ABSTRACT
The photo-Fenton process is an appropriate method of the Advanced Oxidation Process that is used in the photocatalysis of organic dyes like crystal violet (CV). La3+ ion substituted gadolinium zirconium oxide Gd(2-x)La(x)Zr2O7 nanopowders (x = 0.1, 0.2, 0.3, and 0.5) have been successfully prepared by using sol-gel auto-combustion method to be used for the efficient photocatalysis of CV with photo-Fenton process. The well-crystallized defect-fluorite, structured with space group: Fm-3m, was detected using X-ray diffraction analysis. The lattice parameters were found to increase with the evaluated La3+ ion concentration. The grain size of the synthesized powders increased with the increase in La3+ ion content. The SAED patterns depicted fluorite structured fluorite. UV/Vis. spectrophotometer was used for the determination of band gap energy of Gd(2-x)La(x)Zr2O7 nanopowders which increased with increasing La3+ ion content. It was found to enhance from 4 to 3.6 eV. The visible spectrophotometer was used for determining unknown concentrations during the photocatalysis process to assure the effectiveness of the process. Overall, results illustrate that the photo-Fenton reaction on Gd(2-x)La(x)Zr2O7 performed excellently in removing crystal violet (CV). The photo-remediation ratio of CV reached 90% within 1 h.
ABSTRACT
A TiO2/GO/CuFe2O4 heterostructure photocatalyst is fabricated by a simple and low-cost ball-milling pathway for enhancing the photocatalytic degradation of chlorinated pesticides under UV light irradiation. Based on the advantages of graphene oxide, TiO2, and CuFe2O4, the nanocomposite exhibited visible light absorption, magnetic properties, and adsorption capacity. Integrated analyses using XRD, SEM, TEM, and UV-visible techniques demonstrated that the nanocomposite exhibited a well-defined crystalline phase, sizes of 10-15 nm, and evincing a visible light absorption feature with an optical bandgap energy of 2.4 eV. The photocatalytic degradations of 17 different chlorinated pesticides (persistent organic pollutants) were assayed using the prepared photocatalyst. The photocatalytic activity of the nanocomposite generated almost 96.5% photocatalytic removal efficiency of typical pesticide DDE from water under UV irradiation. The superior photocatalytic performance was exhibited by the TiO2/GO/CuFeO4 catalyst owing to its high adsorption performance and separation efficiency of photo-generated carriers. The photocatalyst was examined in 5 cycles for treating uncolored pesticides with purposeful separation using an external magnetic field.
ABSTRACT
Inspired by their distinctive properties, transition metal phosphides have gained immense attention as promising electrode materials for energy storage and conversion applications. The introduction of a safe and large-scale method of synthesizing a composite of these materials with carbon is of great significance in the fields of electrochemical and materials sciences. In the current effort, we successfully synthesize an iron phosphide/carbon (FeP/C) with a high specific surface area by the pyrolysis of the gel resulting from the hydrothermal treatment of an iron nitrate-phytic acid mixed solution. In comparison with the blank (P/C), the as-synthesized FeP/C appears to be an efficient electrode material for supercapacitor as well as oxygen reduction reaction (ORR) applications in an alkaline medium in a three-electrode system. In the study of supercapacitors, FeP/C shows areal capacitance of 313 mF cm-2 at 1.2 mA cm-2 while retaining 95% of its initial capacitance value after 10 000 cycles, while in the ORR, the synthesized material exhibits high electrocatalytic activity with an onset potential of ca. 0.86 V vs. RHE through the preferred four-electron pathway and less than 6% H2O2 production calculated in the potential range of 0.0-0.7 V vs. RHE. The stability is found to be better than those of the benchmark Pt/C (20 wt%) catalyst.
ABSTRACT
The fabrication of hydroxyapatite-Co-ferrite nanocomposite coatings was performed on stainless steel by chronoamperometry technique. HA-CoFe2O4 nanocomposite films were characterized using X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometer (VSM). The results reveal that CoFe2O4 nanoparticles dispersed within the HA matrix have flake and strip shapes. The magnetic property of the nanocomposite was increased by increasing the concentration of CoFe2O4 and a good saturation magnetization value was found to be 20.6emu/g with 50% CoFe2O4. By comparing with pure CoFe2O4, the composite still retain moderate magnetization as well as its biocompatible characters. The specific absorption rate (SAR) values were altered according to the change in CoFe2O4 concentration and the maximum SAR value was 125W/g. The incorporation of CoFe2O4 nanoparticles with HA coating was increased the corrosion resistance of HA in simulated body fluid (SBF). The results indicated that HA-CoFe2O4 nanocomposite coating could be a promising surface treatment technique for stainless steel medical implants as well hyperthermia treatment of cancer.
