This paper is concerned with the observability problem of a parallelow twouid heat exchanger equation with di usion term. First, the case where two uid temperatures are measured at the outlet is considered. It is shown that the observed system with the measurements becomes observable on any interval of time through a concrete series expression of the solution. Next, the two cases where each one...

Systematic control structure design requires the use of a model of the plant. Developing rigorous plant models based on physical and chemical principles is often a laborious and time consuming task. This paper studies the effect of simplifications of the heat exchanger model on the resulting control structure design for the PRICO LNG process. It is found that significant model simplifications m...

The ClC family encompasses two classes of proteins with distinct transport functions: anion channels and transporters. ClC-type transporters usually mediate secondary active anion-proton exchange. However, under certain conditions they assume slippage mode behavior in which proton and anion transport are uncoupled, resulting in passive anion fluxes without associated proton movements. Here, we ...

The need for energy efficient, low cost, and reduced material solutions are encouraging HVAC&R engineers to explore new heat exchanger designs, including those using small diameter tubes and tubes with internal enhancements. Such developments thus require review and consideration for new and/or improved heat exchanger manufacturing techniques. Experimental and analytical study of a pressure exp...

In the Compressed Air Energy Storage (CAES) approach, air is compressed to high pressure, stored, and expanded to output work when needed. The temperature of air tends to rise during compression, and the rise in the air internal energy is wasted during the later storage period as the compressed air cools back to ambient temperature. The present study focuses on designing an interrupted-plate he...

The focus of this work is the modeling and performance comparison of different models of pulse tube refrigerators, namely, the Orifice Pulse Tube Refrigerator (OPTR) and the Inertancetube Pulse Tube Refrigerator (IPTR) with both in-line as well as coaxial configurations. A detailed analysis of the flow and heat transfer in various components of the above mentioned models under oscillating flow ...

1 A theoretical treatment of potentiometric data is applied to calculate coextraction 2 constants (K IA) for three potassium salts from water into a liquid nitrobenzene phase. 3 The experiment involves treating nitrobenzene as a membrane and contacting it with 4 two aqueous solutions of different ion activities. In the presence of either a cation or 5 anion exchanger, the ratio of activities of...

A rise in cytosolic Ca2+ concentration ([Ca2+]cyt) in pulmonary artery smooth muscle cells (PASMC) is an important stimulus for cell contraction, migration, and proliferation. Depletion of intracellular Ca2+ stores opens store-operated Ca2+ channels (SOC) and causes Ca2+ entry. Transient receptor potential (TRP) cation channels that are permeable to Na+ and Ca2+ are believed to form functional ...

Mechanisms that regulate endolymphatic pH are unknown. It has long been recognized that, because of the large positive endolymphatic potential in the cochlea, a passive movement of protons would be directed out of endolymph leading to endolymphatic alkalization. However, endolymphatic pH is close to that of blood, suggesting that H+ is being secreted into endolymph. Since the kidney and the inn...