ORIGINAL_ARTICLE
RECOVERY OF ZINC AND RARE EARTHS FROM ABU RUSHIED FERRUGINOUS ORE MATERIAL, SOUTH EASTERN DESERT, EGYPT
This paper is concerned with the recovery of separate Zn and REEs pure concentrates from a sulphate leach liquor of Abu Rushied ferruginous ore material. Preparation of separate Zn/REEs concentrates was carried out by either selective oxalate precipitation of the REEs or else by bulk hydroxides precipitation followed by re-dissolution of Zn as zincate. The leached REE values could also be recovered in two main steps namely; precipitation of LREEs as their double sulphate during or directly after the acid leaching while the potentiality of individual separation of the HREEs concentrate left behind was studied through the displacement technique using the cationic exchange resin Dowex 50W-X8. A tentative flowsheet for the overall treatment of Abu Rushied ore material is also presented.
https://absb.journals.ekb.eg/article_10870_5f746191c2bd1d18da3f7ea56a98c640.pdf
2007-06-01
75
85
10.21608/absb.2007.10870
zinc
Rare Earths
ABU RUSHIED FERRUGINOUS
N.
EL-HAZEK
1
Nuclear Materials Authority, P.O. Box: 530 El-Maadi, Cairo, Egypt
LEAD_AUTHOR
T.
AMER
2
Nuclear Materials Authority, P.O. Box: 530 El-Maadi, Cairo, Egypt
AUTHOR
M.
BADR
3
El-Azhar University, Faculty of Science (Girls), Chemistry Department.
AUTHOR
N.
SHAWKY
4
El-Azhar University, Faculty of Science (Girls), Chemistry Department.
AUTHOR
D.
ZAKY
5
Nuclear Materials Authority, P.O. Box: 530 El-Maadi, Cairo, Egypt
AUTHOR
ORIGINAL_ARTICLE
NEW SYNTHESIS OF 1,4-DIARYLPIPERAZINE-2,5-DIONE AND 3,4,5-TRISUBSTITUTEDPYRIDINE-2(1H)-ONE
Treatment of N-aryl 2-chloroacetamides (2a-f) with sodium isopropoxide in isopropyl alcohol afforded 1,4-diarylppiperazine-2,5-dione (3a-f). Treatment of malononitrile dimer (9), ethyl cyanoacetate (11) and the arylidines of cyanothioacetamide (13) with DMFDMA afforded the corresponding enamines (10, 12 and 14) respectively. Reaction of 14 with either sodium ethoxide or sodium methoxide affords 5-cyano-4-ethoxy-6-oxo-1,6-dihydro-pyridine-3-carboxylic acid amide (15) and 5-cyano-4-methoxy-6-oxo-1,6-dihydro-pyridine-3-carboxylic acid amide (16) respectively.
https://absb.journals.ekb.eg/article_10871_70e46bf74778a7eaf710a3cef785499d.pdf
2007-06-01
151
161
10.21608/absb.2007.10871
1,4-DIARYLPIPERAZINE-2,5-DIONE
3,4,5-TRISUBSTITUTEDPYRIDINE-2(1H)-ONE
FATHI
ABU-SHANAB
1
Chemistry Department, Faculty of Science, Al-Azhar University, Assiut 71524,
LEAD_AUTHOR
ORIGINAL_ARTICLE
SOME REACTIONS OF 6,8-DIBROMO-2-PROPENYL-4H-3,1-BENZOXAZIN-4-ONE WITH NITROGEN NUCLEOPHILES UNDER MICROWAVE IRRADIATION
The benzoxazinone derivative (1) was prepared upon the action of crotonoyl chloride on 3,5-dibromoanthranilic acid in pyridine. Microwave irradiation assisted the aminolysis of (1) with nitrogen nucleophiles as benzyl amine, hydrazine hydrate and formamide to give the amide derivatives (2a-c) respectively. Quinazolinone derivatives (3a-e) were produced upon the action of primary amines such as m-nitroaniline, p-toluidine, p-anisidine, benzyl amine and/or hydrazine hydrate respectively on the benzoxazinone derivative (1). An excess amount of p-anisidine, phenylhydrazine and/or p-toluidine afforded the amide and quinazolinone derivatives (4a & 5a), (4b & 5b) and/or (5c) respectively. The benzoxazinone derivative (1) was subjected to react with secondary amines as piperidine or morpholine giving the amide derivatives (6a) or (6b) respectively under 1 : 1 molar ratio, while under 1 : 2 molar ratio, the dipiperidiyl or dimorphonyl derivatives (7a) or (7b) were formed respectively. Ammonolysis of (1) using ammonium acetate, yielded the quinazolinone derivative (8).
