Moisture Absorption Behavior of Treated and Untreated Eggshell Particulate Epoxy Composites

Weight gain and thickness swelling in bio-waste composites material leads to an adverse effect on properties. In the present investigation the effect of different environments (saline, mineral, kerosene, subzero temperature) on the physical properties of the composites which are fabricated with unboiled(untreated) and boiled(treated 200 °C) eggshell filler materials are studied. XRD, SEM and ultimate analysis of the unboiled and boiled eggshells are also studied. The composites of different weight percentage 4, 8 and 12 wt% of unboiled and boiled eggshell filler epoxy composites are fabricated by a hand lay-up technique. The 12 wt% of boiled eggshell particulates reinforced epoxy composites showed the highest weight gains when exposed to different environments. Least absorption rate observed was for 4 wt% eggshell filler composite in subzero temperature condition. The composites showed a peculiar environmental behavior when exposed to kerosene.

     

Effect of velocity slip on porous-walled squeeze films

The analysis of the squeeze films between porous discs of various shapes is extended to include the effect of velocity slip at the fluid and porous material interface. Modified equations for calculating the pressure, load carrying capacity and the film thickness and time relation are presented. A simple mathematical analogue for determination of the squeeze film behaviour for porous discs with slip consideration from the already available solution (without slip) is given.     

Theoretical Analysis of Thermal Stresses in Electro-discharge Diamond Grinding

Excessive heat generated at the machining zone, during Electro-discharge diamond grinding (EDDG), is the major cause of thermal stresses, untempered martensite, overtempered martensite, and cracks. Therefore, the key to achieve good surface integrity in a machined part is to prevent excessive temperature and thermal stresses generated during machining process. A finite element model has been developed to estimate thermal stresses during EDDG when the current is switched-off. First, the developed code calculates the temperature in the workpiece and then the thermal stress field is estimated using this temperature field. Computations were carried out in plane strain condition for different down feeds of the grinding wheel. The effects of time of grinding and feed on thermal stress distribution have been reported. The thermal stresses are found to be higher near top surface at initial time of grinding but shifted away towards bottom after some grinding time.     

Quadratic Discriminant Analysis Based Ensemble Machine Learning Models for Groundwater Potential Modeling and Mapping

In this study, the AdaBoost, MultiBoost and RealAdaBoost methods were combined with the Quadratic Discriminant Analysis method to develop three new GIS-based Machine Learning ensemble models, i.e., ABQDA, MBQDA, and RABQDA for groundwater potential mapping in the Dak Nong Province, Vietnam. In total, 227 groundwater wells and 12 conditioning factors (infiltration, rainfall, river density, topographic wetness index, sediment transport index, stream power index, elevation, aspect, curvature, slope, soil, and land use) were used for this study. Performance of the models was evaluated using the Area Under the Receiver Operating Characteristics Curve AUC (AUC) and several other performance metrics. The results showed that the ABQDA model that achieved AUC?=?0.741 was superior to the other models in producing an accurate map of groundwater potential for the Dak Nong Province. The models and potential maps produced here can help policymakers and water resources managers to preserve an optimal exploit from these vital resources.

     

Benevolent behavior ofKleinia grandifloraleaf extract as a green corrosion inhibitor for mild steel in sulfuric acid solution

The ethanolic extract of Kleinia grandiflora leaves was characterized and tested for its potential anticorrosion properties on mild steel in 1 M H2SO4 medium using mass-loss analysis, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, UV–visible spectroscopy, and X-ray diffraction analysis. The effect of temperature on the corrosion behavior of mild steel was studied in the range of 308 to 328 K. The inhibition efficiency was observed to increase with increasing concentration of the extract. Polarization curves revealed that the Kleinia grandiflora leaf extract is a mixed inhibitor. Impedance diagrams revealed that an increase of Kleinia grandiflora leaf extract concentration increased the charge transfer resistance and decreased the double-layer capacitance. The adsorption process obeys Langmuir＇s model, with a standard free energy of adsorption（ΔGads） of-18.62 k J/mol. The obtained results indicate that the Kleinia grandiflora leaf extract can serve as an effective inhibitor for the corrosion of mild steel in a sulfuric acid medium.     

Minimum assured fidelity and minimum average fidelity in quantum teleportation of single qubit using non-maximally entangled states

We study use of non-maximally entangled states (NME) in quantum teleportation (QT) of single qubit. We find that if NME states are written in the form ${| E \rangle =\sum_{j,k} {E_{jk} | j \rangle | k \rangle}}$ , where (j, k) = 0 and 1, and maximally entangled Bell-basis is used in measurement by the sender, the ??Minimum Assured Fidelity?? (the minimum value of fidelity for all possible information states) for QT is 2C/(1?+?C), where C is the concurrence of ${| E \rangle }$ given by C?=?2|det (E)| and E is the matrix defined by the coefficients E _jk . We also find the average of fidelity over various results of Bell-state measurement and its minimum value over all possible information states and discuss it for some special cases. We also show that, to evaluate quality of imperfect QT, minimum assured fidelity is a better measure than concurrence or minimum average fidelity.     

