Pyrolysis of petroleum asphaltenes from different geological origins and use of methylnaphthalenes and methylphenanthrenes as maturity indicators for asphaltenes

Asphaltenes separated from two different crude oils from upper Assam, India, having different geological origins, viz. DK (eocene) and JN (oligocene–miocene) were pyrolysed at 600 °C and the products were analysed by gas chromatography–mass spectrometry (GC/MS) especially for the generated alkylnaphthalenes and alkylphenanthrenes. Both the asphaltenes produce aliphatic as well as aromatic compound classes. Alkylnaphthalenes and alkylphenanthrenes were identified by using reference chromatograms and literature data and the distributions used to assess thermal maturity of the asphaltenes. The ratios of β -substituted to α -substituted isomers of both alkylnaphthalenes and alkylphenanthrenes revealed higher maturity of the JN asphaltenes than the DK asphaltenes. For both the asphaltenes, the abundance of 1-methylphenanthrene dominates over that of 9-methylphenanthrene showing the terrestrial nature of the organic matter.     

Aged rare earth doped silicates as optoelectronic material

Samples of various concentrations were prepared and kept unsintered for a period of three years to study the consistency of composition prepared and structural evolution of glass. The expanded peaks in the Raman spectra arise due to thermal agitation, and a Boltzmann type of distribution was expected in the silicate gels. The behavior of the gels during the dehydroxylation and dehydration is conditioned by its microstructure, which depends upon the physical conditions, I.e., pH, and drying conditions.     

Synthesis and characterization of CuO nanoparticles using strong base electrolyte through electrochemical discharge process

In the present study, cupric oxide (CuO) nanoparticles were synthesized by electrochemical discharge process using strong base electrolytes. The experiments were carried out separately using NaOH and KOH electrolytes. The mass output rate and the crystal size were obtained with variation of the rotation speed of magnetic stirrer for both types of electrolytes. The mass output rate of CuO nanoparticles increased with the increase in the speed of rotation, and, after an optimum speed, it started decreasing. However, the size of the particles reduced with the increase of the rotation speed. The crystal plane of the obtained CuO nanoparticles was similar for both the electrolytes whereas the yield of nanoparticles was higher in KOH as compared with NaOH under the same experiment conditions. In this set of experiments, the maximum output rates obtained were 21.66 mg h^?1 for NaOH and 24.66 mg h^?1 for KOH at 200 rpm for a single discharge arrangement. The average crystal size of CuO particles obtained was in the range of 13–18 nm for KOH electrolyte and 15–20 nm for NaOH electrolyte. Scanning electron microscopy images revealed that flower-like and caddice clew-shaped CuO nanocrystalline particles were synthesized by the electrochemical discharge process. Fourier transform infrared spectrum showed that the CuO nanoparticles have a pure and monolithic phase. UV–vis–NIR spectroscopy was used to monitor oxidation course of Cu → CuO and the band gap energy was measured as 2 and 2.6 eV for CuO nanoparticle synthesized in NaOH and KOH solutions, respectively.     

获得GRC美学效果和耐久性能的一些实用技巧

本文着重介绍改善美学和耐久性能所采用的各种措施.有某些关于提高GRC的美学性能参数来保证质量,而另一些参数来保证耐久性.有关优化美学性能的参数是一个好的设计,工艺控制包括在工厂和现场的材料和模具质量以及构件的检查、测试和修改,还有在现场的表面处理.有关改善GRC耐久性的参数是耐碱玻璃纤维的种类和质量,整个功能链包括设计和安装工艺、包括修复和最终表面处理在内的GRC的生产和养护.基于实践经验,本文回顾了工厂质量控制的发展,以及着重于能够获得更好的美学和耐久性能GRC的作、安装和包括最终表面处理在内的现场修复.     

TEXTURAL CHARACTERISTICS OF FIVE MICROORGANISMS FOR RAPID DETECTION USING IMAGE PROCESSING

A rapid and cost-effective technique for identification and classification of microorganisms was explored using fluorescence microscopy and image analysis. After staining the microorganisms with fluorescent dyes (diamidino-2-phenyl-indole [DAPI] and acridine orange [AO], images of the microorganisms were captured using a charge-coupled device camera attached to a light microscope. Textural features were extracted from the images. Fluorescence emission from Bacillus thuringiensis is the highest compared with other microbes, and the emission from Lactobacillus brevis is the lowest. Various microorganisms can be differentiated using various textural features from images using AO or DAPI dye. Many textural features of the images obtained from the two dyes were different.

PRACTICAL APPLICATIONS

Conventional microbial detection methods take considerable time and are laborious. Rapid methods are required so that pathogens and spoilage microorganisms in foods and water can be identified and counted in a much shorter time. This work investigates image processing techniques particularly based on textural properties of the images of microorganisms. Images of microorganisms in samples can be captured using light microscopes after concentrating using centrifuge or membrane separation devices. This work will assist in developing a commercial method for rapid detection of microbes in food samples.     

DEVELOPMENT OF A HIGH-MOISTURE SHELF-STABLE GRATED CARROT PRODUCT USING HURDLE TECHNOLOGY

Carrot (Daucus carota) can be highly perishable and difficult to preserve fresh for long periods at ambient temperature and humidity. Studies on grated carrots were carried out for the development of a shelf‐stable moist‐preservation process based on infusion of additives using hurdle technology. Additives comprising 3.0% sodium chloride (to reduce water activity [A_w] to 0.94), 0.9% citric acid (to reduce pH to below 4.5), 1.0% sodium citrate and 0.2% sodium benzoate (as antimicrobial agents) were followed by partial dehydration. The product was stored in flexible polymeric pouches. The physical, chemical and pathological stability was monitored during storage at ambient temperatures (19–33C). The partially dehydrated grated carrots (moisture 66.2%) were acceptable for more than six months at ambient temperature with the retention of carotenoid up to 82.5%. The product was microbiologically safe throughout the study.     

Fuzzy clustering of mechanisms

During the course of development of Mechanical Engineering, a large number of mechanisms (that is, linkages to perform various types of tasks) have been conceived and developed. Quite a few atlases and catalogues were prepared by the designers of machines and mechanical systems. However, often it is felt that a clustering technique for handling the list of large number of mechanisms can be very useful, if it is developed based on a scientific principle. In this paper, it has been shown that the concept of fuzzy sets can be conveniently used for this purpose, if an adequate number of properly chosen attributes (also called characteristics) are identified. Using two clustering techniques, the mechanisms have been classified in the present work and in future, it may be extended to develop an expert system, which can automate type synthesis phase of mechanical design. To the best of the authors?? knowledge, this type of clustering of mechanisms has not been attempted before. Thus, this is the first attempt to cluster the mechanisms based on some quantitative measures. It may help the engineers to carry out type synthesis of the mechanisms.     

Time delayed control of classically damped structural systems

The effects of time delays on collocated as well as non-collocated point control of classically damped discrete dynamic systems have been examined. Controllers of PID type nave been considered. Analytical estimates of time delays to maintain/obtain stability for small gains have been given. Several new results dealing with the effect of time delays on collocated and non-collocated control designs are obtained. It is shown that undamped structural systems cannot be stabilized with pure velocity (or integral) feedback without time delays while using a controller that is not collocated with the sensor, when the mass matrix is diagonal. However, with the appropriate choice of time delays, for certain classes of commonly occurring structural systems, stable non-collocated control can be achieved. Analytical results providing the upper bound on the controller's gain necessary for stability have been presented. The theoretical results obtained are illustrated and verified with numerical examples.