https://absb.journals.ekb.eg/article_10873_51350641bc724bc5fbeb700c44acc04b.pdf
2007-06-01
163
171
10.21608/absb.2007.10873
A.
ABDALHA
1
Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt
LEAD_AUTHOR
M.
ABOU EL-REGAL
2
Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt
AUTHOR
M.
EL-KASSABY
3
Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt
AUTHOR
A.
NAZEER
4
Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt
AUTHOR
ORIGINAL_ARTICLE
HETEROAROMATIZATION WITH SULPHONAMIDO PHENYL ETHANONE: PART (III)*. SYNTHESIS, REACTIONS AND BIOLOGICAL ACTIVITY OF ENAMINONE CONJUGATED WITH DIMETHYLAMINOSULFONYL MOIETY
4-(3-Dimethylaminoacryloyl)-N,N-dimethylbenzenesulfonamide (2) was prepared and used as key intermediate in the synthesis of the title compounds, the structure of these compounds were elucidated on the bases of elemental analysis, IR, 1H-NMR and mass spectra. The Antimicrobial and Antifungal activities of the prepared compounds are also reported.
https://absb.journals.ekb.eg/article_10880_723aaf5f44a08a3a412c5493d686acaa.pdf
2007-06-01
173
187
10.21608/absb.2007.10880
sulfonamido phenyl ethanone
Enaminone
pyrazole
triazole
imidazole
pyranone
N,N-dimethylbenzenesulfonamide
MAHMOUD
ABDEL AAL
1
Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.
LEAD_AUTHOR
AHMED
EL-MAGHRABY
2
Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.
AUTHOR
SABER
HASSAN
3
Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.
AUTHOR
MAHMOUD
BASHANDY
4
Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.
AUTHOR
ORIGINAL_ARTICLE
EFFECT OF INORGANIC ACID SOLUTIONS ON ELECTROCHEMICAL BEHAVIOR OF TIN ELECTRODE
The electrochemical behavior of tin metal was studied in some inorganic acid solutions; HCl, HNO3, H2SO4 and H3PO4, using the open circuit potential measurements and the potentiodynamic polarization technique. In addition, the metallographic structure of tin electrode was examined before and after immersion in test solution by using scanning electron microscope (SEM). The identification of the elements presented in the surface of specimen after immersion in different solutions was performed using an energy dispersion X-ray analysis(EDAX). The obtained results demonstrated that the aqueous dilution of HCl, H2SO4 and H3PO4 retarded the corrosion of tin electrode, (hydroxyl ion plays a part in basic salt formation), while dilution of HNO3 acid accelerated the corrosion. It is evident from SEM image that, there were grain boundaries and the surface was more active and rougher in case of mechanically polished electrode. In non-polished electrode, the surface was covered with a protective layer; generally SnO2. In potentiodynamic polarization study, the formation of basic salt Sn(OH)Cl was preference to any other oxide in HCl solutions. The increase in NO2 concentration was responsible for the increase in the rate of dissolution in HNO3. The tin dissolution in sulphuric acid occurred through an intermediate of (SnHSO4OH) species.
https://absb.journals.ekb.eg/article_10881_497e062b9bda782ef69899addd981d7f.pdf
2007-06-01
189
205
10.21608/absb.2007.10881
INORGANIC ACID SOLUTIONS
ELECTROCHEMICAL BEHAVIOR
TIN ELECTRODE
R.
