Acidophilic iron-oxidizing bacteria were enriched from mine water samples with ferrous sulfate as the substrate at incubation temperatures in the range of 4 to 46 degrees C. After several subcultures at each test temperature except 46 degrees C, which was prohibitive to growth, the rates of iron oxidation were determined in batch cultures. The results yielded linear rates in a semilogarithmic s...

Textural difEerences between Cheddar and Cheshire cheeses were examined rheologically to provide a means of distinguishing these two English cheeses. Body breakdown of a 6@wk Cheshire sample occurred at a lower strain than did a 20-wk sample, whereas a 60-wk Cheddar sample did not break down under the same conditions. All cheeses followed the Arrhenius equation, and the energy of activation obt...

Measurements of the quasistatic and frequency dependent electrical conductivity below 1 MHz were carried out on wet-spun, macroscopically oriented, calf thymus deoxyribonucleic (DNA) and umbilical cord hyaluronic acid (HA) bulk samples. The frequency dependence of the electrical conductivity in the frequency range of approximately 10(-3) - 10(6) Hz of both materials is surprisingly rather simil...

The reconstitution of active holoenzyme containing calcium from inactive calcium-free methanol dehydrogenase, isolated from a moxA mutant of Methylobacterium extorquens, has a pH optimum of about pH 10, with a well defined pK for the process at pH 9.3. Two Ca2+ ions were irreversibly incorporated per alpha 2 beta 2 tetramer. Calcium could be replaced in the incorporation process by strontium or...

Mitochondria were isolated from fruit of six cultivars of apples differing in susceptibility to the physiological disorder, low temperature breakdown. The state 3 rate of succinate-dependent oxygen uptake and the motion of a spin label were measured at from 0 to 25 C. Arrhenius plots of the data showed that the apparent energy of activation of both respiration and motion of the spin label incre...

Potassium monopersulfate has been decomposed in aqueous solution in the presence of Co(II). The effect of the main operating variables has been assessed. Minimum variations in pH exert a considerable influence on the process kinetics. Thus, when no pH adjustment is considered, the actual effect of variables like initial monopersulfate and/or catalyst concentration may be hindered. As expected, ...

The degradation behavior of cefquinome sulphate in alkaline medium at different temperatures was investigated using both first derivative spectrophotometric and HPLC methods. The drug degradation was found to be pH and temperature dependant. The pH-rate profile indicated a first order dependence of Kobs on [OH(-)] at pHs ranging between 9 and 11. Arrhenius plot obtained at pH 10 was linear betw...

The internal rotations around the some within a ylide involving theophylline has been studied using the dynamic 1H NMR spectroscopic technique in different temperatures. The kinetic and activation quantities were calculated. Arrhenius, Eyring and classic methods were applied for isomers. compared for carbon-carbon double, carbon-carbon single bond for Z isomer. The results obtained by classic m...

The rate constant k1 for Cl + H2S has been measured over 290-914 K using the laser flash photolysis/resonance fluorescence technique. Atomic chlorine was generated by pulsed 193 nm photolysis of CCl4 and C6H5Cl and monitored by time-resolved resonance fluorescence at 130-140 nm. The data are summarized as k1 = (2.90 ± 0.10) × 10-11 exp(2.38 ± 0.11 kJ mol-1/RT) cm3 molecule-1 s-1 where the uncer...

The transport of ion-implanted F in amorphous Si is studied using secondary ion mass spectroscopy and transmission electron microscopy. Significant redistribution of F is observed at temperatures in the range 600–700 °C. The measured F depth profiles are modeled using a simple Gaussian solution to the diffusion equation, and the diffusion coefficient is deduced at each temperature. An activatio...