Iranian Journal of Chemistry and Chemical Engineering
Volume:17 Issue: 2, Nov-Dec 1998

This article introduces a new tri-parameter law of correspondingstates from the known regularities,namely the LIR and the Zeno line for densefluids (when T<0.5Tz =Tc). Two of these parameters are the Zeno line Para-meters and the third parameter (the fluid parameter), has been obtained fromthe LIR, this parameter is solely dependent upon the fluid characteristics. Thethird parameter can be obtaind from p-v-T data of at least two different iso-therms of the fluid. These three parameters enable us to calculate quantities suchas the density of the fluid, within a reasonable accuracy (the maximum error isless than 5%). Comparing the calculated results with the experimental valuesshows that this law can at least be applied to spherical, polar and hydrocarbonfluids.

Polycyclic aromatic hydrocarbons (PAHS) have been determined in theatmosphere of Isfahan, Iran. Airborne particulate matter was sampled using a high-volume air sampler at roof-top level (~6m). Extraction of PAHS from airborneparticulate matter has been performed using SFE system and the relationship bet-ween the extraction temperature and the recovery of PAHS from airborne particu-lates is investigated. Determination of 16 PAHS has been carried out by GC-MStechnique. Variation in concentration of PAHS has been compared to those fororganic carbon and total suspended particles (TSP). A good agreement was foundbetween the variation in concentration of PAHS and that for organic carbon, butweak correlation (p=0.06, r 2=0.42) was found to exist between the PAHS and TSP.

Abstract: Detritylation of 5إ-dimethoxytrityl nucleosides have been quantita-tively achieved in minutes at room temperature under aprotic neutral conditionsby using stannous chloride. Of additional practical consideration and in contrastto protic acids, no depurination was observed with this reagent.

195Pt and 1H NMR has been used to show that addition of chlorineand bromine to [Pt(CN)4]2- in presence of perchloric acid in water results incyanide and water scrambling with formation of eleven complexes of the type[Pt(CN)4-nCl(H2O)n+1](n-1)+ (n= 0, 1, 2, 3, 4). Addition of NBu4OH to thissolution gives (NBu4)2[Pt(CN)4Cl(OH)]. NMR measurements in acetone alsoshow cyanide and hydroxyl group scrambling with formation of complexes of thetype [Pt(CN)4-nCl(OH)n+1]2-, (n= 0, 1, 2, 3, 4).

The beta-diketone derivatives of nitroimidazole were synthesizedfrom the reaction of magnesium salt of beta-ketoacids 3 with imidazolide 4. Thereaction of beta-diketones with hydroxylamine hydrochloride afforded either theisoxazoles or the 5-hydroxy-2-isoxazolines.

Commercial detergents, in spite of their various names and marks,are used to remove foreign matter (dirt) from substrate. Following removal of dirtfrom the surface, it is necessary to prevent redeposition, so the detergent musthave suspending power. In this experimental work, a simple method has been developed to evaluatethe cleaning power of commercial detergents. The method, showing the change ofsurface tension of detergent solution versus concentration, makes possible thedynamic study of the cleaning power of different commercial detergents withoutconcerning their formulation. It has been found that the method differentiatesbetween various detergents. The examined detergents were: Arial, Barf, Bianco,Darya, Paak, Persil, Sepid, Shoma, Vash and Yes.

In this study fungi isolated from the effluent of ethanol factorieswere identified. Optimal conditions for single cell protein (SCP) production andCOD reduction of sugar beet stillage are specified for a species of Hansenula in acontinuous culture. Under these conditions 5.7 g dm-3 biomass was producedand 31% of COD was reduced without addition of further nutrients to the beetmolasses stillage. Adding nitrogen and phosphorus sources, increased the biomassproduction and COD reduction to 8.5 g dm-3 and 35.7%, respectively. The crudeprotein content of SCP in the absence and presence of additives was 39.6% andto 50.6% respectively. The amounts of essential amino acids measured weregreater than that of the FAO standards reference and are comparable with someother food proteins, such as soya bean and fish meal.

A mixing rule for the mixtures of hard-spheres is presented whichcan be reduced to the standard van der Waals mixing rule at low densities. Theeffectiveness of the mixing rule for the size and energy parameters of Lennard-Jones fluids are examined by combining them with an equation of state to calcu-late thermodynamic properties. The results of calculation are compared with themolecular dynamic simulation data and the superiority of the present mixing ruleover the standard van der Waals mixing rule is demonstrated.

A second virial coefficient correlation suitable for two differenttemperatures ranges, (T*) -2ہ180 and (T*) -2>180, where T* is RT/DHvap ispresented. The equation of state can be calculated for different, complicated non-polar, and slightly polar liquid mixtures at any temperature over the range fromTtp to Tc and up to high pressures. The latent heat of vaporization and density atthe triple point are the only two parameters that are needed in these calculations. The results indicate that the liquid densities of liquid mixtures with quite differentacentric factors can be predicted to within about 5%.