National Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Synthesis, Characterization and Biological Evaluation Studies of 4‐((3‐Formyl‐4‐hydroxyphenyl) diazinyl) ‐N‐(4‐methyloxazol‐2‐yl) Benzene Sulfonamide with Cu(II), Ni (II), Zn(II) and Ag(I) Using a Microwave Irradiation.569580763310.21608/ejchem.2018.3679.1305ENHanyEl AlfyKahira pharma, Chemistry, Industry Company, Cairo, Egypt./
Branch of Inorganic Chemistry ,Department of Chemistry, Faculty of
Science ,Al-Azher University, Cairo, Egypt0000-0002-8256-4250AliHassanChemistry Department, Faculty of Science, Al-Azhar University, Nasr City,11884, Cairo, EgyptEssam Shawky A. E. HKhattabChemistry Department, Faculty of Science, Al-Azhar University, Nasr City,11884, Cairo, EgyptBassem H.HeakalResearch Laboratory, Cairo Oil Refining Company, Mostorod,
Kaliobia, Egypt.Journal Article20180510Green chemistry, a novel and simple method have been developed for the synthesis of some a new series of complexes of 4‐((3‐Formyl‐4‐hydroxyphenyl) diazenyl) ‐N‐(4‐methyloxazol‐2‐yl) benzenesulfonamide with the metal salts of Cu(II), Ni(II), Zn(II), and Ag(I)using a microwave irradiation. The structure of these sulfonamide compounds has been investigated by using elemental analysis, FT-IR, 1H NMR, UV-Vis spectrometric methods, magnetic susceptibility, conductivity measurements and thermal studies. These compounds were screened for in-vitro antibacterial activity against staphylococcus aureus and Streptococcus mutans (Gram positive bacteria), Escherichia coli, Pseudomonas aeruginosa and klebsiella (Gram negative bacteria) and for in-vitro antifungal activity against Candida albicans. The results of the antimicrobial activity studies showed that metal complexes have higher activities than parent ligand. Also, ligand displayed potent antioxidant activity.https://ejchem.journals.ekb.eg/article_7633_cde772e019b0b8430097fca9f9fa0df7.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Chemical Analysis of Engine Oils as an Indicator to Estimate the Rate of Wear581590733010.21608/ejchem.2018.3412.1289ENNehad A.AhmadAgricultural Engineering Department, Faculty of Agriculture, Cairo University, Giza, EgyptKhaled MohamedAbdelbaryAgricultural Engineering Department, Faculty of Agriculture, Cairo University, Giza, EgyptSamy M.YounisAgricultural Engineering Department, Faculty of Agriculture, Cairo University, Giza, EgyptJournal Article20180403Current research aims to inspect the chemical analysis of engine oils as an indicator of wear in engine. The novelty of work is to test lubricating oil quality and to determine the wear rate in a simple way by taking oil sample of 10 cm3 and analyzed it in about 5 minutes. This can be done during the operation of equipment without need to stop them, furthermore, this method is a quick indicator of the need to change oil as soon as the initial evidence of wear in the oil molecules. Fresh and used oil samples were chemically analyzed for its elemental analysis for additive elements such as Fe, Cr, pb, Cu, Sn, Al, Ti and Zn, to clarification the wear generation of engine from the contamination present in the lubricating oil. Obtained results showed that increasing percentage of particles of Fe, Cr, pb, Cu, Sn, Al, Ti and Zn metals accompanied by the wear caused in these metals. Height ratio in element Si was not too high this indicated the quality and efficiency of air filters after 100 hours working. Salts such as Na, Ca have increased, but Ba decreased by chemical action at hot temperature of engine.https://ejchem.journals.ekb.eg/article_7330_c9cd514e139c6a5de471ffcacbe2304a.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Optimization, Characterization and Thermodynamic Studies on B. licheniformis ALW1 Keratinase591607732910.21608/ejchem.2018.3379.1287ENAmal MohamedHashemChemistry of Natural and Microbial Products Department, National Research Centre, Dokki, Giza, Egypt.0000-0002-7066-7324AzzaAbdel-FattahChemistry of Natural and Microbial Products Department, National Research Centre, Dokki, Giza, Egypt.SihamIsmailChemistry of Natural and Microbial Products Department, National Research Centre, Dokki, Giza, Egypt.MamdouhEl-GamalDepartment of Botany and Microbiology. Faculty of Science (Boys), Al-Azhar University, Cairo, EgyptMonaEsawyChemistry of Natural and Microbial Products Department, National