Long term and performance testing of NaMg double salts for H2/CO2 separation

This work investigates the synthesis and performance of double salts for H₂/CO₂ separation. A series of NaMg double salts were prepared based on xMg(NO₃)₂: yNa₂CO₃: zH₂O and characterised. The best sorbents reached CO₂ uptake of 17.9 wt% at 0.62 MPa and 375 °C. The NaMg double salts preferentially sorbed CO₂ as determined by breakthrough tests. The NaMg double salts were packed in a sorbent bed and tested for H₂/CO₂ separation at the back end of a water gas shift reactor. The space velocity had the largest impact on the performance of the sorbent bed, as increasing the space velocity from 2.16 × 10^?3 to 9.51 × 10^?3 s^?1 sped up the breakthrough time by 84%. Increasing the feed gas pressure from 0.3 to 0.6 MPa reduced the breakthrough time by ～45%. The NaMg double salt sorbents were exposed for over 1000 h of continuous temperature including 28 cycles of sorption and desorption, and proved to be stable during changes of operating conditions such as flow rates and pressures.     

Efficiency of a Combined Desalination and Power System Utilizing a Two-Phase Flow Multistream Heat Exchanger

ABSTRACT

The aim of this study is to simplify the process of discharge thermal energy combined desalination with power system by integrating the two existing heat exchangers (condensers) into a new multistream one. This system is a heat recovery unit, which is used to cogenerate water and power. Two shell-and-tube condensers operate in a closed power cycle and a desalination system for cooling an ammonia mixture as a working fluid and condensing a pure vapor, respectively. Here, a two-phase flow multistream condenser is utilized instead of the two low-exergy-efficiency shell-and-tube condensers. The results proved that the proposed technique leads to improving its exergy efficiency by 15%. The performance of the proposed condenser was analyzed by applying parametric optimization.     

Design and layout techniques for a mm‐wave body‐biased variable‐gain amplifier

A two‐stage mm‐wave variable‐gain amplifier is designed and implemented in a 65‐nm CMOS technology. A fully symmetric layout has been utilized to suppress the odd‐mode of propagation and increase the quality factor in co‐planar waveguide transmission lines. Moreover, a new design technique is proposed for implementing decoupling capacitors for mm‐wave frequencies. Body‐biasing technique is utilized to change the amplifier gain without significant change in the overall power consumption of the circuit. The measurement results show that the amplifier achieves a peak gain of 10 dB with a gain variation range of 25 dB while consuming 12 mW from a 1.2‐V supply. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:470–477, 2014.     

A miniature cell for gas solubility measurements in oils and bitumen

A miniature cell has been designed and constructed to measure gas solubility in crude oils and bitumen. The cell was made of stainless steel with a total internal volume of 1.835 cc and only an oil sample of 0.4 cc was required for one set of measurements at different pressures. By using this small cell, the waiting time for reaching equilibrium was less than 10 min. The technique was validated by measuring CO(2) gas solubility in two bitumen samples. The results were compared and found to be in very good agreement with available data. The apparatus was also used to study the effect of ashphaltene on CO(2) solubility in bitumen. It was shown that ashphaltene had a negligible effect on CO(2) solubility in bitumen.     

An active sensing strategy for contact location without tactile sensors using robot geometry and kinematics

In this study, we develop new techniques to sense contact locations and control robots in contact situations in order to enable articulated robotic systems to perform manipulations and grasping actions. Active sensing approaches are investigated by utilizing robot kinematics and geometry to improve upon existing sensing methods for contact. Compliant motion control is used so that a robot can actively search for and localize the desired contact location. Robot control in a contact situation is improved by the precise estimation of the contact location. From this viewpoint, we investigate a new control strategy to accommodate the proposed sensing techniques in contact situations. The proposed estimation algorithm and the control strategy both work complementarily. Then, we verify the proposed algorithm through experiments using 7-DOF hardware and a simulation environment. The two major contributions of the proposed active sensing strategy are the estimation algorithm for contact location without any tactile sensors, and the control strategy complementing the proposed estimation algorithm.     

TBM performance prediction developing a hybrid ANFIS-PNN predictive model optimized by imperialism competitive algorithm

Neural Computing and Applications - A reliable and accurate prediction of the tunnel boring machine (TBM) performance can assist in minimizing the relevant risks of high capital costs and in...     

An efficient Markov energy predictor for software defined wireless sensor networks

Wireless Networks - Software-defined wireless sensor networks (SDWSNs) are a great step forward to centralize and facilitate the management of low-power networks. However, the continuous sending of...