ABOU SHAHBA
1
Chemistry Department, Faculty of science (for girls), AL- Azhar University, Nasr City, Cairo, Egypt
LEAD_AUTHOR
A.
AHMED
2
Chemistry Department, Faculty of science (for girls), AL- Azhar University, Nasr City, Cairo, Egypt
AUTHOR
E.
ATTIA
3
Chemistry Department, Faculty of science (for girls), AL- Azhar University, Nasr City, Cairo, Egypt
AUTHOR
A.
EL-SHENNAWY
4
Chemistry Department, Faculty of science (for girls), AL- Azhar University, Nasr City, Cairo, Egypt
AUTHOR
ORIGINAL_ARTICLE
A NEW APPROACH FOR GRAFT COPOLYMERIZATION OF JUTE
The graft copolymerization of glycidyl methacrylate (GMA) on jute fibers at ambient conditions is the desired goal. Graft copolymerization of (GMA) on jute fibers was carried out using Ammonium Persulphate Acetone Sodium Bisulphite (APS/ASBS) initiating redox system. The grafting reaction was studied with respect to graft yield (GY), grafting efficiency (GE) and total conversion (TC). Factors such as pH value, liquor ratio (L: R), redox initiator concentration, addition sequence, reaction time, temperature and GMA concentration [M], were investigated. The results obtained showed that the optimal grafting yield is obtained at the following conditions: initiator concentration of 20/40 mmole/l for APS/ASBS respectively, liquor ratio(I:20), pH value 3, time 120 min., temperature 20°C, and monomer concentration [M] 150% based on weight of substrate (OWS). Grafted and scoured jute fibers were characterized via thermal gravimetric analysis (TGA) and infra red spectroscopic analysis (IR).
https://absb.journals.ekb.eg/article_10882_2608e812c5c1396386f46ee0453f6c0b.pdf
2007-06-01
207
221
10.21608/absb.2007.10882
Ammonium Persulphate
Acetone Sodium Bisulphite
glycidyl
Methacrylate
graft copolymerization
Jute fibers
E.
El-ALFY
1
Textile Research Division, National Research Center, Dokki, Cairo, Egypt
AUTHOR
N.
ZAMZAM
2
Textile Research Division, National Research Center, Dokki, Cairo, Egypt
AUTHOR
M.
FIKRY
3
Textile Research Division, National Research Center, Dokki, Cairo, Egypt
AUTHOR
M.
YOUSEF
4
Faculty of Science, Helwan University
AUTHOR
A.
ABOU-OKEIL
5
Textile Research Division, National Research Center, Dokki, Cairo, Egypt
LEAD_AUTHOR
ORIGINAL_ARTICLE
ELECTROCHEMICAL AND DENSITOMETRIC DETERMINATION OF ZOLMITRIPTAN IN PHARMACEUTICAL DOSAGE FORMS
Two methods for the determination of antimigrain drug zolmitriptan in bulk powder and in pharmaceutical dosage forms by voltammetric and densitometric methods are developed. Voltammetric method depends on the oxidation of zolmitriptan on an activated carbon paste electrode. The compound is oxidized irreversibly at high positive potential. The response was evaluated with respect to pH; scan rate, nature of the buffer and other variables. The peak current at about 0.76V, with the maximum current at pH 5 ±0.2 acetate buffer. The mechanism of the reaction is controlled by oxidation of the N-H group in the indole ring. By differential pulse voltammetry, the calibration plot was linear in the range 3.99 x10-7 – 2.90 x10-6 M.
The second method is based on the application of thin layer chromatographic separation of the studied drug in the presence of its degradation product followed by the densitometric measurements of the spot areas of the drug. After separation on silica gel GF254 plates using methanol: ammonia 25% (100:1.5 v/v) as mobile phase, the chromatographic zones corresponding to the spots of zolmitriptan were scanned at 285nm. The calibration function was established in the range of 1.00- 9.00 µg/ spot. The suggested methods were used to determine the cited drug in bulk powder, and pharmaceutical dosage forms. Results were compared statistically with the reported method.
https://absb.journals.ekb.eg/article_11098_12e5d8aae3c0eb4cf2ad2f781fd26826.pdf
2007-06-01
223
236
10.21608/absb.2007.11098
Voltammetry
Densitometry
Zolmitriptan
A.
