in visible to ultraviolet zones.The spin-up(↑)and spin-down(↓)channel thermoelectric factors combine and report the performance by conductivities,Seebeck coefficient,and power factor.Therefore,the studied materials'optical and thermoelectric behaviours will allow researchers to realize them for technological applications.
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.
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.
基金Project supported by the State Key Development Program for Basic Research of China (Grant No. 2011CB606403)
文摘Grain boundary activity in nanocrystalline Al under an indenter is studied by using a multiscale method. It is found that grain boundaries and twin boundaries can be transformed into each other by emitting and absorbing dislocations. The transition processes might result in grain coarsening and refinement events. Dislocation reflection generated by a piece of stable grain boundary is also observed, because of the complex local atomic structure within the nanocrystalline Al. This implies that nanocrystalline metals might improve their internal structural stability with the help of some special local grain boundaries.
基金Project supported by the National Basic Research Program of China(Grant No.2011CB606403)
文摘The effects of stacking fault energy,unstable stacking fault energy,and unstable twinning fault energy on the fracture behavior of nanocrystalline Ni are studied via quasicontinuum simulations.Two semi-empirical potentials for Ni are used to vary the values of these generalized planar fault energies.When the above three energies are reduced,a brittle-to-ductile transition of the fracture behavior is observed.In the model with higher generalized planar fault energies,a nanocrack proceeds along a grain boundary,while in the model with lower energies,the tip of the nanocrack becomes blunt.A greater twinning tendency is also observed in the more ductile model.These results indicate that the fracture toughness of nanocrystalline face-centered-cubic metals and alloys might be efficiently improved by controlling the generalized planar fault energies.
文摘Climate change has become a serious global challenge. Developing countries are the worst affected due to poor response mechanism to associated disasters. This study examined the application of the indigenous knowledge (IK) methods to predict the changes in seasonal rainfall. The study used data collected through individual interviews using a structured questionnaire. The study found vegetation changes (i.e. shading off leaves, excessive branching);changes in animal behavior (i.e. eating soil, restlessness), and other atmospheric indicators (i.e. changes in wind, color of stars and moon, earthquake, migrating of birds, swarming of bees, cold windy mornings and warm nights) being used to observe and monitor the changes in rainfall over the season. The study recommends a more detailed study to validate the IK and integrate it with the scientific knowledge so as to reduce local farmers’ vulnerability, increase resilience and strengthen their adaptive capacity to cope with climate change effects.
文摘The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas,Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots..This is done for the purpose of finding a replacement for conventional insecticides which has been found to be harmful to man.The seed oil was applied topically at the rate of 0.1,0.2,0.3 and 0.4 mL per insect.There were a total of 20 insects per Petri-dish.There were four replicates per treatment.Insect mortality was recorded on 12 hourly basis for 48 hours.The results of insects treated with all dosage rates of C.nucifera showed a significantly higher mortality when compared with the control.In the case ofH.annus,insect mortality ranged from 40-100,70-100,60-100 and 80-100%and for J.curcas the result ranged from 0.0-100,40-100,80-100 and 80-100%for rates of 0.1,0.2,0.3 and 0.4 mL,respectively,from 12 hrs to 48 hrs post application.The control experiment remained at 0%level throughout the period of the experiments.
