Period of acceleration

Pull-up torque For an alternating current motor, this is the minimum external torque developed hy the motor during the period of acceleration from rest to the speed at which breakdown torque occurs. For motors that do not have a definite breakdown torque, the pull-up torque is the minimum torque developed up to the rated speed. 

Assuming Stokes law is valid, the distance travelled including the period of acceleration... 

Postmenopausal osteoporosis represents a period of accelerated loss of bone mass. The lower the preexisting bone mass, the earlier the clinical signs become manifest. 

A period of induction is characteristic of chemical reactions which take place in a series of intermediate stages. This is a necessary consequence of the law of mass action. The duration of the period depends on the relative magnitude of the velocity constants of the intermediate reactions. For example, with the reaction A=M=B, the rate of formation of the intermediate compound, M in the A=M reaction, will be quickest at the start, and the rate of formation of B by the destruction of M in the M=B reaction will be slowest at first, and increase with time as the amount of M accumulates in the system. At first, during the period of acceleration, the speed of the A=M reaction exerts a preponderating influence and M accumulates in the system but the increasing speed of the M=B reaction gradually neutralizes the effect of the first reaction, until the rate of formation of M by the A=M reaction is equal to the rate of its destruction by the M=B reaction, and finally, the M is consumed faster than it is formed. The amount of M in the system at any moment thus determines the rate of formation of B, so that the curves showing (i) the rate of formation of B, and (ii) the amount of M in the system at different moments, are similar in shape. This is illustrated by the dotted line in Fig. 6. The duration of the period of induction naturally depends upon the relative speeds of the two reactions. If the rate of formation of the intermediate compound is immeasurably fast, there will be no appreciable period of induction. 

Although the Richards model does not provide mechanistic information, it does point out a need for further study and understanding of the uptake mechanisms. Brisbin et al. (30) reported that one consequence of sigmoidal accumulation is that there must be a period of accelerated or enhanced accumulation after the lag period in order to attain equilibrium levels similar to the classical model. In contrast to reports that cellular processes play no role in the accumulation of contaminants by phytoplankton (23, 25, 34-36), a sigmoidal accumulation curve may indicate that cellular processes such as the cycling of materials within the cell may enhance the rate of accumulation or depuration to a level above that which is attainable by diffusion alone. 

The initial period was followed for many expls by a period of acceleration , which was autocatalytic in character. This resulted in complete decompn of the expl. The temp of this final stage of decompn was designated as T,7" for decompn at atm pressure and for that at pressure of 25000kg/cm2 as Tp Results of tests are given in table... 

A typical conversion-time curve exhibits a short period of acceleration followed by a nearly constant rate up to 50% conversion or more, then followed in turn by a diminishing rate. The acceleration period is sometimes reported to persist to quite high conversion. Although some... 

At butyllithium concentrations less than 0.020 moles/liter there is a period of accelerating rate accompanied by the development of a red-brown color, the intensity of which reaches a maximum when the rate reaches a maximum. The color which is ascribed to the styryl carbanion remains indefinitely which is further evidence of no termination reaction. Furthermore,... 

Iron is stored in intestinal mucosal cells as ferritin (an iron/protein complex) until needed by the body. Iron deficiency results from acute or chronic blood loss, from insufficient intake during periods of accelerated growth in children, or in heavily menstruating or pregnant women. Therefore it essentially results from a negative iron balance due to depletion of iron stores and inadequate intake, culminating in hypochromic microcytic anemia. Supplementation with ferrous sulfate is required to correct the deficiency. Gastrointestinal disturbances caused by local irritation are the most common adverse effects caused by iron supplements. 

The presence of parathion in the pond water and pond bottom muds was attributed to insecticide-laden soil washed in during a period of accelerated erosion. One-hundredth /xgram per liter of parathion, 0.02 /xgram per liter of DDD, and 0.01 /xgram per liter of BHC were found in the pond water 4 months after the last application of insecticides. Dunstan, Proctor, and Hindin (2) reported the presence of DDT, aldrin, and the isopropyl ester of 2, 4-D in a number of irrigation return flow wasteways in the Columbia Basin Project of Eastern Washington. 

Figure 9. The temperature rise needed to maintain 102.4 RON during the periode of accelerated deactivation 16 bar pressure and H2/HC= 2.2.

For example, supported TiCl4/MgCl2 catalysts show a short period of acceleration, followed by a prolonged steady period 92,93). However, in the presence of electron donors, they may show the typical decay rate kinetics observed during propylene polymerization 93). Bulk catalysts prepared by interaction of TiCU with Mg(OR)2 show either a stationary rate, or a non-stationary rate, according to the titanium content 88,94). Bulk catalysts prepared by reduction of TiCl4 with organomagnesium compounds show a decay type rate 92-95>. 

The initial period of acceleration is not very evident if the initial O2 /fuel ratio is high. For ratios greater than unity the maximum rate of pressure decrease (pm a x) is attained somewhere between one-quarter and one-third of the total reaction. Most investigators have found Pmax oxygen independent (except for O2 /fuel ratios very much less than unity) and approximately second order with respect to the initial aldehyde pressure (Table 1). The overall activation energy (based on the maximum rate of pressure change) between 90 and 150 °C is about 15 kcal. mole" (Table 2). 

Following a short period of acceleration, decomposition fitted the contracting volume equation between 0.1 < ar < 0.7 with values of = 88 and 96 kJ mol for the sodiiun and potassium salts, respectively. 

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