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Strategically fabricated Ag loaded Fe-g-C3N4 nanosheet for photocatalytic removal of aqueous organic pollutant
The efficiency of the photocatalyst towards the degradation of organic pollutants depends on the harvesting of the visible light and inhibiting the recombination rate of electron-hole pairs to create a large number of charge carriers to drive the redox reaction. Most charge carriers recombine in 2D photocatalyst like g-C3N4 through the bulk process within the stacked layered structure. The recombination through bulk can be suppressed through nanosheet formation, while surface recombination can be inhibited via fast interfacial photogenerated charge transfer. In the present work, Ag-loaded Fe-doped g-C3N4 nanosheet (Ag/Fe-g-C3N4 NS) photocatalyst was synthesized by combining three effective strategies i.e., Fe doping, nanostructuring, and Ag loading. Various analytical techniques have been employed to characterize all the prepared samples. The results indicate that Fe doping influences visible light absorption by modifying the electronic and optical properties. In contrast, nanosheet formation leads to a significant increment in the number of active sites due to the increased surface area. Ag anchoring over Fe-g-C3N4 NS favors charge separation at the interface of Fe-g-C3N4 and Ag due to the presence of the Schottky barrier. Integration of all the three strategies in Ag/Fe-g-C3N4 NS creates a synergistic effect to add beneficial properties and displays a 5-fold improvement in photocatalytic degradation of organic pollutants, as compared to pure g-C3N4. The present study provides a novel and facile approach for realizing an efficient photocatalyst for environmental remediation. 2022 Elsevier B.V. -
Strategies for facilitating listening skills among foreign language learners in US Universities
Developing from the thesis that understanding is the key to any and all meaningful conversation/s, this study focuses on the facilitation of listening skills among foreign language learners. It is conducted with the objective to find out the most effective ways in which an instructor can enable the development of listening skills among the learners of a foreign language. This paper reports the findings of an empirical study which followed a cross-sectional research design and employed a survey method to elicit the data. Twenty-seven Foreign Language Instructors/ Associate Instructors teaching around thirteen different foreign languages across sixteen different universities in the United States of America participated and reported to a survey on effective pre-listening, listening, and post-listening tasks, activities, and strategies which they found to be the most powerful in their respective classrooms. Thirteen of the Seventeen strategies and or/ tasks which were provided in the Strategies for Facilitating Listening (SFL) questionnaire were rated to be highly effective in the facilitation of the development of listening skills among the learners. The paper after discussing the efficacies of the strategies and tasks at hand ends by analyzing the pedagogical implications of the findings. 2020 The authors and IJLTER.ORG. All rights reserved. -
Strategy for low cost airlines in India
Research Revolution Vol. 1, Issue 6, pp.1-3 ISSN No. 2319-300X -
Strategy Formulation and Implementation in Zimbabwe's Food Manufacturing Industry
International Journal of Science and Research, Vol-3 (5), pp. 849-855. ISSN-2319-7064 -
Stratified Bioconvective Jet Flow of Williamson Nanofluid in Porous Medium in the Presence of Arrhenius Activation Energy
Due to the higher coefficients of heat and mass transfer, the jet flow has become an effective source for the transfer of heat and mass in various industries. Due to these high coefficients, the heat and mass transfer rates will be high in the appliances equipped with the jet flow. Further, the existence of the magnetic field helps in controlling the velocity and the presence of the gyrotactic microorganisms ensure proper mixing of nanoparticles. A dilute nanoparticle suspension is assumed so that it will not affect the movement of motile cells that leads to bioconvection. Hence, this paper aims to analyze the characteristics of heat transfer as well as mass transfer of the jet flow of Williamson nanofluid past a porous stretching sheet in the existence of microorganisms. The mathematical model obtained as a result of these assumptions is transformed into nonlinear ordinary differential equations for which acceptable solutions are obtained using the numerical method. The results thus obtained are presented graphically and based on the outcomes, it is perceived that the magnetic field has control over the velocity profile thus influencing the thermal profile. The increase in the Williamson parameter also reduces the velocity of the fluid flow. Further, an increase was noticed in the thermal and concentration profiles of the nanofluid for higher values of thermophoresis parameter and the increase in the porosity reduced the speed of the flow of nanofluid. 2023 World Scientific Publishing Company. -
Streamlined electrochemical harvesting of cobalt and nickel from soft cemented carbide scrap for superior supercapacitors
