Synthesis of electro‐active membranes by chemical vapor deposition (CVD) process

In the past two decades, many research is being carried out on coating of textile membranes with conductive polymers. In order to functionalize the textile membranes, coating of different intrinsically conductive polymers can be applied on these membranes through appropriate coating techniques like electrochemical polymerization, wet chemical oxidation and chemical vapor deposition (CVD). Noticeably, CVD process is one of the most suitable and environment friendly technique. In this research, microporous polyester and polytetrafluoroethylene (PTFE) membranes were coated with conductive poly(3,4‐ethylenedioxythiophene) (PEDOT) by CVD process in the presence of ferric(III)chloride (FeCl₃) used as an oxidant. Polymerization of PEDOT on the surface of membranes and pore size was examined by optical microscope and scanning electron microscopy (SEM). Structural analysis investigated with ATR‐FTIR, which revealed the successful deposition of PEDOT on membranes without damaging their parent structures. The amount of PEDOT in PEDOT‐coated polyester and PTFE membranes was explored with the help of thermogravimeteric analysis. Electrical resistance values of PEDOT‐coated membranes were measured by two probe method. The effect of different electrolyte solutions such as, distilled H₂O, Na₂SO₄, HCl, and H₂SO₄ on electrical properties of produced conductive membranes was investigated after dipping for certain period of time. It was found that membranes dipped in H₂SO₄ show very low electrical resistance values, i.e. 0.85 kΩ for polyester membrane and 1.17 kΩ for PTFE membrane. The obtained PEDOT‐coated electro‐active membranes may find their possible utility in fuel cells, enzymatic fuel cells, and antistatic air filter applications. Copyright © 2014 John Wiley & Sons, Ltd.     

Simulation of the temperature and wear behaviour of a disc brake

Aerosols are defined in the simplest form as a mixture of solid or liquid particles suspended in a gas [1]. Brake dust is an aerosol, generated as a result of erosion between brake disc and brake pad. The aerosols can cause visual disorder, heart and lung diseases, short term acute symptoms like asthma, bronchitis and long term chronic irritation and inflammation of the respiratory track, which can lead to cancer. Therefore, it is important to know which factors are affecting the erosion rate of brakes. The main objective of this work is to measure the erosion rate of brake discs and brake pads, depending on temperature changes and deformation by performing experiments and simulations at varying velocities and load conditions. The general purpose, commercially available finite element solver Abaqus is used for performing the thermomechanically coupled simulations. Archad's Wear Law is used for the wear calculation. Experiments are conducted by using a pin on disc test bench. Temperature changes are measured by using thermocouples and erosion rates by measuring the total volume loss. At the end, relationships between erosion rates and temperature changes for different brake disc velocities and load conditions are investigated and experimental and simulation results are compared and discussed. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and characterization of laterally substituted bis(alkoxybenzoyloxy)hydroquinones

A new series of laterally substituted bis(alkoxybenzoyloxy)hydroquinone compounds has been synthesized and their mesomorphic properties studied. A number of hydroquinone compounds were synthesized with terminal n-alkoxy chains ranging from n-butyloxy to n-decyloxy. Additionally, lateral substituents ranging from n-butyl to n-octyl were incorporated through esterification at the remaining unsubstituted phenolic oxygen atoms. By optimizing the combination of the end group and lateral moieties we were able to tailor the molecular structure to form different liquid crystalline phases.     

Fully Coprime Comodules and Fully Coprime Corings

Prime objects were defined as generalization of simple objects in the categories of rings (modules). In this paper we introduce and investigate what turns out to be a suitable generalization of simple corings (simple comodules), namely fully coprime corings (fully coprime comodules). Moreover, we consider several primeness notions in the category of comodules of a given coring and investigate their relations with the fully coprimeness and the simplicity of these comodules. These notions are applied then to study primeness and coprimeness properties of a given coring, considered as an object in its category of right (left) comodules. Supported by King Fahd University of Petroleum and Minerals, Research Project # INT/296.     

