Spatio-Temporal Dynamics and Structure Preserving Algorithm for Computer Virus Model

The present work is related to the numerical investigation of the spatio-temporal susceptible-latent-breaking out-recovered (SLBR) epidemic model. It describes the computer virus dynamics with vertical transmission via the internet. In these types of dynamics models, the absolute values of the state variables are the fundamental requirement that must be fulfilled by the numerical design. By taking into account this key property, the positivity preserving algorithm is designed to solve the underlying SLBR system. Since, the state variables associated with the phenomenon, represent the computer nodes, so they must take in absolute. Moreover, the continuous system (SLBR) acquires two steady states i.e., the virus-free state and the virus existence state. The stability of the numerical design, at the equilibrium points, portrays an exceptional aspect about the propagation of the virus. The designed discretization algorithm sustains the stability of both the steady states. The computer simulations also endorse that the proposed discretization algorithm retains all the traits of the continuous SLBR model with spatial content. The stability and consistency of the proposed algorithm are verified, mathematically. All the facts are also ascertained by numerical simulations.     

Divergent Synthesis and Evaluation of the in vitro Cytotoxicity Profiles of 3,4-Ethylenedioxythiophenyl-2-propen-1-one Analogues

A new series of 3,4-ethylenedioxythiophene (EDOT)-appended propenones were prepared by condensation reaction and their in vitro cytotoxicity effects were evaluated against five human cancer cell lines. Preliminary structure–activity relationships of EDOT-incorporated 2-propenone derivatives were also established. The EDOT-appended enones demonstrated significant cytotoxicity against human cancer cell lines. The most active analogue, (E)-3-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one ( 3 p , GI₅₀=110 nm ), severely inhibited the clonogenic potential of cancer cells, and induced cell-cycle arrest in the G2/M phase and caused an accumulation of HCT116 colon cancer cells with >4 N DNA content. Also, 3 p exhibited weak inhibition of the enzymatic activity of human topoisomerase I. Molecular docking studies indicated preferential binding of the compounds to the ATP-binding pocket of the human checkpoint 2 kinase (Chk2) catalytic domain, thus, identifying a novel diaryl 2-propenone chemotype for the development of potent inhibitors of Chk2.     

2D Transition Metal Carbides (MXenes): Applications as an Electrically Conducting Material

Since their discovery in 2011, 2D transition metal carbides, nitrides, and carbonitrides, known as MXenes, have attracted considerable global research interest owing to their outstanding electrical conductivity coupled with light weight, flexibility, transparency, surface chemistry tunability, and easy solution processability. Here, the promising abilities of 2D MXenes, from both experimental and theoretical perspectives, for designing conductive materials for a range of applications, including electromagnetic interference shielding, flexible optoelectronics, sensors, and thermal heaters, are presented.     

Silicon Coating on Maize Seed Mitigates Saline Stress in Yermosols of Southern Punjab

Silicon - Silicon (Si) has been identified as a key nutrient in plants to lower the pressures of environmental stress. In pot experiment, seeds of different maize hybrids (Pioneer-1543,...     

A density functional theory study of the structural,electronic, and optical properties of XGaO3 (X = V,Nb) perovskites for optoelectronic applications

An ab initio study using density functional theory (DFT) is carried out to explore the structural, electronic, and optical properties of vanadium gallate (VGaO₃) and niobium gallate (NbGaO₃). The structural properties of these compounds are determined by using the full-potential linearized augmented plane wave (FP-LAPW) technique as implemented in WIEN2k with a standard functional, i.e., the Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA). In addition, the local density approximation plus Hubbard parameter (LDA?+?U) is employed to calculate the electronic bandgap and total and partial density of states (TDOS and PDOS), to overcome the limitation of the PBE-GGA functional in terms of underestimation of the electronic bandgap. The values computed for the indirect bandgap of VGaO₃ and NbGaO₃ are 0.45 and 0.51 eV, respectively, indicating that both materials are semiconductors in nature. The PDOS of the studied materials reveal that 3d-states of vanadium atoms, 4d-states of niobium atoms, and 2p-states of oxygen atoms form the valence band. Moreover, the Kramer–Kronig relations are used to compute the optical properties of the title compounds. The dielectric functions, refractive index, optical conductivity, absorption coefficient, extinction coefficient, energy loss function, and reflectivity of these materials are also computed. The results for the studied properties reveal that NbGaO₃ exhibits better properties than VGaO₃ for use in optoelectronic applications.