WASSEL
anwar_wasil@yahoo.com
1
National Organization for Drug Control and Research
LEAD_AUTHOR
L.
BEBAWY
2
National Organization for Drug Control and Research
AUTHOR
M.
EL.RIES
3
National Organization for Drug Control and Research
AUTHOR
ORIGINAL_ARTICLE
PRINTING OF DIRECT DYE ON SILK FABRIC WITH IMPROVED DYE FIXATION AND WET –FASTNESS
Application of direct dyes on silk fabric suffer from problems of poor fastness properties as well as decrease in dye fixation .A formaldehyde donor agent, i.e. Hexamine, (hexamethylene tetramine), was used for improving dye fixation and wet fastness when added to the printing paste during printing silk fabric with a direct dye containing free amino groups (Diamine Supra Blue GRL200% ).
https://absb.journals.ekb.eg/article_11099_a0db1a72284a621f185c8a9322cf2865.pdf
2007-06-01
1
7
10.21608/absb.2007.11099
Crosslinking agent
Hexamine
silk fabric
direct dyes
printing
wet fastness
levelness
WAGIH
ABDALLAH
1
Textile printing, Dyeing and Finishing Department, Faculty of Applied Arts, Helwan University, Cairo, Egypt.
LEAD_AUTHOR
ABEER
FATH ALLA
2
Textile printing, Dyeing and Finishing Department, Faculty of Applied Arts, Helwan University, Cairo, Egypt.
LEAD_AUTHOR
ORIGINAL_ARTICLE
INHIBITION EFFECT OF SOME POLYETHYLENE GLYCOLS (PEG) ON THE CORROSION OF ALUMINUM IN 1.0 M PHOSPHORIC ACID
The effect of some polyethylene glycols (PEG) as inhibitors on the corrosion of aluminum in 1.0 M H3PO4 has been studied using weight loss and polarization measurements in various concentrations of PEG and at different temperatures. The dissolution of aluminum in phosphoric acids increases by increasing temperatures and decreases by increasing the additive concentrations. The inhibition efficienciy values proceed according to the following order of the molecular weights of the used inhibitors PEG 4000 > PEG 2000 > PEG 1500 > PEG 400. For relatively higher molecular weights inhibitor (beginning from 1500) the type of adsorption taking place at the surface of aluminum was physical adsorption whereas for the molecular weight. = 400 had different behavior till 50oC and then the inhibition efficiency decreasing at 60oC indicating physical adsorptions. The lone pair of electrons of oxygen atom of hydroxyl groups play an important role in the adsorptions of additives on aluminum surface, which affected by polarization. The thermodynamic calculated values of activation and adsorption were calculated and discussed.
https://absb.journals.ekb.eg/article_11100_c43dc7958a95982f9a109327fdb42834.pdf
2007-06-01
9
19
10.21608/absb.2007.11100
POLYETHYLENE GLYCOLS
Corrosion
Aluminum
S.
SOLIMAN
1
Chemistry Department, Faculty of Science, Al-Azhar University, Cairo, Egypt
LEAD_AUTHOR
ORIGINAL_ARTICLE
STUDIES OF THE EFFECT OF VOLATILE COMPOUNDS IN ATMOSPHERE OF GREATER CAIRO AREA
Volatile organic compounds (VOCs) have been determined to be human risk factor in urban environments, as well as primary contributors to the formation of photochemical oxidants. Concentrations of VOCs were measured at five monitoring sites located in the greater Cairo area, Egypt, as a part of the air pollution study. On each sampling day, 22 abundant VOCs were collected three times per day (7-9 in the morning, 2-4 afternoon and 8-10 evening) during the period from March 2003 to March 2004, to observe diurnal variations of volatile organic compounds on the air of Greater Cairo area and air quality information system in Egypt. Most of the VOCs species showed diurnal variations with higher concentrations during the morning and evening, and lower concentrations during the afternoon. However, in the afternoon , the concentrations of aromatic compounds, closely correlated with solvent usage such as toluene, ethyl benzene, m-/p- xylene, and o-xylene, were slightly higher than or comparable to those in the morning. This may be due to the increase of evaporative emissions derived from the rise in ambient temperature and additional sources such as the use of solvents in petrol, painting, printing and dry cleaning.