We propose a complete circular economy and sustainability model from soft cemented carbide scrap to supercapacitor application. An enhanced recovery of cobalt and nickel was observed when deep eutectic solvent was used. A comparative in-situ electrochemical deposition of the recovered metals was done on stainless steel (SS), SS/activated carbon (AC), and SS/AC/polyaniline (PANI). The optimization of electrochemical extraction was carried out by varying voltage, time, and temperature. The surface area and conductive polymer's electronic distribution contributed to different surface morphological deposition of specific metals on them. Unique fluffy particle deposition was observed on the surface as fine grain particles with uniform particle size within 1 m. The fabricated supercapacitors showed the pseudocapacitance behaviour. The presence of metal oxide nanocomposite deposition as the active material is particularly pronounced in the SS/AC/PANI device due to the inclusion of PANI as an active material and its substantial contribution to pseudocapacitance. The higher charge-discharge time of SS/AC/PANI at the same current densities compared to SS/AC may be due to the above-mentioned additional contribution of PANI's quickly reversible redox behavior. Hence, the overall electrochemical extraction from scrap to supercapacitor will undoubtedly lead to achieving the sustainable development goals (SDGs) 2024 -
Strength and durability properties of geopolymer paver blocks made with fly ash and brick kiln rice husk ash
In India the generation of agro waste rice husk ash is abundant. The utilization of rice husk ash in development of geopolymer binders can be suitable to alleviate the environmental problems associated with disposal of rice husk ash. Further, the utilization of rice husk ash generated from the stacks of brick kilns has not been addressed in past, particularly in development of geopolymer binders. This study proposes development of geopolymer paver (GEOPAV) blocks utilizing brick kiln rice husk ash (BKRHA). It presents fresh, mechanical and durability properties of GEOPAV blocks blended with fly ash, BKRHA, natural aggregates, NaOH and Na2SiO3 solution, and cured in both sundry and room temperature conditions. Microstructural analysis using scanning electron microscope (SEM) and X-ray diffraction (XRD) was adopted to study the influence of BKRHA on hardened properties of GEOPAV blocks. The results show that addition of BKRHA reduce the workability of GEOPAV mixes due to micro porous surface with honeycombed structure of BKRHA particles. The addition of BKRHA showed negligible improvement in compressive strength of GEOPAV blocks. However, the major advantage was observed with improved split tensile strength and flexural strength for GEOPAV blocks with BKRHA. Further, the durability properties in terms of resistance to acid and frost attack was significantly improved with the addition of BKRHA in GEOPAV blocks. Such improvements can be attributed to high amounts of amorphous silica in BKRHA which contribute towards dissolution and formation of polymeric gel, and thereby serve as a binder to enhance the geopolymer matrix making it dense. Finally, all the developed GEOPAV blocks satisfy the IS 156582021 specification requirements and perform much better when compared to commercially available paver blocks. 2021 The Authors -
Strength and leaching characteristics of red mud (bauxite residue) as a geomaterial in synergy with fly ash and gypsum
Red mud (Bauxite residue) comprises microscopic particles and other chemical constituents that pose a major threat to the environment. The most common solution to resolve issues related to any solid waste is its reuse in construction. This paper delves into the possibility of using red mud as a geomaterial in synergy with fly ash and gypsum. In this regard upon finding the geotechnical properties of virgin red mud, it is strengthened with fly ash by replacing 10, 20, and 30% of red mud by its dry weight and to these combinations gypsum was added by 0.5% and 1% and prepared various combinations. The impact of these material additions on the characteristics of red mud were investigated using the Unconfined compressive strength and California bearing ratio values and their environmental compatibility was further studied by conducting the leaching characteristics using Toxicity Characteristics Leaching Procudure (TCLP) method. The findings of the tests indicated that fly ash and gypsum significantly enhanced the strength qualities of red mud as compared to unstabilized red mud. The stabilization helps red mud to attain a minimum strength required to use as a subgrade material. Furthermore, leaching investigations performed on stabilised samples have revealed that the vast majority of leaching heavy metals are within the WHO's authorised threshold for toxicity. 2022 -
Strength Development of Geopolymer Composites Made from Red Mud-Fly Ash as a Subgrade Material in Road Construction
