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Abstract Compact multi-rotor unmanned aerial vehicles (UAVs) can be operated in many challenging environmental conditions. In case the UAV requires certain considerations in designing like lightweight, efficient propulsion system and others depending upon the application, the hybrid UAV comes into play when the usual UAV types cannot be sufficient to meet the requirements. The propulsion system for the UAV was selected to be coaxial rotors because it has a high thrust-to-weight ratio and to increase the efficiency of the propulsion system, a unique propeller was proposed to achieve higher thrust. The proposed propeller was uniquely designed by analyzing various airfoil sections under different Reynolds’s number using X-Foil tool to obtain the optimum airfoil section for the propellers. Since the design with duct increases efficiency, the Hybrid UAV presented in this paper has the modified novel convergent–divergent (C–D)-based duct which is a simplified model of a conventional C–D duct. The yawing and rolling maneuverings of the UAV could be achieved by the thrust vectoring method so that the design is simpler from a structural and mechanical perspective. The use of UAVs has risen in recent years, especially compact UAVs, which can be applied for applications like surveillance, detection and inspection, and monitoring in a narrow region of space. The design of the UAV is modeled in CATIA, and its further performance enactment factors are picked from advanced computational simulations relayed bottom-up approach. The predominant computational fluid dynamics (CFD) and fluid structure interaction (FSI) investigations are imposed and optimized through Computational Analyses using Ansys Workbench 17.2, which includes analysis of structural behaviour of various alloys, CFRP and GFRP based composite materials. From the structural analysis Titanium alloy came out to be the best performing materials among the others by having lower total deformation and other parameters such as normal and equivalent stress. The dynamics control response is obtained using MATLAB Simulink. The validations are carried out on the propeller using a thrust stand for CFD and on the duct through a high-jet facility for structural outcomes to meet the expected outcome.

ABSTRACTThis study focuses on developing a fiber stacking of polymer laminate for high-impact load-absorbing applications, such as aircraft, automotive, and soundproofing structures. Therefore, the effect of high-strength fiber position effect on the tensile and dynamic behaviors of woven glass intertwined kenaf fiber thermoset composites was investigated in this research work. The tensile strength and dynamic mechanical properties of a hybrid stacking composite designed with maximum glass fiber, especially glass as an outer layer, are relatively higher. The outer layer of glass fiber is particularly effective in containing stress due to its high-strength characteristics, reducing stress transmission to the other core layers. The maximum storage of outer glass and inner kenaf woven stacking composite S1 were 7692.4 MPa, respectively. Besides, the most significant improvement in damping value was observed for the outer glass stacking kenaf (S1) composite compared to the all-other woven glass stacked composite. Furthermore, the composite with the outer glass layers and inner kenaf layers shows a more significant damping value due to the porous structure of the kenaf fibers, allowing for more excellent vibration energy dissipation. Overall, the stacking composites with a glass and kenaf layering arrangement exhibit good mechanical properties for high-impact load-absorbing applications.

Hexokinases (Hks) and mitochondrial complex I (MCI) are involved in the energy metabolism of cells; glycolysis/fermentation and oxidative phosphorylation. Both Hks and MCI are known to play critical roles in either division of metabolic plasticity which enables tumor progression and proliferation in the presence of chemotherapies. Therefore, targeting these enzymes are important in cancer drug resistance. Here, computational models for the prediction of inhibition of Hks were developed based on experimental data and an optimal feature subset that was selected by the Boruta algorithm (a wrapper feature selection algorithm coupled with random forest). Out of the seven models that were explored, a random forest classifier gave the best prediction (GA = 0.84, FNR = 0.12 and AUC = 0.96 for the external dataset). Fragmentation analysis led to the identification of the unique structural scaffolds that characterize hexokinase inhibitors and non-inhibitors. The best Hks inhibition model predicted that 23 molecules out of the 191 dataset of MCI actives (IC50 ≤ 10 µM) that were screened, have more than 60 % probability of exhibiting Hk inhibitory activity. Hence, they are possible dual inhibitors of both targets. Furthermore, the 23 molecules’ core structures are members of the scaffolds that are unique to Hk inhibitors earlier predicted by fragment analysis. The need for dual targeting agents in cancer therapy, particularly in combating cancer drug resistance, highlights the relevance of these findings.