https://absb.journals.ekb.eg/article_11101_332901866fd6e73a7e0b57d62774df02.pdf
2007-06-01
21
35
10.21608/absb.2007.11101
volatile compounds
CAIRO AREA
M.
EMARA
1
Chemistry Dept. Faculty of Science, Al-Azhar University, Cairo, Egypt.
LEAD_AUTHOR
S.
SOLIMAN
2
Chemistry Dept. Faculty of Science, Al-Azhar University, Cairo, Egypt
AUTHOR
A.
RAMADAN
3
Egyptian Atomic Energy Authority, Cairo, Egypt.
AUTHOR
H.
EL-KORDY
4
Badr El-Deen Petroleum Company, Cairo, Egypt
AUTHOR
ORIGINAL_ARTICLE
MINIMIZING THE CHLORINATION BY-PRODUCTS BY OPTIMIZING THE CHLORINE DOSE AND TEMPERATURE
Disinfectionof water by chlorine produces a number of halogenated disinfection by-products(DBPs). Trihalomethanes (THMs) and haloacetic acids (HAAs) are the domin0antspecies found in finished drinking water. Several toxicological studies shownsome disinfection by-products (DBPs), including certain (THMs) and (HAAs), tobe carcinogenic in laboratory animals. Due to all these potential problemsassociated with the formation of disinfection by-products (DBPs) during thefree chlorination of drinking water have been well documented and due to thehealth risks associated with them, the US Environmental Protection Agency(USEPA) began regulating the levels of these disinfection by-products (DBPs) infinished drinking water in 1979. Manyresearchers suggested different procedures in order to minimize theconcentrations of the formed DBPs. These procedures based upon the decreasingof the natural organic matter (NOM) in the raw water e.g. ultrafiltration(UF)–nanofiltration (NF) combined membrane process which showed better removalefficiency of NOM. Another studies suggested usage of another disinfectantse.g. ozone. This study aimed to minimizethe concentrations of the (DBPs) via the optimization of the added chlorinedose which complies with the microbiological requirements. Also the effect oftemperature on the formed DBPs was studied. The results showed that theconcentrations of the various (DBPs) are inversely proportional with thetemperature. Also this study suggested another procedure to calculate the mostsuitable chlorine dose.
https://absb.journals.ekb.eg/article_11102_484215a4f2adbea327c830918b39bded.pdf
2007-06-01
37
50
10.21608/absb.2007.11102
MINIMIZING
chlorination
CHLORINE DOSE
ORIGINAL_ARTICLE
MONITORING AND INVESTIGATION OF THE CONCENTRATION LEVELS OF THE REGULATED FIVE HALOACETIC ACIDS AND DALAPON IN THE DRINKING WATER AND DURING THE TREATMENT STAGES
https://absb.journals.ekb.eg/article_11103_f9de87412d30e4aa3349d177ef466636.pdf
2007-06-01
51
61
10.21608/absb.2007.11103
Monitoring
HALOACETIC ACIDS
DALAPON
ORIGINAL_ARTICLE
CHARACTERISTICS AND LEACHABILITY OF ZINC AND RARE EARTHS FROM ABU RUSHIED ORE MATERIAL, SOUTH EASTERN DESERT, EGYPT
A rare earth (REEs) and Zn ore martial belonging to a poly-metallic mineralization of Abu Rushied area, Southern Eastern Desert of Egypt is subjected to mineralogical analysis and acid leaching. The former proved that both Zn (assaying 5%) and REEs (assaying 3.1%) are found adsorbed upon the iron oxide mineral goethite (equivalent to 15 % Fe2O3). Acid leaching studies using sulphuric acid defined the optimum conditions for dissolving about 94% of Zn and 92.5% of REEs. Besides being a powerful oxidizing agent and can create chloric acid, NaClO3 was incorporated in the leaching process to decrease the required input sulphuric acid. In addition, NaClO3 adequate Na2SO4 that could be used in the early precipitation of the (light REEs)LREEs as their double sulphates.
