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.     

Biosynthesis and characterisation of solid lipid nanoparticles and investigation of toxicity against breast cancer cell line

Solid lipid nanoparticles (SLNs) comprise non‐toxic surface‐active lipidic agents combined with appropriate ratios of drugs or essential oils. The goal of this research was to investigate the effects of the SLN synthesised using essential oils of Foeniculum vulgare on the MCF‐7 breast cancer cell line. SLNs were prepared by homogenisation and ultrasound techniques and characterised by dynamic light scattering (DLS), zeta potential assessment, and transmission electron microscopy (TEM). 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay (MTT assay), flow‐cytometry, and Acridine‐Orange assay were employed for assessing the biological activities of the SLNs. The average particle size was 55.43 nm and the net surface charge was −29.54 ± 11.67 mV. TEM showed that the mean particle size was 33.55 nm and the synthesised SLNs had a uniform round morphology. The MTT assay showed that the prepared SLNs had high toxicity against MCF‐7 cells and low toxicity against normal HUVECs cells. Flow‐cytometry revealed a noteworthy rise in the subG1 peak of the cell cycle in the cancer cells treated with SLNs compared to the controls, indicating apoptosis in cancer cells. The results also showed discolouration in SLNs‐treated cells, which further confirmed the induction of apoptosis and the toxicity of the SLNs against MCF‐7 cells.     

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 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...     

Lattice Boltzmann Simulation of Conjugate Heat Transfer from Multiple Heated Obstacles Mounted in a Walled Parallel Plate Channel

In the present study, lattice Boltzmann simulation of conjugate heat transfer from multiple heated obstacles mounted in a walled parallel-plate channel is carried out. The aim is to investigate the effects of the pertinent thermophysical and geometrical parameters on the local Nusselt number around the obstacle's periphery. The result showed that increasing the obstacle to fluid thermal conductivity ratio and decreasing wall-to-obstacle thermal conductivity ratio results in increasing the local Nusselt number around the obstacle's periphery. The results of the present study are compared with those available from the conventional numerical methods, and good agreement is observed.     

Cavitation in Diesel Fuel Injector Nozzles and its Influence on Atomization and Spray

In combustors, high‐pressure fuel injector nozzles are employed for liquid atomization and spray generation. The internal flow within nozzles, especially cavitation, plays an important role in promoting the breakup of liquid jets. The formation mechanism and evolvement of cavitation are reviewed and described. Different cavitation regimes were characterized experimentally and the positive effect of cavitation on liquid atomization was confirmed. Different empirical formulas correlating the discharge coefficient with fluid‐dynamical parameters are summarized. The applicability, advantages, and disadvantages of two popular computational models for flow modeling, i.e., the interface tracking model and the homogeneous equilibrium model, are reviewed. The effects of cavitation on the generated spray are discussed.