Social media assimilation in firms: Investigating the roles of absorptive capacity and institutional pressures

Firms are increasingly employing social media to manage relationships with partner organizations, yet the role of institutional pressures in social media assimilation has not been studied. We investigate social media assimilation in firms using a model that combines the two theoretical streams of IT adoption: organizational innovation and institutional theory. The study uses a composite view of absorptive capacity that includes both previous experience with similar technology and the general ability to learn and exploit new technologies. We find that institutional pressures are an important antecedent to absorptive capacity, an important measure of organizational learning capability. The paper augments theory in finding the role and limits of institutional pressures. Institutional pressures are found to have no direct effect on social media assimilation but to impact absorptive capacity, which mediates its influence on assimilation.     

Using honeynodes for defense against jamming attacks in wireless infrastructure-based networks

The advent of wireless networks has brought a new set of security issues with it. One of the most feared of these is the jamming-based attacks. In this paper, we propose a pre-emptive detection strategy using honeynodes and a response mechanism based on the existing Channel Surfing Algorithm [Xu W, Trappe W, Zhang Y, Wood T. Channel surfing and spatial retreats: defenses against wireless denial of service. ACM Wireless Security 2004;80-9] to protect wireless nodes from a jammer. Honeynodes generate dummy communication at a frequency close to the actual frequency of operation, and pre-emptively alert authentic nodes of imminent attacks, so that the authentic nodes can jump to another frequency even before a jammer starts scanning that frequency. The next frequency is selected using a novel approach which uses a hybrid of reactive and proactive channel selection procedures. We have simulated the proposed approach using NS-2. The experimental results further prove a marked improvement in the performance of the proposed system over the Channel Surfing Algorithm in terms of the packet delivery ratio, the jammed duration, control message overhead and the number of channel re-configurations.     

Extraction of low-toxicity nanodiamonds from carbonaceous wastes

Being innocuous, nanodiamonds find huge applications in bioimaging, drug delivery and biomedical sensing. Their synthesis is generally carried out by detonation or shock wave methods. This article reports novel, economical and risk-free extraction of nanodiamonds from carbonaceous waste (smoke deposits of Hawan kund). Structural and morphological studies of extracted material revealed that the nanodiamonds have a size range of 4–5 nm and consists of sp³ core and sp² shell. Extracted nanodiamonds contain various functional groups on its surface which make it suitable for various applications. Cytotoxicity assay revealed very less toxicity of extracted nanodiamonds, which makes them suitable candidate for biological applications. The proposed method offers the possibility of economical and detonation free production of nanodiamonds.     

Carbon nanotube-based electrochemical sensor for the determination of halobetasol propionate, a topical corticosteroid

Electrocatalytic reduction of halobetasol propionate (HBP) at single-walled carbon nanotube (SWCNT) modified edge plane pyrolytic graphite electrode (EPPGE) was performed by square wave voltammetry and cyclic voltammerty in phosphate buffer of pH 7.2. The surface morphology of SWCNT/EPPGE was characterized by field emission scanning electron microscopy. The enhanced peak current (i _p) and lower reduction peak potential (E _p) at modified electrode as compared to bare electrode were obvious evidences for the electrocatalytic ability of SWCNT toward the reduction of HBP. The cathodic peak current varied linearly with concentration of HBP in the range 0.02 to 1 mM with sensitivity of 2.432 μA mM⁻¹ and detection limit (3σ/slope) of 10 μM. The product of electrochemical reduction of HBP was characterized using FT-IR and ¹H-NMR spectroscopic techniques. A tentative mechanism for the formation of product was suggested and it was found that reduction of >C=O occurred at position three. The proposed methodology was successfully applied to the detection of HBP in pharmaceutical preparations.     

