Adsorption of Polymers from the Melt and Solutions of Finite Concentration

1980 ◽  
pp. 591-600 ◽  
Author(s):  
A. Silberberg
Keyword(s):  
Finite Concentration

Theory of the propagation of finite concentration bands in gas chromatography. A numerical solution of the ideal problem

1985 ◽  
Vol 89 (10) ◽  
pp. 2076-2082 ◽  
Author(s):  
Pierre Rouchon ◽  
Marc Schoenauer ◽  
Patrick Valentin ◽  
Claire Vidal-Madjar ◽  
Georges Guiochon
Keyword(s):  
Gas Chromatography ◽  
Numerical Solution ◽  
Finite Concentration ◽  
The Ideal

Desflurane-mediated Neurocirculatory Activation in Humans

1996 ◽  
Vol 84 (5) ◽  
pp. 1035-1042 ◽  
Author(s):  
Michael Muzi ◽  
Craig W. Lopatka ◽  
Thomas J. Ebert
Keyword(s):  
Blood Pressure ◽  
Threshold Concentration ◽  
Rate Of Change ◽  
Measured Variable ◽  
Mechanically Ventilated ◽  
Institutional Review ◽  
Isoflurane Group ◽  
Finite Concentration ◽  
Desflurane Concentration ◽  
End Tidal

Background Rapid increases in the inspired concentration of desflurane have been associated with sympathetic activation, tachycardia, hypertension, and in select cases, myocardial ischemia. The current study examined the effects of the rate of change of the desflurane concentration on the sympathetic and hemodynamic responses to desflurane and sought to determine whether a finite concentration (end-tidal) of desflurane consistently initiated these responses. Methods After Institutional Review Board approval, 23 healthy male volunteers were instrumented for electrocardiogram (heart rate (HR)), intraarterial blood pressure, and peroneal nerve microneurography (sympathetic nerve activity (SNA)). Subjects were given propofol (2.5 mg/kg) and vecuronium (0.15 mg/kg), and their lungs were mechanically ventilated for 30 min at a minimum alveolar concentration of 0.5 MAC with either desflurane or isoflurane (random assignment). The end-tidal concentration was increased at either 1% per min (n = 7) or 0.5% per min (n = 7) for desflurane or 0.16% per min (n = 9) for isoflurane (MAC-multiple comparable to 1% per min desflurane group) until 1.5 MAC was reached. HR, blood pressure, and SNA were averaged over 1-min segments from 0.5 to 1.5 MAC levels. Results Awake neurocirculatory variables did not differ among the three groups. At 0.5 MAC, blood pressure had decreased (12-15%) and HR increased (12-20%) similarly in both groups. SNA decreased 77% in the isoflurane group but was not significantly changed in the desflurane groups. In the desflurane groups, the threshold (end-tidal concentration associated with a 10% increase in the measured variable) ranged between 4% and 10% for HR and between 4% and 7.7% for SNA. In the isoflurane group, the threshold occurred between 1.0% and 1.6% for HR and between 0.7% and 1.3% for SNA. The rate of change did not affect the threshold concentration or the peak HR increase in the desflurane groups. In contrast, SNA responses to desflurane were directly proportional to the rate of change. Conclusion There was no consistent threshold for the neurocirculatory activation associated with desflurane, and the HR and SNA thresholds generally were less than 1 MAC. The HR increase associated with desflurane was not rate- or concentration-dependent. In contrast, SNA responses were proportional to the rate of change and the concentration of desflurane.

Finite concentration fluorescence quenching in the presence of diffusion

1983 ◽  
Vol 78 (11) ◽  
pp. 6598-6601 ◽  
Author(s):  
J. K. Baird ◽  
J. S. McCaskill ◽  
N. H. March
Keyword(s):  
Fluorescence Quenching ◽  
Finite Concentration

Vapour pressures of aqueous solutions of (Ag,Tl,Cd)NO3 at 98.5 °C. II. Henry's law and excess free energy

1978 ◽  
Vol 56 (5) ◽  
pp. 635-637 ◽  
Author(s):  
Marie-Christine Abraham ◽  
Maurice Abraham ◽  
James Malcolm Sangster
Keyword(s):  
Free Energy ◽  
Activity Coefficient ◽  
Excess Free Energy ◽  
Cadmium Content ◽  
Henry's Law ◽  
Henry’S Law ◽  
Finite Concentration ◽  
Pass Through ◽  
Extremum Value ◽  
Bet Equation

Curves of the water activity coefficient γw have been obtained as a function of water mole fraction in the mixtures AgNO3 + TlNO3 + Cd(NO3)2 + H2O at 98.5 °C. It has been shown, in this study, from the BET equation itself and verified experimentally, that γw may pass through an extremum value for certain systems. The position of such an extremum near the fused salt end of the concentration scale can explain the appearance of a 'practical' Henry's law in a finite concentration range. The curves of the excess free energy of the system undergo rather unusual changes of shape as the cadmium content of the melt is varied.

The theory of titration of polybasic acids. II. Conditions for the existence of inflexions near equivalence points

1970 ◽  
Vol 23 (9) ◽  
pp. 1749
Author(s):  
SD Hamann
Keyword(s):  
Activity Coefficients ◽  
Acid Concentration ◽  
Equivalence Point ◽  
Titration Curves ◽  
Finite Concentration

Calculations have been made of the conditions that are necessary for the existence of vertical equivalence point inflexions in the titration curves of dibasic, tribasic, and polybasic acids. Account has been taken of the effects of finite acid concentration, of finite concentration of the titrating base, of finite strength of the titrating base, and of activity coefficients. As a rule, each of these effects causes a flattening of the titration curves and the ultimate disappearance of inflexions.

Stress Distribution in and Around Spheroidal Inclusions and Voids at Finite Concentration

1986 ◽  
Vol 53 (3) ◽  
pp. 511-518 ◽  
Author(s):  
G. P. Tandon ◽  
G. J. Weng
Keyword(s):  
Stress Distribution ◽  
Energy Distribution ◽  
Uniaxial Tension ◽  
Elastic Stress ◽  
Three Dimensional ◽  
Tensile Loading ◽  
Form Solution ◽  
Finite Concentration ◽  
The Matrix ◽  
Close Form

A simple, albeit approximate, close-form solution is developed to study the elastic stress and energy distribution in and around spheroidal inclusions and voids at finite concentration. This theory combines Eshelby’s solution of an ellipsoidal inclusion and Mori- Tanaka’s concept of average stress in the matrix. The inclusions are taken to be homogeneously dispersed and undirectionally aligned. The analytical results are obtained for the general three-dimensional loading, and further simplified for uniaxial tension applied parallel to the axis of inclusions. The ensuing stress and energy fields under tensile loading are illustrated for both hard inclusions and voids, ranging from prolate to oblate shapes, at several concentrations.

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