Search

This work initiates a concept of reduced reverse degree based RR D M -Polynomial for a graph, and differential and integral operators by using this RR D M -Polynomial. In this study twelve reduced reverse degree-based topological descriptors are formulated using the RR D M -Polynomial. The topological descriptors, denoted as T D 's, are numerical invariants that offer significant insights into the molecular topology of a molecular graph. These descriptors are essential for conducting QSPR investigations and accurately estimating physicochemical attributes. The structural and algebraic characteristics of the graphene and graphdiyne are studied to apply this methodology. The study involves the analysis and estimation of Reduced reverse degree-based topological descriptors and physicochemical features of graphene derivatives using best-fit quadratic regression models. This work opens up new directions for scientists and researchers to pursue, taking them into new fields of study. [ABSTRACT FROM AUTHOR]

Software requirements play a vital role in ensuring a software product's success. However, it remains a challenging task to implement all of the user requirements, especially in a resource-constrained development environment. To deal with this situation, a requirements prioritization (RP) process can help determine the sequence for the user requirements to be implemented. However, existing RP techniques are suffered from some major challenges such as lack of automation, excessive effort, and reliance on stakeholders' involvement to initiate the process. This study intends to propose an automated requirements prioritization approach called association rule mining-oriented (ARMO) to address these challenges. The automation process of the ARMO approach incorporates activities to first pre-process the requirements description and extract features. The features are then examined and analyzed through the applied rule mining technique to prioritize the requirements automatically and efficiently without the involvement of stakeholders. In this work, an evaluation model was further developed to assess the effectiveness of the proposed ARMO approach. To validate the efficacy of ARMO approach, a case study was conducted on real-world software projects grounded on the accuracy, precision, recall, and f1-score measures. The promising experimental results demonstrate the ability of the proposed approach to prioritize user requirements. The proposed approach can successfully prioritize user requirements automatically without requiring a significant amount of effort and stakeholders' involvement to initiate the RP process. [ABSTRACT FROM AUTHOR]

Low yields of crops, especially rice, are caused by climate change and environmental stress concerns such as drought, temperature fluctuations, and salinity in arid and semi-arid locations around the globe. Rice is one of the essential crops for human consumption and one of the most commonly farmed cereals on the planet earth, but its growth is severely retarded by excessive salt, which influences rice development and production, leading to economic loss. Salt stress induces osmotic stress and ionic toxicity in rice by altering the environment, leading to water deprivation and accumulation of toxic ions, thereby triggering specific physiological and molecular responses in the rice plants. Many factors may affect rice production and cereal quality via its interaction with salinity. This review focuses on some influential factors (photosynthesis, osmosis, micro and macronutrients, microbial flora, rice growth, development, and genes) that may reduce rice production in saline soils. The review also describes the responsive mechanism of rice to salinity and the genetic susceptibility of rice. In light of the challenges posed by the growing global population and limited agricultural land, it is imperative to consider the influential factors discussed in this review, along with genetic susceptibility to improve rice production in terms of quantity and quality under saline soil conditions. [ABSTRACT FROM AUTHOR]

In this work, polypyrrole (PPy) is synthesized, characterized, and employed as an active sensing material for the fabrication of humidity sensors. An 80 nm thick layer of PPy is spin coated on the pre-patterned thermally deposited silver (Ag) electrodes spaced 50 µm apart to fabricate Ag/PPy/Ag surface-type sensor. Atomic force microscopy analysis revealed granular microstructure morphology in the thin films of PPy. Additionally, X-ray diffraction (XRD), ultraviolet–visible (UV-Vis) and Fourier transformed infrared (FTIR) spectra of PPy are analyzed to study its crystallinity, optical bandgap and bond dynamics to confirm the molecular composition of PPy. The fabricated Ag/PPy/Ag sensor is characterized by varying the humidity levels between a broad range [0–95% relative humidity (RH)] at different frequencies of 120 Hz and 1 kHz. The prepared sensor showed promising sensing features such as higher sensitivity 233 nF/%RH (at 120 Hz), 83 pF/%RH (at 1 kHz), quick response time (5.20 ± 0.2 s) and recovery times (6.43 ± 0.2 s), a wide working range of relative humidity (20–95%RH) and low hysteresis gap (1.57%) with outstanding recyclability. This study reveals the potential of PPy as the best candidate for humidity sensing applications. [ABSTRACT FROM AUTHOR]

Silicon carbide is a captivating semiconductor material for electrical and electro-optical applications requiring high temperatures. Silicon carbide is a crucial non-oxide ceramic with a wide range of uses in manufacturing. It has special properties like high rigidity and durability, heat and chemical constancy, a high melting point, oxidation resistance, powerful erosion resistance, etc. Due to all of these properties, silicon carbide is the perfect material for high-power, high-temperature electrical devices as well as erosion and cutting purposes. Silicon carbide materials are frequently used in different fields of nuclear materials and semiconductor materials because of their outstanding radiation resistance, thermal conductivity, oxidation resistance, and mechanical strength. This study presents various K-Banhatti entropies, redefines Zagreb entropies, and the atom-bond sum connectivity entropy of the double and strong double graphs of silicon carbide [ S i 2 C 3 - I (r , s) ], and presents a numerical and graphical analysis of these results. The QSPR analysis of silicon carbide is performed for four characteristics Poisson's ratio, shear modulus, Young's modulus and bulk modulus through linear and quadratic regression analysis and found the best prediction. These models provide scientists with a new way of estimating physicochemical properties. [ABSTRACT FROM AUTHOR]

Crop cultivars have an influence on greenhouse gas (GHG) emissions, and there is variation between varieties. However, there are few reports available on the differences in GHG emissions and their driving factors among vegetable varieties. In this study, we conducted a field experiment to examine the variances in GHG emissions and their contributing factors among eight flowering Chinese cabbage varieties (considering growth period, leaf shape, and colour). The results showed significant differences in GHG emissions within varieties; early-maturing varieties exhibited GHG by 25.6% and 15.3%, respectively, when compared to mid- and late-maturing varieties. Among the different leaf types and color classifications, light-colored and sharp-leafed varieties had the lower global warming potential (GWP) overall. Cumulative CO2 emissions were influenced by leaf SPAD values and biomass, while cumulative N2O emissions were driven mainly by stem thickness, carbon accumulation, leaf SPAD values, and biomass. In summary, the selection of light-colored varieties with pointed leaves and shorter growth periods in actual production contributed positively to the reduction of carbon emissions from flowering Chinese cabbage production. Through efficient variety screening, this study provides a win-win strategy for achieving efficient vegetable production while also addressing the global climate challenge. [ABSTRACT FROM AUTHOR]