The Arabian Gulf (hereafter ‘the Gulf’) is renowned for its unique ecological characteristics and distinct marine life. It offers a diverse range of ecosystems that have adapted to the impacts posed by natural stress and human activities. Regular biomonitoring and diversity assessments are necessary to document the health of the Gulf ecosystem and to implement appropriate measures for effective conservation and management. Recently, environmental DNA (eDNA), a total pool of DNA isolated from environmental samples, has emerged as a highly effective tool for ecological studies. This review explores the opportunities, prospects, and challenges associated with employing eDNA metabarcoding in the ecological assessment and biomonitoring of the Gulf. It provides an overview of the status of the Gulf ecosystem and discusses the potential applications of eDNA metabarcoding in assessing biodiversity, monitoring invasive species, and evaluating ecosystem health. Additionally, the investigation addresses the challenges inherent in implementing this technique, considering environmental complexities, methodological intricacies, and data interpretation. Overall, this review emphasizes the immense potential of eDNA metabarcoding in advancing ecological assessment in the Gulf and calls for further research and collaboration to harness its benefits in this unique marine ecosystem.

Single crystal of 2-amino-4,6-dimethylpyrimidium 3,5-dinitrobenzoate dihydrate (2APDBD) was grown by solution growth technique. The X-ray diffraction reveals that 2APDBD crystal belongs to a centrosymmetric triclinic crystal system with space group P-1. The UV visible-NIR spectra confirm a peak at 350 nm with lower cut off wavelength shows a wide transmission window in the entire visible region. The electrical characteristics of 2APDBD crystal have a low density of defects and a low value of dielectric loss found from the dielectric studies. To find out the third order nonlinear susceptibilities (χ(3)) Z-can analysis was used.

In this investigation, the dynamic mechanical properties of Indian almond – Kenaf fiber composite were investigated and the effect of stacking sequence was analyzed. Four types of composites viz. kenaf, Kenaf/Indian almond/Kenaf, Indian almond/Kenaf/Indian almond, and Indian almond were fabricated by hand layup technique. The experimental results revealed that the kenaf fiber composite showed the superior storage modulus and loss modulus values compared to all other composites due to the high stiffness of kenaf fiber and better bonding between the matrix and fiber. Among hybrid composites, Kenaf/Indian almond/Kenaf composite displayed a greater storage modulus and loss modulus than Indian almond/Kenaf/Indian almond composite due to the presence of two layers of high stiffness kenaf fiber. Further, the order of thermal stability of the composites was observed as: Kenaf > Kenaf/Indian almond/Kenaf > Indian almond/Kenaf/Indian almond > Indian almond. In addition, the Indian almond fiber composite and Indian almond/Kenaf/Indian almond composite exhibited good damping properties than other composites owing to the more mobility of polymer chain. Cole – cole plot showed that the structure of all the fabricated composites was heterogeneous in nature and kenaf fiber composite displayed the higher heterogeneity among all other materials. Moreover, the modeling of storage modulus and damping factor was performed and compared with the experimental results. The results showed good agreement with the theoretical and experimental values.