Subject(s)
Nanocomposites , Coated Materials, Biocompatible , Cobalt , Durapatite , Electrochemical Techniques , Ferric Compounds , Humans , NeoplasmsABSTRACT
Cu0.5Zn0.5Fe2O4 nanocrystallite powders (average size 13 nm) were synthesized from Cu-Zn spent catalyst (fertilizers) industries and ferrous sulfate wastes formed during iron and steel making. Cu-Zn catalyst (22.4% Cu and 26.4% Zn) was chemically treated with sulfuric acid at temperature 80 degrees C for 1 hr for the complete dissolving of copper and zinc into sulfate solution, then the produced solution was mixed with stoichiometric ratio of ferrous sulfate and the mixture was chemically precipitated as hydroxides followed by hydrothermal processing. The parameters affecting the magnetic properties and crystallite size of the produced ferrites powder e.g., temperature, time, and pH were systemically studied. X-ray diffraction analysis was used in order to determine the average crystallite size and phase identifications of the produced powder. The magnetic properties were studied by vibrating sample magnetometry. The results showed that the average crystallite size of the powder decreased for the ferrites powder formed at 150 degrees C and then increased by increasing the temperature to 200 degrees C. Interestingly, the saturation magnetization (Bs), remanent magnetization (Br) and coercive force (Hc) were 25.03 emu/g, 0.71 emu/g, and 4.83 Oe, respectively at hydrothermal temperature 150 degrees C for 24 hr and changed to 16.38 emu/g, 0.3864 emu/g, and 5.2 Oe at 150 degrees C and 72 hr. The produced nanoferrite powders are used for studying the catalytic activity of CO conversion to CO2 at different temperatures, pH and times. The maximum conversion (82%) is obtained at temperature 150 degrees C for 24 hrs and pH 12.
Subject(s)
Copper/chemistry , Ferric Compounds/chemistry , Oxides/chemistry , Zinc/chemistry , Catalysis , Crystallization , Nanostructures/chemistry , Thermodynamics , X-Ray DiffractionABSTRACT
The effect of surface-active agents (surfactants), as additives, on the crystallization of gypsum was studied under conditions of the simulated dihydrate process of phosphoric acid production. Calcium hydrogen phosphate and sulfuric acid were mixed with dilute phosphoric acid at 80 degrees C, and the turbidity of the reaction mixture was measured at different time periods to determine the induction time of gypsum crystal formation. Two types of surfactants, namely, cetyltrimethylammonium bromide (CTAB) as a cationic surfactant and sodium dodecyl sulfate (SDS) as an anionic surfactant were added to investigate their effects on the crystallization of gypsum. Addition of CTAB decreased the induction time and increased the growth efficiency, while addition of SDS increased the induction time and decreased the growth efficiency compared with the baseline (without additives). The surface energy increased with CTAB and decreased with SDS compared with the baseline. The percentage of fine crystals decreased in the presence of CTAB and increased in the presence of SDS compared with the baseline. Gypsum morphology changed from needle-like in the absence of additives to tabular in the presence of CTAB.
ABSTRACT
Date waste dietary fibers were examined as a hypolipidemic agent. White albino rats were fed on three experimental diets: I) high carbohydrate diet free of fiber; II) and III) diets consisted of diet I substituted with 100 g/kg of date waste dietary fibers cultured with Endomycopsis fibuligera at zero time and after 60 h of culturing respectively for 8 weeks. The total lipids, total cholesterol, triglycerides and phospholipids in the liver of rats given diets II and III were significantly decreased over those rats fed the control diet throughout the feeding period (8 weeks). The highest decrease in content of all these parameters was produced by diet III. Comparing diets II and III with the control diet I, total serum lipids and low density lipoprotein cholesterol (LDL-cholesterol) were decreased by 32-48%, while serum triglycerides and total cholesterol levels were lowered in the groups fed diets II and III by 23-35% respectively. Concerning high density lipoprotein cholesterol (HDL-cholesterol), the decrease was only 2-6% in rats fed diets II and III. The highest decrease level was shown in the phospholipids content (51-56%) during all of the experimental period (8 weeks).
