Analysis of a solar chimney power plant in the Arabian Gulf region

A simplified thermodynamics analytical model for steady airflow inside a solar chimney is performed. A simplified Bernoulli equation combined with fluid statics and ideal gas equation was implemented and solved using EES solver to predict the performance of the solar chimney power plant. The analytical model matched the experimental data and numerical study available in the literature. The developed analytical model was used to evaluate the effect of geometric parameters on the solar plant power generation. The analysis showed that chimney height and turbine pressure head are the most important physical variables for the solar chimney design. The study showed that second-law efficiency has non-monotonic relation with turbine pressure head. The model shows that second-law efficiency and power harvested increase with the increase of chimney height and/or diameter. The developed model is used to analyze the feasibility of solar chimney power plants for the UAE climate which possesses typical characteristics of the Gulf climate. The solar characteristics of the UAE are shown along with characteristic meteorological data. A solar chimney power plant with a chimney height of 500 m and a collector roof diameter of 1000 m would produce at least 8 MW of power. The amount of power produced during the summer would be higher where the demand in the Gulf area is the highest.     

Acoustical,thermal, and morphological properties of zein reinforced oil palm empty fruit bunch fiber bio‐composites

In this research, biodegradable composites were prepared with zein as a polymer matrix and oil palm empty fruit bunch (OPEFB) as fiber reinforcement. The fibers were treated with sodium hydroxide (NaOH). The effects of sodium hydroxide treatment on sound absorption, thermal stability, and fiber‐polymer matrix interaction in composites were examined. The acoustical sound absorption coefficients of the composites were evaluated using two‐microphone transfer function impedance tube method. The spectral, thermal, and morphological studies of the composites were analyzed and characterized using scanning electron microscope (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) spectroscopy. It was found that in all the biodegradable composites, the sound absorption coefficients increased as the frequency increased. Increases in fiber loading caused sound absorption coefficients of the composites to increase. The sodium hydroxide treatment showed a better interface adhesion on fiber and zein matrix. It was also found that this treatment increased the sound absorption coefficients. This was supported by qualitative analysis on the SEM micrographs and FTIR spectrum. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44164.     

Fourier-Stieltjes Transforms of Rajman Measures with Full Support on the Circle

We prove that the Fourier-Stieltjes transforms of probability measures absolutely continuous with respect to a Rajman measure ν on the circle are uniformly dense in the set of Fourier-Stieltjes transforms of all Rajman probability measures if and only if ν has support the circle.     

Modeling and Docking Studies on Novel Mutants (K71L and T204V) of the ATPase Domain of Human Heat Shock 70 kDa Protein 1

The purpose of exploring protein interactions between human adenovirus and heat shock protein 70 is to exploit a potentially synergistic interaction to enhance anti-tumoral efficacy and decrease toxicity in cancer treatment. However, the protein interaction of Hsp70 with E1A32 kDa of human adenovirus serotype 5 remains to be elucidated. In this study, two residues of ATPase domain of human heat shock 70 kDa protein 1 (PDB: 1 HJO) were mutated. 3D mutant models (K71L and T204V) using PyMol software were then constructed. The structures were evaluated by PROCHECK, ProQ, ERRAT, Verify 3D and ProSA modules. All evidence suggests that all protein models are acceptable and of good quality. The E1A32 kDa motif was retrieved from UniProt ({"type":"entrez-protein","attrs":{"text":"P03255","term_id":"119020","term_text":"P03255"}}P03255), as well as subjected to docking interaction with NBD, K71L and T204V, using the Autodock 4.2 program. The best lowest binding energy value of −9.09 kcal/mol was selected for novel T204V. Moreover, the protein-ligand complex structures were validated by RMSD, RMSF, hydrogen bonds and salt bridge analysis. This revealed that the T204V-E1A32 kDa motif complex was the most stable among all three complex structures. This study provides information about the interaction between Hsp70 and the E1A32 kDa motif, which emphasizes future perspectives to design rational drugs and vaccines in cancer therapy.     

