•Modeling of CZTS solar cells.•AZTS as buffer layer.•Effect of various parameters.•Efficiency enhanced.
This paper presents the use of AZTS, a non-toxic and earth abundant material as buffer layer in ...CZTS solar cells due to its good lattice match. We have performed simulation on the experimentally fabricated AZTS/CZTS hetero-junction device by adding CZTS as back surface field (BSF) layer. In this work, first we have reconstructed the AZTS/CZTS experimentally designed solar cell then BSF layer is added to boost the solar cell performance in SCAPS simulator. Several parametersof AZTS buffer layer such as generation/recombination rate and doping concentration are varied during simulationto enhance the performance of investigated solar cells structures. It has been noticed that addition ofBSF layer increasesthe efficiency of AZTS/CZTS solar cell from 4.51% to 5.05% along with improvement of both Voc and FF.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Agrobacterium-mediated floral dip protocol is the most extensively used transformation method for a model plant Arabidopsis thaliana. Several useful methods for Agrobacterium tumefaciens-mediated ...transformations of Arabidopsis are existing, but they are time consuming and with low transformation efficiency. Here, we developed a transgenic Arabidopsis lines TET12p::TET12-RFP in a short period of time and enhanced transformation efficiency by using a modified transformation method by applying drought stress after floral dip. In this protocol, Agrobacterium cells carrying TET12p::TET12-RFP recombinant vectors were resuspended in a solution of 5% sucrose, 0.05% (v/v) silwet L-77 to transform female gametes of developing Arabidopsis inflorescences. Treated Arabidopsis were then applied with different levels of drought stresses to stimulate plants for the utilization of maximum plant energy in seed maturation process. The applied stresses achieved the fast maturation of already treated inflorescences while stopped the growing of newly arising untreated inflorescence, thus decreased the chances of wrong collection of untransformed seeds. Consequently, the collected seeds were mostly transgenic with a transformation frequency of at least 10%, thus the screening for positive transformants selection was more advantageous on a selective medium as compared to a classical floral dip method. Within 2-3 months, two hundred of individual transgenic plants were produced from just 10 infiltrated plants. This study concludes that application of drought stresses in a specific stage of plant is a beneficial strategy for achieving the transgenic Arabidopsis in a short period of time with high transformation efficiency.
Design and development of an effective drug to combat the 2019 novel coronavirus remains a challenge. Therefore, it is of interest to study the binding features of 1615 FDA approved drugs with the ...recently known 2019-nCoV main protease structure having high sequence homology with that from SARS-CoV. We document the binding features of top 10 drugs with the target protein. We further report that Conivaptan and Azelastine are mainly involved in hydrophobic interactions with active site residues. Both drugs can maintain close proximity to the binding pocket of main protease during simulation. However, these data need further in vitro and in vivo evaluation to repurpose these two drugs against 2019-nCoV.
Over the past years, vehicular ad hoc networks (VANETs) have been commonly used in intelligent traffic systems. VANET's design encompasses critical features that include autonomy, distributed ...networking, and rapidly changing topology. The characteristics of VANET and its implementations for road safety have attracted considerable industry and academia interest, particularly in research involving transport systems enhancement that could potentially save lives. Message broadcasting in an open access system, such as VANET, is the main and utmost challenging problem with regard to security and privacy in VANETs. Various studies on VANET security and privacy have been proposed. Nevertheless, none has considered overall privacy requirements such as unobservability. In order to address these shortcomings, we propose a VANET based privacy-preserving communication scheme (VPPCS), which meets the requirements for content and contextual privacy. It leverages elliptic curve cryptography (ECC) and an identity-based encryption scheme.We have carried out a detailed security analysis (burrows-abadi-needham (BAN) logic, random oracle model, security of proof, and security attributes) to validate and verify the proposed scheme. The analysis has shown that our scheme is secure and also shown to be effective in a performance evaluation. The proposed scheme does not only meet the previously mentioned security and privacy requirements, but also impervious to various types of attacks such as replay, impersonation, modification, and man-in-themiddle attacks.