Construction industries demand a material with high strength to endure severe environmental conditions like high temperature and humid and hence, it is noteworthy to assess the thermal and water transport properties of the material. In this investigation, the natural fibers based composites were fabricated using Indian almond and kenaf fibers by hand layup method. Entirely, two natural fiber composites viz. epoxy/Indian almond & epoxy/kenaf and two hybrid composites viz. kenaf/India almond/kenaf (K/I/K) & Indian almond/kenaf/Indian almond (I/K/I) were prepared. Thermogravimetric analysis (TGA) was carried out to analyze the thermal properties and water absorption study was carried out to analyze the transport properties. TGA study showed that the epoxy/kenaf composite exhibited a maximum onset temperature of 340.49°C owing to good bonding strength and the K/I/K composite displayed a maximum decomposition temperature of 380.21 ° with a minimum mass loss of 1.29 mg/min. Further, the epoxy/Indian almond composite showed a better flame retardancy property due to more char formation. Water absorption study resulted that the epoxy/Indian almond composite absorbed more water (35% at 50°C) compared to other composites due to spongy like structure and the presence of more voids on the surface of the fiber. Further, the epoxy/kenaf composite displayed more resistance to water penetration with maximum activation energy of diffusion of 2.63 kJ/mole. Transport properties such as diffusion coefficient, sorption coefficient and permeability coefficient were varied in line with temperature. The epoxy/kenaf composite showed least diffusion coefficient of 2.48 × 10−5 cm2/s, sorption coefficient of 1.05, and permeability coefficient of 2.61 × 10−5 cm2/s at 30°C among all other composites due to good bonding strength.

Thermogravimetric analysis of Indian almond leaf was carried out at four different heating rates such as 5°C/min, 10°C/min, 15°C/min and 20°C/min. The kinetic study was performed using model free methods and the kinetic parameters were calculated by Kissinger, Friedman, KAS and FWO models. Thermogravimetric analysis resulted that the Indian almond leaf showed four stages of decomposition. Most of the mass loss occurred at stage II (188–460°C) owing to the simultaneous decomposition of cellulose, hemicellulose, and lignin. The shifting of pyrolysis curve occurred with increase of heating rate due to the limitation of heat transfer. The rate of mass loss decreased while increasing the heating rate due to the presence of more inert content i.e. ash and less volatile matters. The mean activation energy calculated by Kissinger, Friedman, KAS, and FWO showed as 52.67, 45.53, 73.73, and 72.28 kJ/mole. The mean activation energy of different leaves reported by earlier researcher was compared with the activation energy of Indian almond leaf and concluded that it stick to the range of activation energy of reported leaves.

In this investigation, hybrid composites were prepared for structural applications using Indian almond and Banana fibers by hand layup method. Five types of composites were fabricated viz. I-I-I-I, I-B-B-I, I-B-I-B, B-I-I-B & B-B-B-B and the mechanical & moisture absorption characteristics were studied. The tensile and flexural studies showed that the I-I-I-I composite displayed the maximum tensile and flexural strength of 61 MPa and 53 MPa, respectively, due to the placing of high strength Indian almond fiber at outer skin. The impact study resulted that the B-B-B-B composite exhibited the maximum impact strength (6.2 kJ/m2) owing to the presence of more void content (6.83%) that absorbed more impact energy. The moisture absorption study reported that the B-B-B-B composite absorbed the maximum moisture percentage of 21% at 11 days due to more void content whereas the I-I-I-I composite showed least moisture absorption of 15% at 11 days because of low void percentage. Further, the biodegradation study revealed that the B-B-B-B composite exhibited the maximum weight loss of 38% at 60 days due to more moisture absorption that weakened the bonding strength of matrix and fiber and the microorganism accelerated the degradation.

Natural fibers-reinforced hybrid composites are acquiring more interest in automobile, marine, and aerospace fields due to its light weight characteristics. The purpose of this research is to develop a new material based on natural fibers for the aforementioned applications. The natural fibers such as Veli Karuvelam and Neem were selected for the investigation. As both the fibers are considered as weed in the agricultural fields, it could be a noteworthy to convert weed into useful material. Hybrid composites were fabricated using Veli Karuvelam and Neem fibers by hand layup method. Totally, five different types of composites were fabricated viz. N:V (1:0), N:V (0:1), N:V (1:3), N:V (1:1), and N:V (3:1). The fibers characteristics were analyzed by TGA and FTIR techniques. Further, the mechanical and moisture uptake behaviors of composites were investigated. TGA results showed that the Veli Karuvelam fiber possessed better thermal stability than Neem fiber. Tensile and flexural studies revealed that the N:V (0:1) composite exhibited the maximum tensile strength of 65 MPa and maximum flexural strength of 240 MPa due to the stuffing of more amount of high strength Veli Karuvelam fibers that involved in better stress transfer. Impact study resulted that the N:V (0:1) composite displayed the maximum impact energy of 6.5 kJ/m2 owing to the better energy absorption behavior of inner structure of composite. Further, the moisture absorption study revealed that the N:V (1:0) composite absorbed more moisture compared to all other composites due to the intrinsic property of Neem fiber to hold more moisture. Furthermore, it was concluded from this research that the I:V (0:1) composite could a potential candidate for the application in automobile, marine, and aviation fields as showed better performance.