Combinatorial auctions

Combinatorial auctions are an important class of market mechanisms in which participants are allowed to bid on bundles of multiple heterogeneous items. In this paper, we discuss several complex issues that are encountered in the design of combinatorial auctions. These issues are related to the formulation of the winner determination problem, the expression of combined bids, the design of progressive combinatorial auctions that require less information revelation, and the need for decision support tools to help participants make profitable bidding decisions. For each issue, we survey the existing literature and propose avenues for further research. An earlier version of this paper appeared in 4OR 2, 1–33, 2004.     

A dual Zariski topology for modules

We introduce a dual Zariski topology on the spectrum of fully coprime R-submodules of a given duo module M over an associative (not necessarily commutative) ring R. This topology is defined in a way dual to that of defining the Zariski topology on the prime spectrum of R. We investigate this topology and clarify the interplay between the properties of this space and the algebraic properties of the module under consideration.     

Trace determination of lanthanum,cerium, and praseodymium based on adsorptive stripping voltammetry

A sensitive stripping procedure is described for quantifying lanthanum, cerium and praseodymium ions, based on the controlled adsorptive accumulation of the lanthanide/o- cresolphthalexon complex onto the static mercury drop electrode. The effect of various operational parameters on the stripping response is discussed. A 20-min accumulation period coupled with differential pulse measurement of the current resulting from the adsorbed complex permits quantitation down to the 1 × 10^?10 M level. For concentrations ranging from 2.5 × 10^?8 M to 2.5 × 10^?9 M, a 0.5- to 4-min accumulation period is sufficient. The relative standard deviation ar the 7 × 10^?8 M level ranges from 1 to 6%.     

Non-minimal coupling of torsion–matter satisfying null energy condition for wormhole solutions

We explore wormhole solutions in a non-minimal torsion–matter coupled gravity by taking an explicit non-minimal coupling between the matter Lagrangian density and an arbitrary function of the torsion scalar. This coupling describes the transfer of energy and momentum between matter and torsion scalar terms. The violation of the null energy condition occurred through an effective energy-momentum tensor incorporating the torsion–matter non-minimal coupling, while normal matter is responsible for supporting the respective wormhole geometries. We consider the energy density in the form of non-monotonically decreasing function along with two types of models. The first model is analogous to the curvature–matter coupling scenario, that is, the torsion scalar with T-matter coupling, while the second one involves a quadratic torsion term. In both cases, we obtain wormhole solutions satisfying the null energy condition. Also, we find that the increasing value of the coupling constant minimizes or vanishes on the violation of the null energy condition through matter.     

Antioxidant,antimicrobial and urease inhibiting activities of methanolic extracts from Cyphostemma digitatum stem and roots

Cyphostemma digitatum stem and roots extracts were investigated for antioxidant, antimicrobial, urease inhibition potential and phytochemical analysis. Phytochemical screening of the roots and stem extract revealed the presence of secondary metabolites including flavonoids, alkaloids, coumarins, saponins, terpenoids, tannins, carbohydrates/reducing sugars and phenolic compounds. The methanolic extracts of the roots displayed highest antioxidant activity (93.518%) against DPPH while the crude methanolic extract of the stem showed highest antioxidant activity (66.163%) at 100 μg/mL concentration. The methanolic extracts of both stem and roots were moderately active or even found to be less active against the selected bacterial and fungal strains (Tables S2 and S3). The roots extract (methanol) showed significant urease enzyme inhibition activity (IC₅₀ = 41.2 ± 0.66; 0.2 mg/mL) while the stem extract was found moderately active (IC₅₀ = 401.1 ± 0.58; 0.2 mg/mL) against thiourea (IC₅₀ = 21.011; 0.2 mg/mL).     

Thermodynamics of gravitationally induced particle creation scenario in DGP braneworld

In this paper, we discuss the thermodynamical analysis for gravitationally induced particle creation scenario in the framework of DGP braneworld model. For this purpose, we consider apparent horizon as the boundary of the universe. We take three types of entropy such as Bakenstein entropy, logarithmic corrected entropy and power law corrected entropy with ordinary creation rate \(\Gamma \). We analyze the first law and generalized second law of thermodynamics analytically for these entropies which hold under some constraints. The behavior of total entropy in each case is also discussed which implies the validity of generalized second law of thermodynamics. Also, we check the thermodynamical equilibrium condition for two phases of creation rate, that is constant and variable \(\Gamma \) and found its vitality in all cases of entropy.