Adsorption equilibria of methane on multi-walled carbon nanotube (MWCNT) were measured. For comparison of the adsorption properties, two zeolites (DAY and HSZ-320) were chosen. The isotherm data were obtained using a static volumetric method at 303.15 K, 313.15 K, 323.15 K and at pressures up to 3 MPa. Experimental data of zeolites and carbon nanotube were correlated by the Sips isotherm and the hybrid Langmuir-Sips equations, respectively. Isosteric enthalpies of adsorption were calculated as a function of surface loading.

The influence of pore size distribution of the phenol-based adsorbents (RP-15 and RP-20) on adsorption and desorption of methane was investigated. The isotherm data were measured using a static volumetric method at three different temperatures (293.15, 303.15, and 313.15) K and at pressures up to 35 atm. Experimental data were well-correlated by the Sips and Toth isotherm models. The surface energetic characteristics of the adsorbents were evaluated by using the Clausius-Clapeyron equation.

The join or correlated filtering of sensor readings is one of the fundamental query operations in wireless sensor networks (WSNs). Although the join in centralized or distributed databases is a well-researched problem, join processing in WSNs has quite different characteristics and is much more difficult to perform due to the lack of statistics on sensor readings and the resource constraints of sensor nodes. Since data transmission is orders of magnitude more costly than processing at a sensor node, in-network processing of joins is essential. In this paper, the state-of-the-art techniques for join implementation in WSNs are surveyed. The requirements and challenges, join types, and components of join implementation are described. The open issues for further research are identified.