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The primary objective of the present study is to compare the result of adding a microwave-heating pre-step (MW) to the conventional electrical heating method (CE) to synthesize chromium benzenedicarboxylate, MIL-101(Cr), for CO2 adsorption applications. The results show that using conventional CE the time required to complete the synthesis reaction is 24 h while adding a short-period MW to CE as a pre-step can reduce this time to 5 h. The MW pre-step can be carried out under either autogenous pressure or atmospheric condition. The results also revealed that both methods are capable of producing MIL-101(Cr); however, CE method can produce the adsorbent with the CO2 adsorption capacity 7.7 mmol/g at 5.0 bar and 25˚C, while the adsorbent synthesized using hybrid method can possess the adsorption capacity 6.1 mmol/g at the same condition. [ABSTRACT FROM AUTHOR]

This research was carried out to compare several attributes pertaining to the growth, fruit and yield of four apple cultivars, i.e. 'Golab-kohans', 'Fuji', 'Starking' and 'Delbar estival'. These cultivars were grafted onto M.9 rootstocks trained into 'Guttingen V-slender-spindle (or V-system) and 'Geneva Y-trellis (or Y-system) systems. Compared to the Y-system, it was observed that the V-system caused the trees to yield more fruits, dry matter, ash and total soluble solids (TSS). In contrast, the Y-system caused the trees to have broader trunk cross sectional areas (TCSA), along with higher yield, fruit weight, fruit diameter, fruit length and fruit firmness, compared to trees trained with the V-system. In summary, these results showed that both systems can be employed as promising approaches, but the 'Y-system' appears to be more productive than the 'V-system'. In addition, among the studied cultivars, it seems that the 'Delbar estival' and 'Fuji' were more adaptive to these intensive training systems, especially when considering the fruit traits. [ABSTRACT FROM AUTHOR]

Increasing the walnut shelf life with non-synthetic materials is considered. The effect of edible coating and different packaging methods on physicochemical properties of Persian walnut kernel during 120 days of storage at 25 °C temperature was evaluated. The treatments were: C (control sample, uncoated), K (coated with 1 % chitosan) and K500 and K1000, coated with chitosan 1 % containing 500 and 1000 μL L-1 of thyme essential oil, respectively, and MP (Mass packaging), PP (packaging in Polypropylene bags) and AP (Active packaging using sachets made by ascorbic acid, sodium bicarbonate and iron oxide). The color properties and oxidation of walnuts have relationship together. The results showed that the amount of a* and b* values were in the following order: K1000> K500> K> C. At the end of storage L* value of all samples decreased. Coated samples had less peroxide value and free fatty acid than control. Amount of free fatty acid in the coated samples with mass packaging was less than 0.5 %. The moisture content of coated samples was more than control samples, active packaging and PP packaging had minimum moisture fluctuations respectively, and control sample had less amount of moisture. [ABSTRACT FROM AUTHOR]

Methyl tertiary butyl ether (MTBE) belongs to the group of gasoline oxygenates and persistent environment contaminants, and shows potential for biodegradation in aerobic and anaerobic conditions, through application of pure microbial cultures. Presented research shows that indigenous bacterial isolates 6sy and 24p, selected from oil hydrocarbons-contaminated environments, were capable of utilizing MTBE as sole carbon and energy source. Based on 16S rDNA sequence analysis, bacterial isolates 6sy and 24p were identified as Staphylococcus saprophyticus subsp. saprophyticus and Pseudomonas sp., respectively. The MTBE biodegradation rate was affected by longevity of incubation period and initial MTBE concentration. After 3 weeks of incubation at 25°C in a dark, the removal rates of initial 25 and 125 ppm MTBE concentrations by Staphylococcus saprophyticus 6sy were found to be 97, and 63%, respectively, while efficiency of Pseudomonas sp. in degradation of indicated concentrations was 96, and 40%, respectively. Both bacterial isolates were able to grow in MTBE-containing growth medium. Highest growth rate of bacterial isolates was observed at the end of incubation period. The presented results indicated the potential of these bacterial isolates in bioremediation of MTBE-contaminated environments. [ABSTRACT FROM AUTHOR]