The global practical implementation of proton exchange membrane fuel cells (PEMFCs) heavily relies on the advancement of highly effective platinum (Pt)-based electrocatalysts for the oxygen reduction reaction (ORR). To achieve high ORR performance, electrocatalysts with highly accessible reactive surfaces are needed to promote the uncovering of active positions for easy mass transportation. In this critical review, we introduce different approaches for the emerging development of effective ORR electrocatalysts, which offer high activity and durability. The strategies, including morphological engineering, geometric configuration modification via supporting materials, alloys regulation, core-shell, and confinement engineering of single atom electrocatalysts (SAEs), are discussed in line with the goals and requirements of ORR performance enhancement. We review the ongoing development of Pt electrocatalysts based on the syntheses, nanoarchitecture, electrochemical performances, and stability. We eventually explore the obstacles and research directions on further developing more effective electrocatalysts. [ABSTRACT FROM AUTHOR]

The hydroxyapatite (HA) powder has been successfully prepared by using calcined Indian clam seashells through the hydrothermal technique. Initially, the clam seashell is calcined at 900 ℃ to achieve calcium oxide (CaO). The obtained seashell-based calcium oxide is mixed properly with pre-determined tri-calcium phosphate in demineralized water. Further, the colloidal solution is heat-treated at a temperature of 1000 ℃ for various time durations (1 h, 1:30 h, 1:45 h, 2 h, 2:30 h, and 3 h) to perform the hydrothermal reactions. Quantification of HA and different phases present in the synthesized powders is carried out with the help of the Rietveld refinement method. The phases, crystallite size, and crystallinity of synthesized powder are evaluated by the X-ray diffraction (XRD) technique. The microstructure of the powder is analyzed through Field Emission Scanning Electron Microscopy (FESEM). The Ca/P ratio and particle size of the prepared powder are estimated by energy-dispersive X-ray spectroscopy (EDS) and the image analysis technique, respectively. The results indicate that the heating duration of the hydrothermal reaction is a crucial parameter in modifying the various properties, specifically the phase quantity of prepared HA. All six synthesized powders show the presence of the HA phase, along with a few secondary phases in those. Spherical and cylindrical nano-crystals of HA are observed to form. With an increase in time duration, coarsening of crystallite is observed. The average particle size and crystallinity of HA are also noticed to be increased with increased time duration. [ABSTRACT FROM AUTHOR]

Brown rot Polypores are ecologically significant as they play a crucial role in maintaining the carbon cycle and contribute to humus formation in forest ecosystems through their lignocellulose degradation ability. It is important to note that some species can significantly impact timber, potentially causing decay in economically valuable wood. Many Asian countries including Pakistan are still under the exploratory phase and have undocumented species diversity in Polypore fungi. In the current study, collections representing five different species belonging to two families, Postiaceae and Adustoporiaceae, were subjected to detailed morphoanatomical and molecular analyses. A combined matrix of two gene datasets (ITS and nrLSU) was analyzed using three different phylogenetic methods viz. Maximum Parsimony (MP), Maximum Likelihood (ML), and Bayesian inference (BI). Our study presents descriptions of five previously undocumented brown rot Polypore species from the country including Fuscopostia fragilis (Fr.) B.K. Cui, L.L. Shen & Y.C. Dai, Amaropostia stiptica (Pers.) B.K. Cui, L.L. Shen & Y.C. Dai, Cyanosporus piceicola B.K. Cui, L.L. Shen & Y.C. Dai, Spongiporus balsameus (Peck) A. David, Rhodonia placenta (Fr.) Niemelä, K.H. Larss. & Schigel. Regarding the molecular data, nodes of our subject sequences were substantially supported and fell under their respective species clades with high ML bootstrap values (≥ 95), MP bootstrap ≥ 74 and BI probabilities ≥ 0.98. Findings of the study will not only contribute to our understanding of local Polypores species diversity but also enhance knowledge of geographical distribution in global context. [ABSTRACT FROM AUTHOR]

This research studies how recent Finnish smart mobility innovation projects have addressed sustainability in their objectives. A framework and a coding scheme were built upon scientific literature and was used for analysing documented project materials. A truth table was generated that quantifies how the different aspects of sustainability have been addressed in the projects' objectives. The observed differences between the projects were analysed from two directions: in terms of funding sources (European Union vs. national) and project location (urban vs. rural areas). The results of qualitative comparative analysis showed that while sustainability was by and large present in the projects, some of the aspects of sustainability were more dominantly addressed than others. Also, there were differences in how sustainability was addressed between the projects in urban areas and the projects in rural areas. [ABSTRACT FROM AUTHOR]

Constructing superior Z-type photocatalytic heterojunction is beneficial to effectively enlarge interface contact, improve the photo-generated carrier separation rate, and retain the high redox ability. In this work, we designed a hierarchical core–shell g-C3N4/TiO2 structure to build Z-type heterojunction via combining simple template method and pyrolysis process. A close-knit Z-type heterojunction was constructed using TiO2 as a thick core and g-C3N4 as an ultra-thin shell. The effects of lamp source, wavelength, tetracycline (TC) concentration, and photocatalyst dose on the degradation performance on TC of g-C3N4/TiO2 were inspected. 0.1TiO2/g-C3N4 photocatalyst had the best degradation rate and highest removal rate within 30 min, and its degradation rate was about 49, 23, and 5 times than pure g-C3N4, TiO2, and commercial TiO2/g-C3N4 in respect. Moreover, compared with degradation ability under Xenon lamp, LED irradiation for g-C3N4/TiO2 composites showed a remarkable selective degradation. The fast and efficient Z-type transfer pathway of 0.1 g-C3N4/TiO2 was realized by forming an optimized interface and abundant surface active sites ascribed to the combined action of thick TiO2 core and ultra-thin g-C3N4 shell. In addition, the degradation intermediates were analyzed by LC–MS and suggested pathways of degradation. The work could provide novel design concept to obtain reliable Z-type photocatalysts with hierarchical core–shell structure applied in degradation of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

Green synthesis has always been the preferred choice for nanoparticles because it uses biological extract from plant sources that are nonhazardous to the environment. Specifically, the physicochemical and optical properties of ZnO nanoparticles (ZnO NPs) make them economically feasible for various industrial applications. In the present study, ZnO NPs were synthesized by using Gomphrena serrata leaf extract (GS-ZnO NPs). Structural characterization of GS-ZnO NPs was performed by XRD and FTIR. The thermal nature of the GS-ZnO NPs was analyzed by DSC and TGA. The agar disc diffusion technique was used to assay the antimicrobial properties of nanoparticles against pathogenic bacterial strains. The efficiency of photocatalytic degradation was assessed by employing methylene blue (MB) as the test dye, with exposure to sunlight. The observed sizes of the metallic nanoparticles were in the range of 20–30 nm. XRD analyses revealed that the GS-ZnO NPs were hexagonal wurtzite structures. SEM analysis exhibited the spherical morphology of the GS-ZnO NPs. Thermal gravimetric analysis showed various phases of percent weight loss of GS-ZnO NPs within the temperature range of 50–460 °C. A photocatalytic efficiency of 90.5% was achieved after 180 min of sunlight irradiation. G. serrata leaf extract could be used as an efficient reductant and capping material in the synthesis of zinc oxide nanoparticles. These findings on the thermal and antimicrobial properties of GS-ZnO NPs may validate their efficacy in pharmaceutical applications. The photocatalytic dye degradation activity of the nanoparticles was explored to determine their significance in wastewater treatment. [ABSTRACT FROM AUTHOR]

