Non‐fragile reliable control synthesis of the sugarcane borer

This study considers the problem of non‐fragile reliable control synthesis for mathematical model of interaction between the sugarcane borer (Diatraea saccharalis) and its egg parasitoid Trichogramma galloi. In particular, the control could be substituted by periodic releases of a small population of natural enemies and hence it is important to propose the time‐varying controller in sugarcane borer. The main aim of this study is to design a state feedback non‐fragile (time‐varying) reliable controller such that the states of the sugarcane borer system reach the equilibrium point within the desired period. A novel approach is proposed to deal with the uncertain matrices which appear in non‐fragile reliable control. Finally, simulations based on sugarcane borer systems are conducted to illustrate the advantages and effectiveness of the proposed design technique. The result reveals that the proposed non‐fragile control provides good performance in spite of periodic releases of a small population of natural enemies occurs.Inspec keywords: microorganisms, plant diseases, biology computing, state feedback, biocontrol, control system synthesisOther keywords: nonfragile reliable control synthesis, sugarcane borer, mathematical model, Diatraea saccharalis, egg parasitoid, Trichogramma galloi, periodic releases, natural enemies, state feedback nonfragile time‐varying reliable controller, equilibrium point, design technique     

Boron‐ and nitrogen‐doped penta‐graphene as a promising material for hydrogen storage: A computational study

We fulfill a comprehensive study based on density functional theory (DFT) computations to cast insight into the dissociation mechanism of hydrogen molecule on pristine, B‐, and N‐doped penta‐graphene. The doping effect has been also illustrated by varying the concentration of dopant from 4.2 at% (one doping atom in 24 host atoms) to 8.3 at% (two doping atoms in 24 host atoms) and by contemplating different doping sites. Our theoretical investigation shows that the adsorption energy of H₂ molecule and H atom on the substrate can be substantially enhanced by incorporating boron or nitrogen into penta‐graphene sheet. The B‐ and N‐doped penta‐graphene can effectively decompose H₂ molecule into two H atoms. Our results demonstrate that activation energies for H₂ dissociation and H diffusion on the B‐ and N‐doped penta‐graphene are much smaller than the pristine penta‐graphene. Further investigation of increasing concentration dopants of the penta‐graphene sheet gives sufficiently low activation barrier for H₂ dissociation process. This investigation reveals that the boron and nitrogen dopants can act as effective active site for H₂ dissociation and storage.     

Screening of β1- and β2-Adrenergic Receptor Modulators through Advanced Pharmacoinformatics and Machine Learning Approaches

Cardiovascular diseases (CDs) are a major concern in the human race and one of the leading causes of death worldwide. β-Adrenergic receptors (β1-AR and β2-AR) play a crucial role in the overall regulation of cardiac function. In the present study, structure-based virtual screening, machine learning (ML), and a ligand-based similarity search were conducted for the PubChem database against both β1- and β2-AR. Initially, all docked molecules were screened using the threshold binding energy value. Molecules with a better binding affinity were further used for segregation as active and inactive through ML. The pharmacokinetic assessment was carried out on molecules retained in the above step. Further, similarity searching of the ChEMBL and DrugBank databases was performed. From detailed analysis of the above data, four compounds for each of β1- and β2-AR were found to be promising in nature. A number of critical ligand-binding amino acids formed potential hydrogen bonds and hydrophobic interactions. Finally, a molecular dynamics (MD) simulation study of each molecule bound with the respective target was performed. A number of parameters obtained from the MD simulation trajectories were calculated and substantiated the stability between the protein-ligand complex. Hence, it can be postulated that the final molecules might be crucial for CDs subjected to experimental validation.     

HPA immobilized on the functionalized Ti-MCM-41 nanochannels for photocatalytic degradation of ternary azo dye effluents

Solid-state heteropolytungstic acid (HPA) clusters were covalently linked into amino and mercapto functionalized Ti-MCM-41 nanoporous channel by in situ synthesis processes to effectively use as a recyclable photocatalyst for degradation of ternary azo dyes consisting of methyl orange (MeOr), acid orange 10 (AO-10) and acid red 88 (AR88) before and after dying processes. The structure and morphology of as synthesized nanoporous hybrid catalyst (HPA immobilized mercapto and amino functionalized Ti-MCM41) was characterized by means of Fourier transform infrared analysis (FT-IR), Phosphorus-31 Nuclear Magnetic Resonance (³¹P-NMR) analysis, X-ray diffraction (XRD) analysis, N₂ adsorption studies, diffused reflectance studies (DRS) and transmission electron microscope (TEM) measurements. The immobilization of HPA on functionalized Ti-MCM-41 acts as coupled semiconductor with higher specific area and superior active sites for photocatalytic degradation of ternary azo dyes. The hybrid catalyst was found to be very stable and did not lose it activity even after performing three consecutive irradiation experiments with azo dye mixtures; hence it may be reusable for further degradation of dye mixtures.     

Biochemical characteristics of tea fungus produced during kombucha fermentation

Tea fungus is symbiotic culture of acetic acid bacteria and yeasts, widely used to produce kombucha tea. Due to the rich biomass in tea fungus, it can be utilized as protein supplement in animal feed. The present study aimed to analyze the biochemical characteristics of tea fungus with the effect of fermentation time. Proximate, amino acids, and elemental analysis of tea fungus produced during kombucha fermentation were studied along with total count of microflora. Results suggested that tea fungus is rich in crude protein, crude fibre, and amino acid lysine. The biochemical characteristics of tea fungus studied were increased throughout the fermentation time.     