Research Centre, Dokki, Giza, Egypt.Mohamed AbdelrahmanEmranChemistry of Natural and Microbial Products Department, National Research Centre, Dokki, Giza, Egypt.Journal Article20180404Optimization of B. licheniformis ALW1 keratinase was investigated by using a Plackett – Burman design (PBD) and Central Composite Design (CCD). PBD showed that galactose, inoculum size and corn steep liquorwere the most effectivevariables played a rolein improving the enzyme productivity (87.65U/mL). CCD results recorded an increase in enzyme productivity to about1.4-fold compared to the basal medium (99.1 U/mL). The optimum activity for the partial purified enzyme was obtained at pH 8.5 and 70˚C. The activation and deactivation energy were calculated to be25.37 kJmol-1 and73.38 kJmol-1 respectively. The half-life time was 1380,690,530, and383 min. at 50˚C,55˚C,60˚C and 65˚C respectively. Also, D values were 4600,2300,1769, 1277min. at the same degree respectively. ∆G° (kJmol-1) kept relatively constant between 50-60˚C (191.49 kJmol-1-193.31 kJmol-1) and noticeably increase at 65˚C (212.86 kJmol-1). ∆H° (kJmol-1) recorded minor decrease by the increase of temperature. Approximately, most of the tested metals ions have stimulation effect in enzyme activityand MgSO4.H2O was the best (146%). Among all the tested detergents tween 80 retained 97% of original enzyme activity. DMSO increased the enzyme activity about 11%, while propanol and acetonitrile reduced the enzyme activity to about 14% and 10% respectively. All the reducing agents had a stimulating effect on enzyme activity with variable degrees. The enzyme (980 U) had the ability to hydrolyze 74% of the feather to nutritional valuable protein.https://ejchem.journals.ekb.eg/article_7329_70b37436f061881c69afd4715bab7ff4.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Reno-protective Effect of Methanolic Extract of Stevia Rebaudiana Bertoni and Bioactive Phenolic Compounds In Type-1- Diabetes609615733110.21608/ejchem.2018.3550.1297ENAmani MDEl-MesallamyDepartment of Organic Chemistry, Faculty of Science, Zagazig University, Zagazig, EgyptSaharHusseinDepartment of Phytochemistry and Plant Systematics ,National Research Center , Egypt0000-0002-6305-508XAbdel Aziz MHusseinDepartment of Physiology, Faculty of Medicine, Mansoura University, Mansoura, EgyptSeham AMahmoudDepartment of Organic Chemistry, Faculty of Science, Zagazig University, Zagazig, EgyptKhalid M.El-AzabDepartment of Biology, Faculty of Science, JazanUniversity, Jazan, Saudi ArabiaJournal Article20180415The aim of this study is to evaluate the reno-protective effect of the defatted methanolic extract of Stevia rebaudiana which showed the highest improvement of renal parameters, as it reduced the protein urea, blood urea nitrogen and blood creatinine and nephroprotective properties with reduced hyperglycemia complications through protection of renal tissues in type-1 diabetes. Also, identification of bioactive phenolic compounds of defatted methanolic extract using HPLC analysis, demonstrate the presence of diterpene glycosides, stevioside, rebaudioside A and chlorogenic acidhttps://ejchem.journals.ekb.eg/article_7331_a0da2548c846ecb2558dc7cb989c15bf.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Removal of Fe (III) from Aqueous Solution Using Thiosalcylic Acid as An Efficient Adsorbent617627741710.21608/ejchem.2018.3312.1280ENA. IAbd El-HamidComposite and Nanomaterials Department, Advanced Technology and New Materials Research Institute, City for Scientific Research and Technology Applications, P. O. Box 21934, SRTA, EgyptH.FAlyHot Laboratories Center, Atomic Energy Authority, Nasr 13759, EgyptJournal Article20180325The removal of Fe (III) from aqueous solution using thiosalcylic acid (TSA) as adsorbent have been demonstrated in this work. TSA was Characterized by SEM, EDX, FTIR and XRD. Various factors affecting on the removal include the contact time, initial concentration of ions, adsorbent dose, initial pH and temperature have been studied. The experimental data showed that, the removal percent of Fe (III) ion is increased by increasing contact time, adsorbent dose and pH values. The sorption reaction was found to obey a pseudo second-order rate model with qe = 275.78 mg g-1. The sorption isotherms data fit Langmuir and Freundlich models. The waste solid from the adsorption process (thiosalcylic acid adsorbed Fe (TSA-Fe)) successful in removal of methylene blue (MB) and crystal violet (CV) dyes from binary system.https://ejchem.journals.ekb.eg/article_7417_91f1bacd74a9937ce44fdd90089e0c7a.