Robust Model Reference Adaptive Intelligent Control

In this paper a Neural Network based Model Reference Adaptive Control scheme (NNMRAC) is proposed. In this scheme, the controller is designed by using parallel combination of the conventional Model Reference Adaptive Control (MRAC) scheme and Neural Network (NN) controller. In the conventional MRAC scheme, the controller is designed to realize plant output converging to reference model output based on the plant which is linear. This scheme is used to control linear plant effectively with unknown parameters. However, it is difficult for a nonlinear system to control the plant output in real time applications. In order to overcome the above limitations, the NN-MRAC scheme is proposed to improve the system performances. The control input of the plant is given by the sum of the MRAC output and NN controller output. The NN controller is used to compensate the nonlinearities and disturbances of the plant that are not taken into consideration in the conventional MRAC. The simulation results clearly show that the proposed NN-MRAC scheme have better steady state and transient performances than those of the current adaptive control schemes. Thus, the proposed NN-MRAC scheme named as Robust Model Reference Adaptive Intelligent Control (RMRAIC) is found to be extremely effective, efficient and useful in the field of control system.     

Microstructure and mechanical properties of ultrafine-grained hardmetals

The interest in ultrafine-grained hardmetals as woodcutting tool materials derives from their excellent mechanical properties compared with those of conventional hardmetals. The aim of this work was to determine the mechanical properties of ultrafine-grained hardmetals and to correlate the measured effects with microstructural parameters. The ultrafine-grained hardmetals (WC grain size 0.3 μm) investigated consisted of different WC powders and different binder systems: Co and complex binder systems. The mechanical properties of ultrafine-grained hardmetals were tested under two different loading conditions: monotonically increasing and cyclic alternating bending loads. It could be shown that the binder systems of different compositions show different behaviours under cyclic loads. Ultrafine-grained hardmetals with Co binder exhibit high bending strength values, but high fatigue sensitivity. Ultrafine-grained hardmetals with complex binders show lower bending strength values but their sensitivity to fatigue is lower. This implies that different damaging mechanisms exist for ultrafine-grained hardmetals with Co and complex binders.     

Polyaniline–polyelectrolyte–gold(0) ternary nanocomposites: Synthesis and electrochemical properties

Ternary composites based on polyaniline (PAni), a polyelectrolyte-namely poly(diallyldimethylammoniumchloride) (PDDMAC) and gold (Au(0)) nanoparticles have been formulated and synthesized where the high concentration of PDDMAC acted as medium of reaction. The nanocomposites are characterized by FT-IR, UV–vis, XRD, XPS, SEM, AFM and TEM techniques. XRD showed the presence of all three viz., polyaniline, PDDMAC and Au(0) components in the ternary system. The composites exhibited higher conductivities in the range 26 × 10⁻⁶ to 217 × 10⁻⁶ S/cm compared with the binary composite of PAni–PDDMAC. The ternary composites were adsorbed on a GC electrode and used for sensing dopamine. The composites are useful in sensing as low as 0.05 mM concentration of dopamine at lower potential values compared to some binary PAni–Au nanocomposites.     

Phospholipid,Oleic Acid Micelles and Dietary Olive Oil Influence the Lutein Absorption and Activity of Antioxidant Enzymes in Rats

This study reports on the results of repeated gavages and dietary feeding of lutein dispersed either in phospholipids or fatty acid micelles or vegetable oils and the effects on lutein bioavailability and antioxidant enzymes in rats. For the gavage study, rats (n = 5/group) were intubated with lutein solubilized either in oleic acid (OLA, 18:1n-9) or linoleic acid (LNA, 18:2n-6) or phosphatidylcholine (PC) or lysophosphatidylcholine (LPC) or no phospholipid (NoPL) micelles for 10 days. For the dietary study, rats (n = 5/group) were fed a diet containing fenugreek leaf (lutein source), either with olive (OO) or sunflower (SFO) or groundnut (GNO, control) oil or l-α-lecithin (PL) for 4 weeks. The gavage study showed that the plasma, liver and eye lutein levels in OLA and LPC groups were higher by 23.9, 20.8 and 25.5% and 16.1, 28.5 and 14.0% than LNA and PC groups, respectively. The dietary study showed the plasma (35.0 and 43.5%) and eye (18.5 and 37.0%) lutein levels in OO were higher than SFO and GNO groups. The plasma and eye lutein levels in the PL group were higher by 20 and 31.3% than in the control. It is evident that OO and PL modulate lutein absorption, which in turn modulates antioxidant enzymes and fatty acids in plasma and tissues compared to SFO. Hence, selection of the fat source may be vital to enhancing the lutein bioavailability.