Bismuth effect in the structural, magnetic and dielectric properties of CoZn ferrite

Nano particles of Co_0.5Zn_0.5Bi_xFe_(2−x)O₄, with x varying from 0.0 to 0.3 in steps of 0.1 were synthesized using the chemical co-precipitation method. The powder X-Ray diffraction pattern confirms the formation of spinel phase for all prepared samples. The lattice parameters are calculated by powder X-Ray diffraction, and it is observed that the values of the lattice parameter are less than those of bulk materials. The saturation magnetization is found to decrease with the increase of concentration of Bi ion up to x = 0.2 and then increases for x = 0.3. The hysteresis loop for concentration x = 0.0, 0.1 and 0.3 shows almost zero coercivity and remanance at 300 K, implying that the samples behave as superparamagnetic at this temperature; whereas for the concentration at x = 0.2 the coercivity was found to be 32 Oe at 300 K. The dielectric measurements were carried out in the Co_0.5Zn_0.5Bi_xFe_(2−x)O₄ system over the temperature range from 300 to 700 K as a function of frequency, from 5 to 5 MHz. The variation of dielectric constant and dielectric loss factor for the prepared samples are explained on the basis of Maxwell–Wagner interfacial polarization.     

Synthesis,characterization, crystal structure,hirshfeld surface analysis and DFT calculations of N-(pyridin-2-ylmethyl)furan-2-carboxamide and its molecular docking

The crystal structure of N-(pyridin-2-ylmethyl)furan-2-carboxamide was elucidated by single crystal X-ray diffraction and characterized by NMR, FT-IR, UV–Vis spectroscopic techniques. In this molecule, the dihedral angle between furan and pyridine rings is 73.52(14)°. The compound crystallized in an orthorhombic lattice with a space group of Pca2₁ [a?=?9.677(5), b?=?10.674(5), and c?=?9.087(4)Å]. The Hirshfeld surface analysis (HSA) for determining the N–H···O intermolecular hydrogen bonding interactions, generated the chain shaped 3D network structure and associated fingerprint plot calculations gave the contribution ratios for C–H, H–H, O–H, and N–H contacts, indicating a higher propensity for H–H interactions to form the crystal. The energies of frontier molecular orbitals (FMO) were computed to make clear knowledge about the global reactivity and charge transfer property of the compound by density functional theory (DFT). Also, to get the charge distribution details, the molecular electrostatic potential (MEP) of the compound was measured. The molecular docking study was carried out to understand the binding of the compounds toward the molecular targets c-Jun N-terminal kinase 3, PMI2, and CDC7 kinase.

     

Parametric investigation on hydrogen driven homogeneous charge compression ignition mode with advanced diesel injection using chemical kinetics based numerical model

In the present study, a numerical model based on chemical kinetics was developed to investigate the effect of different parameters on characteristics of hydrogen diesel homogeneous charge compression ignition (HDHCCI) mode. The results showed that the combustion process was retarded with diminished cool flame as increasing hydrogen energy share (HES) due to reduction of H₂O₂, H₂O and OH radicals with hydrogen addition. Thus, it increased the indicated thermal efficiency (ITE) and decreased the indicated specific energy consumption (ISEC). The levels of NO_x and soot emissions were reduced by 22% and 63% at maximum HES. A spray angle of 10° decreased the total fuel impingement compared with a spray angle of 74° because of improvement in air-fuel mixing phenomena. Incomplete combustion was recovered at HES of 25% when increasing the charge temperature or adapting the twin-pulse in HDHCCI mode, consequently the ITE was improved with a decrease in ISEC.     

Investigation on the effect of injection schedule and EGR in hydrogen energy share using common rail direct injection dual fuel engine

In this research work, four different diesel injection schedules have been experimented at a BMEP of 2 bar (Low load) in hydrogen diesel dual fuel (HDDF) mode, which are namely single pulse, double pulse phase-1, double pulse phase-2 and multi-pulse. The maximum possible hydrogen energy shares (HES) for single pulse, double pulse phase-1, double pulse phase-2 and multi-pulse injection schedules were 73.99%, 48.98%, 34.46% and 24.39% respectively. Over the injection schedules, double pulse phase-2 improved the brake thermal efficiency (BTE) from 19.50% (single pulse) to 21.61% with a penalty in NO emission. On the other hand, multi-pulse moderately increased the BTE with significant reduction in NO beside rise in smoke emission. At a BMEP of 5 bar (Medium load) operation, there was a considerable reduction in NO emission at maximum range of HES level with 18.21% of EGR, moreover the engine stability was improved with minor increase in smoke emission.     

Research updates on graphene oxide‐based polymeric nanocomposites

Graphene oxide (GO) is a carbon‐based material, which is one atom thick sheet of graphite. The nanofillers have exceptional stiffness and strength owing to the presence of two‐dimensional graphene backbone. Especially owing to this reason, nanocomposites have been developed using GO for several applications. This review article explores the synthesis of GO from flake graphite. Main emphasis has been afforded on the preparation and characterization of GO nanocomposites, utilizing various industrial polymers for wide application in aerospace, biomedical, military, supercapacitors, electrical, sensor, and so on. Morphological characterization exploring the interaction and extent of dispersion of GO nanosheets in the polymer matrices is extensively accounted. From the reports, it is clear that exfoliation and strong interaction of GO tremendously improved the physical, mechanical, thermal, electrochemical, biocompatibility, and tribological properties of the added polymer. POLYM. COMPOS., 35:2297–2310, 2014. © 2014 Society of Plastics Engineers