Energy crisis of the current society have attract the research attention for alternative energy sources. Methanol oxidation is source of energy but need efficient electrocatalyst like Pt. However, their practical ability is hinder due to cost and poisoning effect. In this regard, efficient catalyst is required for methanol oxidation. Herein, high temperature, pressure, and diethylenetryamine (DETA) as reaction medium/structure directing agent during solvothermal method are used for nanobelt Cu3Se2/Cu1.8Se (mostly hexagonal appearance) formation. The electrocatalyst shows optimized methanol electrooxidation reaction (MOR) response in 1 M KOH and 0.5 M methanol at scan rate of 50 mV/s and delivers a current density 7.12 mA/mg at potential of 0.65 V (vs Ag/AgCl). The catalyst exhibits high electrochemical active surface area (ECSA) (0.088 mF/cm2) and low Rct with good stability for 3600 s which favor its high MOR performance. This high response is due to its 2D hexagonal nanobelt morphology, which provides large surface area for reaction. The space among nanobelt reduce diffusion kinetics and rough/irregular edge increase reaction site to overall improve the methanol oxidation reaction. [ABSTRACT FROM AUTHOR]

The hydroxyapatite (HA) powder is successfully synthesized from calcined eggshell by the hydrothermal reaction method. The colloidal solution made of calcined eggshell powder, tricalcium phosphate powder, and demineralized water is kept in a closed ceramic vessel to perform hydrothermal reactions. For this purpose, different temperatures (700 - 1000 °C) for various time durations (1, 2, and 3 h) are applied to the solution. X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDS) are employed to characterize the prepared powders. The synthesized powders are further assessed in terms of crystalline phase, microstructure, crystallite size, particle size, Ca/P ratio, and crystallinity. In all the reaction products, majorly the HA powders are obtained. The spherical HA grains are found to have a tendency to agglomerate at higher reaction temperatures and times. The applied temperature and heating duration are found to be the crucial parameters that control the properties of the synthesized HA. The HA with the largest crystallite size is obtained from 1000 oC of heating temperature applied for 3 h. However, the HA with high crystallinity is obtained from 800 oC temperature applied for 1 h of time. Non-stoichiometric HAs are obtained from all different reaction temperatures and time durations. Mostly Ca-rich (Ca/P > 1.67) HAs are formed in all powders except the one prepared at 900 ° C, where the formation of Ca-deficient (Ca/P < 1.67) HA is noticed. The near-stoichiometric HA can be produced from 900 oC of reaction temperature applied for 1 h. The study illustrates that HA can be synthesized successfully from chicken eggshell by hydrothermal reaction method in less time by applying high heating temperature. [ABSTRACT FROM AUTHOR]

During the synthesis of hydroxyapatite (HA) powder by hydrothermal reaction via Indian clam seashell, different phases are noticed to form along with HA. This is due to the incomplete forward reaction resulting in the retention of the reactants, absorption of moisture, or backward reaction. In the present work, the weight fraction of different phases for synthesized powders has been calculated through the Rietveld refinement method by using X-ray diffraction data. The reactions are carried out at different temperatures (700°C, 800°C, 900°C, 1000°C, and 1100°C) for several time durations (1 h, 2 h, and 3 h) in various independent hydrothermal reactions. The different phases formed in the synthesized powders were examined by the X-ray diffraction (XRD) technique in our previous study. In the present work, through Rietveld refinement, it is revealed that the powders synthesized at 700, 800, and 900°C for 2 h duration contain the highest amount of HA phase among the various time durations. On the other hand, highly pure HA powders can be prepared at 1000°C, and 1100°C applied for 3 h time. The vibration modes of PO43- tetrahedral for all the synthesized powders are studied through Raman spectroscopy. [ABSTRACT FROM AUTHOR]

This study examines the effect of grit blasting on the surface and subsurface characteristics of low-carbon steel substrates under dry and wet environments. Three types of wet environments have been simulated: tap water, saline water, and ethyl alcohol. The variation in average surface roughness with grit size, standoff distance (SOD), and blasting time has been analyzed under all conditions. A mathematical model has been developed to estimate the increment in the contact area of each rough surface created by grit blasting. The optimal sets of process parameters for each environment have been suggested based on the maximum increment. The optimal conditions have been found to shift toward higher SODs and time periods under wet conditions. Vickers microhardness testing has been undertaken to study the hardness of the subsurface zone of the grit-blasted samples. Work hardening of the subsurface regions is higher under dry conditions compared to the same in wet conditions. The depth of the affected layer is higher in case of higher surface hardening. X-Ray Diffraction analysis has been carried out to identify the phases formed on the as-blasted substrate surfaces. Nascent surface metallurgy remains unchanged under dry and wet conditions, except in saline water environments where significant contamination has been observed. Subsurface microstructures of the blasted substrates have been studied using Field Emission Scanning Electron Microscopy and Energy Dispersive Spectroscopy. Subsurface damage is substantial under dry conditions. The deformation effect and formation of subsurface cracks are found to be localized in the vicinity of the grit-blasted surfaces. Among all the blasting environments, the alcohol medium offered reasonably high roughness with minimum hardening effect on the substrate. [ABSTRACT FROM AUTHOR]

Over the years, public infrastructure projects have generated substantial attention as they take the initiative to enrich sustainable community development. This paper looks to identify if the delays in public projects significantly impact the sustainable community development. A questionnaire survey approach is used to collect data. This study employed the partial least square structural equation modeling to examine the hypothesized model. Data obtained from 325 project experts in the Pakistani construction industry provided empirical support for the study. The outcome of the statistical analysis showed that project delay significantly influences sustainable community development. Based on the findings, this study suggests valuable insights to project management planners and executors to improve strategic planning for project executions through proper sustainability approaches. [ABSTRACT FROM AUTHOR]