Hybrid composites composed of neem fiber (N), banana (B) fiber and epoxy resin were fabricated by hand layup method. Three types of composites with blending ratio of B:N (1:4), B:N (1:1) and B:N (4:1) respectively were fabricated and the effects of fiber loading, chemical treatment and moisture absorption on tensile strength of the composites were investigated. The results showed that the fiber loading influenced the tensile strength and the B:N (4:1) composite displayed the superior tensile strength of 52 MPa compared to other composites due to the presence of more amount of banana fiber with high strength. The B:N (1:4) composite exhibited the lowest tensile strength of 47 MPa owing to the presence of more amount of neem fiber with low strength. Chemical treatment of fiber surface improved the tensile strength significantly due to the removal of impurities, lignin and hemicellulose. Silane-treated composite showed the greater tensile strength compared to alkali treated and untreated composites. Silane treated B:N (4:1) composite exhibited 17.5% and 42.3% improvement in tensile strength compared to the tensile strength of alkali treated and untreated composites respectively. Moisture absorption study revealed that the moisture uptake behavior of composite reduced the tensile strength due to the breakage of H-bond. Moisture absorption reduced the tensile strength of B:N (1:4), B:N (1:1) and B:N (4:1) composites by 14.7%, 10% and 5.8% respectively compared to dry samples.

The organic single crystal of 1,2,3- benzotriazole 2-chloro 4-nitrobenzoic acid (BCNB) was successfully grown by slow evaporation solution method using methanol as a solvent. The single crystal X-ray diffraction was used to analyse the lattice cell parameters of the grown BCNB crystal. The cell and lattice parameters of the BCNB crystal confirms the formation of monoclinic crystal structure with the P21/n space group. The diffraction planes (h,k,l) were determined by the powder X-ray diffraction (PXRD), which is in good agreement with the corresponding CIF file. The BCNB crystal exhibits good optical transmittance in the entire visible region, which is evident from the UV-Visible-NIR analysis. The photoconductivity analysis exposes the negative photoconductive nature of BCNB crystal. The self-defocusing and reverse saturable absorption effects of the BCNB is evident from the Z-scan experiment, which is prescribed in closed and open apertures and these results were used to deduce the 3rd order NLO parameters like n2, β and (χ(3)).

Tri-layer hybrid composites composed of Indian almond and kenaf fibers were fabricated using hand layup method. Two types of hybrid composites namely Kenaf/Indian almond/Kenaf (K/I/K) and Indian almond/Kenaf/Indian almond (I/K/I) were prepared for the investigation. Tensile, flexural, impact, moisture absorption and biodegradation studies were performed on the prepared composites. Tensile and flexural studies revealed that the K/I/K composite showed the maximum average tensile and flexural strength of 85 MPa and 92 MPa, respectively, due to the presence of high strength kenaf fiber as outer layer. The impact study exhibited that the I/K/I composite displayed the maximum average impact strength (5 kJ/m2) owing to the presence of Indian almond fiber at outer layer that absorbed more impact energy due to more surface cracks. Moisture absorption and biodegradation studies showed that the I/K/I composite absorbed more moisture and degraded greatly compared to that of K/I/K composite. The experimental investigations concluded that the K/I/K composite could be used in structural applications as showed better tensile and flexural properties and I/K/I composite could be used in damping environments as displayed better impact strength.