The application of industrial waste in construction reduces the dependency on natural resources. The materials, including red mud (RM) and fly ash (FA), proved to be favorable materials. However, the materials potential together as a geopolymer composite for road applications has rarely been explored. This study will examine the possibility of the replacement of natural materials in subgrade applications. To achieve this, the geopolymer compositions will be prepared by replacing RM with FA at replacement rates of 10%, 20%, and 30% by dry weight basis. The alkaline activator solution of 8 M will be prepared using sodium hydroxide (NaOH) and sodium silicate to develop geopolymer composites. The strength properties will be studied using the California Bearing Ratio (CBR) and unconfined compression strength (UCS) and validated with microstructural analysis using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The results reveal that geopolymer composites could achieve a maximum CBR value of 12% and UCS of 2,700 kPa. The microstructural analysis revealed that the formation of dense calcium aluminate hydrate (C-A-H) and calcium silicate hydrate (C-S-H) are the reason for strength improvement. The leaching studies show that the toxic elements were within the permissible limits. Overall, the test results confirmed that the geopolymer composites meet the required strength and could be used as a subgrade material in road construction. 2020 American Society of Civil Engineers. -
Strengthening of brick masonry using biaxial polypropylene geogrid as confinement reinforcement
Recent and past earthquakes have once again reiterated the requirement of strengthening the masonry structures to withstand both in-plane and out-of-plane loads. In this experimental investigation, biaxial polypropylene geogrid was used as a confinement reinforcement on the surfaces to strengthen masonry specimens. The masonry specimens without and with geogrid have been subjected to a compression test, flexural bond strength test and diagonal tension (shear) test as per IS 1905, ASTM E518 and ASTM E519, respectively. From the results, it has been found that biaxial polypropylene geogrid significantly enhances the strength in masonry specimens with geogrid and also reduces crack propagation in all three tests. The relationship between compressive strength and flexural bond strength, compressive strength and shear strength of masonry specimens with geogrid has been established. Furthermore, based on the cost analysis of various strengthening techniques, it was concluded that the use of biaxial polypropylene geogrid is an economically feasible alternative to other reinforcing materials, such as stainless-steel wire mesh and polyester geogrid. The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024. -
Stress analysis of the vertical tail skin joint and estimation of fatigue life due to fluctuating side loads
Vertical tail VT is one of the main components of the airframe. VT is attached with a rudder, which is the control surface, which is used for controlling the yawing motion of the aircraft. The deflection of the rudder introduces side load on the VT. Without rudder deflection, the aerodynamic load will not be applied to the VT. The load due to the deflection of the rudder is the major load for the VT. From a design point of view side, gust load is also important in transport aircraft. The present study is on a critical region with a riveted joint in the VT skin. A stiffened panel of the vertical tail with the spliced skin will be considered for the identification of the critical location. FEM will be used for the analysis of the component. In this study, loads of small transport aircraft will be considered. The maximum stress location and distribution of stresses on the stiffened panel are conducted by the FEM method. To obtain the mesh independent magnitude of stress, a refined local analysis is conducted. The tensile stresses on the skin are caused by the side loads of VT on the stiffened panel. Rivet holes are the stress concentration locations. The locations for fatigue crack initiation is the rivet holes. Fatigue damage estimation is calculated by the use of Miners rule. Fluctuating loads due to rudder deflection will be considered for damage calculation. SN data curve of the aluminium alloy material used for the VT skin will be considered for stress-based damage calculation. TJPRC Pvt. Ltd. -
Stress and resilience in British Indian parents with an autistic child: a comparative study with white British and Indian parents
Purpose: This study aims to examine the levels of stress and resilience in a sample of British Indian parents bringing up a child with autism. Design/methodology/approach: A total of 52 British Indian parents took part in a survey that included measures of stress, resilience, support and child adaptive functioning. Results were compared to a sample of white British (n = 120) and Indian parents (n = 120). Findings: The British Indian parents recorded higher levels of stress and less perceived social support than their white British counterparts. British Indian parents took longer to register concern about their childs development and sought a diagnosis at a later age than the white British group. The delay in concern and diagnosis was similar to that found in the India group. Originality/value: The research suggests that British Indian parents are disadvantaged in social support and mental well-being compared to white British parents and may face similar community pressures to parents bringing up a child in India. 2023, Emerald Publishing Limited. -