A suitable mixture of Ba(NO3)2 and Al powders, known as pyrotechnic mixture, was burned to deposit pure BaAl2O4 and Ni-BaAl2O4 coatings on low-carbon steel by a new explosive spray coating method. Ni-5Al is a bonding coating material commonly used in thermal spraying to deposit ceramics on metal substrates to achieve strong coating-substrate adhesion. In addition, because it is hard in nature, this material has the potential to impart toughness to a brittle composite. Therefore, Ni-5Al powder was added to the explosive spray charge to deposit a Ni-BaAl2O4 composite coating. Various characterization techniques, such as x-ray diffraction, field emission scanning electron microscopy with energy-dispersive spectroscopy analysis, transmission electron microscopy (TEM), Vickers hardness test, scratch test, image analysis, and roughness estimation were used to compare various properties of the two coatings. It was found that the Ni-based globules are uniformly distributed in the Ni-BaAl2O4 coating. BaAl2O4 and Ba phases were observed in the pure BaAl2O4 coating, while Ni, BaAl2O4 and Ba2Al2O5 phases were mainly formed in the Ni-BaAl2O4 coating. The formation of Ni-Fe and Ni-Al based compounds and the interdiffusion of materials in the interface region of this type of coating significantly improved the coating-substrate adhesion. The TEM analysis confirmed the presence of brittle crystalline and amorphous phases in both coatings. The overall crystallinity of Ni-BaAl2O4 was higher than that of the pure BaAl2O4 coating material. The increase in hardness and reduction in crack formation in the Ni-BaAl2O4 composite also suggests an improvement in toughness. In addition, the average surface roughness and porosity of the Ni-BaAl2O4 coating were lower than that of the pure BaAl2O4 coating. The addition of Ni-5Al to the feedstock improved the mechanical properties of the explosively deposited BaAl2O4-based coating. [ABSTRACT FROM AUTHOR]

Morels (fruiting bodies of Morchella spp.) are ascomycetous mushrooms known for their prime edibility and medicinal value. Their wild harvesting is potentially one of the off-farm income sources for the mountainous communities in Pakistan. Over the years, the local resource harvesters (RHs) attained a rich indigenous knowledge of morel ecological characteristics, habitation and marketing. The body of traditional ecological knowledge (TEK) thus acquired is increasingly becoming threatened in the ongoing forest degradation era which is further aggravated by the loss of morel-specific habitats. Furthermore, there are still many gaps in the ecological understanding regarding forest mycological services. The current study, therefore, focused on various aspects of the morel mushrooms like TEK, bulk collected, pre and post-harvest processing, value addition and marketing. To procure TEK related to morel mushrooms, informed consent and semi-structured interviews were conducted with 52 commercial resource harvesters and 10 resource dealers. The referral sampling method was applied to identify the informants while for the value chain and productivity assessment regular field-market monitoring was performed during 2014–2018. Data indicated that the total annual production of wild morels during 2014 was 4624 kg which generated a revenue of about USD 0.256 million. Among the total estimated 4000–5000 harvesters, 90% were male and 10% were female who earned up to 25% of total annual income from morel harvest. The study further revealed that a large part of morel marketing remained unknown and quite unpredictable due to a lack of government interest and public policy. The RHs receive a minimal advantage of the supply chain i.e., 25–30% of an export value. Our study proposed a mechanism for sustainable resource management of morel mushrooms based on contemporary ecological knowledge and existing TEK from the local forest users. The main objective of the study was to scientifically document indigenous understandings, level of commercial extraction and marketing of morel fungi from the area. [ABSTRACT FROM AUTHOR]

In this study, a comprehensive analysis of visco-hyper-elastic thick soft arches under an external time-independent as well as time-dependent loads is presented from bending and internal resonance phenomenon perspectives. Axial, transverse and rotation motions are considered for modelling the thick and soft arch in the framework of the Mooney–Rivlin and Kelvin–Voigt visco-hyper-elastic schemes and third-order shear deformable models. The arch is assumed to be incompressible and is modelled using von Kármán geometric nonlinearity in the strain–displacement relationship. Using a virtual work method, the bending equations are derived. For the vibration analysis, three, coupled, highly nonlinear equations of motions are obtained using force-moment balance method. The Newton–Raphson method together with the dynamic equilibrium technique is used for the bending and vibration analyses. A detailed study on the influence of having visco-hyper-elasticity and arch curvature in the frequency response of the system is given in detail, and the bending deformation due to the applied static load is presented. The influence of having thick, soft arches with different slenderness ratios is shown, and the forced vibration response is discussed. Moreover, internal resonance in the system is studied showing that the curvature term in the structure can lead to three-to-one internal resonances, showing a rich nonlinear frequency response. The results of this study are a step forward in studying the visco-hyper-elastic behaviour of biological structures and soft tissues. [ABSTRACT FROM AUTHOR]

The current study investigates the MHD flow of nanofluid across an elongating surface while taking into account non-uniform heat flux. For this, we have considered the flow of a boundary layer over a stretched sheet containing (water-based) Al2O3 nanoparticles. The convective boundary conditions for temperature have been invoked. The flow created by a surface that is exponentially expanding in the presence of a magnetic field and a non-uniform heat flux has been mathematically formulated by using laws of conservation. Transformed non-dimensional systems of governing equations have been analyzed numerically by using Adam's Bashforth predictor corrector approach. The effects of emerging parameters on the fluid velocity and temperature profiles have been further described by plotting graphs. An experimental design and a sensitivity analysis based on Response Surface Methodology (RSM) are used to examine the effects of various physical factors and the dependence of the response factors of interest on the change of the input parameter. To establish the model dependencies of the output response variables, which include the skin friction coefficient and the local Nusselt number, on the independent input parameters, which include the magnetic field parameter, the nanoparticle volume fraction, and the heat transfer Biot number, RSM is used. On the basis of statistical measures such as Q - Q residual plots, adjusted and hypothesis testing using p values, it is observed that both of our models for Skin Friction Coefficient (SFC) and the Local Nusselt Number (LNN) are best fitted. Further, it is concluded that the sensitivity of the SFC, as well as the LNN through heat transfer Biot number, is greater than that of nanoparticle volume fraction and magnetic field parameter. The SFC is sensitive to all combinations of the input parameters. At high levels of heat transfer Biot number, the LNN displays negative sensitivity via magnetic field parameters. [ABSTRACT FROM AUTHOR]

In the recent past, plasma waste technology has emerged to be an environmental friendly and beneficial technology. In this review, current status of thermal plasma, non-thermal plasma and its application for nano-scale high-tech plasmonic materials based on the scientific and technical comprehensive observation are included. Generally, thermal plasma is used for solid waste treatment but non-thermal plasma is being utilized for plasmonic materials. The current research incorporated in two phases: thermal plasma and non-thermal plasma. In the first phase, understanding and detailed information about plasma torches have been included such as DC transfer and non-transfer arc plasma torches. In addition, solid waste treatment, municipal waste, healthcare issue, steel making and treatment through plasma jet injection have been reviewed extensively. In the second phase, state-of-the-art review has been addressed for dielectric barrier discharge (DBD) and its utility for plasmonic materials. The analysis concluded that the thermal plasma is the optimal choice for treating solid waste issues and the application of non-thermal plasma such as DBD is the most useful and latest approach for plasmonic material. The prime objective of this review is not only to provide the comparison between thermal or non-thermal plasma but to recommend the ideal and most optimized suitable technique for solid waste treatment and bio-medical applications. [ABSTRACT FROM AUTHOR]

