One of the major challenges in wireless sensor networks (WSN) is to meet the energy constraint of its sensor nodes while ensuring reliability of the system. Clustering is an effective self-organization approach to offer energy-efficient communication for WSNs. However, energy of a sensor node dynamically decreases when it plays a role of a cluster head. As a result some nodes die faster that sh...

effects of binary mixtures of ionic/nonionic (sodium dodecyl sulfate/2-heptanol or 1-decanol) and nonionic/nonionic surfactants (2-heptnol/1-decanol) on drop/interface coalescence of water drops in a continuous n-heptane phase were examined. the drop size reduced appreciably and the multi-step coalescence was suppressed finally as the concentration of each of the constituting components of surf...

A simple derivation is given for a formula obtained previously for the effective size of random-mating populations with overlapping generations. The effective population size is the same as that for a population with discrete generations having the same variance of lifetime family size and the same number of individuals entering the population per generation.

Russia has one of the world's fastest growing HIV epidemics, and HIV screening has been widespread. Whether such screening is an effective use of resources is unclear. We used epidemiologic and economic data from Russia to develop a Markov model to estimate costs, quality of life and survival associated with a voluntary HIV screening programme compared with no screening in Russia. We measured d...

Many different designs of total hip arthroplasty (THA) with varying performance and cost are available. The identification of those which are the most cost-effective could allow significant cost-savings. We used an established Markov model to examine the cost effectiveness of five frequently used categories of THA which differed according to bearing surface and mode of fixation, using data from...

OBJECTIVES To investigate the long-term cost-effectiveness (measured as the ratio of incremental NHS cost to incremental quality-adjusted life years) of a telehealth intervention for patients with raised cardiovascular disease (CVD) risk. DESIGN A cohort simulation model developed as part of the economic evaluation conducted alongside the Healthlines randomised controlled trial. SETTING Pat...

Surface texturing is a more permanent and effective solution to eliminate reflections compared with antireflection coatings in optical devices. In this study texturing was performed using a reactive ion etching technique, reflectance was measured and the resultant damage on the surfaces was monitored through the minority carrier lifetime measurements. High minority carrier lifetime is an indica...