Swift heavy ion induced structural modifications in zircon and scheelite phases of ThGeO4

Structural modifications in the zircon and scheelite phases of ThGeO₄ induced by swift heavy ions (93 MeV Ni⁷⁺) at different fluences as well as pressure quenching effects are reported. X-ray diffraction and Raman measurements at room temperature on the irradiated zircon phase of ThGeO₄ indicate the occurrence of stresses that lead to a reduction of the cell volume up to 2% followed by its transformation to a mixture of nano-crystalline and amorphous scheelite phases. Irradiation of the zircon phase at liquid nitrogen temperature induces amorphization at a lower fluence (7.5 × 10¹⁶ ions/m²), as compared to that at room temperature (6 × 10¹⁷ ions/m²). Scheelite type ThGeO₄ irradiated at room temperature undergoes complete amorphization at a lower fluence of 7.5 × 10¹⁶ ions/m² without any volume reduction. The track radii deduced from X-ray diffraction measurements on room temperature irradiated zircon, scheelite and low temperature irradiated zircon phases of ThGeO₄ are, 3.9, 3.5 and 4.5 nm, respectively. X-ray structural investigations on the zircon phase of ThGeO₄ recovered after pressurization to about 3.5 and 9 GPa at ambient temperature show the coexistence of zircon and disordered scheelite phases with a larger fraction of scheelite phase occurring at 9 GPa. On the other hand, the scheelite phase quenched from 9 GPa shows crystalline scheelite phase pattern.     

Emission characteristic of hydrogen and gasoline blend in spark-ignited engine

Hydrogen is an energy carrier that can transform our fossil fuel-dependent economy into a hydrogen economy, which can provide an emission-free transportation fuel. Hydrogen-fuelled engines are known for several advantages, among which is the very low concentration of pollutants in the exhaust gases compared with internal combustion engines using traditional or other alternative fuels. Hydrogen-driven vehicles thus reduce both local and global emissions. It is an energy carrier that can be used in internal combustion engines or fuel cells producing virtually no greenhouse gas emissions when combusted with oxygen. The only significant emission is water vapour. The effect of blending of hydrogen with gasoline is analysed in this current paper. Both HC and NO_x concentration decrease with the increase in hydrogen fractions. The results were analysed by collecting data on different crank angles and at 5%, 10%, 15% and 20% of hydrogen introduction into combustion chamber along with gasoline as base fuel.     

三轴感应电阻率测井新技术

一种新型感应电阻率测井仪器能够提供远离井筒地层的三维信息,提高斜井和倾斜地层的电阻率测量精度,而且不需要接触井壁就能够直接测量地层倾角大小和方位。采用这种高精度三轴电阻率测井仪器可以减少漏掉油气层的机会,加强对储层的认识。     

Non-discrete ant colony optimisation (NdACO) to optimise the development cycle time and cost in overlapped product development

In order to expedite the process of introducing a product to market, organisations have shifted their paradigm towards concurrent engineering. This involves the simultaneous execution of successive activities on the basis of information available in rudimentary form. For this, cross-functional teams sporadically communicate to exchange available updated information at the cost of augmented time and money. Therefore, the aim of this paper is to present a model-based methodology to estimate the optimal amount of overlapping and communication policy with a view to minimising the product development cycle time at the lowest additional cost. In the first step of the methodology, an objective function comprising the cycle time and the cost of the complete project is formulated mathematically. To reach the optimal solution, a novel meta-heuristic, non-discrete ant colony optimisation, is proposed. The algorithm derives its governing traits from the traditional ant algorithms over a discrete domain, but has been modified to search results in a continuous search space. The salient feature of the proposed meta-heuristic is that it utilises the weighted sum of numerous probability distribution functions (PDFs) to represent the long-term pheromone information. This paper utilises a novel approach for pheromone maintenance to adequately update the PDFs after each tour by the ants. The performance of the proposed algorithm has been tested on a hypothetical illustrative example of mobile phones and its robustness has been authenticated against variants of particle swarm optimisation.     

First and second law analyses of a typical solar air dryer system: a case study

This communication presents an experimental study based on energy and exergy analyses of a typical solar air dryer. On the basis of the experimental results, the first and the second law efficiencies are calculated with respect to the available solar radiation. It is found that the second law efficiency is much less than the first law efficiency irrespective of the mass flow rate of the circulating fluid. It is also found that both efficiencies are an increasing function with respect to the mass flow rate of the working fluid. For a particular day, it is also found that first and second law efficiencies fluctuate according to radiation. The results obtained in this article are found to be consistent with those obtained by earlier authors as given in the literature.     

