Dilatometric study of streptococcal growth and metabolism

1969 ◽  
Vol 15 (8) ◽  
pp. 933-940 ◽  
Author(s):  
Robert E. Marquis ◽  
Wallace O. Fenn
Keyword(s):  
Lactic Acid ◽  
Volume Change ◽  
Small Volume ◽  
Partial Molar Volumes ◽  
Pressure Sensitivity ◽  
Volume Changes ◽  
Streptococcus Faecalis ◽  
Dilatometric Study ◽  
Cell Synthesis ◽  
Metabolic Volume

A simply constructed dilatometer or volumeter was used to measure small volume changes (ca. 6 × 10−4 ml per milliliter) accompanying growth of Streptococcus faecalis cultures. Polymerization reactions involved in cell synthesis appeared to contribute little to the observed changes, and dilatation of cultures in glucose-containing media could be interpreted mainly in terms of volume changes associated with cleavage of glucose to lactic acid, ionization of lactic acid, and protonation of buffer ions in the culture. Glycolysis in suspensions of nongrowing cells was accompanied by similar increases in volume. In contrast, arginine degradation by S. faecalis was accompanied by contraction, and in this case the volume change could be almost completely accounted for by differences in partial molar volumes of products and reactants. Possible relationships between metabolic volume changes and pressure sensitivity of bacteria are discussed.

The volume change on ionizatin of weak electrolytes

1954 ◽  
Vol 7 (4) ◽  
pp. 329 ◽  
Author(s):  
SD Hamann ◽  
SC Lim
Keyword(s):  
Volume Change ◽  
Solvent Effects ◽  
Partial Molar Volumes ◽  
Volume Changes ◽  
Molar Volumes ◽  
Weak Electrolytes

The standard partial molar volumes of some strong and weak electrolytes have been measured in water and three other solvents. The results have been used to estimate the volume changes which accompany the ionization of weak electrolytes. Solvent effects are discussed.

Mechanical impedances of lungs and chest wall in the cat

1992 ◽  
Vol 73 (2) ◽  
pp. 427-433 ◽  
Author(s):  
Z. Hantos ◽  
A. Adamicza ◽  
E. Govaerts ◽  
B. Daroczy
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Small Volume ◽  
Angular Frequency ◽  
Forced Oscillations ◽  
Amplitude Dependence ◽  
Volume Changes ◽  
The Real ◽  
Output Flow ◽  
Frequency Independent

In nine anesthetized and paralyzed cats, the mechanical impedances of the total respiratory system (Zrs) and the lungs (ZL) were measured with small-volume pseudorandom forced oscillations between 0.2 and 20 Hz. ZL was measured after thoracotomy, and chest wall impedance (Zw) was calculated as Zw = Zrs-ZL. All impedances were determined by using input airflow [input impedance (Zi)] and output flow measured with a body box [transfer impedance (Zt)]. The differences between Zi and Zt were small for Zrs and negligible for ZL. At 0.2 Hz, the real and imaginary parts of ZL amounted to 33 +/- 4 and 35 +/- 3% (SD), respectively, of Zrs. Up to 8 Hz, all impedances were consistent with a model containing a frequency-independent resistance and inertance and a constant-phase tissue part (G-jH)/omega alpha, where G and H are coefficients for damping and elastance, respectively, omega is angular frequency, and alpha determines the frequency dependence of the real and imaginary parts. G/H was higher for Zw than for ZL (0.29 +/- 0.05 vs. 0.22 +/- 0.04, P less than 0.01). In four cats, the amplitude dependence of impedances was studied: between oscillation volumes of 0.8 and 3 ml, GL, HL, Gw, and Hw decreased on average by 3, 9, 26, and 29%, respectively, whereas the change in G/H was small for both ZL (7%) and Zw (-4%). The values of H were two to three times higher than the quasistatic elastances estimated with greater volume changes (greater than 20 ml).