Presence of higher breast density (BD) and persistence over time are risk factors for breast cancer. A quantitatively accurate and highly reproducible BD measure that relies on precise and reproducible whole-breast segmentation is desirable. In this study, we aimed to develop a highly reproducible and accurate whole-breast segmentation algorithm for the generation of reproducible BD measures. Three datasets of volunteers from two clinical trials were included. Breast MR images were acquired on 3 T Siemens Biograph mMR, Prisma, and Skyra using 3D Cartesian six-echo GRE sequences with a fat-water separation technique. Two whole-breast segmentation strategies, utilizing image registration and 3D U-Net, were developed. Manual segmentation was performed. A task-based analysis was performed: a previously developed MR-based BD measure, MagDensity, was calculated and assessed using automated and manual segmentation. The mean squared error (MSE) and intraclass correlation coefficient (ICC) between MagDensity were evaluated using the manual segmentation as a reference. The test-retest reproducibility of MagDensity derived from different breast segmentation methods was assessed using the difference between the test and retest measures (Δ2-1), MSE, and ICC. The results showed that MagDensity derived by the registration and deep learning segmentation methods exhibited high concordance with manual segmentation, with ICCs of 0.986 (95%CI: 0.974-0.993) and 0.983 (95%CI: 0.961-0.992), respectively. For test-retest analysis, MagDensity derived using the registration algorithm achieved the smallest MSE of 0.370 and highest ICC of 0.993 (95%CI: 0.982-0.997) when compared to other segmentation methods. In conclusion, the proposed registration and deep learning whole-breast segmentation methods are accurate and reliable for estimating BD. Both methods outperformed a previously developed algorithm and manual segmentation in the test-retest assessment, with the registration exhibiting superior performance for highly reproducible BD measurements. [ABSTRACT FROM AUTHOR]

This study examines the endogenous growth theory for technological innovation and economic growth with the role of foreign direct investment (FDI) and air transport freight in seven emerging BRICS-MT economies. In the existing literature, there is no significant empirical evidence on the dynamic relationship among technological innovation, air transport freight, FDI, and economic growth in BRICS-MT countries. Thus, the current study contributes to the growing literature regarding the role of technological Innovation, air transport, and FDI on economic growth. To this end, we explore the dynamic nexus between technological innovation, air transport, FDI, and economic growth in 7 selected emerging BRICS-MT countries, including Brazil, Russia, India, China, South Africa, Mexico, and Turkey. This study covers the most recent updated period for panel data from 2000 to 2019. We applied panel cointegration, dynamic ordinary least square (DOLS), fully modified ordinary least square (FMOLS), and Granger causality tests to draw empirical inferences. The Pedroni panel and Kao residual cointegration tests confirm the long-run relationships among the variables. The DOLS results indicate that air transport freight, technological innovation, and FDI significantly positively impact economic growth. This study's findings confirmed the endogenous growth model in BRICS-MT countries. Furthermore, the Granger causality test results show the feedback effect of FDI on economic growth. The outcomes of this study also show the unidirectional causal relationship between air transport freight and economic growth. Moreover, the results provide support to economic policymakers in their decision-making. These results fill the gaps that assist policymakers of BRICS-MT countries in removing barriers to air transport freight, technological innovation, and foreign direct investment, thereby achieving sustainable economic development. [ABSTRACT FROM AUTHOR]

In this article, we present a stabilized finite element method to solve the Stokes-Stokes interface system. To couple the Stokes equations in two different domains, we utilize Nitsche's type interface conditions. Numerical instability arises due to the coupling conditions that produce the artificial energy transfer across the interface, which causes the local instability of the approximation of the pressure and velocity. In the present work, we propose a robust stabilized scheme by introducing a stabilization term and a consistency term to deal with the instability of the system, which also ensures the well-posedness of the algorithm. The continuity and weak coercivity are derived for the proposed stabilized scheme. The optimal convergence analysis is carried out rigorously. Finally, several numerical experiments are conducted to illustrate the applicability, validity, and efficiency of the numerical method for the Stokes-Stokes interface model. [ABSTRACT FROM AUTHOR]

Vanadium pentoxide (V2O5), as a common supercapacitor electrode material, has unsatisfactory electrochemical performance due to its low conductivity and ionic diffusion rate, especially its specific capacitance and rate capability, which limits its practical use. In this work, V2O5 rich in oxygen vacancies is successfully prepared by a controllable two-step reduction method. A variety of advanced characterization techniques, especially X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) spectra, have been used to qualitatively monitor changes in oxygen vacancy content. Compared with the untreated hydrated V2O5 nanosheets, the oxygen vacancy V2O5 (Vö V2O5) has a larger specific surface area (4.002 m2 g−1); besides, its specific capacitance (619.5 F g−1 in 1 A g−1) being not only better than that of V2O5 without oxygen vacancy treatment (308.0 F g−1 in 1 A g−1) but also its cycle stability being improved (70.7% capacity retention after 1000 cycles), it is possible to develop high-performance supercapacitors by using it as an electrode material. [ABSTRACT FROM AUTHOR]

In this study, the time-dependent mechanics of multilayered thick hyperelastic beams are investigated for the first time using five different types of shear deformation models for modelling the beam (i.e. the Euler–Bernoulli, Timoshenko, third-order, trigonometric and exponential shear deformable models), together with the von Kármán geometrical nonlinearity and Mooney–Rivlin hyperelastic strain energy density. The laminated hyperelastic beam is assumed to be resting on a nonlinear foundation and undergoing a time-dependent external force. The coupled highly nonlinear hyperelastic equations of motion are obtained by considering the longitudinal, transverse and rotation motions and are solved using a dynamic equilibrium technique. Both the linear and nonlinear time-dependent mechanics of the structure are analysed for clamped–clamped and pinned–pinned boundaries, and the impact of considering the shear effect using different shear deformation theories is discussed in detail. The influence of layering, each layer's thickness, hyperelastic material positioning and many other parameters on the nonlinear frequency response is analysed, and it is shown that the resonance position, maximum amplitude, coupled motion and natural frequencies vary significantly for various hyperelastic and layer properties. The results of this study should be useful when studying layered soft structures, such as multilayer plastic packaging and laminated tubes, as well as modelling layered soft tissues. [ABSTRACT FROM AUTHOR]

The present article reports a computer-aided teaching strategy, which is novel, using a MATLAB toolbox (i.e. SimMechanics) for project-based learning in a mechanical engineering robotics course (i.e. robot analysis). The effectiveness of the proposed teaching strategy was evaluated using multiple lenses of critical reflection such as student-reflection using numerous students' surveys, and students' grades comparison. Furthermore, the performance of this new teaching strategy was compared with a traditional teaching method, during which, traditional MATLAB solvers (e.g. ODE) were employed rather than SimMechanics. The results showed that the proposed teaching strategy helped students more than traditional teaching method to better understand and visualize 'robot analysis' concepts such as 3D drawing, dynamic modelling, and solving differential equations. The majority of students were more involved in learning, were able to achieve better learning outcomes, and performances. [ABSTRACT FROM AUTHOR]