Methyl tertiary butyl ether (MTBE) belongs to the group of gasoline oxygenates and persistent environment contaminants, and shows potential for biodegradation in aerobic and anaerobic conditions, through application of pure microbial cultures. Presented research shows that indigenous bacterial isolates 6sy and 24p, selected from oil hydrocarbons-contaminated environments, were capable of utilizing MTBE as sole carbon and energy source. Based on 16S rDNA sequence analysis, bacterial isolates 6sy and 24p were identified as Staphylococcus saprophyticus subsp. saprophyticus and Pseudomonas sp., respectively. The MTBE biodegradation rate was affected by longevity of incubation period and initial MTBE concentration. After 3 weeks of incubation at 25°C in a dark, the removal rates of initial 25 and 125 ppm MTBE concentrations by Staphylococcus saprophyticus 6sy were found to be 97, and 63%, respectively, while efficiency of Pseudomonas sp. in degradation of indicated concentrations was 96, and 40%, respectively. Both bacterial isolates were able to grow in MTBE-containing growth medium. Highest growth rate of bacterial isolates was observed at the end of incubation period. The presented results indicated the potential of these bacterial isolates in bioremediation of MTBE-contaminated environments. [ABSTRACT FROM AUTHOR]

Oil pollution is one of the important environmental problems in the world. In order to degrade floating crude oil in the wastewater, two soil samples were taken from the oil-contaminated soils in Ahwaz (Iran) and an oil refinery complex in Tehran (Iran). Fourteen strains of bacteria isolated from these samples. Among these bacteria a strain marked as A-14 could treat 91% of total petroleum hydrocarbons and 83% of aromatic compounds in the floating crude oil after 10 d. Also the optimum time to reach the maximum removal percent (90%) was found to be 7 d. A-14 was identified to be Pseudomonas aeruginosa. All isolated bacteria in this study were able to produce biosurfactant. A-12 resulted in the best emulsification index that was about 36%. However, this strain could remove only 46% and 37% of the total petroleum hydrocarbons and aromatic compound, respectively. Most of the isolated microorganisms in this study had higher efficiency for the degradation of total petroleum hydrocarbons (TPH) than aromatic compounds. In most of the previous studies, only dissolved or tiny droplet of crude oil were degraded but the pure culture of P. aeruginosa that we isolated them from the oil contaminated soils could degrade floating crude oil with high removal efficiency (90%). [ABSTRACT FROM AUTHOR]

Two strains of Pseudomonas aeruginosa were isolated from crude oil of Isfahan oil refinery and used in a lab scale fermenter for removal of floating crude oil pollution from water. Maximum stable removal efficiency of 92% was reached despite the stepwise increase in the culture medium crude oil concentration from 0.1 g/l to 0.3 g/l and maximum biodegradation rate of 98.6 mg/l h was obtained. During 91 d mixed liquid suspended solid (MLSS) changed between 4000 and 8000 mg/l and sludge volume index (SVI) changed between 20 and 90 mg/l. The performance was investigated during a 91 d continuous operation of a fermenter which was intermittently fed with oil-polluted water. It seems biodegradation of this mixed culture is high removal efficiency (92%) in low time (7.5 d). [ABSTRACT FROM AUTHOR]

In this study, a comprehensive mathematical model was developed to investigate the simplifying assumptions in modeling of natural gas dehydration by the adsorption process. In the developed model the variations of pressure, velocity, and temperature along the bed and the temperature changes inside the particles were considered. Convective heat and mass transfer were considered outside the particles and a diffusion mechanism was taken into account for the heat and mass transfer inside the particles. A dual site Langmuir model was selected to predict adsorption equilibrium and the Peng−Robinson equation of state was used to calculate the gas compressibility factor. The experimental data of Mohamadinejad et al. [Mohamadinejad, H.; et al. Sep. Sci. Technol.2000, 35, 1] was used to verify the model. Good agreement was observed between the predictions of the comprehensive model and the experimental data. The results showed that applying the assumptions of uniform temperature distribution inside the pellet (lump method), thermal equilibrium between gas and particles, and isothermal and isobaric conditions had no significant effects on the predictions. It was also concluded that external mass transfer resistance was negligible at the industrial operating conditions of gas dehydration processes and common linear driving force models (LDFs) were not able to predict the performance of the dehydration bed well. Also, a new accurate correlation was introduced for an LDF proportionality coefficient applicable in gas dehydration systems. The predictions based on the proposed correlation were in good agreement with the results of the comprehensive model. Using this new accurate LDF model instead of diffusion model saves a large amount of CPU time without a loss of accuracy. [ABSTRACT FROM AUTHOR]

Presents a model, which predicts pressure drop in an orifice scrubber based on a Lagrangian approach. Calculation of droplet concentration distribution; Effects of orifice size on pressure drop; Comparison between the calculated results and the experimental data.