Synthesis of Mineral Nanofiller using Solution Spray Method and its Influence on Mechanical and Thermal Properties of EPDM Nanocomposites

Calcium carbonate (CaCO₃) nanoparticles were synthesized by solution spray of CaCl₂ and NH₄HCO₃ with sodium lauryl sulfate (SLS) as a stabilizing agent. Synthesized nano-CaCO₃ of 20 nm and commercial CaCO₃ (40 mircron) were reinforced in EPDM rubber composites of by varying 2–10 wt% of loading. The rubber nanocomposites were prepared on two roll mill and molded on compression molding machine and were subjected to characterizations like mechanical and thermal. The results were then compared with fly ash (10–60 wt%) filled EPDM rubber composites. It was found that with increase in wt% of nano-CaCO₃ loadings the mechanical and thermal properties of EPDM rubber nanocomposites increases drastically. Improvements in properties were due to uniform dispersion of nano-CaCO₃ into the rubber chain. It means that nano-CaCO₃ gets exfoliated within the rubber chains uniformly. It is also due to fine size of nano-CaCO₃ (20 nm) with uniform transfer of heat during vulcanization, which keeps the rubber chains intact on cross-linking. Results of commercial CaCO₃ and fly ash filled EPDM composites were found to be very inferior over nano-CaCO₃ filled EPDM rubber nanocomposites even though the amount of loading nanofiller was less (2–10 wt% of loading) compared to fly ash of 75 micron (10–60 wt%).     

Heat Transfer Studies in an Agitated Vessel During Aqueous Alkaline Depolymerization of Poly(Ethylene Terephthalate) (PET) Waste

Depolymerization reactions of poly(ethylene terephthalate) (PET) waste in aqueous sodium hydroxide solution were carried out in a batch reactor at 150°C at atmospheric pressure. Disodium terephthalate (terephthalic acid salt) and ethylene glycol (EG) remain in the liquid phase. Terephthalic acid (TPA) salt was converted into TPA. The produced monomeric products (TPA and EG) were recovered. Various design parameters were estimated. Design of a batch reactor was undertaken for depolymerization of PET waste in aqueous sodium hydroxide solution. As expected, the Reynolds numbers, Prandtl numbers, Nusselt numbers, coil-side heat transfer coefficients, and overall heat transfer coefficients were consistent with the fluid velocities. It shows excellent potential for commercialization of the depolymerization of PET waste.     

Nonisothermal Crystallization Modeling and Simulation for Polypropylene/Nano CaSO4 Composites with Variations in Nanosizes and Wt.% of Loading

Avrami and Ozawa's combined analysis was employed to study the nonisothermal crystallization kinetics of Polypropylene (PP): CaSO₄ (of 12 and 22 nm) composites using a Differential Scanning Calorimeter (DSC). The parameters, such as Avrami's exponent (n) and growth rate constant (Z_t), that characterized the system of different nanosize composites and virgin PP, were determined. The relative degree of crystallinity as a function of temperature for PP/nano CaSO₄ composites at the same cooling rate and the Sigmoidal shape of curves indicate a strong interaction between PP molecules and the nanolayer, which leads to greater nucleation with a reduction in nanosizes. The theoretical combination of kinetic equations was found to be suitable to describe the physical phenomena of real system. The values of parameters n, Z_t and predicted time t for crystallization at a single cooling rate were obtained from the mathematical model.     

Bacillus cereus adhesion: an investigation of the physicochemical characteristics of surface and effect of bio adhesion on the properties of silicone

The initial microorganism adhesion on substrate is an important step for biofilm formation. The surface properties of the silicone and Bacillus cereus were characterized by the sessile drop technique. Moreover, the physicochemical properties (hydrophobicity; electron donor/electron acceptor) of surface adhesion and the impact of bio adhesion on the silicone were determined at different time of contact (3, 7, and 24?h). The results showed that the strain was hydrophilic (Giwi?=?3.37?mJ/m²), whereas the silicone has hydrophobic character (Giwi?=??68.28?mJ/m²). Silicone surface presents a weak electron-donor character (γ ^??=?2.2?mJ/m²) conversely to B. cereus that presents an important electron donor-parameter (γ ^??=?31.6?mJ/m²). The adhesion of B. cereus to silicone was investigated using environmental scanning electron microscope and image analysis was assessed with the Matlab^® program. After 3?h of contact, the data analysis, confirmed the bio adhesion with an amount of 9.610⁵?cfu/cm² adhered cells. After 24?h, the percentage of silicone covered reached 93%. Furthermore, despite the difference in hydrophohbicity, the interaction between B. cereus and substrata was favoured by the thermodynamic model of adhesion (ΔG _adhesion ?<?0). The real time investigation of the effect of B. cereus adhesion on the physicochemical properties of silicone has revealed that the substrata becomes hydrophilic (θ°?=?47.3, ΔGiwi?=?23.7?mJ/m²), after 7?h of contact. This bio adhesion had also favoured the increase of electron donor/acceptor character of silicone (γ ^??=?53.1?mJ/m² and γ ⁺?=?5.3?mJ/m²).     

Experimental study of paddy drying in a vortex chamber

The intensification of interfacial mass, heat, and momentum transfer makes vortex chambers potentially interesting for the efficient drying of paddy, allowing shorter drying times and/or more compact equipment. The presence of a shell introduces particular challenges. Intraparticle diffusion limitations are strong and may reduce the advantage from intensified interfacial mass and heat transfer and the efficiency of air usage. Furthermore, high shear and normal stresses in the fast rotating particle bed may cause damage to the paddy shell, posing problems for transport and storage. With these specific aspects in mind, the use of vortex chambers for paddy drying is experimentally evaluated.     