     

Synthesis,characterization, enhanced dielectric and antimicrobial properties of WxCu1−xO nanostructures

Herein, we report the chemical synthesis of W_x Cu_1?xO nanostructures with varying concentration of dopant (x = 0.00, 0.01, 0.03 and 0.05). The as-obtained doped CuO nanostructures have been investigated to evaluate their physio-chemical properties like crystallinity, morphology, optical features and infrared active modes. The dielectric study shows that doping induces a significant increase in real permittivity. In addition, the doped nanostructures also show potential towards inhibition of pathogenic microbes. The antimicrobial activity of prepared nanostructures determined against four different bacterial strains shows that W doped CuO nanostructures possess a strong antimicrobial activity against S. aureus, and K. pneumoniae and an intermediate activity against E. coli and C. albicans. These finding recognize the use of W doped CuO nanostructures in permittivity materials and bacterial disinfection nanomaterials.     

An optimal heat treatment cycle for a 26Cr, 2Mo stainless steel

Stainless steels containing 26Cr, 2Mo, and 1.6C are shown to contain primary and/or secondary carbides when subjected to various heat treatment routines. The soaking temperatures were found to have a pronounced effect on the types of carbides formed. It is also shown that a high volume fraction of fine secondary carbides (M23C6) results in inducing maximum hardness. Based on the results, optimal heat treatment cycles are proposed.     

Prediction of moisture,color and pH in cooked,pre-sliced turkey hams by NIR hyperspectral imaging system

The investigation was conducted to develop a hyperspectral imaging system in the near infrared (NIR) region (900–1700 nm) to predict the moisture content, pH and color in cooked, pre-sliced turkey hams. Hyperspectral images were acquired by scanning the ham slices (900–1700 nm) originated from different quality grade of turkey hams. Spectral data were then extracted and analyzed using partial least-squares (PLSs) regression, as a multivariate calibration method, to reduce the high dimensionality of the data and to correlate the NIR reflectance spectra with quality attributes of the samples considered. Instead of using a wide range of spectra, the number of wavebands was reduced for more stable, comprehensive and faster model in the subsequent multispectral imaging system. From this point of view, important wavelengths were selected to improve the predictive power of the calibration models as well as to simplify the model by avoiding repetition of information or redundancies. With the help of PLS regression analysis, nine wavelengths (927, 944, 1004, 1058, 1108, 1212, 1259, 1362 and 1406 nm) were selected as the optimum wavelengths for moisture prediction, eight wavelengths (927, 947, 1004, 1071, 1121, 1255, 1312 and 1641 nm) for pH prediction and nine wavelengths (914, 931, 991, 1115, 1164, 1218, 1282, 1362 and 1638 nm) were identified for color (a^*) prediction. With the identified reduced number wavelengths, good coefficients of determination (R²) of 0.88, 0.81 and 0.74 with RMSECV of 2.51, 0.02 and 0.35 for moisture, pH and color, respectively, were achieved, reflecting reasonable accuracy and robustness of the models.     

Novel high performance hollow fiber ultrafiltration membranes spun from LiBr doped solutions

The objective of this research is to evaluate the performance of the polyethersulfone (PES) hollow fiber ultrafiltration membranes spun from LiBr doped solutions prepared using the newly developed microwave heating technique. In addition the resultant hollow fiber membranes were introduced to a new post-treatment method where the membranes were placed in water and irradiated using the microwave technique. Various concentrations of the additive, LiBr, (1-4 wt.%) were added into the PES dope solutions. The dissolution of PES and LiBr in DMF was facilitated by the microwave heating technique. The performance of the membranes was evaluated in terms of pure water permeation and polyethylene glycol separation and its molecular weight cutoff (MWCO) was determined. The results revealed that the microwave post-treatment technique was proven to be effective in producing higher performance membranes. The best performance was obtained at 3% LiBr with MWCO at 90% rejection in the range of 2.83 kDa and high flux range of 222.18 (Lm^− 2 h^− 1 bar^− 1). LiBr interacts in the membrane matrix resulting in the enhancement of the hydrophilic property of the membrane and this is confirmed by the contact angle measurement.