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Bio-immobilization of Cr (VI) and its Impact on the Performance of a Pilot Scale Anaerobic Sludge Reactor Treating Municipal Wastewater629637745310.21608/ejchem.2018.3849.1333ENSohair I.Abou-ElelaWater Pollution Research Department, National Research Centre, Giza, 12622, Egypt.Mariam E.FawzyWater Pollution Research Department, National Research Centre, Giza, 12622, Egypt.0000-0002-0552-5581Mohamed M.El-SorogyHolding Company for Water and Wastewater, Giza, 12577, Egypt.Salah A.Abo-El-EneinChemistry Department, Faculty of Science, Ain Shams University, Cairo, 11566, Egypt.Journal Article20180516This study aimed to emphasize the effect of hexavalent chromium Cr (VI) on the performance of a pilot scale hybrid up-flow anaerobic sludge blanket (H-UASB). The system was packed with non-woven poly ester fabric (NWPF) and continuously fed with real municipal wastewater at a hydraulic retention time (HRT) 7.5 h and average organic loading rate (OLR) 1.24 Kg COD m3/d. The system achieved satisfactory removal rates for total suspended solids (TSS) (86.44 %), chemical oxygen demand (COD) (74.18 %) and biological oxygen demand (BOD5) (84.8%) without the addition of Cr (VI). Results indicated that feeding the reactor with different concentrations of chromium ions ranged from 0.1 – 1.3 mg/l (i.e: 600 mg / m3. d to 6000 mg / m3. d) decreased the residual concentration of Cr (VI) in the final effluent to 0.019 mg/l, while the accumulation of chromium ion increased in the biobed (160 mg/kg) and in excess sludge (165.44 mg/kg). This was due to the biological reduction of Cr (VI) to Cr (III) by the action of sulphate and chromate reducing bacteria. Increasing the concentration of Cr (VI) up to 6000 mg / m3. d reduce the biochemical reactions of the anaerobic microorganisms and consequently decrease the removal efficiency of TSS from 86.44% to 62.06, COD from 74.2 % to 57.07 % and BOD5 from 84.8% to 61.92%.https://ejchem.journals.ekb.eg/article_7453_3a694e9f5448b0986b53f39628f11a63.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801A Green and Simple Technique for Flotation and Spectrophotometric Determination of Cobalt(II) in Pharmaceutical and Water Samples639650745410.21608/ejchem.2018.3586.1300ENMagda AliAklProfessor of Analytical Chemistry, Faculty of Science, Mansoura University, EgyptWegdan SAAlharawiChemistry Department, Faculty of Science, Mansoura University, Mansoura, EgyptJournal Article20180424In the present study, a green and simple technique has been used for the preconcentration , flotation and spectrophotometric detection of Co (II) in pharmaceutical and water samples is established. At pH 4, the chromogenic reagent 4-(2pyridyl azo) resorcinol (NaPAR) reacts with Co(II) to form a pink 1:2 (M:L) complex in aqueous solution. This complex has been successfully separated by flotation by the aid of the anionic surfactant, oleic acid(HOL). The concentration of Co(II) in the scum layer was determined easily by spectrophotometry at 510 nm. The parameters that influence the flotation and spectrophotometric determination of Co (II) were studied. Beer’s law was obeyed over a concentration range 0.01-0.32 µg ml-1 in the aqueous as well as in the scum layer. The molar absorptivity of the Co(II)-NaPAR in the aqueous and scum layer were found to be 1.2×104 L mol-1 cm-1and 1.54×105 L mol-1 cm-1, respectively. The detection limit of the proposed technique, the recovery % (R%) and the relative standard deviation(RSD%) are 3.09 ng ml-1, 98 % and 1.5%, respectively. The method was verified by analysis of real certified samples. The proposed procedure was applied to determine Co (II) in water, pharmaceutical samples as well as in synthetic mixtures. The mechanism of flotation is proposed.https://ejchem.journals.ekb.eg/article_7454_59bd3d4c64c9b739d63682c8c158e621.