In this paper, two-grid finite element method for the steady dual-permeability-Stokes fluid flow model is proposed and analyzed. Dual-permeability-Stokes interface system has vast applications in many areas such as hydrocarbon recovery process, especially in hydraulically fractured tight/shale oil/gas reservoirs. Two-grid method is popular and convenient to solve a large multiphysics interface system by decoupling the coupled problem into several subproblems. Herein, the two-grid approach is used to reduce the coding task substantially, which provides computational flexibility without losing the approximate accuracy. Firstly, we solve a global problem through standard Pk − Pk− 1 − Pk − Pk finite elements on the coarse grid. After that, a coarse grid solution is applied for the decoupling between the interface terms and the mass exchange terms to solve three independent subproblems on the fine grid. The three independent parallel subproblems are the Stokes equations, the microfracture equations, and the matrix equations, respectively. Four numerical tests are presented to validate the numerical methods and illustrate the features of the dual-permeability-Stokes model. [ABSTRACT FROM AUTHOR]

Arsenic (As) is one of the most toxic metalloids for humans. Above permissible levels of As cause severe health implications. Contaminated drinking water and food items may be the leading sources of As exposure to people all around the world. The current study assessed the levels of As in drinking water, vegetables, irrigation water, agricultural soils, and the human population (adult women and men) of rural and peri-urban areas of Multan (Pakistan). For a comparison between peri-urban (exposed site) and rural areas (control site), we sampled irrigation water, vegetables and vegetable-grown soils, drinking water, and human blood. In all sample types, As concentration was significantly higher at exposed site than at control site. Alarmingly, As concentration in drinking groundwater (34 µg As L−1) of exposed site was 3.4-folds higher than the permissible limit (set by WHO). Among the studied vegetables, the cumulative daily dietary intake of As was recorded maximum by the consumption of okra (474 ng d–1 on exposed site) and minimum by long melon (1 ng d–1 on control site). However, As intake via drinking water was estimated to contribute ≥ 98% of total As intake at both sites. Hence, the health risks associated with drinking As-contaminated groundwater were recorded much higher than the health risks associated with the consumption of As-contaminated vegetables. Blood As levels in most of the subjects at exposed site exceeded the safe limit of 12 µg L−1. Conclusively, the findings of the current study indicated that drinking contaminated groundwater may be the major cause of As-associated health risks in the region. [ABSTRACT FROM AUTHOR]

Nb-Si based alloys are considered as a potential candidates to substitute for Ni-based super alloys. However, its poor mechanical properties and high temperature oxidation resistance greatly limit its development and application. Alloying can effectively improve the mechanical properties and oxidation resistance of Nb-Si based alloy. In this work, the effects of Al, Cr, B elements addition on the mechanical properties and oxidation resistance of niobium-silicon ternary alloys are summarized. The microstructure, oxidation behavior and mechanical properties of various alloys were analyzed and compared. Moreover, the fracture and oxidation failure mechanism of the alloys are also summarized. Finally, the development trend of ternary Nb-Si based oxidation-resistant alloys in the future has been prospected. [ABSTRACT FROM AUTHOR]

This article examines the free size-dependent vibration behaviour of an Euler–Bernoulli type double-microbeam system, made of two microbeams elastically connected, with simply supported, clamped–clamped and clamped–pinned boundary conditions using an assumed-mode expansion technique (AMET) along with finite-element verifications; effects of altering the couple-stress-tensor-related parameter and the stiffness coefficient of the elastic connection are studied. The double-microbeam problem is formulated nonlinearly utilising Hamilton's principle, alongside the modified couple stress theory (MCST), and energy terms. Employing the AMET, the free vibration characteristics were obtained through solving motion equations. For the double-microbeam system and the elastic connection, a finite-element method (FEM) based model and simulations are developed which enabled us in a partial verification of our results; the agreement is excellent. Moreover, another set of partial verifications is performed with available data in the literature by neglecting one of the microbeams and the spring connection. The study revealed increasing either the couple-stress-tensor-related parameter or stiffness coefficient of the elastic connection increases the natural frequencies of the double-microbeam system. It is also found that both the microbeams vibrate in the same manner in the first mode expansion and out of phase by 180° in the second mode expansion. Altering the boundary effect from pinned–pinned to clamped–pinned, and again to clamped–clamped was found to increase the natural frequencies of the double-microbeam system accordingly. [ABSTRACT FROM AUTHOR]

Cu3SbSe4, featuring its earth-abundant, cheap, nontoxic and environmentally friendly constituent elements, can be considered as a promising intermediate temperature thermoelectric (TE) material. Herein, a series of p-type Bi-doped Cu3Sb1−xBixSe4 (x = 0–0.04) samples were fabricated through melting and hot pressing process, and the effects of isovalent Bi-doping on their TE properties were comparatively investigated by experimental and computational methods. TEM analysis indicates that Bi-doped samples consist of Cu3SbSe4 and Cu2−xSe impurity phases, which is in good agreement with the results of XRD, SEM and XPS. For Bi-doped samples, the reduced electrical resistivity (ρ) caused by the optimized carrier concentrations and enhanced Seebeck coefficient derived from the densities of states near the Fermi level give rise to a high power factor of ~ 1000 µWm−1 K−2 at 673 K for the Cu3Sb0.985Bi0.015Se4 sample. Additionally, the multiscale defects of Cu3SbSe4-based materials involving point defects, nanoprecipitates, amorphous phases and grain boundaries can strongly scatter phonons to depress lattice thermal conductivity (κlat), resulting in a low κlat of ~ 0.53 Wm−1 K−1 and thermal conductivity (κtot) of ~ 0.62 Wm−1 K−1 at 673 K for the Cu3Sb0.98Bi0.02Se4 sample. As a consequence, a maximum ZT value ~ 0.95 at 673 K is obtained for the Cu3Sb0.985Bi0.015Se4 sample, which is ~ 1.9 times higher than that of pristine Cu3SbSe4. This work shows that isovalent heavy element doping is an effective strategy to optimize thermoelectric properties of copper-based chalcogenides. [ABSTRACT FROM AUTHOR]