Stress mindset as a mediator between self-efficacy and coping styles
Stress mindset is a lens through which one views stress and its consequences as beneficial or harmful for them. It is a distinct variable that differs from frequency, amount, and intensity of stress. The literature review indicated that stress mindset could mediate the link between self-efficacy and coping style, which was previously not tested. Hence, the study aimed; 1) to examine the relationship between self-efficacy, stress mindset, and coping style; 2) to investigate the influence of stress mindset and self-efficacy on coping styles; 3) to find whether stress mindset mediates the association between self-efficacy and coping styles. The study employed a correlational research design, whereby through multi-phase sampling recruited 727 participants (male = 300, female = 427, mean age = 16.26) studying in 11th and 12th standard. The researchers administered validated stress mindset, self-efficacy, and coping style and performed a multiple correlational and regression analysis. They computed mediation analysis using Hayes model 4 in Process Macro. The finding indicated that the association between self-efficacy and self-controlling coping style is mediated by stress mindset. Furthermore, it mediated the connection between some sub-domains of self-efficacy and coping styles. The data were evident to infer that individual with high self-efficacy can interpret social stressors as beneficial and improve their coping skills. 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. -
Strongly connected interval-valued fuzzy graphs
In interval-valued fuzzy graphs (IVFGs) strong paths need not exist between every two nodes in contrast with fuzzy graphs. Based on this, we define a particular class of interval-valued fuzzy graphs called strongly connected interval valued fuzzy graphs (SCIVFGs). A connected IVFG in which a strong path always exists between every two nodes is called a SCIVFG. We prove several sufficient conditions for an IVFG to be strongly connected. Finally we show that strong connectedness is preserved under isomorphism and co-weak isomorphism. 2020, Research Publication. All rights reserved. -
Structural and antibacterial assessment of two distinct dihydroxy biphenyls encapsulated with ?-cyclodextrin supramolecular complex
?-Cyclodextrin plays a vital role in biological application because it can enhance the stability and solubility of the guest molecules in the supramolecular inclusion complexes. Moreover, the ?-Cyclodextrin inclusion complex has control-releasing behavior and lower toxicity than bare guest molecules. To improve the solubility and stability properties of two structurally different fluorescent guest molecules, namely 2,2?-dihydroxy biphenyl and 3,3?-dihydroxy biphenyls, they involve the ?-Cyclodextrin inclusion complex process. Optical measurements clearly described the efficient binding through the changes in the absorbance and emission intensities of guest molecules in the presence of ?-Cyclodextrin. The Job's plot from absorbance measurements reveals the 1:1 stochiometric ratio of binding of guests and the ?-Cyclodextrin host. The FT-IR spectra of the solid complex show the characteristic stretching and bending vibrations from both the guests and the host molecule. The 1HNMR spectra of the inclusion complex promote downfield shifting of guest molecule protons upon binding with the ?-Cyclodextrin host. The solid complex prepared using the solution method exhibits superior antibacterial activity against both gram-positive and gram-negative bacteria compared to the kneading and physical mixing methods. 2024 -
Structural and functional characterization of a hypothetical protein in the RD7 region in clinical isolates of Mycobacterium tuberculosis an in silico approach to candidate vaccines
Background: Mycobacterium tuberculosis has been ravaging humans by inflicting respiratory tuberculosis since centuries. Bacillus Calmette Guerine (BCG) is the only vaccine available for tuberculosis, and it is known to be poorly effective against adult tuberculosis. Proteins belonging to the ESAT-6 family and PE/PPE family show immune responses and are included in different vaccine trials. Herein, we study the functional and structural characterization of a 248 amino acid long putative protein novel hypothetical protein 1 (NHP1) present in the RD7 region of Mycobacterium tuberculosis (identified first by subtractive hybridization in the clinical isolate RGTB123) using bioinformatics tools. Results: Physicochemical properties were studied using Expasy ProtParam and SMS software. We predicted different B-cell and T-cell epitopes by using the immune epitope database (IEDB) and also tested antigenicity, immunogenicity, and allergenicity. Secondary structure of the protein predicted 30% alpha helices, 20% beta strands, and 48% random coils. Tertiary structure of the protein was predicted using the Robetta server using the Mycobacterium smegmatis protein as the putative protein with homology. Structural evaluations were done with