93 research outputs found

    Mathematical Model for Unsteady Remediation of River Pollution by Aeration

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    The governing coupled pair of nonlinear unsteady-state equations describing the concentration of the pollutant P(x,t) and the dissolved oxygen concentration X(x,t) in a river are solved numerically in one dimension x. The initial values of both P(x,t) and X(x,t) are assumed to be decreasing exponential functions in x. The results are presented and discussed graphically. We have proved mathematically the fact that the high concentration of pollutant can be reduced by releasing adequate discharges from barrage in a river. The different effects of parameters controlling the flow on both P(x,t) and X(x,t) are studied along the river at different time t

    Mathematical Model for Unsteady Remediation of River Pollution by Aeration

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    The governing coupled pair of nonlinear unsteady-state equations describing the concentration of the pollutant P(x,t) and the dissolved oxygen concentration X(x,t) in a river are solved numerically in one dimension x. The initial values of both P(x,t) and X(x,t) are assumed to be decreasing exponential functions in x. The results are presented and discussed graphically. We have proved mathematically the fact that the high concentration of pollutant can be reduced by releasing adequate discharges from barrage in a river. The different effects of parameters controlling the flow on both P(x,t) and X(x,t) are studied along the river at different time t

    Monosodium glutamate induced histological change in the Zona Fasiculata of rats' adrenal and the possible amelioration effect of vitamin C supplementation

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    Monosodium glutamate in gesting (MSG) is steadily increasing worldwide as a flavour enhancer and food additive. On the other hand, vitamins C has antioxidant properties and can play an important role in preventing or improving many diseases. So, the aim of the present study is to study the impact of MSG administration on the histological structure of the zonafasciculata (ZF) of adult albino rat adrenal cortex and to clarify the possible amelioration effect of vitamin C cosupplementation. Thirty adult male albino rats were divided equally into three groups: group I; negative and positive (received100mg/kg vitamin C) control subgroups. MSG-treated group were administered 2 mg/g body weight MSG via gastric tube andascorbic acid supplemented group were given the same dose of MSG, followed by vitamin C at a dose similar to the positive control group. Tissue sections were obtained and proceeded for light and electron microscope examination. Plasma ACTH and cortisone were estimated. Morphometric and statistical analysis of the results were performed. Plasma ACTH and corticosterone levels in the MSG-treated group were significantly increased comparing to control and MSGtreated group receiving vitamin C. Histologically, in the MSG-treated group, ZF contained highly vacuolated cells and congested blood vessels. The reticular fibres were increased in MSG-treated group decreased in ascorbic acid supplemented group. Ultrastructurally, ZF contained cells with shrunken nuclei and numerous macrophages containing many lysosomes. On the other hand, the cellular architecture of ascorbic acid supplemented group was less affected and congested blood sinusoids were still detected. The reticular fibres were decreased in ascorbic acid supplemented group. Oral administration of MSG caused histological and functional degenerative changes in the ZF of adrenalin adult male albino rat which was ameliorated by supplementation of vitamin C. So, it is recommended to minimize consumption of foodstuffs containing MSG and to eat foods rich in vitamin C after performing more researchers to be sure of these effects on humans.MS

    Broadband Dielectric Spectroscopic Detection of Ethanol: A Side-by-Side Comparison of ZnO and HKUST-1 MOFs as Sensing Media

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    The most common gas sensors are based on chemically induced changes in electrical resistivity and necessarily involve making imperfect electrical contacts to the sensing materials, which introduce errors into the measurements. We leverage thermal- and chemical-induced changes in microwave propagation characteristics (i.e., S-parameters) to compare ZnO and surface-anchored metal-organic-framework (HKUST-1 MOF) thin films as sensing materials for detecting ethanol vapor, a typical volatile organic compound (VOC), at low temperatures. We show that the microwave propagation technique can detect ethanol at relatively low temperatures (\u3c100 \u3e°C), and afford new mechanistic insights that are inaccessible with the traditional dc-resistance-based measurements. In addition, the metrological technique avoids the inimical measurand distortions due to parasitic electrical effects inherent in the conductometric volatile organic compound detection

    Broadband Dielectric Spectroscopic Detection of Ethanol: A Side-by-Side Comparison of ZnO and HKUST-1 MOFs as Sensing Media†,‡

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    The most common gas sensors are based on chemically induced changes in electrical resistivity and necessarily involve making imperfect electrical contacts to the sensing materials, which introduce errors into the measurements. We leverage thermal- and chemical-induced changes in microwave propagation characteristics (i.e., S-parameters) to compare ZnO and surface-anchored metal–organic-framework (HKUST-1 MOF) thin films as sensing materials for detecting ethanol vapor, a typical volatile organic compound (VOC), at low temperatures. We show that the microwave propagation technique can detect ethanol at relatively low temperatures (<100 °C), and afford new mechanistic insights that are inaccessible with the traditional dc-resistance-based measurements. In addition, the metrological technique avoids the inimical measurand distortions due to parasitic electrical effects inherent in the conductometric volatile organic compound detection