https://absb.journals.ekb.eg/article_11104_5a657d3e1702667c4b9bd0de9561fe91.pdf
2007-06-19
63
74
10.21608/absb.2007.11104
LEACHABILITY
zinc
Rare Earths
ABU RUSHIED ORE MATERIAL
ORIGINAL_ARTICLE
PREPARATION CONDITIONS OF HUMIC ACIDS FROM VILLAGE'S COMPOST FUEL (VCF) AND THEIR EFFECTS ON HUMIC ACIDS CHEMICAL CHARACTERISTIC ALTERNATION DURING ISOLATION PART II. EFFECT OF THE EXTRACTION CONDITIONS ON THE FUNCTIONAL GROUPS CONTENTS OF HUMIC ACIDS AS REVEALED BY SPECTROSCOPIC ANALYSIS
IR spectra of humic acids ( HAs) extracted by NaOH solution under different conditions showed that HAs extracted by 0.1 M after 6h and 16 h have identical finger print regions. These spectra indicate the presence of highest number of functional groups and highest aromatic COOH group content, in comparison with ( HAs) extracted by 0.1M after 2h and 24 h. IR spectrum of humic acids HAs extracted by 0.2M after 2h was generally similar with the two latter spectra. The IR spectra of HAs extracted after 2h by 0.5M, 1M, and 2M not only show the disappearance of aromatic COOH bands but also indicate the hydrolysis of ester moieties and increase the OH groups content of the extracted HAs. The IR spectra of HAs extracted at the latter three concentrations showed attacked finger print regions. Uv-Vis spectra show two clearly observable peaks at 208 and 280 nm which are characteristic to these humic acids. The spectral change of the latter are in agreement with the results obtained by IR analysis According to results obtained, the extraction by 0.1M NaOH after 16h leads to production of HAs of highest condensation, highest functional group content.
https://absb.journals.ekb.eg/article_11105_438c59c131c4f61aab0ba4cf1cf593e8.pdf
2007-06-01
87
101
10.21608/absb.2007.11105
Humic acids
VCF
M.
BADR
1
Chemistry Department, Faculty of Science, Al-Azhar University (For Girls)
LEAD_AUTHOR
ORIGINAL_ARTICLE
SYNTHESIS OF SOME NEW BENZOFURAN DERIVATIVES OF EXPECTED BIOLOGICAL ACTIVITY
Treatment of 1-[6-hydroxy-4-methoxybenzofuran-5-yl]ethanone (1) with cinnamaldehyde gave 1-[6-hydroxy-4-methoxybenzofuran-5-yl]-5-phenylpenta-2,4-diene-1-one (2) which reacted with formaline and 4-chloroniline to give benzofuran derivative (3) according to Mannich reaction. Interaction of 2 with 20% of sulphuric acid, malononitrile, ethylcyano acetate, phenyl hydrazine and guanidine hydrochloride afforded the corresponding furo[3,2-g]chromon-5-one (4), pyridine, pyrazole and pyrimidine derivatives (5-8). Also, compound 8 reacted with phosphorus-oxychloride in dimethyl formamide and p-flurobenzylidenemalononitrile to give formyl and pyrimidopyrimidene derivatives (10, 12).
https://absb.journals.ekb.eg/article_11106_176870003d2e876a0c9418fc19ae09ea.pdf
2007-06-01
103
114
10.21608/absb.2007.11106
BENZOFURAN DERIVATIVES
Biological Activity
S.