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Improved Manual Dishwashing Liquid Detergent Compared to that Produced by Multinational Companies in Egyptian Market651659763110.21608/ejchem.2018.2756.1222ENAhmedGad Elmawlachemistry , Ain shams univesrsity0000-0002-1796-7125Youssef AlyEl-ShattoryFat and Oil department, National research Centre, Behooth street, DokkiHoda AbdelhayAbd El-Hamidedepartment. Faculty of Science. Ain Shams University.Journal Article20180125In this study, formulation of manual dishwashing liquid detergent with ionic, nonionic and zwitterionic surfactants mixtures were investigated in respect to viscosity, cloud point, foaming power, foam features, washing performance, irritation test, in addition to its cost, in comparison with that produced by multinational companies in their own factories in Egypt. It has been found that the formulations containing Linear alkyl benzene sulphonic acid are characterized by higher performance of removing stain, without any stain deposition on dishes, in addition to moderate foaming power which is diminished with hard water. Our proposed formulations 10% Sodium alkylbenzene sulfonate with 2% sodium laurylether sulphate and 2% coconut diethanolamide or 2% Cocamidopropylamine Oxide have resulted in better washing performances, less irritations, higher viscosity, comparable cloud points and lower cost than multinational market products H and P which contain 12% Sodium linear alkylbenzene sulfonate with 6% sodium laurylether sulphate and 9% sodium laurylether sulphate and 6% Cocamidopropylamine oxide respectively.https://ejchem.journals.ekb.eg/article_7631_aed50d75c833b783095ca669b368d51a.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801An Efficient Catalytic Synthesis of 1,8-Dioxo-octahydroxanthene Derivatives with Anti-oxidant Scanning661666763210.21608/ejchem.2018.3381.1285ENTamer KKhatabaOrganometallic-Organometalloid Chemistry Department, Chemical Industries Research Division, National Research Centre, 33 El-Behouth St., Dokki, 12622, Cairo, Egypt0000-0002-1065-0643AhmedEl-MekabatybChemistry Department, Faculty of Science, Mansoura University, Mansoura, EgyptZeinabM.GamalaChemistry Department, Faculty of Science, Mansoura University, Mansoura, EgyptEzzKandilChemistry Department, Faculty of Science, Mansoura University, Mansoura, EgyptJournal Article20180331Eco-friendly one pot synthesis is developed for 1,8-dioxo-octahydroxanthenes from aldehydes and dimedone using non-toxic, easily prepared and recyclable catalyst (Sm2O3/SiO2) as a silica supported rare earth element under solvent –free conditions. four of the synthesized compounds showed promising ABTS (3i, 68.7; 3b, 59.2; 3h, 50.2 inhibition%) compared with ascorbic acid.https://ejchem.journals.ekb.eg/article_7632_03cbd70328ce23e74dbf851b5c500d6d.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Immobilization and Characterization of Levansucrase Enzyme onto Functionalized Multi-walled Carbon Nanotubes667678798310.21608/ejchem.2018.3583.1299ENAhmedHarounNational research centre0000-0001-5864-6486EmanFadlChemistry of natural &Microbial products Dept, National Research Centre,MonaEsawyChemistry of natural &Microbial products Dept, National Research CentreJournal Article20180418Using of enzymes in some industrial applications is still limited due to their instability under severe conditions, and relatively high production charge. Accordingly, this work deals with preparation and characterization of novel biocatalysts based on functionalized multi-walled carbon nanotubes (MWCNTs) with calix[8]arene in presence of N-ethyl-N-(3-dimethylaminopropyl) carbodiimide, (EDC) and glutardialdehyde (GA) crosslinkers. Among 5 honey isolates, the most potent levansucrase producer was identified based on 16S rRNA as Bacillus subtilis. Moreover, in case of using 4000 U/g enzyme concentration, the enzyme gave the highest immobilization yield (81%) onto uncrosslinked MWCNTs/calix[8]arene. The prepared materials were characterized using: FTIR, TEM and particle size distribution analysis. EDC had significant effect on the particle size (938 nm) relative to that in case of GA (746-784 nm) and un-functionalized MWCNTs (419 nm). Besides, the cytotoxicity of the immobilized enzyme could be minimized up to100 μg/mL concentration against BHK fibroblast normal cells in comparison with the free enzyme and MWCNTs. In general, all the prepared formulations improved the enzyme stability to great instance in comparison with the free enzyme.https://ejchem.journals.ekb.eg/article_7983_597eb9056bdf424203cfee04f5d332b2.