    Broadband Dielectric Spectroscopic Detection of Aliphatic Alcohol Vapors With Surface-Mounted HKUST-1 MOFs as Sensing Media

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    We leveraged chemical-induced changes to microwave signal propagation characteristics (i.e., S-parameters) to characterize the detection of aliphatic alcohol (methanol, ethanol, and 2-propanol) vapors using TCNQ-doped HKUST-1 metal-organic-framework films as the sensing material, at temperatures under 100 °C. We show that the sensitivity of aliphatic alcohol detection depends on the oxidation potential of the analyte, and the impedance of the detection setup depends on the analyte-loading of the sensing medium. The microwaves-based detection technique can also afford new mechanistic insights into VOC detection, with surface-anchored metal-organic frameworks (SURMOFs), which is inaccessible with the traditional coulometric (i.e., resistance-based) measurements

    Broadband Dielectric Spectroscopic Detection of Aliphatic Alcohol Vapors with Surface-Mounted HKUST-1 MOFs as Sensing Media †

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    We leveraged chemical-induced changes to microwave signal propagation characteristics (i.e., S-parameters) to characterize the detection of aliphatic alcohol (methanol, ethanol, and 2-propanol) vapors using TCNQ-doped HKUST-1 metal-organic-framework films as the sensing material, at temperatures under 100 ◩C. We show that the sensitivity of aliphatic alcohol detection depends on the oxidation potential of the analyte, and the impedance of the detection setup depends on the analyte-loading of the sensing medium. The microwaves-based detection technique can also afford new mechanistic insights into VOC detection, with surface-anchored metal-organic frameworks (SURMOFs), which is inaccessible with the traditional coulometric (i.e., resistance-based) measurements

    A Simple and Highly Structured Procaine Hydrochloride as Fluorescent Quenching Chemosensor for Trace Determination of Mercury Species in Water

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    An ultrasensitive, simple and highly selective spectrofluorometric strategy for quantifying traces of mercury(II) in environmental water has been established using the fluorescent probe procaine hydrochloride (PQ+.Cl−). The procedure was based upon the formation of the ternary ion associate complex [(PQ+)2.(HgI4)2−] between PQ+.Cl− and mercury(II) in iodide media at pH 9.0–10.0 with its subsequent extraction onto dichloromethane accompanied by a change in fluorescence intensity at λex/em = 268/333 nm. The developed strategy exhibited a linear range of 1–114 Όg L−1 with lower limit of detection (LOD) and quantification (LOQ) of mercury(II) 1.3 and 3.98 nM, respectively. Intra and inter-day laboratory accuracy and precision for trace analysis of mercury(II) in water were performed. Complexed mercury(II) in environmental water, chemical speciation and successful literature comparison was performed. The proposed system offered excellent selectivity towards mercury(II) ions examined in the presence of competent ions in excess, relevant to real water samples. The method was applied for analysis of mercury(II) in tap water samples. Statistical comparison (Student’s t and F tests) of the proposed method with the reference ICP-OES method revealed no significant differences in the accuracy and precision

    The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

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    The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (Fragaria ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds

    Chromatographic Separation, Total Determination and Chemical Speciation of Mercury in Environmental Water Samples Using 4-(2-Thiazolylazo) Resorcinol-Based Polyurethane Foam Sorbent-Packed Column

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    A simple method has been developed for quantitative retention of traces of mercury(II) ions from aqueous media using polyurethane foams (PUFs) loaded with 4-(2-thiazolylazo) resorcinol (TAR). The kinetics and thermodynamics of the sorption of mercury(II) ions onto PUFs were studied. The sorption of mercury(II) ions onto PUF follows a first-order rate equation with k = 0.176 ± 0.010 min−1. The negative values of ΔH and ΔS may be interpreted as the exothermic chemisorption process and indicative of a faster chemisorption onto the active sites of the sorbent. The sorption data followed Langmuir, Freundlich and Dubinin-Radushkevich (D–R) isotherm models. The D-R parameters ÎČ, KDR and E were 0.329 mol2 kJ−2, 0.001 Όmol g−1 and 1.23 ± 0.07 kJ/mol for the TAR-loaded PUFs, respectively. An acceptable retention and recovery (99.6 ± 1.1%) of mercury(II) ions in water at ≀10 ppb by the TAR-treated PUFs packed columns were achieved. A retention mechanism, involving absorption related to “solvent extraction” and an “added component” for surface adsorption, was suggested for the retention of mercury(II) ions by the used solid phase extractor. The performance of TAR-immobilized PUFs packed column in terms of the number (N), the height equivalent to a theoretical plate (HETP), the breakthrough and critical capacities of mercury(II) ion uptake by the sorbent packed column were found to be 50.0 ± 1.0, 1.01 ± 0.02 mm, 8.75 and 13.75 mg/g, respectively, at 5 mL/min flow rate
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