Volume Change Associated to Carbon Partitioning from Martensite to Austenite

2012 ◽  
Vol 706-709 ◽  
pp. 2290-2295 ◽  
Author(s):  
M. J. Santofimia ◽  
Lie Zhao ◽  
Jilt Sietsma
Keyword(s):  
Volume Change ◽  
Chemical Potential ◽  
Theoretical Models ◽  
Carbon Partitioning ◽  
Volume Changes ◽  
Measured Volume

Annealing of martensite/austenite microstructures leads to the partitioning of carbon from martensite to austenite until the chemical potential of carbon equilibrates in both phases. This work calculates the volume change associated with this phenomenon using theoretical models for the carbon partitioning from martensite to austenite. Calculations are compared with experimentally determined volume changes. This comparison reveals that in the case of steels with higher contents of austenite-stabilizing elements, reported volume changes are satisfactory predicted assuming a low mobilily martensite/austenite interface. In the case of a steel with lower additions of austenite-stabilizing elements, experimentally measured expansions are considerably larger than predicted ones. The large measured volume expansions probably reflect the decomposition of the austenite.

scholarly journals Temporary prosthetic fitting for below-knee amputation

1989 ◽  
Vol 13 (2) ◽  
pp. 86-89 ◽  
Author(s):  
H. Ozyalcin ◽  
E. Sesli
Keyword(s):  
Developing Countries ◽  
Small Volume ◽  
High Pressures ◽  
Knee Prosthesis ◽  
High Price ◽  
Volume Changes ◽  
Dressing Method ◽  
Knee Amputation ◽  
Long Period ◽  
Prosthetic Fitting

The problems encountered in fitting and using the permanent below-knee prosthesis in developing countries are the high price of the prosthesis, inadequate fitting and lack of proper rehabilitation. In Turkey, the preferred treatment of the stump post-operatively is by the soft dressing method with bandaging for maturation and shrinkage. Generally, the application of the permanent prosthesis is in the sixth month post-operatively. Since in patellar-tendon-bearing (PTB) sockets, stumps have to withstand high pressures in limited areas, the PTB socket can only tolerate small volume changes in the stump. For this reason bandaging over a long period may be insufficient for adequate stump shrinkage and amputees will need another below-knee prosthesis, which most of them cannot afford after only a few weeks use. In the authors' clinic, 19 amputees were fitted with simple, effective and inexpensive temporary prostheses following either conventional immediate post-operative dressing or the soft dressing method. The temporary prosthesis is worn for two months. It produces fast stump shrinkage, helps maturation and permits ambulatory discharge even in bilateral amputees. For economical reasons, only eight of nineteen patients were fitted with permanent prostheses, all wearing them successfully without the necessity of further rehabilitation.

A New Micro-Respirometer with Automatic Setting and Recording Apparatus

1950 ◽  
Vol 27 (3) ◽  
pp. 334-349
Author(s):  
PETER TUFT
Keyword(s):  
Volume Change ◽  
Constant Pressure ◽  
Volume Changes ◽  
Recording Apparatus

A new micro-respirometer is described, capable of measuring rates of volume change from 5 µl./hr. down to 0.01 µl./hr. to the nearest 0.001 µl. It is a constant-pressure nul-reading instrument and the actual volumes of gas absorbed or evolved are obtained from readings of the instrument by a simple multiplication. A device is described which sets the instrument automatically and records the volume changes at regular intervals.

A DILATOMETRIC STUDY OF SOLID METHANOL-d

1956 ◽  
Vol 34 (9) ◽  
pp. 1243-1248 ◽  
Author(s):  
D. W. Davidson
Keyword(s):  
Melting Point ◽  
Molar Volume ◽  
The Other ◽  
Gradual Transition ◽  
Calorimetric Data ◽  
Volume Changes ◽  
First Order ◽  
Dilatometric Study

With isopentane as the dilatometric liquid, CH3OD was examined between 120 °K. and the melting point. There is evidence of two transitions within the solid: one, in the vicinity of 158 °K., appears to be a gradual transition, the other, at 163 °K., a first-order one. The corresponding molar volume changes are 0.04 and 0.43 ml. A further change of volume of 2.67 ml./mole occurs at the melting point. These results are compared with recent dilatometric results for CH3OH and discussed with reference to the available calorimetric data. The molar volume of CH3OD is slightly greater than that of CH3OH in both liquid and solid forms.

