a simple and rapid method has been developed for the determination of ascorbic acid in fruit and pharmaceutical products. the method is based on the measurement of the reaction rate between ammonium molybdate and ascorbic acid in acidic media. the reaction was monitored spectrophotometrically at 800 nm by fixed-time and variable-time methods. the calibration graph was linear in the range of 5 0...

Single step pretreatment-saccharification of corn stover was investigated in aqueous p-toluenesulfonic and sulfuric acid media. Dilute aqueous solution of p-toluenesulfonic acid was a better catalyst than aqueous sulfuric acid of the same H(+) ion concentration for single step pretreatment-saccharification of corn stover at moderate temperatures and pressures. For example, 100mg corn stover hea...

in this work, we investigated the stability of molybdate-phosphonic acid (mpa) complex by density functionaltheory (dft) computations in six solvents with the dielectric constant ranging from 1.92 to 10.36. the methodsare used for calculations are b3lyp and b3pw9 i that have been studied in two series of basis sets: d95nand6-31+g (d,p) for hydrogen and oxygen atoms; lanl2dz for mo and phosphoru...

in the present study, sulfuric acid was used for artemia cysts decapsulation. cysts of artemia franciscana were hatched out in regular manner or following hypochlorite or acid decapsulation. two acid concentrations (1 and 5%), three acid immersion times (10, 30 and 50 min) were used and hatching rates were recorded after 15, 18 and 24 h incubation. hatching rates increased but hatching time dec...

original paper   the mass-transfer media plays a significant role on the performance of a packed tower. in this paper three counter-current single-stage packed towers at laboratory scale, randomly packed with two different sizes of two types of packing material were experimentally tested to study the role of the packing on the performance of them in the removal of sulfuric acid mists. gas sampl...

The aim of this study was to evaluate the effects of adding sulfuric acid to sugarcane topssilage on rumen bacteria and whole rumen microorganisms (WRM) and compare the digestibility of sugarcane tops treated with different amount of urea, molasses and sulfuric acid between Holstein cow and Khouzestan buffalo. Regardless of the type of the treatment, potential of gas production (B) by cow WRM (...

in order to find the most effective method to overcome seed dormancy in teucrium chamaedrys  l. medicinal plant species the effect of some chemical and physical breaking methods including: cold stratification (5 °c), scarification with sandpaper, stratification with needle, concentrated sulfuric acid, gibberellic acid and combination of these methods were investigated. treated seeds along with ...

Ferric Species Standard ferric sulfate solutions were prepared by dissolving spectrographically pure iron rod (Johnson Matthey) in sulfuric acid and oxidizing with hydrogen peroxide. The decadic molar extinction coefficient of ferric ion in 0.8 N sulfuric acid at 24.9?C was found to be 2199 ? 4 liters mole-' cm-l at 304 m,/. The effect of a decrease of acidity and of added ferrous and cupric su...