The growth and deformation of a spheroidal void in an infinite viscous matrix is addressed. In the case of a linearly viscous (newtonian) matrix (c = ke), an exact solution is obtained. On the basis of this solution the case of a power law viscoplastic matrix ( o = ke ) is dealt with by a variational approach. Finally, the Galerkine method is used to take into account inertia effects. This work...

Bullwhip costs money, wastes resources, and loses customers. So drawing on a basis of analytical, simulation and experiential techniques, the authors’ present four material flow principles which can be recommended as strategies to reduce the bullwhip effect. A real-world case study from the precision mechanical engineering sector is employed to illustrate the effect of rapid response manufactur...

Weight control system on the feeder conveyor determines the factor of the quality of products within an industry. The dynamics of the flow rate of material through the feeder conveyor weigh requires a good level of performance controllers. The base of current controllers such as FLC (Fuzzy Logic Controller) requires a certain amount of knowledge and expertise in its design that will make it dif...

Blood pressure, heart rate, and changes in facial and finger blood flow were monitored in 24 male Chinese and 24 male Caucasians while they described anger-provoking incidents and read out neutral material, either loudly and rapidly or softly and slowly. Describing the incidents loudly and rapidly heightened anger ratings and enhanced digital vasoconstriction but not blood pressure or heart rat...

When a sample material is subjected to a linear temperature program, the heat flow rate into the sample i s proportional to its instantaneous specific heat. By recording this heat flow rate as a function of temperature, and comparing it with the heat flow rate into a standard material under the same conditions, the specific heat of the sample i s determined as a fundion of temperature. The meth...

A multilayered microchip (25 x 95 mm) used for vacuum distillation is designed, fabricated and tested by rectification of a water-methanol mixture. The polymer chip employs a cooling channel to generate a temperature gradient along a distillation channel below, which is separated into a channel (72 microm deep) for liquid phase and a channel (72 microm deep) for vapor phase by an incorporated m...

This paper addresses the gradient estimation of transfer lines comprising two machines separated by a buffer of finite capacity. A continuous flow model is considered, where machines are subject to operation-dependent failures, i.e., a machine cannot fail when it is idle. Both repair times and failure times may be general, i.e., they need not be exponentially distributed. The system is hybrid i...

This paper discusses the negative impact of errors in the time datation of data as they are gathered accross a distributed newtork of sensors to be treated by a centralized monitoring algorithm. An example of flow monitoring serves as basis for the analysis. Using a simple probability model, we establish the variance of an estimator serving for loss detection and show how it varies with the tim...

A major disadvantage of gradient elution in terms of speed results from the need to adequately re-equilibrate the column. This work distinguishes two states of re-equilibration: (1) run-to-run repeatability and (2) full equilibration. We find that excellent repeatability (+/-0.002 min in retention time) is achieved with at most 2 column volumes of re-equilibration whereas full equilibration can...