High strength thermoresponsive semi‐IPN hydrogels reinforced with nanoclays

Two series of nanoclay reinforced, thermoresponsive hydrogels were prepared, one based on poly(N‐isopropylacrylamide) (PNIPA) and the other on semi‐interpenetrating networks containing PNIPA and poly(N‐vinyl pyrrolidone) (PVP), designated as SIPNs. The gels were crosslinked with 1, 3, and 5 wt % inorganic clay (hectorite) and SIPN gels additionally contained 1 wt % of PVP. The hydrogels were tested in the “as‐prepared state,” i.e., at 10 wt % PNIPA concentration in water and at equilibrium (maximum) swelling. Increasing the concentration of nanoclays increases crosslink density, modulus, tensile strength, elongation (except in equilibrium swollen gels), hysteresis and with decreases in the degree of swelling, broadening of the phase transition region, and a decrease in elastic recovery at high deformations. The presence of linear PVP in the networks increases porosity and the pore size, increases swelling, deswelling rates, and hysteresis, but decreases slightly lower critical solution temperature (LCST), tensile strength, elongation, and elastic recovery. The strongest hydrogels were ones with 10 wt % PNIPA and 5 wt % of nanoclays, displaying tensile strengths of 85 kPa and elongation of 955%. All properties of hydrogels at the equilibrium swollen state are lower than in the as‐prepared state, due to the lower concentration of chains per unit volume, but the trends are preserved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Profile of IS research published in the <Emphasis Type="Italic">European Journal of Information Systems</Emphasis>

This paper profiles the types of research activity that have been published in EJIS from 1997 to 2007. Our analysis includes variables such as the most productive authors, citation analysis, universities associated with the most research publications, geographic diversity, authors’ background, subject areas most often investigated, unit of analysis and research methodologies. The classification of the topics and methodologies used by the most highly published authors will help prospective authors gauge whether their paper is suitable for EJIS. The major geographical source of information system (IS) research published in EJIS is from AIS region 2 (Europe, the Middle East and Africa), but with a substantial AIS region 1 (American-based researchers and universities) and AIS region 3 (Asia–Pacific) contribution. The most common research method used is the case study approach, with other methods such as surveys and library research also used frequently. IS management and IS development are the two most researched IS topics published in EJIS. This research and results reported in this paper are comparable with a previous paper published about the Information Systems Journal. Any further such studies will thus be able to make similar comparisons between these journals and any others that have subsequently been covered in this way. The paper concludes with the need for more substantive research on the topic if journal comparisons are to achieve their potential.     

Temperature influence on energy losses in MOSFET capacitors

The paper deals with the investigation of energy dissipated during processes of charging and discharging of nonlinear MOSFET capacitors. The analysis concerns the CMOS circuits. The effect of simultaneous change of gate-to-source and drain-to-source voltages of one transistor is taken into account. The temperature influence on nonlinear MOSFET capacitors and energy gathered by them is also considered. The theoretical assessment is compared with HSPICE simulation results (BSIM3v3 model) for 0.35 μm technology.     

Current developments at Giprokoks for coke-battery construction and reconstruction

Approaches developed at Giprokoks for coke-battery construction and reconstruction are considered. Recommendations regarding furnace construction and reconstruction are made on the basis of Ukrainian and world experience.