Synthesis and Performance Properties of Cationic Fabric Softeners Derived from Different Fatty Acids and 1(2-Hydroxyethylpiperazine)

Quaternary ammonium salts (otherwise known as “quats”) commonly form the foundation of formulations in the antimicrobial industry. Many studies have been conducted on the biological activity of surfactants derived from fatty acids viz. lauric acid, myristic acid, stearic acid and palmitic acid and palm fatty acid with polyamine, i.e. 1(2-hydroxyethylpiperazine). The present paper investigates the synthesis and surface-active properties of esteramide quats derived from the esterification of the above-mentioned fatty acids and 1(2-hydroxyethylpiperazine) followed by quaternization using dimethyl sulphate (DMS). These derivatives were fully characterized by using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, and 13C-NMR spectroscopy. In addition to the cationic content, surface tension, CMC (critical micelle concentration), fabric softening, rewettability, emulsification and dispersing power were determined as their surface-active properties.

Polyether based amphiphiles for delivery of active components

The bioavailability of hydrophobic drugs is critically dependent on the development of efficient and safe drug delivery vehicles. Nanoparticulate pharmaceutical carriers commonly used in delivery of active components are often non-ionic in nature. Among them polyether based amphiphiles have become increasingly relevant over the past decades. Polyether based amphiphiles exhibit good chemical stability, high water solubility, low toxicity, have decreased interaction with blood components, and are highly biocompatible; and thus have been applied in biomedical and pharmaceutical areas. The current review highlights the synthetic progression and biomedical applications of these non-ionic polyether-based amphiphilic architectures, some unresolved issues and challenges, along with the future perspective of polyether based nanocarriers for delivery of active components.     

Scapania nemorea liverwort extracts: Investigation on volatile compounds, in vitro antimicrobial activity and control of Saccharomyces cerevisiae in fruit juice

This study was focused on chemical characterisation of liverwort Scapania nemorea extracts and their antimicrobial activity against pathogenic and food-spoiling yeasts and bacteria. The chemical composition of three different extracts of the liverwort S. nemorea was determined by solid phase microextraction gas chromatography-mass spectrometry (SPME GC–MS). The dominant compounds in extracts were sesquiterpenes β-bazzanene (11%, 17.9% and 14.6%), isobazzanene (10.2%, 15.8% and 11.7%) and aromadendrene (8.8%, 12.9% and 10.6%) in the methanol, ethanol and ethyl acetate extracts, respectively. Antimicrobial potential of S. nemorea extracts against food spoiling yeasts and bacteria was determined in vitro by microdilution method. The Minimum Inhibitory Concentration (MIC) varied from 0.5 to 3 mg/mL for bacteria, and from 0.2 to 1 mg/mL for yeasts. Moreover, the combined effects of dry methanol extract of S. nemorea and heat processing on the survival and growth of a spoilage yeast in an apple/orange-based beverage, have been assessed through a Central Composite Design. Changes in color and flavor of the beverages were considered acceptable also after one week of storage at 25 °C. The results provide evidence of antimicrobial potential of S. nemorea extracts and suggest its potential as natural antimicrobial agent for food preservation.     

Catalytic action of gold and copper crystals in the growth of carbon nanotubes

Multi-wall carbon nanotubes are grown in a chemical vapor deposition process by using bulk gold and copper substrates as catalysts. Nanotube growth starts from a nanometer-sized roughness on the metal surfaces and occurs in a mechanism where the catalyst particle is either at the tip (Au) or root (Cu) of the growing nanotube. Whereas Au leads to nanotubes with good structural perfection, nanotubes grown from Cu show a higher density of defects. High-resolution transmission electron microscopy shows the bonding between Au and carbon at the metal-nanotube interface whereas no bonds between Cu and carbon occur. Highly mobile Au or Cu atoms adsorb at the growing edge of a carbon nanotube from where diffusion along the nanotube wall can lead to the formation of Au or Cu nanowires inside the central hollow of carbon nanotubes.     

纤维横截面对环锭纱和喷气纱织物舒适性的影响

描述了纤维横截面形状对涤棉和涤粘环锭纱织物及喷气纱织物的影响.纱线结构在影响衣服舒适性的众多因素中扮演着重要角色.事实证明用喷气纱制成的面料在透气性、透湿性和吸湿性方面优于环锭纱面料.非圆形截面的涤纶纤维制成的面料具有较好的透气性、导湿性、吸湿性、绝热性和芯吸性.除了绝热性能外涤粘混纺面料的其他各项性能均比涤棉混纺面料好.