Subject(s)
Dietary Fiber/pharmacology , Fruit , Hypolipidemic Agents/pharmacology , Lipid Metabolism , Liver/metabolism , Animals , Cholesterol/metabolism , Cholesterol, LDL/blood , Food Handling , Lipids/blood , Liver/drug effects , Male , Phospholipids/metabolism , Rats , Saccharomycetales , Triglycerides/blood , Triglycerides/metabolismABSTRACT
The technical feasibility of using agricultural wastes (mango and date industry wastes) as a substrate for the cultivation of Pleurotus ostreatus NRRL-0366 is evaluated. When comparing the biological efficiency of mushroom production, the highest yield of fruiting bodies was obtained using a mixture of date waste and rice straw at a ratio (1:1) (11.96%), followed by a mixture 3:1 (11.16%). The lowest one was the mixture 2:1 (9.19%). Fungus Pleurotus ostreatus NRRL-0366 can also be cultivated on mango waste supplemented with rice straw at a different ratio. The best one was the 1:1 mixture (10.18%), whereas the lowest was a mixture 3:1 (6.4%). Comparing the results obtained favored the use of date waste as a substrate for growing Pleurotus ostreatus NRRL-0366. Spawn was cultured on three different substrates as follows: Date waste alone (I); 1:1 (by wt) date waste and rice straw (II); 1:1:1 date waste, rice straw, and corncobs (III). Final dry weight and composition of the fruiting bodies are tabulated for the three sets of conditions. Date waste and rice straw mixture (II) is a good source of nonstarchy carbohydrate (67%) and protein (27.44%) containing amounts of essential amino acids, especially lysine and low RNA (3.81%). Elemental analysis were studied in the fruit bodies of the three media.
Subject(s)
Hydroponics , Polyporaceae/growth & development , Culture Media , Egypt , Fermentation , Fruit , Polyporaceae/chemistry , Proteins/analysisABSTRACT
The utilization of methanol by Candida lipolytica was studied with respect to the biomass, protein, lipid and other metabolites contents. Supplementation of the methanol medium with certain redox agents such as 2,6-dichlorophenol indophenol, reduced glutathione and methyl red, showed a stimulation of both growth and protein production of C. lipolytica. At certain growth conditions the cellular yield of C. lipolytica was 0.3 g of cells/g of methanol and the protein of the biomass was 41.0%. The amino acid composition of the protein especially of the essential ones was comparable to FAO standards. Thin-layer chromatography of the lipids indicated a dominance of total glycerides. Analyses of the acylated unsaponified fraction by gas liquid chromatography showed that campesterol was the major component.
Subject(s)
Candida/metabolism , Dietary Proteins/biosynthesis , Fungal Proteins/biosynthesis , Methanol/metabolism , Phytosterols , 2,6-Dichloroindophenol/pharmacology , Amino Acids/analysis , Azo Compounds/pharmacology , Biotin/pharmacology , Candida/analysis , Candida/growth & development , Cholesterol/analogs & derivatives , Cholesterol/analysis , Culture Media , Dietary Proteins/analysis , Fungal Proteins/analysis , Glutathione/pharmacology , Glycerides/analysis , Guanine/pharmacology , Lipids/analysis , Phosphorus/analysisABSTRACT
Total, free, and conjugated urinary catecholamines and their metabolites are studied in diabetes before and after treatment. There are abnormalities in catecholamines metabolism and their metabolites caused by the diabetic condition. The 24 hour urinary excretion of the total catecholamines is significantly increased in diabetics. Epinephrine, as a free fraction, conjugated fraction, and, consequently, as a total metabolite, is significantly increased. No change in dopamine concentration is observed in diabetes although dopamine is known to inhibit insuline release. No sex difference is, however, observed in the diabetic patients with regards to the catecholamines excretion. After controlling the diabetic state, abnormalities in catecholamine metabolism and their metabolites are normalized.