Search Results

You are looking at 1 - 10 of 19 items for

  • Author or Editor: M. Saleh x
  • All content x
Clear All Modify Search

Abstract  

Crushing or otherwise processing potato and subsequent mild washing of the pulp produces mostly granular and fibrous starch. These fibers are experimental carrier material for microbes in bioremediation of polluted waters. This method offers the benefit of increasing the exposure of the microbes to the pollutant by increasing their residency within the site. Because of the physical nature of the material, it also offers the possibility of carrying, in addition to the microbes, essential macronutrients such as nitrogen and phosphorous that would be limited in availability in contaminated waters. We have previously reported on the physical nature of these fibers through thermal analysis and on their ability to bind/aggregate bacteria. We have extended that study in this report by infusing the fibers with a source of nitrogen and phosphorous, namely ammonium phosphate. The TG curves for ammonium phosphate-infused white and sweet potato fibers exhibited three main mass loss steps corresponding to the three exothermic DTG peaks. Infusion with the ammonium phosphate salt also affected the bacterial binding/aggregation capacities. The range of their binding capacities decreased to a range of 26.9–43.3% compared to untreated fibers.

Restricted access

Magnetotelluric method (MT) offers opportunity to detect crustal fluids along faults due to their high conductivity anomaly. Supposing that fluids deposited minerals in the conductive fractures (faults, dykes) decreasing the resistivity, the high seismicity in the area can be explained by the presence of these fluids. MT measurements were carried out in the period range 0.001–420 s crossing the Kalabsha fault (Aswan, Egypt) and Remiremont fault (Southern Vosges, France). In these work we detect geoelectrical resistivity anomalies of the Earth’s crust and link them to local seismic activity. Seismic events having magnitude (M<5) are found along fault zones in Kalabsha and Remiremont. The goals of our measurements are various. We would like to determine the precise location of the active faults, to study the connection of the Remiremont and Kalabsha seismicity to the MT resistivity structures, and to support the idea of the influence of the fluid-bearing conducting faults in the Remiremont and Kalabsha areas to the earthquake. These applications afford the unusual opportunity to study the percolation of water into the faults system and its effect on the seismicity, to reveal geological structures and the stress field covered by thin Quaternary formations. Data are analysed by 2D simultaneous inversion of both polarizations. The resulting models are compared with the local seismicity map. Our MT model reveals the conductive signature of the fault, as well as geological and tectonic stresses prevailing in active regions.

Restricted access

Abu-Dabbab area is characterized by high seismicity and complex tectonic setting, for these facts, a local geodetic network consisting of eleven geodetic benchmarks has been established. The crustal deformation data in this area are collected using the GPS techniques. Five campaigns of GPS measurements have been collected, processed and adjusted to get the more accurate positions of the GPS stations. The horizontal velocity vectors, the dilatational, the maximum shear strains and the principal strain rates were estimated. The magnitude of the movements is distributed inhomogeneous over the area and it varies in average between 3 and 6 mm/yr. The results of the deformation analyses indicate a significant contraction and extension across the southern central part of the study area which is characterized by high seismic activity represented by the clustering shape of the microearthquakes that trending NE-SW direction. The north and north-eastern parts are characterized by small strain rates. This study is an attempt to provide valuable information about the present state of the crustal deformation and its relationship to seismic activity and tectonic setting at Abu-Dabbab area.

Restricted access

Abstract  

The K-shell X-ray intensity ratios
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$I(I_{\alpha _2 } )/I(K_{\alpha _1 } ), I(K_{\beta _1 } )/I(K_{\alpha _1 } )$$ \end{document}
and
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$I(K_{\beta _2 } )/I(K_{\alpha _1 } )$$ \end{document}
for W, Au, Tl, Pb, Bi, Th and U have been measured at a photon incident energy of 121.9 keV from57Co radionuclide. A comparison between the experimental results and the theoretically calculated values shows that the experimental results are, in general, higher than the theoretical values. To the best of our knowledge, the measured intensities are reported for the first time.
Restricted access

A potential bacterial carrier for bioremediation

Characterization of insoluble potato fiber

Journal of Thermal Analysis and Calorimetry
Authors: C. Elliott, Z. Ye, S. Mojumdar, and M. Saleh

Abstract  

One of the limiting factors to the effectiveness of biostimulation and bioremediation is the loss of inoculated material from the site. This can occur by a number of pathways, but is particularly problematic in open water systems where the inoculated material is simply lost in the water. It is desirable to develop new material, a matrix, within which bacteria and/or biostimulants can be incorporated. We have investigated the basic physical properties of insoluble potato starch to eventually evaluate its use as such a matrix. Insoluble starch fibers were prepared from white potato (Solanum tuberosum) and sweet potato (Ipomoea batatas) and were compared for their melting temperature by DSC and their ability to bind/aggregate bacteria. The DSC curves for white and sweet potato showed that the melting temperature is 127.34 and 133.05�C for white and sweet potato fibers, respectively. The TG curves for white and sweet potato starches exhibited one main mass loss step corresponding to the DTG peak temperature at 323.39 and 346.93�C, respectively. The two types of fibers, however, showed different binding/aggregation capacities for bacteria, with white potato approximately twice as many cells of Burkholderia cepacia (22.6 billion/g) as cells of Pseudomonas putida. The reverse was true for fibers from sweet potato, binding twice as many cells of Pseudomonas putida (23 billion/g) as cells of Burkholderia cepacia.

