Fabrication and characterization of electrospun psyllium husk-based nanofibers for tissue regeneration

The present study reports for first time the blending of psyllium husk (PH) powder/gelatin (G) in the polymer-rich composition of polyvinyl alcohol (PVA) to make an electrospinnable solution. The composite was prepared in 3 different ratios viz., 100% (wt/wt) (PVA + PH), 75% + 25% (PVA + 75PH + 25G) (wt/wt) and 50% + 50% (PVA + 50PH + 50G) (wt/wt) in 6% PVA solution. Optimum electrospinning parameters were evaluated for all the prepared blends. The fabricated nanofibers were characterized by scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared, differential scanning calorimetry, porosity percentage, and fiber orientation using ImageJ software. A qualitative in vitro degradation study at room temperature is supported by SEM images. The cellular interactions were characterized by MTT assay of NIH-3T3 fibroblast cells for 2 and 4 days with an optimum cell growth of >50% by fourth day of culture and long-term cultivation of L929-RFP cells was observed for 10 days. The nanofibers were formed in the range of 49–600 nm. PVA + 75PH + 25G when cultured with L929-RFP cells exhibited highest fluorescence intensity and thus supported cellular proliferation significantly. Based on the results obtained from various analyses, we anticipate that fabricated psyllium-based nanofiber can be used as a promising candidate for wound healing and other biomedical applications.     

The synthesis of pixelated metamaterial cross polarizer using binary wind driven optimization algorithm

Microsystem Technologies - In this paper synthesis of two wideband Metamaterial Cross Polarizer (MCPs) is proposed. The synthesis of proposed MCPs is done by using Binary Wind Driven Optimization...     

Remote-sensing-based study of impact of a rock avalanche on North Terong Glacier in Karakorum Himalaya

ABSTRACT

In this article, we report the results of a study on occurrence of a mass-movement event classified as ‘rock avalanche’ over the North Terong glacier (a tributary of the Siachen Glacier in the Nubra Valley), using multi-date remote-sensing data of Landsat Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+), and Operational Land Imager (OLI) and its effects on glacier-surface velocity. Normalized cross-correlation image matching method for displacement measurements at sub-pixel level using Computer Imaging Analysis Software (CIAS), an add-on module of Environment for Visualizing Images (ENVI) software, was used to map changes in the position of debris-deposits of the rock avalanche and assess variations in glacier-surface velocities. Well-defined debris margins gave positions of debris on different dates. Study indicated that this rock avalanche must have occurred between 21 April 2000 and 8 May 2000 (possibly on 3 or 4 May). It induced a kinematic wave or a ‘mini-surge’ in the glacier with its surface velocity showing almost twofold increase in post-event period.     

An empirical correlation for estimating the viscosity of non-Newtonian waxy crude oils

Non-Newtonian fluids are the most complex ones when it comes to predicting their flow behavior. In the pre-existing models, rheological behavior in waxy crude oils is mainly affected by shear rate and thermal history of crude oils. In the present work, rheological characteristics of four different crude oils were studied by coaxial cylindrical rheometer at three different temperatures (40°C, 50°C, and 60°C) and a model was proposed keeping into consideration wax content for the first time. This model is prepared to predict the viscosity of four different crude oils with different wax content and at different temperature. The proposed model can efficiently estimate the viscosity as compared to other established models.     

Wax Deposition in Flow Lines Under Dynamic Conditions

The wax deposition in the tubing, pipeline, and surface flow line is the major problem in the oil fields. It generates additional pressure drop and causes fauling and ultimately increases the operating cost during production, transportation, and handling of waxy crude oil. In this work, attempts were made to study the wax deposition in the flow lines due to Indian crude oil under dynamic condition. The experimental work was carried out for neat crude oil and pour point depressants treated crude oil at different ambient/surface temperature and pumping/reservoir temperature. It was observed that temperature has significant effect on the wax deposition of the crude oils. From these studies, ideal temperature of crude oil to pump in the pipeline or flow line was determined. The present investigations also furnishes that the selected pour point depressant in this work decreases the wax deposition significantly and may be used for controlling the wax deposition problems in case of Indian crude oil.     

Characterization of Indian Bentonite Clay Samples for Water-based Drilling Fluids

Abstract

The rheological properties and filtration loss property of water-based drilling fluids greatly depends upon the quality and quantity of the bentonite clay, as well as the additives that are used in their formulations. To ascertain the quality of the bentonite clay, three raw Indian bentonite clays have been characterized using X-ray diffraction techniques and X-ray fluorescence techniques. The physicochemical properties, like swelling index, cation exchange capacities, and yield of clay, have also been carried out using standard API recommended procedures. The laboratory investigation reveals that these three bentonite clays are quite suitable for the development of water-based oil well drilling fluids.     

Statistical inference on progressive-stress accelerated life testing for the logistic exponential distribution under progressive type-II censoring

The accelerated life testing (ALT) is an efficient approach and has been used in several fields to obtain failure time data of test units in a much shorter time than testing at normal operating conditions. In this article, a progressive-stress ALT under progressive type-II censoring is considered when the lifetime of test units follows logistic exponential distribution. We assume that the scale parameter of the distribution satisfying the inverse power law. First, the maximum likelihood estimates of the model parameters and their approximate confidence intervals are obtained. Next, we obtain Bayes estimators under squared error loss function with the help of Metropolis-Hasting (MH) algorithm. We also derive highest posterior density (HPD) credible intervals of the model parameters. Monte Carlo simulations are performed to compare the performances of the proposed methods of estimation. Finally, one data set has been analyzed for illustrative purposes.     

Emulsification of Indian heavy crude oil using a novel surfactant for pipeline transportation

The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower(Helianthus annuus)oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension(IFT)between the crude oil(diluted)and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.     

Web-based recruitment: Effects of information, organizational brand, and attitudes toward a Web site on applicant attraction.

Recruitment theory and research show that objective characteristics, subjective considerations, and critical contact send signals to prospective applicants about the organization and available opportunities. In the generating applicants phase of recruitment, critical contact may consist largely of interactions with recruitment sources (e.g., newspaper ads, job fairs, organization Web sites); however, research has yet to fully address how all 3 types of signaling mechanisms influence early job pursuit decisions in the context of organizational recruitment Web sites. Results based on data from 814 student participants searching actual organization Web sites support and extend signaling and brand equity theories by showing that job information (directly) and organization information (indirectly) are related to intentions to pursue employment when a priori perceptions of image are controlled. A priori organization image is related to pursuit intentions when subsequent information search is controlled, but organization familiarity is not, and attitudes about a recruitment source also influence attraction and partially mediate the effects of organization information. Theoretical and practical implications for recruitment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speed of Venture Financing for Emerging Technology‐Based Entrepreneurial Firms as a Function of Founder Reputation

One of the major commercialization hurdles for technology‐based entrepreneurial enterprises is financing and the speed of its acquisition. This is compounded in the case of emerging technology‐based enterprises by the nature of their technology acquisition and founding team structure. Many of these firms do not have founders with extensive reputations in the financial community. If founder reputation is important to funding sources with regard to speed and access, and emerging technology commercial development is important for solving twenty‐first‐century problems and generating economic growth, then there is cause for concern. Here we build on prior research and data from 140 Internet‐based firms to examine the effect that founder reputation has on the ability of an enterprise to swiftly obtain financing. Our results suggest that founder reputation expedites ventures' quick access to public but not to private financing. In addition, our results demonstrate that venture capital financing obtained early on and financing by large venture capital syndicates delay access to public financing for founders with extensive reputations.