Forced lubrica tionWeight B Vth to th position B3FV-7-C Bevel-helical gearboxes B3

Flender/Flender Gear Units/Bevel-helical gearboxes B3

several authors (1,3,: O2/H1VmO2O2 KmO2/H1O2( where VO2is the 2consumption rate (nmol kg/H1s/H,VmO2is the maximum 2consump- tion rate (nmol kg/H1s/H, 2is the 2concentration (kPa) and KmO2is the Michaelis Postharvest Physiology of Fresh Produce 4 constant for 2consumption (kPa . In this equation it is assumed that the whole respira- tory chain can be described by one enzyme-mediated reaction, with the substrate glucoseconsidered as nonlimiting and the substrate 2as limiting. The KmO2in the equation refers to the 2concentration where the reaction rate ( 2uptake rate) is half the maximum rate. Vm O2is the maximum reaction rate (nmol kg/H1s/H, when 2is nonlimiting. Since not only low 2concentrations, but also high CO 2concentrations, reduce respiration rates, Eq. ( can be modied to include this type of inhibition. Three types of inhibition ofenzyme functioning can be distinguished (, but often the noncompetitive type is used(1,: O2/H1VmO2O2 (KmO2/H1O(1/H1CO 2/KmCO( where KmCO2is the Michaelis constant for CO 2inhibition of 2consumption (kPa CO . 2.3.2 CO 2Production Equation ( is also often applied to describe CO 2production (3,. This approach as- sumes no CO 2production at 0 kPa 2, which is correct if no fermentation takes place or if all of the fermentation that occurs leads to the formation of products such as lactate oralanine. However, ethanol is the primary fermentation product in most plant tissues (2,, leading to additional CO 2production at low 2concentrations. Therefore, Eq. ( is not suitable for products with increasing CO 2production at low 2concentrations, such as asparagus and carrots (, pear (, cherry (, and blueberry (. To overcome this problem, models that make distinction between CO 2produced by oxidative metabo- lism and that produced by fermentative metabolism have been developed (3,.Some prefer to base their models on an extension of Eq. ( (3,. Oxidative CO 2pro- duction is calculated