In this paper, the problems of control and stabilization of switched nonlinear cascade systems is investigated. The so called simultaneous domination limitation (SDL) is introduced in previous works to assure the existence of a common quadratic Lyapunov function (CQLF) for switched nonlinear cascade systems. According to this idea, if all subsystems of a switched system satisfy the SDL, a CQLF ...

Freeze-drying is a low-pressure, low-temperature condensation pumping process widely used in the manufacture of pharmaceuticals for removal of solvents by sublimation. Key performance characteristics of a freezedryer condenser are largely dependent on the vapor and ice dynamics in the low-pressure environment. The main objective of this work is to develop a modeling and computational framework ...

In this research, a water-water heat pump system using waste water as a heat source, a type that is not often used in Turkey and the World, was experimentally modeled. The experiments were performed under the conditions of simulated waste water temperature values of 20 °C, 30 °C and 40 °C. Inlet and outlet water temperatures of the evaporator and condenser, water flow rates in the evaporator an...

Balanced equations of a binary mixture for molecular distillation (MD) were derived on the basis of relation of heat and mass transfer in liquid films on both the evaporating and condensing surface. Effects of feed temperature and condenser temperature on film thickness, film surface temperature and concentration, degree of evaporation and concentration of distillate were analyzed for MD. The l...

This paper presents the analysis, design, fabrication, and testing of a condenser microphone utilizing a thin low-stress polycrystalline silicon diaphragm suspended above a p+ perforated back plate. The microphone is fabricated using a combination of surface and bulk micromachining techniques in a single wafer process without the need of wafer bonding. The device shows sensitivities of -34 dB (...

Botnets represent a global problem and are responsible for causing large financial and operational damage to their victims. They are implemented with evasion in mind, and aim at hiding their architecture and authors, making them difficult to detect in general. These kinds of networks are mainly used for identity theft, virtual extortion, spam campaigns and malware dissemination. Botnets have a ...

Even though there are lots of work studying acoustic resonance in tube bundles, the sound transmission rules barely got researchers attention. And most papers published assume that there is no interaction between the acoustic and structure modes. This paper tries to realize how sound source affects the acoustic transmission and whether the acoustic resonance could couple with the structure. A s...

A. 1 ohansson and P. Lundqvist Dept. of Energy Technology Div. of Applied Thennodynamics and Refrigeration The Royal Institute of Technology, KTH Stockholm, Sweden Test results from field retrofit situations, where R22 has been changed to Isceon 59 1 and R407C in two identical chillers, shows that both substitutes require more subcooling than R22 to give the system a satisfying performance. It ...

during the last years the total cost of lng technology has decreased significantly due to improvements of the liquefaction process. however, many liquefaction plants that are still in operation use a three-cascade refrigeration system. in this paper, an advanced exergetic analysis is applied to better understand the operation of a three-cascade refrigeration system for liquefaction of natural g...

proton exchange membrane fuel cells (pemfcs) with a dead-ended anode and cathode can obtain high hydrogen and oxygen utilization by a comparatively simple system. nevertheless, the accumulation of the water in the anode and cathode channels might cause a local fuel starvation degrading the performance and durability of pemfcs. in this study, a brand new design for a polymer electrolyte membrane...