Kinetics of adsorption of sulfur mustard on Al2O3 nanoparticles with and without impregnants

BACKGROUND: Chemical warfare (CW) agents are highly toxic compounds and have been used in war to produce physical immobilization, so safe and effective ways to detoxify them without endangering human life or the environment is of great concern. One of the important ways to achieve protection against CW agents contaminating air is to utilize suitable adsorbent materials, e.g. activated carbon, nanoparticles, etc. In the present study nanoparticles, synthesized through sol–gel processes and loaded with reactive compounds have been used for the degradation of CW agents and to understand their adsorption kinetics using Fickian and linear driving force models. RESULTS: Nanoparticles of AP‐Al₂O₃ (aerogel‐produced alumina) in the size range 2–30 nm with high surface area (375 m² g^?1) were produced by an alkoxide‐based synthesis, and then characterized using N₂‐Brunauer–Emmet–Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD) and thermogravimetric analysis (TGA) techniques. Thereafter, these were impregnated, and finally tested for kinetics of adsorption of sulfur mustard (HD) under static conditions. The kinetics was studied using linear driving force and Fickian diffusion models and the kinetics parameters determined. CONCLUSION: AP‐Al₂O₃ with 10% impregnation of 9‐molybdo‐3‐vanadophosphoric acid (10%, w/w) showed the maximum uptake (640 mg g^?1) of HD. The highest adsorption potential indicated that the adsorption was due not only to physisorption but also involved chemisorption. Values of the diffusional exponent indicated the mechanism to be Fickian and anomalous. Hydrolysis, dehydrochlorination and oxidation reactions (identified using gas chromatography‐mass spectrometry (GC/MS)) were found to be the route of degradation of HD over the prepared nanoparticle based adsorbents. Copyright © 2009 Society of Chemical Industry     

Laser beam machining—A review

Laser beam machining (LBM) is one of the most widely used thermal energy based non-contact type advance machining process which can be applied for almost whole range of materials. Laser beam is focussed for melting and vaporizing the unwanted material from the parent material. It is suitable for geometrically complex profile cutting and making miniature holes in sheetmetal. Among various type of lasers used for machining in industries, CO₂ and Nd:YAG lasers are most established. In recent years, researchers have explored a number of ways to improve the LBM process performance by analysing the different factors that affect the quality characteristics. The experimental and theoretical studies show that process performance can be improved considerably by proper selection of laser parameters, material parameters and operating parameters. This paper reviews the research work carried out so far in the area of LBM of different materials and shapes. It reports about the experimental and theoretical studies of LBM to improve the process performance. Several modelling and optimization techniques for the determination of optimum laser beam cutting condition have been critically examined. The last part of this paper discusses the LBM developments and outlines the trend for future research.     

Decentralized energy planning model for optimum resource allocation with a case study of the domestic sector of rurals in Nepal

The paper is concerned with the development of a simplified linear model which attempts to optimize the cost function of an energy supply system consisting of a mix of energy resources and conversion devices, each of which may have a constraint with respect to availability, efficiency and cost. The model has been applied in three villages, from three different physiographic zones of Nepal, for which detailed data were collected and analysed. The results of the study show that the optimized use of different energy sources in different regions is strongly dependent on demographic and climatic parameters. For hill villages, hydropower could become the cheapest source of energy if technical options were provided, but until then more efficient use of wood is the only viable solution. Commercial sources like kerosene and LPG are not likely to play any significant role in hill and mountain villages. On the other hand, the use of biogas is economically most feasible in Terai village. The availability of kerosene rules out wood or agriculture waste as feasible solutions for cooking energy needs, as this village is closer to the Indian border and has good road access.     

Anatomic variations in underdeveloped right ventricle related to tricuspid atresia and stenosis

In the anatomy of 416 hearts, the seat of tricuspid stenosis or atresia is examined, with special reference to Fontan-like surgical procedures. A classification is offered which includes cases with and without regular or inverted transposition, and with decreased or increased pulmonary flow. The size and thickness of the right atrium, the size and architecture of the right ventricle, the size of the pulmonary tree, the types of atrial and ventricular septal defects, the condition of the mitral valve, and the size and thickness of the left atrium and left ventricle are analyzed. In addition the various intracardiac and extracardiac abnormalities are enumerated. Reference is also made to the tendency of the aorta and pulmonary trunk to override the septum, in some cases producing double-outlet left ventricle. It is considered that many cases of tricuspid valve atresia and stenosis with or without transposition may be amenable to Fontan-like procedures in the proper age group. All the above anatomic considerations have a bearing on the suitability and type of operative tricuspid bypass procedures, and they may influence the prognosis of surgical therapy.