@article { author = {}, title = {Studies on Preparation, Characterization and Humidity Sensing of Mg- Substituted YPO4}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {343-351}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1049}, abstract = {YPO4 and Mg2P2O7 mixed ceramic semiconductor samples were .........prepared and investigated to be used as humidity sensors. The samples were characterized using XRD. Surface area, SEM, and electrical conductivity under the effect of humidity at room temperature were measured and discussed. X-ray patterns showed the formation of YPO4 in tetragonal phase and Mg2P2O7 in monoclinic form. Adding Mg2P2O7 improves the surface area of YPO4 which affected the electric conductivity. The humidity sensing of the pure and mixture samples was studied by dependences of the electrical conductivity on the mixture content and the sensitivity was also calculated. The results indicated that the electrical conductivity increased as relative humidity increased up to 76% due to the protonic conductivity which specified the action of water content on the phosphate molecules. After 76% relative humidity (RH), the value the electrical conductivity and sensitivity started to decrease due to the blocking of the phosphates molecules under high humidity value.}, keywords = {Yttrium phosphate,Sensing,Preparation and Characterization}, url = {https://ejchem.journals.ekb.eg/article_1049.html}, eprint = {https://ejchem.journals.ekb.eg/article_1049_76b0b2e37b7bf4922dcc49d170ac1986.pdf} } @article { author = {}, title = {Clarification of The Corrosion Inhibition of Mild Steel in Hydrochloric Acid Solutions via Cetyltrimethyl Ammonium Bromide Inhibitor}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {353-371}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1050}, abstract = {CETYLTRIMETHYL ammonium bromide (CTAB) was investigated …….as corrosion inhibitors of mild steel in 0.1 and 0.5 M HCl solutions using weight loss, Tafel polarization and electrochemical impedance spectroscopy techniques. The experimental results showed that the inhibition efficiency increases with increasing of CTAB concentrations but decreases with increasing temperature. The adsorption of CTAB on the mild steel surface obeyed the Langmuir adsorption isotherm. Potentiodynamic polarization curves showed that CTAB acted as a cathodic inhibition predominantly in hydrochloric acid. This was supported by the impedance measurements which showed a change in the charge transfer resistance (Rct) and double layer capacitance (Cdl) indicating adsorption of CTAB on the mild steel surface. Thermodynamic parameters were also calculated to know the mechanism of the inhibition. The thermodynamic functions of the adsorption processes were calculated from the weight loss and effect of temperature data and were used to analyze the inhibitor adsorption mechanism. The thermodynamic parameters indicate that physical adsorption and chemisorptions of the inhibitor on the metal surface may occur.}, keywords = {Cetyltrimethyl ammonium bromide (CTAB),mild steel,Corrosion inhibitor,Langmuir adsorption isotherm,Potentiodynamic polarization and Free energy}, url = {https://ejchem.journals.ekb.eg/article_1050.html}, eprint = {https://ejchem.journals.ekb.eg/article_1050_cd7d29e7ba563ba875e4aebe27c1bd60.pdf} } @article { author = {}, title = {-Irradiation Effect on The Composition and Quality of Screw Pressed Nigella sativa (Black Cumin) Crude Oil during Storage}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {373-385}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1051}, abstract = {NIGELLA sativa (black cumin) seeds were γ-irradiated with …… 10kGy, according to commercial practices, then screw pressed to extract the crude oil. The effect of γ-irradiation on the composition of the oil in terms of content, fatty acid composition, free fatty acids and total phenolics was studied. The effect of γ-irradiation on the quality of the oil during storage was also evaluated by monitoring the storage stability