Optimization of parameters through Taguchi method for enhanced corrosion inhibition of poly (vinyl alcohol-serine)

Parametric optimization was carried out for the mixture of polyvinyl alcohol (PVA) and l-serine using Taguchi statistical approach. L₉ orthogonal array of experiments were designed and the results were analyzed with Qualitek software. Synergistic effect of the mixture was enhanced at the Qualitek predicted optimized conditions. The graft polymer, poly(vinyl alcohol-serine) (PVAS), was synthesized using free radical-initiated reactions of l-serine with PVA in order to achieve effective inhibition. PVAS was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, and powder X-ray diffraction analysis. The thermal properties of PVAS were studied by thermogravimetry, differential thermal analysis, and differential scanning calorimetry. The corrosion inhibition property of PVAS on mild steel corrosion was continuously monitored using electrochemical techniques. Temperature effect on the inhibition properties of PVAS was studied using electrochemical and gravimetric measurements. AFM studies confirmed the formation of polymeric film on mild steel surface which inhibits the rate of corrosion. Theoretical calculations using Hyperchem 7.0 proved the better corrosion mitigation properties of PVAS compared to PVA. The experimental results and surface analysis confirmed the effective inhibition process of the graft polymer which was also supported by the theoretical calculations. A good correlation was obtained between the results of the electrochemical measurements, conventional gravimetric measurement, surface analysis, and theoretical calculations. All the studies proved the enhanced corrosion inhibition properties of PVA through grafting of polyserine.     

High performance computation of human computer interface for neurodegenerative individuals using eye movements and deep learning technique

The Journal of Supercomputing - Disabilities due to neurodegenerative disease are rapidly increasing in number. The need for rehabilitative devices to achieve a normal and comfortable life in the...     

Surface-structured gold-nanotube mats: fabrication, characterization, and application in surface-enhanced Raman scattering

The fabrication and characterization of nanostructured fibrous gold mats having high specific surface areas is reported. Freestanding porous films of 6-20-μm thickness and density 0.43 ± 0.02 g cm(3) are prepared using e-beam evaporation of gold on an electrospun nanoporous polymer template and subsequent removal of the template polymer in a suitable solvent. Structural characterization using electron microscopy techniques shows a nanofiber diameter in the range of 300-6000 nm, and the size of the nanochannels on the fiber surface is ≈200-350 nm. Such surface structuring is achieved through fast evaporation of organic solvent and phase separation of polymers during the electrospinning process. The wedge thickness varies from a few nanometers to a few tens of nanometers. The freestanding films possess good mechanical integrity and robustness. The calculated Young's modulus based on the slope in the elastic region is ≈114 MPa and gives an ultimate breaking strength of 0.7-0.8 MPa at a percentage elongation of 1.5-2.0%. X-ray diffraction and transmission electron microscopy measurements demonstrate the formation of polycrystalline gold nanostructures. Electrical characterization performed on these gold nanotubes reveals pure metallic behavior. Raman spectroscopic characterization of the fibrous membrane is performed using crystal violet (CV) adsorbed on it. Well-defined spectral peaks are obtainable at concentrations as low as 10(-7) M of CV, which did not give spectral signals at this low concentration on its own.     

Directly created electrostatic micro-domains on hydroxyapatite: probing with a Kelvin Force probe and a protein

Micro-domains of modified surface potential (SP) were created on hydroxyapatite films by direct patterning by mid-energy focused electron beam, typically available as a microprobe of Scanning Electron Microscopes. The SP distribution of these patterns has been studied on sub-micrometer scale by the Kelvin Probe Force Microscopy method as well as lysozyme adsorption. Since the lysozyme is positively charged at physiological pH, it allows us to track positively and negatively charged areas of the SP patterns. Distribution of the adsorbed proteins over the domains was in good agreement with the observed SP patterns.     

Influence of graphene oxide on thermal,electrical, and morphological properties of new achiral polyimide

In this study, a new diamine N‐[2‐(1H‐indol‐3‐yl)ethyl]‐3,5‐diaminobenzamide (IEDAB) was synthesized using tryptamine as starting material and characterized by FT‐IR, ¹H‐NMR, ¹³C‐NMR, and mass spectroscopy. Then, it was polymerized with 3,3',4,4'‐benzophenone tetracarboxylic dianhydride (BTDA) via thermal imidization to produce polyimide (PI). A series PI/GO nanocomposite films were prepared by incorporating different ratios (1, 3, and 5 wt%) of synthesized GO by solution casting method. The synthesized PI was confirmed by Ubbelohde viscometer and FT‐IR spectroscopy. SEM and Raman spectroscopy showed that GO was well dispersed in the PI matrix. XRD patterns indicated the PI and PI/GO nanocomposite films were highly amorphous in nature. The synthesized PI and their nanocomposites show high thermal stability as their T_10% weight loss are in the range of 498 to 563°C with 30.6 to 40% of char yield and the glass transition temperatures (T_g s) are in the range of 188 to 262°C. The limited oxygen index (LOI) values increased from 31.4% to 56.0% with increases of 5% GO content in the PI/GO nanocomposite. They have high dielectric constant in the range of 2.6 to 5.1 at 1 MHz and also good mechanical properties with tensile strength of 81 to 116 MPa, elongation at break 5 to 9%. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers     

Effects of Blueberry (Vaccinium corymbosum) Juice on Lipid Oxidation During Spray Drying of Microencapsulated Menhaden Oil

This study investigated the effect of blueberry juice on menhaden oil lipid oxidation during microencapsulation. Oil in water emulsions containing menhaden oil with 0, 5, or 10% blueberry juice were spray dried to produce control-M, 5% BJ-M, and 10% BJ-M microencapsulated powders, respectively. All microencapsulated powders had similar encapsulation efficiencies with low surface oil content. Peroxide value (meq/kg of oil) was 4.50, 4.31, and 3.38 for control-M, 5% BJ-M and 10% BJ-M, respectively. Ten percent BJ-M had lower (P < 0.05) anisidine value, and totox values than 5% BJ-M and control-M. This indicated that 10% blueberry juice reduced lipid oxidation in menhaden oil during microencapsulation to a greater extent than the other formulations.     

Lubrication of a narrow porous journal bearing with a couple stress fluid

This paper describes a theoretical investigation of the rheological effects of couple stress fluids on the performance of narrow porous journal bearings. A most general modified Reynolds equation is derived for narrow porous journal bearings using the Stokes constitutive equations for couple stress fluids. The fluid in the film region and in the porous region has been modelled as a couple stress fluid. The analysis takes into account velocity slip at the porous interface using the Beavers‐Joseph criterion. A closed‐form expression for field pressure is obtained for narrow journal bearings. Eigen‐type expressions for field variations are obtained. The dimensionless load‐carrying capacity, attitude angle, and coefficient of friction are presented for different operating parameters. It is observed that narrow porous journal bearings with couple stress fluids as lubricant show a significant increase in load‐carrying capacity with reduced coefficient of friction as compared to the Newtonian case. The present study predicts the effects of the percolation of polar additives (microstructures) into the porous matrix on the bearing performance.