Restricted access

Abstract  

The radiochemical separation of no-carrier-added cerium from proton irradiated lanthanum was studied by solvent extraction using DEE, TBP and TPPO, the latter reagent being employed for the first time for separation of radiocerium from bulk of lanthanum. Distribution coefficients of cerium and lanthanum were investigated as a function of equilibrium time and concentration of HNO3. A mixture of 0.05M K2Cr2O7 and 0.1M H2SO4 was used as an oxidizing agent to improve the separation efficiency of cerium. A comparative study of the three extractants released that DEE is the best for separation of cerium from bulk of lanthanum oxide. The target was prepared by pressing. The production of 139Ce of high radionuclidic purity and chemical purity via irradiation of lanthanum oxide target at MGC-20 cyclotron with protons of energy 14.5 MeV is described. The experimental yield was found to be 153 kBq/μA·h.

Restricted access

Abstract  

Zinc diethyldithiocarbamate, zinc diethyldithiocarbamate-phosphate and zinc phosphate have been synthesized. They have been characterized using DTA-TG, IR spectra and X-ray. The dithiocarbamate and phosphate contents have been determined spectrophotometrically and volumetrically, respectively. Fungicidal activity of the compounds has been tested by well diffusion method using fungi Fusarium sp.

Restricted access

The discovery of potent antidiabetic drugs is of necessity owing to the rapid prevalence of diabetes worldwide. The investigation of a new separation method for the simultaneous determination of combined antidiabetic drugs is thus an essential issue to cover the usual demands of simple analytical methods for the routine analysis. Therefore, herein, simple and fast chromatographic methods were established for synchronized determination of metformin (MET) and dapagliflozin (DAP), a mixture approved recently by the Food and Drug Administration (FDA) for diabetes therapy. In high-performance liquid chromatography (HPLC), a Water-pak C18 column was used as the stationary phase with an isocratic mobile phase composed of 10 mM NaH2PO4 (pH 3.5 adjusted using ortho-phosphoric acid)‒acetonitrile (65:35, v/v) containing 0.1% trimethylamine at a flow rate of 1.2 mL min−1 and a wavelength detector set at 225 nm. In high-performance thin-layer chromatography (HPTLC), separation was achieved on pre-coated silica gel 60 F254 aluminum plates using acetonitrile‒ammonium acetate 10%‒acetic acid (9:0.9:0.1, v/v). The proposed methods were validated in the light of the International Conference on Harmonization (ICH) guidelines, and it was found that the two chromatographic methods are accurate, precise, and linear in the range of 2–20 μg mL−1 and 1–10 μg per spot for DAP and 20–400 μg mL−1 and 10–100 μg per spot for MET by HPLC and HPTLC, respectively. The methods achieved a reasonable sensitivity as shown by the low limit of detection ranging from 0.58 to 6.1 μg mL−1 and 0.314 to 3.1 μg per spot for HPLC and HPTLC, respectively. The validated methods succeeded in detecting the cited drugs in pharmaceutical formulation without interference of excipients. Although HPLC method is the most applicable method, HPTLC method exhibits a superior sensitivity and is cheap and fast allowing the determination of a large number of samples in due time.

Restricted access

Summary

Reversed phase high-performance liquid chromatography (RP-HPLC) and thin-layer chromatography (TLC)-spectrodensitometric methods have been developed and validated for the separation and quantitation of two binary mixtures: Ofloxacin (OFX) and dexamethasone (DXM) in eye preparation; ciprofloxacin hydrochloride (CIP) and hydrocortisone (HYD) in ear preparation. The linearity ranges of RP-HPLC methods were found to be (2.5–45 μg mL−1) for OFX, (2.5–50 μg mL−1) for DXM and (1–8 μg mL−1) for both CIP and HYD. The percentage recoveries/relative standard deviation (RSD) were found to be 100.36/1.38, 100.13/1.49, 99.98/0.61 and 100.28/1.27, respectively. The linearity ranges of TLC-spectrodensitometric methods were found to be (0.5–2 μg band−1), (0.5–3.5 μg band−1), (0.2–1.6 μg band−1), and (0.6–2 μg band−1) for OFX, DXM, CIP, and HYD, respectively. The percentage recoveries/RSD were found to be 99.98/1.06, 99.93/1.18, 99.74/1.27, and 99.94/1.54, respectively. A comparative study was conducted to show the advantages of the proposed methods which showed that the TLC-spectrodensitometric methods were simpler, more sensitive, and economic, while RP-HPLC methods were more precise and robust. The methods were validated in compliance with the ICH guidelines and were successfully applied for determination of the selected drugs in their laboratory-prepared mixtures and commercial dosage forms.

Restricted access