This study was carried out to determine the efficiency of nitrogen (N) doses (0, 30, 60, and 90 kg N ha⁻¹) under supplemental potassium (K) application (50 kg K₂O ha⁻¹) on black cumin in 2011 and 2012. The results showed that increased N levels resulted in increasing seed yield and N and K contents in seed, while oil content decreased. The seed yield and oil yield were peaked at the doses of 60 kg N ha⁻¹and 50 kg K ha⁻¹. An increase in N doses caused a reduction in oil content regardless of K supply. Saturated fatty acids and oleic acid were slightly increased by K application, while minor changes in linoleic acid were detected. It was concluded that 60 kg N ha⁻¹with supplemental K application should be advised for enhancement in seed yield, oil yield, and N and K contents in seeds of black cumin without significant changes in fatty acid composition.

In this study, the esterification reaction of acetic acid with n-propyl alcohol was studied on a sulfated zeolite catalyst to improve the bio-oil obtained by pyrolysis of lignocellulosic biomass. Temperature (323-353 K), sulfuric acid concentration (1-3 M) and time (1-4 hours) were selected as parameters in the preparation of sulfuric acid-modified clinoptilolite samples. Sulfated zeolites samples are characterized by XRF, XRD, and N(2)adsorption/desorption techniques. It was observed that the zeolites treated with sulfuric acid retained their crystal structures, decreased surface areas, and changed SiO2/Al(2)O(3)ratios. Samples modified with sulfuric acid are more effective in the esterification reaction than unmodified zeolite. The increase in sulfuric acid concentration and temperature in the modification process increased the conversion of acetic acid in the esterification reaction. The highest acetic acid conversion (63.8%) was obtained with zeolite treated at 323 K temperature, 3 M sulfuric acid for 1 hour.

In this study, which incorporates many principles of green chemistry (use of renewable feedstocks, catalysis, improvement of energy efficiency, and harmless solvents and auxiliaries), the single-phase catalytic conversion of cellulose to 5-HMF in over silica-alumina catalysts was investigated. A series of dual-template silica-alumina catalysts with CTAB as the main template and F127 or triethylamine (TEA) as the co-template were synthesized at a low temperature of 60 °C and characterized by XRD, N2 adsorption-desorption technique, FT-IR and pyridine adsorption FT-IR. The surface area is increased by using the second template in silica-alumina catalyst. In addition, the acidity of the surface was changed by using the second template. The cellulose conversion and yield of 5-HMF increased from 36% to 52% and from 3.13% to 4.24%, respectively, due to the properties gained by using the second template. 52% cellulose conversion and 8.13% selectivity of 5-HMF were obtained in aqueous medium, 220 °C and 6 h reaction time with the catalyst using TEA as co-template. Eco-friendly silica catalysts synthesized at low temperatures with a dual template can be considered as a potential alternative for the conversion of cellulose into value-added biobased products.