Three optimum conditions for the tuning of NMR probes are compared: the conventional tuning optimum, which is based on radio-frequency pulse efficiency, the spin noise tuning optimum based on the line shape of the spin noise signal, and the newly introduced frequency shift tuning optimum, which minimizes the frequency pushing effect on strong signals. The latter results if the radiation damping...

Abs t r ac t -1 . The temperature dependence of myosin ATP-ase and intestinal alkaline phosphatase from a variety of lizards having distinct preferred temperatures was compared. 2. The ATP-ase was relatively thermolabile; reductions in activity at temperatures above the optimum resulted primarily from irreversible denaturation. However, pronounced differences were evident in both the optimal te...

rapeseed is one of the important oilseeds, as its oil ranks second in the world after soybean. the rapeseed cultivation has been increased recently in iran. drying of seeds to a safe moisture level is necessary for storage of oilseeds before processing. rapeseed drying conditions affect the seed quality, total oil and germination capacity. hence in this research the effects of different tempera...

Penicillin acylase formation by the hybrid strain Escherichia coli 5K(pHM12) was studied under different culture conditions and reached 200 to 250 mumol of 6-aminopenicillanic acid per min per g of bacteria (wet weight) for penicillin G. The Km of whole-cell acylase was determined with 9 to 11 mM for penicillin G at a pH optimum of 7.8 at 45 degrees C. A competitive product inhibition for pheny...

the nanocrystallization of co67fe4cr7si8b14 amorphous ribbons which prepared by planar flow melt spinning process (pfms) was investigated. crystallization of the ribbons was studied by differential thermal analysis (dta), x-ray diffraction (xrd) and transmission electron microscopy (tem). the dta result of amorphous ribbon at heating rate of 10˚c/min showedoccurrence of phase transitions in two...

The nanocrystallization of Co67Fe4Cr7Si8B14 amorphous ribbons which prepared by planar flow melt spinning process (PFMS) was investigated. Crystallization of the ribbons was studied by differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The DTA result of amorphous ribbon at heating rate of 10˚C/min showedoccurrence of phase transitions in two...

alkylation of biphenyl with 1-octene was investigated using ((al+c3h7cl)+c2h4) catalysts. the catalytic activity of ((al+c3h7cl)+c2h4) for the alkylation was studied at different temperatures, mol ratios of biphenyl to 1-octene, reaction times and catalyst concentrations. it was shown that using this catalyst has more advantagous than another catalysts. experiments show that by increasing tempe...

in this study, the influence of the salts as an additive on the performance of the membrane was investigated and an extensive work was performed to optimize pvdf hollow fiber membranes through a response surface methodology (rsm). the prepared membranes were characterized by sem, contact angle and lep measurement. then, the rsm was used for the optimization of surface pore size, porosity and hy...

Moderation of stream temperatures by riparian shading and groundwater are known to promote growth and survival of salmonid fishes, but effects of riparian shade and groundwater on to be growth of warmwater stream fishes are poorly understood or assumed to be negligible. We used stream temperature models to relate shading from riparian vegetation and groundwater inflow to summer water temperatur...