HESSEIN
1
Chemistry Department, Faculty of Science (Girl’s), Al-Azhar University, Cairo, Egypt
LEAD_AUTHOR
ORIGINAL_ARTICLE
EFFECT OF FLY-ASH AND SILICA FUME ON THE PROPERTIES OF CONCRETE EXPOSED TO HIGH TEMPERATURE
The development of high concrete temperatures could cause a number of effects that have been shown to be determined to long-term concrete performance. High concrete temperatures increase the rate of hydration, thermal stresses, the tendency for drying shrinkage cracking, permeability, and decrease of long-term concrete strengths and durability as a result of cracking. The objective of this study is to investigate the effects of using fly ash and silica fume on the strength and absorption of cement concrete and pozzolanic cement concrete in hot condition. The cement concrete and pozzolanic cement concrete specimens containing fly-ash or silica fume were first cured in water for different periods 1, 3, 7, 28, 90 and 180 days then exposed to high temperature 45oC ( maximum summer temperature in Egypt and Arabian Gulf countries) in oven for 2,8,12 and 24 hours. The effect of fly-ash and silica fume contents on the absorption capacity of concrete specimens was evaluated by measuring 48-hours absorption and volume of permeable voids. The specimens were also tested for compressive strength and moisture content. The results show an increase in the compressive strength and decrease in moisture content of cement concrete and pozzolanic cement concrete specimens with increasing both curing exposing temperature time. The absorption of these concretes decreased with time of curing and increased with exposing temperature time .The absorption of both fly-ash and silica fume cement concrete specimens decreased significantly at early stages (3-7days) of curing. While the absorption of cement concrete specimens were effected significantly by exposing temperature period, no significant change in the absorption of pozzolanic cement concretes due to increasing exposing temperature period was observed, especially after 7 days of curing. The volume of permeable voids also decreased with curing. The highest reduction in the absorption and volume of voids was observed in the fly-ash concrete specimens.
https://absb.journals.ekb.eg/article_11107_69b6f6770ead39d740eef9b45eef4859.pdf
2007-06-01
115
132
10.21608/absb.2007.11107
Fly-ash
Silica Fume
Concrete
Blended cement
Pozzolans
ORIGINAL_ARTICLE
THE INHIBITION EFFECT OF SOME PYRIMIDINE DERIVATIVES ON CORROSION OF ALUMINUM AND SOME OF ITS ALLOYS IN 2.0 M HCl SOLUTIONS
In the present study the corrosion of aluminum and some of its alloys in 2M HCl was studied. The effect of some pyrimidine derivatives, as organic inhibitors, on the corrosion of aluminum and its alloys in HCl solution was studied. The techniques used of measurements were: (i) linear polarization (ii) galvanostatic polarization and (iii) electrochemical impedance spectroscopy. The corrosion rate of the investigated electrodes was found to be depended on the type and composition of the metal electrode. The pyrimidine derivatives acted as mixed inhibitors in acidic media.
It was found that the inhibition efficiency of the inhibitor greatly depended on the type, size, and concentration of the compound and on the electron density of the adsorption centers. The inhibitory effect of the investigated compounds resulted from their adsorption on the metallic surface via adsorption centers and /or electrostatic interaction between the organic compound and electrode. The adsorption of inhibitors on the metallic surface from 2.0 M HCl solutions obeyed the Temkin’s adsorption isotherm. Results obtained from linear polarization, galvanstatic polarization and impedance measurements are in a good agreement.
https://absb.journals.ekb.eg/article_11108_49124feaaa7d95112bd7676ee10b1d5c.pdf
2007-06-01
133
149
10.21608/absb.2007.11108
INHIBITION EFFECT
pyrimidine derivatives
Corrosion
Aluminum
S.
MAHMOUD
1
Chemistry Department, University College of Girls for Arts, Science and Education, Ain Shams University, Heliopolis, Cairo, Egypt
LEAD_AUTHOR
M.
AHMED
2
Chemistry Department, University College of Girls for Arts, Science and Education, Ain Shams University, Heliopolis, Cairo, Egypt
AUTHOR