In this study, we have successfully controlled the number of secondary phases in Zinc Oxide (ZnO) nano-structures by changing the concentration of Copper (Cu) atoms. Zinc Copper Oxide (Zn1-xCuxO) ...nanostructures with x = 0.1, 0.2, 0.3, 0.4 and 0.5 were grown by hydrothermal technique. The increased number of secondary phases with Cu concentration were resulted in the enhancement of Seebeck coefficient (72–124 μV/°C) and power factor (2.3 × 10−4 Wm−1K−2). The secondary phases are served as barrier therefore, filtered the low energy carriers at the interface of two secondary phases which resulted in the enhancement of Seebeck coefficient and electrical conductivity simultaneously. The emergence of secondary phases with Cu concentration was confirmed with the help supplementary measurements. X-Ray Diffraction (XRD) data is confirmed the formation of the wurtzite structure of ZnO along with the presence of Copper Oxide (CuO) based secondary phases. Furthermore, the intensity of secondary phases related XRD peaks were found to be increased with the increase of Cu concentration. Raman spectroscopy data was suggested that the intensity of E2 high mode was decreased due to the development of a number of secondary phases with Cu concentration. Scanning electron microscope images are shown the formation of hexagonal shaped nano structures. Fourier Transform Infrared Spectroscopy (FTIR) data was used to further confirm the presence of secondary phases in the grown Zinc Copper Oxide (ZCO) samples at higher concentration of Cu atoms.
•Growth of Cu doped ZnO by hydrothermal method.•Different concentration of Cu creates secondary phases.•Thermoelectric properties enhanced due to the presence of secondary phases.•Presence of secondary phases verified by XRD, Raman spectroscopy and SEM.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZRSKP
•Growth of MgSnO nanoparticles by hydrothermal method.•Effect of Sn concentration on thermoelectric properties of MgSnO.•Thermoelectric properties enhanced by Sn concentration.•Enhancement of ...thermoelectric properties is due to generation of secondary phases.•Confirmation of secondary phases done by XRD and Raman spectroscopy.
A study is conducted to determine the effects of cobalt doping concentration on structural, morphological and thermoelectric properties of Zinc Oxide (ZnO). To test this hypothesis, cobalt doped zinc oxide nano-particles are prepared by hydrothermal method by modulating the Cobalt (Co) concentration from 0.1 to 0.5. The X-Ray Diffraction (XRD) and Raman data is suggested that crystallinity of grown samples is found to be decreased by increasing the concentration of Co atoms. The poor crystallinity of the sample having higher concentration of Co atoms is due to the emergence of secondary phases. The value of Seebeck coefficient is also improved with doping as indicated by the high Seebeck value (250 µV/°C) of Zn0.5Co0.5O. This enhancement of Seebeck coefficient is linked with the number of secondary phases. In contrast, electrical conductivity is reduced due to the generation of the impurity level close to the conduction band. In conclusion, at higher doping content, the overall power factor is enhanced with a slow increase in Seebeck coefficient and decrease in electrical conductivity by doping content.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZRSKP
In this paper, we have successfully controlled the thermoelectric properties of copper nitride (Cu3N) thin films by optimizing the post growth nitrogen gas flow time. During thermal evaporation ...growth of Cu3N thin films, pure copper power (0.12 g) was evaporated on soda lime glass substrate. The boat temperature and nitrogen gas flow rate were fixed at 1010 °C and 100 sccm respectively in horizontal glass tube furnace. In order to study the annealing time duration, all samples were annealed at 320 °C in tube furnace for 2–8 h with constant flow rate of 100 sccm. The formation of Cu3N phase was confirmed by X-Ray Diffraction (XRD) and it was found that crystallinity of grown thin films was improved with annealing time duration. The Seebeck data demonstrated that the value of Seebeck coefficient was increased form 87.59 μV/°C to 134.79 μV/°C as the annealing time duration was increased from 2 to 8 h. This improvement in Seebeck coefficient was associated with the enhancement of samples crystallinity which ultimately increase the mobility of charge carriers. The value of electrical conductivity was also increased from 26.04 S/cm to 33.49 S/cm, therefore we were able to achieve the highest value of power factor (6.08 × 10−5 Wm−1C−2) for sample annealed for maximum time duration. Raman spectroscopy and SEM measurements were additionally performed to strengthen our proposed argument.