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Fabrication and Characterization of Biodegradable Polymer as Multifunction Finishing Agent for Natural fabrics679689798410.21608/ejchem.2018.3188.1274ENEmanOsmanTextile metrology lab. national Institute of Standards, Egypt0000-0002-4475-7633Journal Article20180314In this work, chitosan solution in aqueous acetic acid used to produce both bulk and nano sized chitosan as finishing agent for cotton and silk fabrics using different coating techniques; pad-dry-cure (for bulk chitosan) and electrospraying (for nano chitosan). The treated fabric samples were characterized via FTIR, XRD and SEM. The obtained coated samples were evaluated for their antibacterial activity towards both E. coli (Gram -ve) and S. aureus (Gram +ve) bacteria. Also, the treated samples were assessed for ultraviolet protection degree through measuring the ultraviolet protection factor (UPF). Moreover, the wettability of the treated samples was evaluated through measuring the contact angle of water droplet on the fabric surface. Additionally, the electrical conductance and capacitance of all treated samples were measured. The obtained nano coated chitosan fabrics have proved to be of high potential eco-friendly and cost-effective products to be used for hygiene, medical and electromagnetic shielding applications.https://ejchem.journals.ekb.eg/article_7984_2f073d81157712560795cf0b778161b4.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Anti-Helicobacter Pylori, Anti-diabetic and Cytotoxicity Activity of Biosynthesized Gold Nanoparticles Using Moricandia nitens Water Extract691703798510.21608/ejchem.2018.3744.1318ENMostafa M.H.KhalilChemistry Department, Faculty of Science, Ain Shams University0000-0002-8031-2447NadiaSolimanFaculty of Science ,Chemistry Department,Ain Shams University,CairoHeba IAbdel- MoatyMedicinal and Aromatic Plants Department, Desert Research Center, El-Mataria, Cairo, EgyptEmanIsmaelChemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, EgyptDina Y.SabryChemistry Department, Faculty of Science, Ain Shams University, Cairo, EgyptJournal Article20180506This study aims to synthesize gold nanoparticles (AuNPs) using water extract of Moricandia nitens (Viv.) E. A. Durand & Barratte aerial parts water extract. The presence of various phytochemicals viz. alkaloids, carbohydrates, glycosides, flavonoids, tannins, cumarines, protein and saponins by following standard biochemical methods was investigated. The effect of different parameters such as extract concentration, pH and temperature on the size and morphology of the gold nanoparticles (AuNPs) were studied. The synthesized gold nanoparticles (AuNPs) were characterized by using UV-Vis spectroscopy, FTIR and XRD. The synthesized nanoparticles were found to be spherical in shape with average size in the range of 5 to 20 nm. The green synthesized GNPs were found to be potent inhibitors of α-glucosidase with an IC50 value of 159.3 μg/ml and showed anti-Helicobacter pylori activity against multidrug resistant H. pylori strains with an MIC 31.25 (µg/ml). Furthermore, biogenic AuNPS possess more significant anticancer activity against HepG2 and HCT-116 withIC50 =44.6 ± 0.8 µg/ml and IC50 = 36 ± 0.7 µg/ml respectively.https://ejchem.journals.ekb.eg/article_7985_6c71a9e05fcd43f3b8d6bdf655937104.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Use of Nanotechnology to Achieve the Best Functional Characteristics of the Fabrics Sheets Used in Hospitals705715809310.21608/ejchem.2018.2892.1238ENSamarM. SamiTextile Research Division, National Research Centre, 33 El Bohouth St., Dokki, Giza, P.O. 12622, EgyptOlaBarakatFaculty of Applied Arts / Helwan University, EgyptJournal Article20180212This research aims to achieve the best functional characteristics of the bed sheets used by hospitals, to be resistant to bacteria, and have the ability to Self-Cleaning. Three fabrics were produced from different weft material (rayon viscose, bamboo, and cotton) and were treated with Nanosilver, and Nano Titanium dioxide (TiO2). Fabrics were coated with the nanoparticles in three different sequences: 1) coating of fabric with 1%TiO2 nanoparticles and Ag nanoparticles in the same bath, 2) coating of fabric by 1% TiO2 post-treated by Ag nanoparticles, 3) coating of fabric by Ag nanoparticles post-treated with -1% TiO2 