Integrated gasification combined cycle using Egyptian Maghara coal-rice straw feedstock.

Rice straw is an agricultural waste that causes an annoying problem in Egypt if it is not well exploited. This study focuses on using this waste in power generation by co-gasification of Egyptian Maghara coal and rice straw blends using entrained flow gasifier technology. Aspen Plus was used to conduct a parametric study for investigation of the effect of changing the inputs to the gasifier on the produced gas composition. Three different input parameters, influencing the performance of the gasifier, including the percentage of coal to rice straw in the blend, the fraction of added water to the blend, and the mass percentage of oxygen with respect to the mass of the blend fed to the gasifier were analysed. Two alternative power production schemes (with and without carbon capturing) have been investigated. The obtained optimum feed conditions are: 40% coal in the feed blend, 20% water concentration in the feed slurry, and 80% oxygen with respect to the dry feed blend to the gasifier. For (10 0000 kg per hour) of the feed blend, the power generated was 270.1 MW in the case of non-carbon capturing, while in the case of carbon capturing, 263.52 MW was generated. Although it produces less power, applying carbon capturing techniques means handling less flue gas and thus using smaller gas turbines and results in more environmentally friendly emissions.

Synthesis and antimicrobial activity of novel pyrazole, pyrazoline, pyrazolinone and pyrazolidinedione derivatives of benzimidazole.

Four novel series of pyrazolylbenzimidazole derivatives have been prepared, namely 2-[(1-substituted phenyl-3,5-dimethyl-4-pyrazolyl)methyl]benzimidazole 5a-d 2-[(1-substituted phenyl-3-methyl-5-oxo-4,5-dihydro-4-pyrazolyl-4-yl)methyl]benzimidazoles 6a-d; 2-[(1-substituted phenyl-3,5-dioxopyrazolidin-4-yl)methyl]benzimidazoles 7a-d and 2-[(4-(1-phenyl-5-aryl-4,5-dihydro-3-pyrazolyl)phenylaminoacetyl]thio- methyl)-benzimidazoles 12a-e. The antimicrobial testing of the prepared compounds was performed using Escherichia Coli (NCTC 5933) as Gram-negative bacteria, Staphylococcus aureus (NCTC 4163) as gram-positive bacteria and Candida albicans (NCTC 5310) as yeast like fungi. The most potent compound was the pyrazolone 6a which exhibits interesting antibacterial activity against the gram-negative bacteria E. coli.

Reactions with pyrrolidine-2,4-diones, Part 4: Synthesis of some 3-substituted 1,5-diphenylpyrrolidine-2,4-diones as potential antimicrobial, anti-HIV-1 and antineoplastic agents.

The condensation of 1,5-diphenylpyrrolidine-2,4-dione (1) with ethyl orthoformate yielded 3-ethoxymethylene-1,5-diphenylpyrrolidine-2,4-dione (2). Reaction of the latter with hydrazine hydrate, secondary amines 7a-c or urea afforded the corresponding 3-substituted aminomethylene-1,5-diphenylpyrrolidene-2,4-diones 3, 8a-c or 9. On the other hand, condensation of 3 with veratraldehyde (5a) yielded 3-[(3,4-dimethoxybenzylidene)hydrazinomethylene]-1,5-diphenylpyrrolidine- 2,4-dione (6). Whereas, cyclization of 9 with the reactive malonate ester 11 produced 3-[(5-butyl-4-hydroxy-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-1-yl) methylene]-1,5-diphenylpyrrolidine-2,4-dione (12). The condensation of some selected aromatic aldehydes 5a-c and addition of morpholine (7c) or piperidine (7d) to some of the resulting 3-arylidene-1,5-diphenylpyrrolidine-2,4-diones 13b, c gave the respective 3-substituted methyl-4-hydroxy-1,5-diphenyl-delta 3-pyrrolin-2-ones 14a-c. Selected members of the new series were screened for their in vitro antimicrobial, anti-HIV-1 and antineoplastic activities. Two compounds 14a, b showed pronounced inhibitory activities against Gram-positive bacteria; whereas, in the in vitro anti-HIV-1 screening, only one compound 13c displayed a moderate activity. However, in the antineoplastic screening protocol, the tested compounds were devoid of activity.

Synthesis and antimicrobial testing of 4H-1,2,4-triazole, 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole and 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine derivatives of 1H-benzimidazole.