In recent years, smartphone devices are becoming progressively popular across a diverse range of users. However, user diversity creates challenges in smartphone application (app) development. The diversity of users is often ignored by designers and developers due to the absence of requirements. Owing to this, many smartphone users face usability issues. Despite that, no dedicated platform found that guide smartphone app designers and developers regarding human universality. The aim of this research is to explore the requirements of diverse users in smartphone apps and provide usability guidelines. The objectives of this research are achieved by following two scientific approaches. The human diversity requirements are located by conducting usability tests that investigated the requirements in the form of usability issues. The systematic literature review (SLR) process is followed in order to resolve the discovered usability issues. Both approaches resulted in a list of usability issues and guidelines. The usability tests returned 27 problems while the SLR came with a comprehensive set of universal usability guidelines that were grouped into eleven categories. The study concluded with some major outcomes. The results show evidence of critical usability problems that must be addressed during the design and development of smartphone apps. Moreover, the study also revealed that people with disabilities were three times severely affected by usability problems in such apps than people of different ages and their needs must be considered a top priority in the development of smartphone apps. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) are evolving as green extraction media in the search for efficient extraction of bioactive compounds. In the current study, four different choline chloride based DESs (eutectics of Choline chloride with ethylene glycol, malic acid, oxalic acid, and tartaric acid) were prepared with their physico-chemical properties and cytotoxicity evaluation. The FT-IR spectra of all solvents showed a very strong and broad band at 3350–3450 cm−1 due to intermolecular hydrogen bonding between choline chloride and hydrogen bond donors. The DESs were employed for the ultrasound-assisted extraction (UAE) of bioactive compounds from Cymbopogon citratus (lemongrass) to signify the extraction efficiency of DESs over aqueous methanol. The optimization of extraction parameters (time, temperature and biomass to solvent ratio) was done using Box–Behnken design (BBD). These solvents have negligible values of cytotoxicity in the range of 3.67 to 10.20%. The extraction yields obtained with DESs were significantly higher than aqueous methanol. The highest quantities of total phenolic contents (TPC) 116 mg GAE/g dry matter, total flavonoids contents (TFC) 98 mg QE/g dry matter and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition 95% were assessed with choline chloride/ethylene glycol solvent due to reduced viscosity. The maximum inhibition zones 45 ± 1.2 mm and 40 ± 1.3 mm against bacterial strains S. aureus and E. coli, respectively and 38 ± 1.2 mm and 29 ± 0.5 mm against fungal strains F. solani and A. niger, respectively were observed by choline chloride/ethylene glycol solvent. The DESs have revealed considerable high extraction yield due to extensive hydrogen bonding, which ultimately relates to the higher antioxidant and antimicrobial activities. The developed DESs would be the best alternative for the green and efficient extraction of phenolic compounds from natural sources. [ABSTRACT FROM AUTHOR]

High room-temperature ionic conductivity and mechanical property are essential for the application of solid electrolyte. In this work, a poly(vinylidene fluoride) (PVDF)-based composite polymer solid electrolyte membrane (CSE) incorporated with Li7La3Zr2O12 (LLZO) fillers and high-strength porous skeleton was prepared. The introduction of LLZO increased the ionic conductivity of PVDF at room temperature by reducing the crystallinity of PVDF matrix, and the addition of skeleton greatly improved the mechanical property of electrolyte membrane and inhibited the growth of lithium dendrites. The prepared PVDF-LLZO CSE has a room-temperature ionic conductivity of 1.75 × 10−4 S/cm, and the tensile strength reaches 95 MPa, which greatly enhanced the ability of lithium dendrite suppression. The assembled LiNi0.6Co0.2Mn0.2O2 (NCM622)/CSE/Li cell shows an initial capacity of 151 mAh/g with a retention capacity of 108 mAh/g after 100 cycles at the current density of 0.5 C. This ultrathin PVDF/LLZO CSE has a great application prospect in solid-state lithium batteries. [ABSTRACT FROM AUTHOR]

Oxygen vacancies (O.Vs) play vital role in tailoring structural, optical and dielectric properties of nanostructures. Here we prepared SnO2/graphite (SG) nanocomposite by growing SnO2 nanoparticles on graphite sheets via hydrothermal method. Enhanced dielectric behavior due to increase in the oxygen vacancies (O.Vs) has been observed in SnO2/graphite (SG) nanocomposite synthesized. To reveal the underlying origin here, we investigated the structural, morphological, optical, electrochemical and dielectric properties. The growth of SnO2 NPs on graphite sheets resulted in small-sized NPs (Average size 10.89 ± 0.24 nm) inducing stresses in the structure causing large defect density (O.Vs). The formation of SG nanocomposite has been validated via SEM, TEM, EDX and FTIR. EDX, XPS and Photoluminescence (PL) spectra of SG nanocomposite manifest the presence of large oxygen vacancies (O.Vs). It is revealed that the bandgap of the host material SnO2 (from ultra violet to the visible window) can be engineered by controlling the assimilation of SnO2 NPs on GNs. SG nanocomposite exhibits reversible redox process with high anodic and cathodic currents, low internal (0.47 Ω) and charge transfer (4.08 Ω) resistances, correspondingly, low voltage drop (IR) 0.56 V and high capacitance 54.8 F/g. Variations in dielectric constant (ɛ), dielectric loss ( ε ″ ) and conductivity (σac) are attributed to the increased concentration of O.Vs and introduction of conductive carbon (graphite). The variations in dielectric properties are attributable to Maxewell–Wagner interfacial polarization and hopping process. [ABSTRACT FROM AUTHOR]

Students have different learning approaches and acquire knowledge in different ways owing to their varied perceptions and grasping abilities. Treating students equally, following the traditional teacher-cantered approach, may not be effective and calls for innovations in knowledge dissemination. This article takes a student-centric approach to implement a 'flipped classroom' model in an engineering course for constructivism (i.e. experience-based learning), and students' personalized learning. The performance of the flipped classroom approach is compared with the traditional lecturing approach using four lenses: students' grades, students' reflection using three surveys at different stages during the semester, teacher's observation, and peer observation. In most of the existing approaches, analysis of the qualitative survey data is performed manually without computer assistance, and therefore these are criticized for being primeval and instinctive. In this research, a novel approach, based on fuzzy logic, is devised to evaluate the qualitative survey responses from the students. It is shown in this research, that the linguistic survey responses can be summarized in an index more meaningfully using a fuzzy logic-based approach. The results further showed that the flipped classroom model helped students to improve their grades and enhance engagements with their teacher and their peers. Increased interaction, during interactive class activities, was instrumental in evolving students' problem-solving and critical analysis skills towards better learning experiences. Furthermore, students' survey results, analyzed using the novel fuzzy indexing and a non-parametric statistical test showed that the intervention in the form of flipped classes was effective and found to be statistically significant. The findings of this study may help other academics, endeavoring for experience-based, and students' personalized learning. [ABSTRACT FROM AUTHOR]

Access control is used to prevent data from access of unauthorized users. Over the years, several access control models have been proposed to meet requirements of various applications and domains. Role-based access control model is one such model which enforces security based on the roles. However, role-based access control model is static in nature and does not provide the dynamism of collaboration required in the multi-domain environment. This paper presents an Ontology-Based Access Control (OBAC) model, which provides a solution by using an ontology-based approach. In OBAC model, agents are used for the identification and classification of Roles, Objects and Permissions (ROP) in distributed environment. The proposed method exploits the ontology-based approach, where agent learns and adapts changes to identify roles, objects and permissions from a given dataset and classify them into ontology according to rules and policies. The proposed ontology also provides extensibility and reusability. Moreover, we simulated our technique on datasets of two different domains. The first dataset is related to the university environment and the second one is about hospital domain. The promising experimental results indicates the effectiveness of proposed approach. [ABSTRACT FROM AUTHOR]