Characterization of Phosphate-Free Detergent Powders Incorporated with Palm C16 Methyl Ester Sulfonate (C16MES) and Linear Alkyl Benzene Sulfonic Acid (LABSA)

Laboratory and pilot scale investigations were carried out on phosphate-free detergent (PFD) formulations comprising binary anionic surfactants of C16 palm methyl ester sulfonates (C16MES) and linear alkyl benzene sulfonic acid (LABSA) with the aim of maximizing the incorporation of C16MES into low density detergent powders without compromising the detergency and other significant properties. Initial laboratory experiments revealed that the detergent powder resulting from C16MES/LABSA with a 50:50 ratio and pH 7–8 has acceptable detergency stability over 1 week of accelerated ageing test at 50 °C and 85 % relative humidity. Subsequent experiments were carried out in a 5-kg/h-capacity pilot spray dryer using PFD formulations of C16MES/LABSA over the whole range of weight ratios under the same pH of 7–8. The concentration of the detergent slurry and cleaning performance (detergency, foaming ability and wetting power) of the resulting spray dried detergent powder (SDDP) were evaluated. C16MES/LABSA in a 40:60 ratio was selected as the ideal formulation based on its optimum detergent slurry concentration and comparable cleaning performance against the control formulation. Further environmental tests have confirmed that SDDP obtained from the ideal formulation is readily biodegradable (60 % in 13 days) and exhibits low eco-toxicity properties (LC₅₀ of 11.3 mg/L).     

Dust explosion of oil shale and olive cake solid fuels: a comparison study

This paper investigates the inhibition of oil shale and olive cake dust explosions when they are used as an alternative source of fuel. Special emphasis was given to the effect of particle size of the same material on the maximum permissible oxygen concentration to prevent dust explosion for different concentrations using nitrogen as the diluent gas. It was found that olive cake is ignited more easily than oil shale all over the range of particle sizes and dust concentration. Tests on different particle sizes were carried out, and it was found that the maximum permissible oxygen concentration for a given dust concentration increases with increasing the particle size for both oil shale and olive cake. Copyright © 2005 John Wiley & Sons, Ltd.     

Surface and bulk investigation of ZSM5 and Al-MCM-41 using synchrotron XPS, XANES, and hexane cracking

We present a comparative study of ZSM5 and Al-MCM-41 catalysts using spectroscopic and chemical techniques. The analysis of conventional and synchrotron XPS spectra of these catalysts reveals the presence of a topmost surface-related Si peak in addition to the bulk peak. XANES results suggest structural modification upon heating Al-MCM-41 at 500 °C. Depth-resolved XPS data show Al depletion from the surface of Al-MCM-41 in contrast to surface enrichment of Al in ZSM5. These surface modifications could be one of the reasons for the weak acidity of Al-MCM-41 in chemical reactions such as hexane cracking at different temperatures.     

A New HPLC Approach for the Determination of Hydrophilic and Hydrophobic Components: The Case of Pseudoephedrine Sulfate and Loratadine in Tablets

Effective isocratic separations of decongestants and antihistamines is a challenging analytical task due to wild differences in their lipohilicities (hydrophilic decongestants and hydrophobic antihistamines). In this paper a new approach for resolving such a problem is described taking pseudoephedrine sulfate and loratadine as an example. The chromatographic behavior of pseudoephedrine sulfate and loratadine on RP C18 and C8 columns were studied in presence and absence of sodium lauryl sulfate (SLS). The effect of combining two different types of stationary phases (cyano and C18 or C8) on the relative retention of the two compounds was investigated. In conclusion, it was found that the combination of a C18 column followed by a standard cyano column provides a stationary phase that separates both compounds effectively and within a reasonable time. This approach was compared to a literature method and demonstrated to have superior selectivity.     

RETRACTED ARTICLE: Dense stereovision using mono-CCD color cameras

Most stereo algorithms are based only on an analysis of the luminance information. However, with advances in camera technology, in addition to the fact that color information can robustly improve matching, color stereovision is receiving more and more attention. Color stereovision setups are usually based on single-sensor cameras which provide color filter array (CFA) images. In these images, a single color component is sampled at each pixel rather than the three required components red, green, and blue (RGB). We show that standard demosaicing techniques, which are used to interpolate the missing components, are not well adapted when the resulting color pixels are matched in order to estimate image disparities. In order to avoid this problem while exploiting color information, we propose a new matching system designed for dense stereovision based on pairs of CFA images.