A correlation study on the phenolic profiles and corrosion inhibition properties of mangrove tannins (Rhizophora apiculata) as affected by extraction solvents

The objective of this study was to investigate the correlation of phenolic compositions and corrosion inhibition properties of Rhizophora apiculata bark extracts as affected by nine solvent systems. Several phenolic compositions, namely, total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC) were investigated. In addition, the inhibitive actions of tannin extracts on mild steel in 1 M HCl solution were studied by potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that extraction solvents had significant effects on TPC, TFC, CTC and inhibition properties of extracts. A correlation between CTC and inhibition properties of R. apiculata bark extracts was revealed.     

Solubility and dissolution enhancement strategies: current understanding and recent trends

Identification of lead compounds with higher molecular weight and lower aqueous solubility has become increasingly prevalent with the advent of high throughput screening. Poor aqueous solubility of these lipophilic compounds can drastically affect the dissolution rate and subsequently the drug absorbed in the systemic circulation, imposing a significant burden of time and money during drug development process. Various pre-formulation and formulation strategies have been applied in the past that can improve the aqueous solubility of lipophilic compounds by manipulating either the crystal lattice properties or the activity coefficient of a solute in solution or both, if possible. However, despite various strategies available in the armor of formulation scientist, solubility issue still remains an overriding problem in the drug development process. It is perhaps due to the insufficient conceptual understanding of solubility and dissolution phenomenon that hinders the judgment in selecting suitable strategy for improving aqueous solubility and/or dissolution rate. This article, therefore, focuses on (i) revisiting the theoretical and mathematical concepts associated with solubility and dissolution, (ii) their application in making rationale decision for selecting suitable pre-formulation and formulation strategies and (iii) the relevant research performed in this field in past decade.     

Experimental and simulation study of magnetorheological miniature gear-profile polishing (MRMGPP) method using flow restrictor

Journal of Mechanical Science and Technology - In this article, a new flow restrictor is utilized in the magnetorheological miniature gear-profile polishing (MRMGPP) method to ensure a consistent...     

Humble,humane and harmonious houses of Laurie Baker

Laurie Baker (1917–2007) was an architect from Birmingham, who settled and worked in India, where he met and was profoundly influenced by Gandhi. In India, he developed simple and indigenous principles of design of houses, which are comfortable and affordable by the poor. Laurie Baker is often called the Mahatma Gandhi of domestic architecture. His work is truly sustainable architecture – ecological, economic and social.     

Gonflement de la chaux dans les briques

Le problème de l'éclatement des briques dû à l'action de la chaux devient grave dans la fabrication des briques en différents endroits de l'lnde et d'ailleurs. Des briques cuites tombent en poussière lorsqu'elles sont exposées à l'air libre, du fait de la présence de particules de chaux. L'Institut central de recherche de la construction de Roorkee s'est attachée à l'étude du mécanisme par lequel les chlorures peuvent prévenir cet inconvénient.     

Easy,operable ionic polymer metal composite actuator based on a platinum‐coated sulfonated poly(vinyl alcohol)–polyaniline composite membrane

In this study, an electric‐stimulus‐responsive bending actuator based on a platinum (Pt)‐coated sulfonated poly(vinyl alcohol) (SPVA)–polyaniline (PANI) composite membrane was developed. The SPVA–PANI membrane was prepared by a solution casting method; it showed good electrochemical properties and an adequate ion‐exchange capacity of 1.6 mequiv/g of dry membrane. The water uptake by the membrane with 4 h of immersion time at 45 °C was found to be 425%. The SPVA–PANI composite membrane based ionic polymer metal composite (IPMC) actuator prepared by the coating of Pt metal layers on both sides of the membrane by an electroless plating process showed a good proton conductivity of 1.75 × 10^?3 S/cm. The smooth and uniform coating of Pt on both surfaces of the membrane, as indicated by scanning electron micrographs, seemed to be responsible for the slow water loss that is necessary for the long life of an IPMC actuator. The maximum water loss was 48% at 6 V for 12 min. This indicated the better performance of the IPMC membrane when an electric potential was applied. According to electromechanical characterization, the maximum tip displacement was 14.5 mm at 5.25 V. A multifinger IPMC membrane based microgripping system was developed, and it showed potential for microrobotics application. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43787.     

Experimental Liquidus Surface Projection of the Ni-Ru-Zr System

SEM with EDX and XRD analyses were used to study 21 as-cast Ni-Ru-Zr alloys. Phases were distinguished by BSE image contrast, and the primary phases were determined by their dendritic morphology, with the solidification sequences derived from the microstructure. Identification of the phases was done by EDX analyses, and they were verified by XRD. From these analyses, the solidus and liquidus surface projections were drawn. Three ternary phases were found: τ₁ of composition ~Zr₂₄Ru₂₂Ni₄₄ (at.%), τ₂ at ~Zr₇₄Ru₄Ni₂₂ (at.%), and τ₃ at ~Zr₃₅Ru₃Ni₆₂ (at.%). Sixteen invariant reactions were identified, and the largest liquidus surface was for ~ZrRu.     

Differential finishing of freeform surfaces (knee joint) using R-MRAFF process and negative replica of workpiece as a fixture

It is difficult and challenging to achieve uniform nanoscale surface finish in the contact zone, particularly on freeform (or sculptured) surfaces having different curvatures at different locations. Femoral (or, Knee joint component) is one of such biomedical freeform component which has complex profile along its curvature. Surface conditions of a femoral decide the life of the implant and they play a crucial role in its functionality. The variation in surface roughness of the femoral should be minimum in the contact zone. For this purpose, a special tooling is being proposed for rotational magnetorheological abrasive flow finishing (R-MRAFF) process. A negative replica of the workpiece (knee joint) as a tool (or a fixture) is used so that the medium flow velocity in the fluid flow channel is almost constant (or minimum possible variations) along the medium flow direction. It is able to do differential finishing also along the curvature. In addition, pulsating magnetic field has been used to generate vibrations in the medium in the finishing zone so that the possibility of fresh abrasive particles interacting with the surface of femoral is high. The surface finish has been achieved ranging from 26 nm to 62 nm using the proposed finishing technique and negative replica of the workpiece (femoral) as a fixture.     

Crystallization of Stoichiometric SbSI Glass

Congruent crystallization of antimony sulphoiodide (SbSI) glass of stoichiometric composition, which is prepared successfully for the first time using rapid melt‐quenching, has been investigated using differential scanning calorimetry (DSC). The results for glass powder show a glass transition at 127°C and two separate exothermal peaks with maxima around 140°C and 190°C. The ratio of the intensities of the exothermal peak at ~190°C to the peak at ~140°C increases as the particle size and heating rate are increased, but their total enthalpy remains constant at 62 ± 2 J/g for all DSC runs. Surface heating of the glass induced by a 520 nm CW laser shows two contracted regions: needle‐like crystalline formations at low temperature and bulk crystallization at high temperature. The observed phenomena and DSC results suggest two different kinds of crystallization of the SbSI phase: one‐dimensional crystallization at low temperature which starts from the sample surface and three‐dimensional bulk crystallization that continues the transformation to crystalline state at higher temperatures. The origin of the two different crystallizations can be traced to the strong anisotropy of the SbSI crystal structure due to the weak van der Waals interaction between covalent‐ionic chains (Sb₂S₂I₂)_n.