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Nanotechnology gained much attention and nanomaterials have diverse applications in every field of life and researchers are consistently working on the methodology for the fabrication of NPs. ...Different chemical, biological and physical methods are in practice for the fabrication of NPs and under the current scenario of pollution, the application of eco-benign methods is of paramount importance. Biogenic synthesis versus other methods proved to be highly efficient for the fabrication of NPs at the nano-scale. It is also an eco-friendly, cost-effective and one-pot synthesis procedure. The use of less energy, less reaction time and ambient conditions are other advantages of the green synthesis. The NPs have been successfully prepared biogenically and employed in different fields, i.e., medicine, biosensors, electrochemistry, biomedicine, water treatment, electronics, photo-electronics and catalysis. Among, noble metal based NPs, Pt has diverse applications and the biogenic synthesis, characterization and applications of Pt NPs have been discussed in this study. The biogenic synthetic route includes plant extract (leaves, roots, flower, peels, stem, bark) and biological derivatives. The plant extracts contain flavonoids, polyphenolics, cannabinoids, terpenes, glycosides, sugars, amine, carbonyl, proteins, aldehyde, amide and alcohols, which reduce, cap and stabilize the metal ions in the solution. The reaction conditions effect on biogenic fabrication of Pt is discussed; the structure and sizes were also compared. The applications of the biogenic Pt NPs in different fields along with future prospects are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Expanding anthropogenic activities, globally and in Egypt, have increased concentrations of heavy metals in surface and ground waters. Contamination of drinking water may threaten public health. In ...the present study, the concentrations of 10 heavy metals were analyzed from natural springs (6) and drilled wells (10) in the Nubian Sandstone Aquifer of the El-Farafra Oasis and the White Desert National Park, Egypt. The average concentrations of heavy metals were in most cases below critical values of the WHO drinking water standard, except for Fe and Mn (average values were 495 and 107 µg·L−1, respectively). There is a surface circulation that develops within limestone (Post-Nubian Aquifer System—PNAS) and feeds the springs, while the water present in the wells (at least for the deeper ones) comes from the ferruginous sandstone (Nubian Sandstone Aquifer System—NSAS). This double circulation could account for the differences in the EC and TDS values (typical of a circulation in limestone-type aquifers for springs) and the Fe and Mn enrichment coming from the ferruginous sandstone of the NSAS. The average chronic daily intake (CDI) values for heavy metals in the study area are listed in decreasing order in the following: Fe > Mn > Zn > Co > Ni > Cr > As > Pb > Co > Cd. The total hazard quotient (HQtotal = HQoral + HQdermal) and Hazard Index (HI) values calculated for different heavy metals were well below the acceptable limit, indicating no significant non-carcinogenic health risks to the residents of both areas via oral and dermal absorption of drinking water. Furthermore, the results obtained for the total risk to human health showed that oral ingestion is the major pathway. Carcinogenic risk analysis indicated that the Incremental Lifetime Cancer Risk (ILCR) values for Pb, Cd, Ni, and Cr were well below the acceptable limits.
In this paper a perovskite solar cell which consists of an inorganic hole transporting layer is studied using a SCAPS simulator. The primary structure of investigated solar cell is ...FTO/TiO2/MAPbI3/Spiro-OMeTAD/Ni which has PEC of 21.30%. The Cu2Zn(Sn1-x Gex)S4 compound is good candidate as HTL in perovskite solar cells due to tunable band gap with different Ge/(Ge + Sn) ratios. The band gap was modulated from 1.5 for Cu2ZnSnS4 to 1.95 for Cu2ZnGeS4 with appropriate valence band offset engineering at the MAPbI3/Cu2Zn(Sn1-x Gex)S4 interface. The solar cell performance was optimized by varying the Ge concentration, leading the PCE 20.86%. The data suggested that maximum efficiency is observed for Ge concentration x = 0.8. It is also observed that an appropriate VBO (0.20eV) with CZT0.2G0.8S hole transporting layer can be achieved.
•Modeling of perovskite solar cells.•Primary structure of cell is FTO/TiO2/MAPbI3/Spiro-OMeTAD/Ni which has PEC of 21.30%.•The band gap was modulated from 1.5 for Cu2ZnSnS4 to 1.95 for Cu2ZnGeS4.•Solar cell performance was optimized by varying the Ge concentration, leading the PCE of 20.86%.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZRSKP
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