for a period of 280 days at ambient temperature (25°C) and in refrigerator (4°C). Results showed that γ-irradiation at 10 kGy increased the crude oil content from 32.7 % to 34.5%, total phenolics from 6.93 to 102.17 (mg GAE /g oil), and free fatty acids from 3.4 to 4.13 %. γ-Irradiation caused an increase in total saturated fatty acids from 20.40% to 21.45 %, accompanied by a significant decrease in total unsaturated fatty acids from 79.55 to 78.55%. The results also showed that exposing Nigella seeds to γ-irradiation at a dose of 10 kGy can affect the oxidative stability of the resulting oil during storage especially at room temperature. The storage stability of the crude oil can be enhanced by storing Nigella oil at 4°C. This data is relevant to dietary supplement industries for keeping the quality of crude Nigella oil by re-considering the dose of γ-irradiation applied for sanitizing the seeds.}, keywords = {Nigella Sativa,crude oil,γ-irradiation,Chemical composition and Storage stability}, url = {https://ejchem.journals.ekb.eg/article_1051.html}, eprint = {https://ejchem.journals.ekb.eg/article_1051_4265e7c981f33abb42d0f7b3397c3b2c.pdf} } @article { author = {}, title = {Chemistry of Optically Active Cyanohydrins-Part 3:[1] Preparation and Reactions of (R)-2-Hydroxy-2-(naphthalen-1-yl)ethane- nitrile using (R)-Hydroxynitrile lyase from Prunus amygdalus. Antitumor and Antimicrobial Evaluation of the New Products}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {387-410}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1057}, abstract = {CYANURATION of 1- naphthaldehyde (1) yielded the racemic …….2-hydroxy-2-(naphthalene-1-yl)ethanenitrile (R,S)-2 . The same reaction can be completed by using acetone cyanohydrin (3) as a transcyanating agent. The optically active cyanohydrin enantiomer (R)-2 could be obtained by hydrocyanation of (1) in presence of (R)-hydroxynitrile lyase (R)-Pa HNL [EC4.1.2.10] from almonds (Prunus amygdalus) as a chiral catalyst. Cyanohydrin 2 in its racemic and optically active forms reacts with the isocyanate reagents 4a-c to give the carbamate derivatives (R,S)-5 and (R)-5, respectively. On the other hand, the reaction of (R,S)-2 and (R)-2 with the isocyanate and/or isothiocyanate reagents 6a-e gave the 4-imino-2-oxazolidinone derivatives, (R,S)-8 and (R)-8, respectively. Moreover, derivatization of (R)-2 with (S)-Naproxen® chloride (S)-10 gave the respective diastereomer (R,2S)-11. The postulated structures for the new products were supported with compatible elementary microanalyses and spectroscopic (IR, 1H NMR, MS) measurements. The antitumor and antimicrobial activities of some selected racemic new products and their respective optically active analogues were also endeavored. The structure-activity relationship (SAR) was also discussed.}, keywords = {aldehydes,Cyanohydrins,Enzymes,Enantioselective synthesis,Antitumor activity and Antimicrobial activity}, url = {https://ejchem.journals.ekb.eg/article_1057.html}, eprint = {https://ejchem.journals.ekb.eg/article_1057_9bfd3196fec8f6af27faf9f5cc4f93e8.pdf} } @article { author = {}, title = {Mercury Uptake Capacity of Chitosan: Kinetic and Isotherm Study}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {411-422}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1060}, abstract = {IN this study, the ability of chitosan (β (1→4) linkage of 2-acetamido-2-deoxy-β-D glucose] to remove mercury from water samples was studied. Chitosan was characterized by FT-IR, XRD and FE-SEM. The Hg (II) uptake capacity was studied; different factors were considered such as pH, contact time, adsorbent dose, metal ion concentration. From the obtained results, it was found that chitosan exhibited a maximum uptake capacity of 32.83 mg/g under the investigated conditions. The uptake process was found to follow Frundlish Adsorption Isotherm and Pseudo Second Order Kinetics}, keywords = {}, url = {https://ejchem.journals.ekb.eg/article_1060.html}, eprint = {https://ejchem.journals.ekb.eg/article_1060_9aa97ee44090758dd99259527dd04225.pdf} } @article { author = {}, title = {Preparation, Characterization and Evaluation of Nano Zinc Oxides as Pigments}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {423-433}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1061}, abstract = {THREE samples of nano zinc oxide are prepared by using both ……..the hydrothermal and the direct precipitation methods. The characterization of the produced samples shows that the prepared samples have different nano size. Also, it is found that there are an agreement between the calculated values of the particle size from the x-ray diffraction and the TEM measurements. On other hand, the prepared samples are tested as pigments according to the ASTM (1980 and 1981) for comparison with a commercial ZnO. The test showed that the nano sized ZnO exhibits an excellent property when used as pigments relative to the commercial sample.}, keywords = {Nano zinc oxide,hydrothermal,Precipitation and Pigment}, url = {https://ejchem.journals.ekb.eg/article_1061.html}, eprint = {https://ejchem.journals.ekb.eg/article_1061_e92e60d34850bb477ffac972fe083240.pdf} } @article { author = {}, title = {Effeciency of Degreasing / Settling Tank Followed by Constructed Wetland for Greywater Treatment}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {435-446}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1062}, abstract = {THE PRESENT study deals with real greywater. The …..objective of this study is to investigate the treatment of greywater for the purposes of reuse. Greywater treatment was examined first to determine the optimum degreasing / settling time. Further treatment by hybrid constructed wetland was examined. Efficient removal of the pollutant parameters was achieved. The experimental method involves evaluation of the treated effluent to reach the allowable limits of water reuse according to “Egyptian Environmental Association Affair, EEAA”. Final removal rates reached 87%, 83%, 88%, 91%, 36%, 92%, and 58% for the TSS, COD, BOD5, TP, NO3, oil & grease and TKN, successively. The E. coli count and the number of cells or eggs of Nematode in the final effluent reached 100/ml and “1 egg/L”, respectively.}, keywords = {Sewage separation,Degreasing,Settling,Hybrid constructed wetlands and Greywater treatment}, url = {https://ejchem.journals.ekb.eg/article_1062.html}, eprint = {https://ejchem.journals.ekb.eg/article_1062_c85586dbfa5666e85929939bc637fb71.pdf} } @article { author = {}, title = {Modification of Egyptian Bagasse Kraft Pulping Using Yield - increasing Additives Ι-Effect on Chemical Properties}, journal = {Egyptian Journal of Chemistry}, volume = {57}, number = {5}, pages = {447-462}, year = {2014}, publisher = {National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRT}, issn = {0449-2285}, eissn = {2357-0245}, doi = {10.21608/ejchem.2014.1063}, abstract = {BAGASSE is one of the potential raw materials for pulp in Egypt. So, our target is to improve the chemical properties of Kraft pulp using yield- increasing additives as anthraquinone (AQ), polysulfide (PS) and sodium borohydride (NaBH4). The effect of the bagasse to liquor ratio B/L ratio was also examined. The yield gains for AQ, PS, NaBH4, AQ-PS and AQ-NaBH4 were 4.73%, 6.46%, 2.99%, 12.15% and 4.05%, respectively for 1:4 B/L ratio. While the yield gains at 1:10 B/L ratio were 1.42%, 2.65%, 5.2%, 6.9% and 5.3%, respectively. Combination of AQ-PS gave synergistic effect. AQ, NaBH4 and AQ-NaBH4 reduced the kappa number by 7%, 14%, 9%, 4.48%, 40.3% and 5.95% for 1:4 and 1:10 B/L ratios, respectively. More dissolution of lignin was promoted at higher B/L ratio. All additives preserved the carbohydrate yield more than the Kraft one, and showed higher delignification selectivity except for PS.}, keywords = {Egyptian bagasse,Kraft pulp,Modified kraft pulp,AQ,NaBH4,PS and Yield-increasing additives}, url = {https://ejchem.journals.ekb.eg/article_1063.html}, eprint = {https://ejchem.journals.ekb.eg/article_1063_f84907b4b7fbe3feca546736734be52f.pdf} }