treated fabric). Treated samples were tested for Pema test (skin model) and Stability of treatment to washing test. The results show that cotton and a little less bamboo are the best treated materials, achieved the high-performance efficiency for the purpose of use, where they gave the best properties directly associated with the comfort (water vapor permeability, air permeability, and thermal conductivity), after treatment with nano-materials . Also, the treatment of fabrics by TiO2 post-treated by silver nanoparticles solution shows higher antibacterial results than other two sequences of treatments, and Bamboo treated samples exhibited more significant efficacy against bacteria. Therefore, the treated fabric believed to have great potential for use as antibacterial fabrics to reduce the likelihood of being infected with the bed sores. All treated samples show high efficiency towards removal of MB dye stains, and bamboo treated samples are the most effective one towards the self-cleaning feature.https://ejchem.journals.ekb.eg/article_8093_86ab30145a8417fe81442dafe8587c83.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Preparation of Quality Control Material for Assuring Quality of Electrical Conductivity Measurements in Soil717722809410.21608/ejchem.2018.3005.1254ENIbrahim FaragTahounNational Institute of Standards, Tersa St, El-Matbah, Haram, P. O. Box: 136 Giza, Code No: 12211 Giza, Egypt0000-0002-0482-6198AdelShehataNational Institute of Standards, Tersa St, El-Matbah, Haram, P. O. Box: 136 Giza, Code No: 12211 Giza, EgyptRandaNasrNational Institute of Standards, Tersa St, El-Matbah, Haram, P. O. Box: 136, Code No: 12211 Giza, EgyptJournal Article20180225Accurate and reliable analytical results of soil have become essential tool for understanding salinity and limiting factors affecting agricultural productivity. Reliability of results depends mainly on the existence and quality of reference materials which are considered as crucial tools for validation and verification of the analytical process and assuring quality of measurement results. The National Metrology Institute of Egypt [NIS] is striving to set up the national standards to ensure all measurement results are traceable to the international system of unit (SI). NIS starting development of a series of soil reference materials to meet Egyptian requirements and customer demands. This article describes the production process of the soil reference material characterized for electrical conductivity from processing to value assignment. Characterization, homogeneity and stability studies of the material were carried out according to ISO guides 34, 35 and 80. The measurement results were statistically analyzed to calculate assigned values. The assigned value and expanded uncertainty for EC1:1 and EC1:5 methods were found 1234 ±58 µS/cm and 973 ±52 µS/cm, respectively.https://ejchem.journals.ekb.eg/article_8094_87b4b5feaa2cba02316586e856214895.pdfNational Information and Documentation Centre (NIDOC), Academy of Scientific Research and Technology, ASRTEgyptian Journal of Chemistry0449-228561420180801Polymers and Ceramics Biomaterials in Orthopedics and Dentistry: A Review Article723730809510.21608/ejchem.2018.3187.1273ENTamer M.HamdyRestorative and Dental Materials Research Department, National Research Centre (NRC),Cairo, Egypt0000-0003-0948-194XJournal Article20180311Nowadays, strong requirements in biomaterials are still to be met, both in polymers and ceramics substitute, repair and regeneration of hard tissues defects. In this framework, tremendous efforts in the biochemistry especially biomaterials field have greatly impacted the advancement of modern biomedicine. According to development of polymer and ceramics biomaterials utilized in orthopedics and dentistry; there are three different generations, namely first generation which include bioinert materials, second generation which include bioactive and biodegradable materials and recently the third generation (materials that designed to stimulate specific molecular responses). In this review, the evolution of different polymers and ceramics most commonly used in bone regeneration is discussed, highlighting the interesting discoveries in biomaterials tissue engineering applications.https://ejchem.journals.ekb.eg/article_8095_df8acd19b3766360d802c9488d037a31.pdf