In this research, new compounds were synthesized via the reaction of dichloroacetic acid with two moles of piperidine. The novel acid 1 was converted to its ester 2. Acid hydrizide 3 was prepared by the reaction of hydrazine hydrate with new ester 2, which was later used to prepare derivatives of Schiff bases 4-13. In the last step, Schiff bases and thioglycolic acid were reacted to give thiazolidine derivatives 14-23. All these compounds were diagnosed using melting points, FTIR, 1HNMR and mass spectroscopy. Scheme 1 shows all the synthesized compounds' reaction steps and structures. Keywords: Thiazolidine; Schiff bases; biological activity; piperidine; dichloroacetic acid.

The purpose of this research is to prepare new vanillic acid derivatives with 1,2,4-triazole-3-thiol heterocyclic ring and evaluate their antimicrobial activity in a preliminary assessment. A multistep synthesis was established for the preparation of new vanillic acid-triazole conjugates. The intermediate of 4-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)-2-methoxyphenol (4) reacts with different heterocyclic aldehydes (thiophene-2-carboxaldehyde, pyrrole-2-carboxaldehyde, thiophene-3-carboxaldehyde, and furfural ) in ethanol containing few drops of acetic acid yielded the corresponding 4-(4-(substituted amino)-5-mercapto-4H-1,2,4-1triazol-3-yl)-2-methoxy phenol derivatives (5-8). These compounds were characterized spectroscopically by

New metal complexes of some transition metal ions Co(II), Cu(II) , Cd(II) and Zn(II) were prepared by their reaction with previously prepared ligands HLI= (P-methyl anilino) phenyl acetonitrile and HLII = (P-methyl anilino) –P– chloro phenyl acetonitrile . The two ligands were prepared by Strecker’s procedure which includ the reaction of p- toluidine with benzaldehyde and P- chlorobenzaldehyde respectively. Structures were proposed depending on atomic absorption , i.r. and u.v.visible spectra in addition to magnetic susceptibility and electrical conductivity measurements.

The purpose of this research is to prepare new vanillic acid derivatives with 1,2,4-triazole-3-thiol heterocyclic ring and evaluate their antimicrobial activity in a preliminary assessment. A multistep synthesis was established for the preparation of new vanillic acid-triazole conjugates. The intermediate of 4-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)-2-methoxyphenol (4) reacts with different heterocyclic aldehydes (thiophene-2-carboxaldehyde, pyrrole-2-carboxaldehyde, thiophene-3-carboxaldehyde, and furfural ) in ethanol containing few drops of acetic acid yielded the corresponding 4-(4-(substituted amino)-5-mercapto-4H-1,2,4-1triazol-3-yl)-2-methoxy phenol derivatives (

Thermal pyrolysis kinetics of virgin high-density polyethylene (HDPE) was investigated. Thermal pyrolysis of HDPE was performed using a thermogravimetric analyzer in nitrogen atmosphere under non-isothermal conditions at different heating rates 4, 7, 10 °C/min. First-order decomposition reaction was assumed, and for the kinetic analysis Kissinger-Akahira-Sunose(KAS), Flynn-Wall-Ozawa(FWO) and Coats and Redfern(CR) method were used. The obtained values of  average activation energy by the KAS and FWO methods were equal to137.43 and 141.52 kJ/mol respectively, these values were considered in good agreement, where the  average activation energy value obtained by CR equation methods was slightly different which equal to 153.16 kJ/

Changes in mechanical properties of material as a result of service in different conditions can be provided by mechanical testing to assist the estimation of current internal situation of these materials, or the degree of deterioration may exist in furnaces serviced at high temperature and exceed their design life. Because of the rarity works on austenitic stainless steel material type AISI 321H, in this work, ultimate tensile strength, yield strength, elongation, hardness, and absorbed energy by impact are evaluated based on experimental data obtained from mechanical testing. Samples of tubes are extracted from furnace belong to hydrotreaterunit, also samples from un-used tube material are used to make comparisons between these properti

Posible interference of vamin with the activity of several antibiotics against E. coli was evaluated in vitro. In MBS- glucose medium, significant growth delay was induced by 8 ug/ml of terramycin (oxytetracycline- polymyxin B) and bactrim (trimethoprim-sulphamethoxazole), and by 16 ug/ml of refocin, lincomycin, and chloramphenicol. Rapid growth inhibition was induced by 32 ug/ml of all an- tibiotic tested separately. Significant inactivation of up to 64 ug/ml of licomycin and bactrim was in- duced by the addition of vamin at a concentration of 1:20 v/v of the medium. This effect was found to be due to the presence of specific amino acids in vamin. Among them is valine, leucine, isoleucine tyrosine, tryptophan, phenylalanine, cysteine, meth

Silver nanoparticles synthesized by different species