The appalling state of Liberia's municipal solid waste management system (MSWM) is the motivation for this review and analysis. Solid waste management protocols and system dynamic modeling support policy development as it uses waste prevention to explain the complex waste management systems and suggests methods for effective management. However, creating an effective waste system goes beyond the formulation of policies and legislation; it involves financial and technological proficiency, skilled human capacity, technical, social, resource recycling, educational awareness programs, and active public participation. Because of urbanization, Liberia's municipal solid waste (MSW) problems have become heightened, thereby impacting the economic, social, and political fabric of society by overburdening infrastructure and social facilities. The impact of urbanization must be addressed because urbanization, amongst several factors, including unsustainable management of MSW, degrades the environment and presents risks to public health. The purpose of this review was to highlight the current waste management activities in Liberia and provide information to the readers about the challenges facing the waste management sector and the challenges impeding the development of a sustainable waste management system. In Liberia, waste management activities are getting worse daily due to shortage of a comprehensive waste management framework, the absence of guidelines regarding the responsibilities of waste generators, and the decision-makers' lack of intent to design and implement a sustainable and integrated management system. Recommendations for collaborative efforts are made by focusing on delivering a waste strategy which concentrates on waste minimization, recycling, resource recovery, and promoting sustainable waste management practices for communities, small businesses, corporations, and government institutions in Liberia and other developing countries. [ABSTRACT FROM AUTHOR]

In the context of video-based image classification, image annotation plays a vital role in improving the image classification decision based on it's semantics. Though, several methods have been introduced to adopt the image annotation such as manual and semi-supervised. However, formal specification, high cost, high probability of errors and computation time remain major issues to perform image annotation. In order to overcome these issues, we propose a new image annotation technique which consists of three tiers namely frames extraction, interest point's generation, and clustering. The aim of the proposed technique is to automate the label generation of video frames. Moreover, an evaluation model to assess the effectiveness of the proposed technique is used. The promising results of the proposed technique indicate the effectiveness (77% in terms of Adjusted Random Index) of the proposed technique in the context label generation for video frames. In the end, a comparative study analysis is made between the existing techniques and proposed methodology. [ABSTRACT FROM AUTHOR]

In this paper, we analyze static traversable wormholes via Noether symmetry technique in modified Gauss–Bonnet f (G) theory of gravity (where G represents Gauss–Bonnet term). We assume isotropic matter configuration and spherically symmetric metric. We construct three f (G) models, i.e, linear, quadratic and exponential forms and examine the consistency of these models. The traversable nature of wormhole solutions is discussed via null energy bound of the effective stress–energy tensor while physical behavior is studied through standard energy bounds of isotropic fluid. We also discuss the stability of these wormholes inside the wormhole throat and conclude the presence of traversable and physically stable wormholes for quadratic as well as exponential f (G) models. [ABSTRACT FROM AUTHOR]

Renewable energy resources play a valuable role in the global increase of energy demand. The research was performed to enhance the performance of plasmonic dye-sensitized solar cells (PDSSCs) by harvesting the maximum sunlight. In this context, the TiO2 nanoparticles for simple DSSCs and the Cu/rGO/TiO2 nanocomposites for PDSSCs were synthesized using the Sol–Gel and chemical reduction method. Authors demonstrated the utilization of synthesized Cu/rGO/TiO2 nanocomposite-based photoanode to fabricate the plasmonic dye-sensitized solar cells (PDSSCs). SEM, EDX, XRD, and UV/Vis techniques were employed to analyze the surface morphology, elemental composition, crystal structure, and absorbance spectra, respectively. Furthermore, IV measurements were performed on the fabricated devices, and it was observed that the Cu/rGO/TiO2 nanocomposite presented an enhanced efficiency of 5.14% in PDSSCs, which is more than that of the DSSCs-based on pure TiO2 nanoparticles. As an enhanced efficiency could be achieved by high optical absorption and electron injection rate, the PDSSCs with Cu/rGO/TiO2 nanocomposite have an enhanced efficiency due to the surface plasmonic resonance. An improved IPCE of 59.79% was also achieved in Cu/rGO/TiO2 nanocomposite-based photoanode, which might be due to the higher surface area of the photoanode. [ABSTRACT FROM AUTHOR]

Human zinc (Zn) deficiency is prevalent in areas where cereals dominate in the diet. Soil Zn application may enhance the concentration of Zn in wheat grains and dietary Zn intake by target populations. However, its value has never been practically quantified in Zn nutrition of any population group. We, therefore, studied farming families in rural Punjab (Pakistan). The selected adults (n = 156, grouped based on age and gender) were Zn undernourished (as assessed by estimated Zn bioavailability in their diet) and their plasma Zn levels also indicated Zn deficiency. On average, wheat consumption by the adults contributed about 68% in total Zn and 93% in total phytate intakes. Soil Zn application to wheat fields significantly increased Zn and decreased phytate concentration in chapati (flatbread made of whole-wheat flour). From dietary phytate intakes by the adults, we calculated desired chapati Zn concentration and dietary Zn intake that would meet their daily Zn requirement. The physiological Zn requirements of adult women and men were estimated to be achieved by intake of, respectively, 10.4–15.3 mg Zn d−1 (37–46 mg Zn kg−1 in chapati) and 14.4–23.3 mg Zn d−1 (41–52 mg Zn kg−1 in chapati). It was evident that soil Zn application aiming at optimum grain yield of wheat significantly improved Zn nutrition of the studied adults, but not up to desired levels. High Zn applications (via soil and/or foliage) to wheat and growing cultivars specifically selected for Zn biofortification may be needed to optimise Zn nutrition in rural Pakistan. [ABSTRACT FROM AUTHOR]

Active screen plasma nitriding (ASPN) of steel has been extensively studied during the past few years. ASPN is a new technique with many advantages and can be used for treating non-electrical conducting materials like oxides and polymers. Recently, ASPN technique has been used for aluminum and aluminum alloys for surface treatment. The current study reports the growth and characterization of the compound aluminum and iron nitride coating on aluminum–silicon (Al–11Si) eutectic alloy using the active screen plasma nitriding setup to improve the surface properties of the alloy. After treatment in low-pressure plasma environment for five-hours, samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), atomic force microscopy, and Vickers's Micro Hardness testing to investigate the changes in surface morphology, elemental composition, and mechanical properties before and after the plasma treatment. XRD peaks (111), (200), (220), (311) of AlN were observed while that of FeXN peaks were also observed. Spherical, highly crystalline, agglomerated aluminum, and iron nitrides were observed in SEM micrographs. Elemental analysis using EDS and laser-induced breakdown spectroscopy confirmed the presence of nitrogen at the surface of the low pressure plasma treated sample. The presence of nitrides on the surface of the alloy resulted in improvement of the hardness as observed from the Vickers' hardness testing. It is concluded that ASPN is a useful technique for the improvement of surface hardness of Al–11Si alloy. [ABSTRACT FROM AUTHOR]