Here, the authors realize fast, all-electrical modulation of the near-field interactions between a layer of erbium emitters and graphene, by in-situ tuning of the graphene Fermi energy. They obtain strong interactions with a >1000-fold increased decay rate for about 25% of the erbium emitters, and electrically modulate these interactions with frequencies up to 300 kHz.

Abstract The present study investigates the fabrication of hierarchical 3D nanostructures with multi-component metal oxides in the presence of highly-porous graphene and characterized for its applications in high-performance supercapacitors. A hierarchical flowers like 3D nanostructure of Co3O4 @MnO2 on nitrogen-doped graphene oxide (NGO) hybrid composite was synthesized by thermal reduction process at 650 °C in the presence of ammonia and urea. The synthesized Co3O4@MnO2/NGO hybrid composites were studied via Raman, XRD, X-ray XPS, FE-SEM, FE-SEM with EDX, FE-TEM and BET analyses. The electrochemical analysis of Co3O4@MnO2/NGO hybrid composite electrode was investigated using cyclic voltammetry, chronopotentiometry and electrochemical impedance measurements. The hybrid composite electrode showed significant specific capacitance results of up to 347 F/g at 0.5 A/g and a corresponding energy density of 34.83 Wh kg−1 with better rate performance and excellent long-term cycling stability were achieved for 10,000 cycles. The obtained electrochemical results paved a way to utilize Co3O4@MnO2/NGO composite electrode as a promising electrode material in high performance supercapacitors.

Target of rapamycin (TOR) kinase operates within two distinct multiprotein complexes named TORC1 and TORC2. Here the authors report a cryo-EM structure of TORC2, establish its subunit organization, providing a rationale for TORC2’s rapamycin insensitivity and the mutually exclusive inclusion of Avo3/Rictor or Raptor within their respective TOR complex.

Drylands cover about 40% of the world’s land area and support two billion people, most of them living in developing countries that are at risk due to land degradation. Over the last few decades, there has been warming, with an escalation of drought and rapid population growth. This will further intensify the risk of desertification, which will seriously affect the local ecological environment, food security and people’s lives. The goal of this research is to analyze the hydrological and land cover characteristics and variability over global arid and semi-arid regions over the last decade (2010–2019) using an integrative approach of remotely sensed and physical process-based numerical modeling (e.g., Global Land Data Assimilation System (GLDAS) and Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS) models) data. Interaction between hydrological and ecological indicators including precipitation, evapotranspiration, surface soil moisture and vegetation indices are presented in the global four types of arid and semi-arid areas. The trends followed by precipitation, evapotranspiration and surface soil moisture over the decade are also mapped using harmonic analysis. This study also shows that some hotspots in these global drylands, which exhibit different processes of land cover change, demonstrate strong coherency with noted groundwater variations. Various types of statistical measures are computed using the satellite and model derived values over global arid and semi-arid regions. Comparisons between satellite- (NASA-USDA Surface Soil Moisture and MODIS Evapotranspiration data) and model (FLDAS and GLDAS)-derived values over arid regions (BSh, BSk, BWh and BWk) have shown the over and underestimation with low accuracy. Moreover, general consistency is apparent in most of the regions between GLDAS and FLDAS model, while a strong discrepancy is also observed in some regions, especially appearing in the Nile Basin downstream hyper-arid region. Data-driven modelling approaches are thus used to enhance the models’ performance in this region, which shows improved results in multiple statistical measures ((RMSE), bias (ψ), the mean absolute percentage difference (|ψ|)) and the linear regression coefficients (i.e., slope, intercept, and coefficient of determination (R2)).

Bis-adducts of 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene and 1,3-butadiene, generated in situ from 3-sulfolene, have been synthesized in excellent yield. Ruthenium catalyzed oxidation of the bis-adducts followed by a one-pot transformation of the resulting α-diketone furnished oxa-bridged compounds. Unambiguous stereochemical assignments of both diastereomeric series are reported.