Cell volume minimum

In 1968, Meryman [ 1.20] presented his idea about the minimum cell volume and hypothesized, that during feezing cell are damaged in two steps. Initially water diffuses from the cell to the surrounding, the freezing solution concentrating the solution in the cell. However only a certain amount of water can be withdrawn from the cell until it has shrunken so much, (minimum cell volume), that any further withdrawal takes water from the mem-... 

Meryman, H. T. The Minimum Cell Volume modes of freezing injury. Nature 218, p. 333, 1968 und International Institute of Refrigeration <1IR> (Comm. X, p. 897-900, Washington... 

Meryman, FLT. The >minimum cell volume< modes of freezing injury. Nature 218, 333,1968, and International 1.30 Institute of Refrigeration (HR) (Comm. 

As described by Fennema (9J, several refined hypotheses such as "physical barrier and structured water hypothesis" (134,178, 179), "ice-moderator hypothesis" (180-183), and "minimum cell volume hypothesis" (184) have been proposed. However, the author will take a more naive approach in interpreting the results on denaturation of muscle proteins during frozen storage at the same time taking advantage of the basic ideas of the above hypotheses. 

Performance criteria for SCR are analogous to those for other catalytic oxidation systems NO conversion, pressure drop, catalyst/system life, cost, and minimum SO2 oxidations to SO. An optimum SCR catalyst is one that meets both the pressure drop and NO conversion targets with the minimum catalyst volume. Because of the interrelationship between cell density, pressure drop, and catalyst volume, a wide range of optional catalyst cell densities are needed for optimizing SCR system performance. 

Meryman, H.T. (1970). The exceeding of a minimum tolerable cell volume in hypertonic suspension as a cause of freezing injury. In The Frozen Cell, Ciba Foundation Symposium (Wolstenholme, G.E.W. O Connor, M., eds.), pp. 51-64, Churchill, London. 

There are high temperature and low temperature methods to remove sulfur from a fuel reformate stream. Low temperature cleanup, such as hydrodesulfurizing (limited to fuels with boiling end points below 205°C), is less difficult and lower in cost so should be used where possible, certainly with low temperature cells. Sulfur species in the fuel are converted to H2S, if necessary, then the H2S is trapped on zinc oxide. As previously mentioned, a minimum bed volume of the zinc oxide reactor is achieved at temperatures of 350 to 400°C. Simple... 

Equation (4) expresses G as a function of temperature and state of applied stress (pressure) (o. Pa), (/(a) is given by the force field for the set of lattice constants a, Vt is the unit cell volume at temperature T, and Oj and are the components of the stress and strain tensors, respectively (in Voigt notation). The equilibrium crystal structure at a specified temperature and stress is determined by minimizing G(r, a) with respect to die lattice parameters, atomic positions, and shell positions, and yields simultaneously the crystal structure and polarization of minimum free energy. 

Thacker [24] reported the design of a miniature flow fluorimeter for liquid chromatography. The body of the fluorimeter was machined from a block of aluminium and contained a low-pressure mercury lamp, an excitation filter, a quartz flow cell, an emission filter, a photomultiplier tube and a photoconducter in order to compensate for fluctuations in lamp intensity. Fluorescence was examined at a direction perpendicular to that of the excitation light. The cell was small enough for it to be attached directly to the end of the column with a minimum dead volume. 

Radioisotope detection of P, 14C, and Tc was reported by Kaniansky et al. (7,8) for isotachophoresis. In their work, isotachophoretic separations were performed using fluorinated ethylene-propylene copolymer capillary tubing (300 pm internal diameter) and either a Geiger-Mueller tube or a plastic scintillator/photomultiplier tube combination to detect emitted fi particles. One of their reported detection schemes involved passing the radiolabeled sample components directly through a plastic scintillator. Detector efficiency for 14C-labeled molecules was reported to be 13-15%, and a minimum detection limit of 0.44 nCi was reported for a 212 nL cell volume. 

From one point of view, (109) can be interpreted as a manifestation of the noncanonical nature of the microscopic equation of motion and supports the idea of dissipative effects on the microscopic level (for time scale t < t/). From another point of view (109) can be related to the coarse graining of the phase volume minimum cells. The concept of fractional evolution is due to the action of the averaging operator [45]. Each application of the averaging operator is equivalent to a loss of information regarding the short time mobility and is closely associated with the renormalization approach ideas [239]. 

In all cases the same minimum was found. To prevent phase transformations for the Zirconia surfaces, the cell volume and shape were kept fixed and only the ionic coordinates were optimised. In this way, we introduced symmetry restrictions to prevent further phase transformations. No such transformations were observed. 

A continuous analog output is provided from the 90° sensor and all the sensors are sampled every 2 sec. The molecular weight range extends from 10 to 10 Daltons and the rms radii from 10 to 50 nm. The total cell volume appears to be about 3 pi and the scattering volume is 0.02 p t. The detector has a sensitivity, defined in terms of the minimum detectable excess Rayleigh ratio of 5 x 10 cm which is difficult to translate into normal concentration units but appears to be equivalent to a minimum detectable concentration of about 10 g/ml. 

An extremely high sensitivity is claimed for this system but it is difficult to interpret the data in terms of minimum detectable concentration The smallest cell (1.4 pi) (a cell volume that would be suitable for use with microbore columns) is reported to give a sensitivity of about 2 x 10 RI units at a signal-to-noise ratio of two. Consequently, for benzene (RI = 1.501) sensed as a solute in n-heptane (RI=1.388 ) this sensitivity would represent a minimum detectable concentration of 5.6 x g/ml. The alternative 7 pi cell would decrease the minimum detectable concentration to about 1 x 10 g/ml, similar to that obtained for other refractive index detectors. However, the cell volume is a little large for modem high efficiency columns. 

Using the MCY potential at constant pressure and temperature the system became structurally unstable as described in ref. [74], even though the first nearest neighbour distance was preserved at about 2.9 A. A considerable distribution was found for the local tetrahedral symmetry. This behaviour is reasonable since a simple 6-12 potential has no preference for a tetrahedral ly bonded structure. However, with a fixed cell volume the simulation became stable. Nearest neighbour molecules move within the energy minimum created by the pair-potential and the pair-wise additive electrostatic forces. At low temperatures, these molecules only sample the parabolic part of the potential... 

The second parameter line is used to specify the maximum possible values of a, b and c (first three quantities in the line with the defaults set at 20 A), then minimum and maximum unit cell volume (next two values with the defaults 0 and 1500 A ) and finally, minimum and maximum P if the monoclinic crystal system is to be tested (the last two values, defaults are set at 90 and 125°, respectively). The second parameter line in our example selects all corresponding parameters as their default values. 

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