Three novel series of benzimidazole derivatives namely 6-substituted 3-[1-(2-alkyl-1 H-benzimidazolyl)methyl]-1,2,4-triazolo[3,4-b][1,3,4] thiadiazoles 5a-h, 6-substituted 3-[1-(2-alkyl-1H-benzimidazolyl)methyl]-7H-1,2,4 -triazolo[3,4-b]-[1,3,4]thiadiazines 6a-j and 6-thioxo-3-[1-(2-alkyl-1H-benzimidazolyl)methyl]-5,6-dihydro-1,2,4 -triazolo[3,4-b][1,3,4]-thiadiazoles 7a, b have been prepared by cyclization of the key intermediate 1-[(4-amino-5-mercapto-4 H-1,2,4-triazol-3-yl)methyl]-2-alkyl-1 H-benzimidazoles 3a, b. Furthermore, 1-[(4-arylideneamino-5-mercapto- 4H-1,2,4-triazol-3-yl)-methyl]-2-alkyl- 1 H-benzimidazoles 4a-h have been prepared and some of them were cyclized to 6-substituted 3-[1-(2-alkyl-1H-benzimidazolyl)methyl]-1,2,4-triazolo [3,4-b][1,3,4]thiadiazoles 5d, h using thionyl chloride. The prepared compounds were tested for antimicrobial activity in vitro; they showed moderate activity.

Synthesis and antimicrobial testing of novel oxadiazolylbenzimidazole derivatives.

Three novel series of oxadiazolylbenzimidazole derivatives have been prepared, namely 1-[(2-alkylthio or aralkylthio-1,3,4-oxadiazol-5-yl)methyl]-2-alkyl-1 H-benzimidazoles 3a-f; 1-[(3-substituted aminomethyl-2-thioxo-2,3-dihydro-1,3,4-oxadiazol-5-yl)methyl ]-2-alkyl-1 H-benzimidazoles 4a-f and 1-[(2-substituted amino-1,3,4-oxidiazol-5-yl)methyl]-2-alkyl-1 H-benzimidazoles 6a-j. The antimicrobial testing of the prepared compounds was performed, some of them showed week activity.

Synthesis of 1,3,4-thiadiazoles, imidazo[2,1-b]1,3,4-thiadiazoles and thiadiazolo[3,2-a]pyrimidines derived from benzimidazole as potential antimicrobial agents.

Several new 1,3,4-thiadiazole, imidazo[2,1-b]1,3,4-thiadiazole and thiadiazole[3,2-al]pyrimidine derivatives of benzimidazole were synthesized. The compounds were obtained from 1-ethyl or benzyl 2-(2-amino-1,3,4-thiadiazol-5-yl)thiomethylbenzimidazole. The antimicrobial activity of the prepared compounds was studied.

Synthesis of certain thiosemicarbazide and triazole derivatives as potential antimicrobial agents.

Two novel series of thiosemicarbazide derivatives were synthesized: 2-[4-(substituted thiocarbamoylhydrazinocarbonyl) phenoxymethyl]-1H-benzimidazoles and 1-benzyl-2-[4-(substituted thiocarbamoylhydrazinocarbonyl) phenoxymethyl]-1H-benzimidazoles, and cyclised to 2-[4-(4-substituted-4H-1,2,4-triazole-5-thion-3-yl)phenoxymethy ]-1H-benzimidazoles and 1-benzyl-2-[4-(4-substituted-4H-1,2,4-triazole-5- 5-thion-3-yl)phenoxymethyl]-1H-benzimidazoles, respectively. The antimicrobial activity of the prepared compounds was tested.

Synthesis of alkyloxybenzamide derivatives as potential antimicrobial agents.

Three series of alkyloxybenzamido derivatives have been prepared. The first comprises N1-[4-(4-alkyloxybenzamido)benzoyl]-N2-substituted alkylidene hydrazine, the second involves 1-[4-(4-alkyloxybenzamido)benzoyl]-4-alkyl, aryl, or aralkyl-3-thiosemicarbazides, and the third includes 1-substituted-5-[4-(4-alkyloxybenzamido)phenyl]-1,3,4-triazole-2-t hione. Representative samples of the prepared compounds were tested for their in-vitro antimicrobial activity.

Synthesis of some alkoxybenzamide derivatives as smooth muscle relaxant agents.

The preparation of 16 new N-substituted p-aminobenzamide derivatives which contain diethylaminoethyl-N-methylpiperazine, piperidine and morpholine moieties were described. Preliminary pharmacological testing of representative compounds showed that some of the prepared compounds possess anticholinergic and antihistaminic activities.

The determination of mixtures of some artificial sweeteners.

A scheme is suggested for the analysis of mixtures of saccharin sodium, sodium cyclamate and sorbitol. It depends upon: --Determination of saccharin sodium by precipitation of silver saccharinate. --Determination of sodium cyclamate by spectrophotometric titration with sodium nitrite. --Complexometric determination of sorbitol via its copper complex.

Synthesis and pharmacological testing on some theophylline esters.

Esters of theophylline-7-acetic acid with different amino alcohols were prepared as possible atropine substitutes, together with esters of some hydroxy acids with beta-hydroxyethyl theophylline. Moreover, esters possessing both theophyllinyl and piperazinyl moieties were prepared with the hope that their spasmolytic activity might be increased. Some of the prepared compounds proved to possess atropine-like activity.