Influence of the coupling agent and graphene oxide on the thermal and mechanical behavior of tea dust–polypropylene composites

In this study, the effects of a coupling agent and additive on the physicomechanical (morphological, mechanical, thermal, and swelling) properties of tea dust (TD)–polypropylene (PP) composites were studied. TD–PP composites were prepared with untreated tea dust (UTD) and tetraethylsilane (TES)‐treated TD or silanated tea dust (STD) particles at ratios of 0:100, 10:90, 20:80, 30:70, and 40:60 w/w. Initially, TD particles were grafted by TES as a coupling agent, and these STD particles were then modified with graphene oxide (GO) as an additive to study their effects on the STD–PP composites; these were compared to the STD–PP and UTD–PP composites in accordance with a study of improvements in the mechanical properties. All of the TD–PP composites were analyzed with Fourier transform infrared spectroscopy, scanning electron microscopy, and mechanical, thermal, and physical tests. The thermal and mechanical properties of both the STD–PP and GO‐modified STD–PP composites were found to be improved as compared to those of the UTD–PP composites. So, the recycling of a large amount of TD as a waste material could be useful in the preparation of TD–PP composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42927.     

Exploring the Bioactive Potentials of C60-AgNPs Nano-Composites against Malignancies and Microbial Infections

At present, the potential role of the AgNPs/endo-fullerene molecule metal nano-composite has been evaluated over the biosystems in-vitro. The intra-atomic configuration of the fullerene molecule (C₆₀) has been studied in-vitro for the anti-proliferative activity of human breast adenocarcinoma (MDA-MB-231) cell lines and antimicrobial activity against a few human pathogens that have been augmented with the pristine surface plasmonic electrons and antibiotic activity of AgNPs. Furthermore, FTIR revealed the basic vibrational signatures at ~3300 cm⁻¹, 1023 cm⁻¹, 1400 cm⁻¹ for O-H, C-O, and C-H groups, respectively, for the carbon and oxygen atoms of the C₆₀ molecule. NMR studies exhibited the different footprints and magnetic moments at ~7.285 ppm, explaining the unique underlying electrochemical attributes of the fullerene molecule. Such unique electronic and physico-chemical properties of the caged carbon structure raise hope for applications into the drug delivery domain. The in-vitro dose-dependent application of C₆₀ elicits a toxic response against both the breast adenocarcinoma cell lines and pathogenic microbes. That enables the use of AgNPs decorated C₆₀ endo fullerene molecules to design an effective anti-cancerous drug delivery and antimicrobial agent in the future, bringing a revolutionary change in the perspective of a treatment regime.     

Differential Physio-Biochemical and Metabolic Responses of Peanut (Arachis hypogaea L.) under Multiple Abiotic Stress Conditions

The frequency and severity of extreme climatic conditions such as drought, salinity, cold, and heat are increasing due to climate change. Moreover, in the field, plants are affected by multiple abiotic stresses simultaneously or sequentially. Thus, it is imperative to compare the effects of stress combinations on crop plants relative to individual stresses. This study investigated the differential regulation of physio-biochemical and metabolomics parameters in peanut (Arachis hypogaea L.) under individual (salt, drought, cold, and heat) and combined stress treatments using multivariate correlation analysis. The results showed that combined heat, salt, and drought stress compounds the stress effect of individual stresses. Combined stresses that included heat had the highest electrolyte leakage and lowest relative water content. Lipid peroxidation and chlorophyll contents did not significantly change under combined stresses. Biochemical parameters, such as free amino acids, polyphenol, starch, and sugars, significantly changed under combined stresses compared to individual stresses. Free amino acids increased under combined stresses that included heat; starch, sugars, and polyphenols increased under combined stresses that included drought; proline concentration increased under combined stresses that included salt. Metabolomics data that were obtained under different individual and combined stresses can be used to identify molecular phenotypes that are involved in the acclimation response of plants under changing abiotic stress conditions. Peanut metabolomics identified 160 metabolites, including amino acids, sugars, sugar alcohols, organic acids, fatty acids, sugar acids, and other organic compounds. Pathway enrichment analysis revealed that abiotic stresses significantly affected amino acid, amino sugar, and sugar metabolism. The stress treatments affected the metabolites that were associated with the tricarboxylic acid (TCA) and urea cycles and associated amino acid biosynthesis pathway intermediates. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and heatmap analysis identified potential marker metabolites (pinitol, malic acid, and xylopyranose) that were associated with abiotic stress combinations, which could be used in breeding efforts to develop peanut cultivars that are resilient to climate change. The study will also facilitate researchers to explore different stress indicators to identify resistant cultivars for future crop improvement programs.     

Morphological,Mechanical Property Analysis and Comparative Study over Structural Properties of CVD TiN Film Grown under Different Substrate Temperature in Nitrogen Gas Atmosphere

Silicon - Titanium Nitride (TiN) thin films were deposited by thermal chemical vapor deposition process (CVD) over Si (100) substrate under different substrate temperatures. Morphological,...     

Comparative study on the structural make-up and mechanical behavior of silicon and silver doped amorphous carbon films

Silicon - Silicon (Si) and silver (Ag) doped amorphous carbon (a-C) thin film were deposited on chrome nitrided 316 LVM stainless steel using filtered cathodic vacuum arc (FCVA) deposition...