Ramachandran plot analysis, ProSA-web, and VERIFY3D, and with GalaxyWEB server, a more stable structure was validated with good stereo chemical properties. Conclusion: The present study of a subtracted genomic locus using various bioinformatics tools indicated good immunological properties of the putative mycobacterial protein, NHP1. Evidence obtained from the analyses of NHP1 using structure prediction tools strongly point to the fact that NHP1 is an ancient protein having flavodoxin folding structure with ATP binding sites. Positive scores were obtained for antigenicity, immunogenicity, and virulence too, implying the possibility of NHP1 to be a potential vaccine candidate. Such computational studies might give clues for developing newer vaccines for tuberculosis, which is the need of the hour. 2022, The Author(s). -
Structural and Optical Properties of Alumino Lead Borate Glasses Containing Copper Oxide
The alumino lead borate glasses with small amounts of copper oxide were synthesized by melting and quenching according to the relation 50B2O3-30PbO-(20x)Al2O3-xCuO with x = 0, 0.10, 0.25, 0.50, 0.75 and 1.00 mol%. The powder XRDs had no sharp peaks which show that the samples are amorphous. Density of the glasses increased as the content of the CuO increased. FTIR spectroscopic studies reveal the presence of BO3, BO4, PbO4, AlO4, pentaborate [B5O8], diborate [B4O72] and dipentaborate B512 structural units. The UV-visible absorption studies showed that the refractive index, indirect energy gap, oxide ion polarizability and optical basicity had composition dependence which were related to the glass structure. As the CuO concentration increased, the refractive index decreased, indirect energy gap increased, oxide ion polarizability decreased and optical basicity decreased. Optical band gap increased with increasing CuO content as the band gap for bridging oxygens is higher than that for non-bridging oxygens. 2024 Indian Ceramic Society. -
Structural and physico-chemical evaluation of melatonin and its solution-state excited properties, with emphasis on its binding with novel coronavirus proteins
Melatonin is a natural hormone from the pineal gland that regulates the sleep-wake cycle. We examined the structure and physico-chemical properties of melatonin using electronic structure methods and molecular-mechanics tools. Density functional theory (DFT) was used to optimise the ground-state geometry of the molecule from frontier molecular orbitals, which were analysed using the B3LYP functional. As its electrons interacted with electromagnetic radiation, electronic excitations between different energy levels were analysed in detail using time-dependent DFT with CAM-B3LYP orbitals. The results provide a wealth of information about melatonin's electronic properties, which will enable the prediction of its bioactivity. Molecular docking studies predict the biological activity of the molecules against the coronavirus2 protein. Excellent docking scores of ?7.28, ?7.20, and ?7.06 kcal/mol indicate that melatonin can help to defend against the viral load in vulnerable populations. Hence it can be investigated as a candidate drug for the management of COVID. 2020 Elsevier B.V. -
Structural domination and coloring of some (P7,C7)-free graphs
We show that every connected induced subgraph of a graph G is dominated by an induced connected split graph if and only if G is C-free, where C is a set of six graphs which includes P7 and C7, and each containing an induced P5. A similar characterization is shown for the class of graphs which are dominated by an induced connected complete split graph. Motivated by these results, we study structural descriptions of some classes of (P7, C7)-free graphs. In particular, we give structural descriptions for the class of (P7, C7, C4, gem)-free graphs and for the class of (P7, C7, C4, diamond)-free graphs. Using these results, we show that every (P7, C7, C4, gem)-free graph G satisfies ?(G)?2?(G)?1, and that every (P7, C7, C4, diamond)-free graph H satisfies ?(H)?max{3,?(H)}. 2020 Elsevier B.V. -
Structural engineering on indole derivative for rechargeable organic lithium-ion battery
In the present work, the indole derivative, namely, 3,3?,3?-methane-triyl-tris-1H-indol(tris-Ind), is synthesized and characterized as an organic electrode material in rechargeable lithium-ion batteries (RLIB). The structural characterization of the synthesized molecule is carried out using physicochemical techniques. The ball milling method is used for the lithiation process to form electroactive lithiated tris-Ind (Li-tris-Ind). The electrochemical activity of Li-tris-Ind is measured in aqueous and non-aqueous electrolytic media, and the results are compared. The aqueous cell system delivers an average cell potential of 0.76V with a discharge capacity of 189 mAhg?1, whereas the non-aqueous cell system delivers an average potential of 1V with 506 mAhg?1. The potentiostatic electrochemical impedance spectroscopic studies reveal the kinetics of finite diffusion. The organic electrode shows good cyclic stability and reproducibility in both systems, making it a significant practical material for RLIB applications. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.