Pressure response to quick volume changes in tetanized isolated ferret hearts

1989 ◽  
Vol 257 (1) ◽  
pp. H38-H46 ◽  
Author(s):  
K. B. Campbell ◽  
A. R. Rahimi ◽  
D. L. Bell ◽  
R. D. Kirkpatrick ◽  
J. A. Ringo
Keyword(s):  
Cardiac Muscle ◽  
Muscle Fiber ◽  
Volume Change ◽  
Initial Pressure ◽  
Recovery Phase ◽  
Left Ventricular ◽  
Fast Recovery ◽  
Volume Changes ◽  
Slow Recovery ◽  
Length Changes

Observed pressure responses to quick volume changes in the isolated tetanized heart of ferrets were compared with previously reported tension responses to quick length changes in isolated cardiac muscle. Hearts were isolated from ferrets, perfused with ryanodine solution, and stimulated rapidly (50 ms between stimulations) to produce repeated 4-s intervals of tetanus. During each tetanus interval, volume increments of different amplitudes were rapidly removed and then reinfused into the left ventricular chamber. The pressure responses to these volume changes were evaluated for differences between withdrawals and infusions and for dependence on the amplitude of the volume change. It was found for both withdrawal and infusion that the response could be divided into three phases: 1) an immediate phase coincident with volume change, 2) a fast-recovery phase, and 3) a slow-recovery phase. The amplitude of the immediate phase was linearly dependent on the volume change so that a single regression line fit all the data (withdrawal and infusion). The fast recovery phase was 2.5 times faster for infusion than for withdrawal and generated a rebound effect with the pressure going below the initial pressure in the response to infusion. The pressure never went above the initial pressure in the response to withdrawal. The slow-recovery phases in infusion and withdrawal did not differ. These responses in the isolated heart bear striking similarities to tension responses to quick length changes in isolated constantly activated cardiac muscle. We concluded that muscle fiber dynamics were being faithfully transformed to left ventricular (LV) chamber dynamics without appreciable distortion because of the many intervening factors between the wall muscle fiber and the LV chamber.(ABSTRACT TRUNCATED AT 250 WORDS)

Photoacoustic detection of phase transitions with a resonant piezoelectric scheme with extreme sensitivity to small volume changes

2005 ◽  
Vol 80 (3) ◽  
pp. 365-371 ◽  
Author(s):  
O. E. MART�NEZ ◽  
Y. CESA ◽  
N. MINGOLO ◽  
R. ROMERO
Keyword(s):  
Phase Transitions ◽  
Small Volume ◽  
Volume Changes ◽  
Photoacoustic Detection ◽  
Extreme Sensitivity

A new simple system for measuring volume changes in unsaturated soils

2002 ◽  
Vol 39 (3) ◽  
pp. 757-764 ◽  
Author(s):  
C W.W Ng ◽  
L T Zhan ◽  
Y J Cui
Keyword(s):  
Volume Change ◽  
Unsaturated Soils ◽  
Volumetric Strain ◽  
Apparent Volume ◽  
Differential Pressure ◽  
Simple System ◽  
Measuring System ◽  
Volume Changes ◽  
Ambient Temperatures ◽  
Triaxial Apparatus

A new simple system for accurately measuring overall total volume changes in unsaturated soil specimens with a triaxial apparatus is introduced in this paper. The basic principle of the measuring system is to record changes in the differential pressure due to changes in the water level inside an open-ended, bottle-shaped inner cell caused by volume change in the specimen and inside a reference tube using an accurate differential pressure transducer. Several important steps were taken to improve the accuracy and sensitivity of the measuring system. Detailed calibrations were carried out to account for apparent volume changes as a result of changes in cell pressure, fluctuation in the ambient temperatures, creep in the inner cell wall, and relative movement between the loading ram and the inner cell. The calibration results demonstrate that the measuring system is reasonably linear, reversible, and repeatable. The estimated accuracy of the measuring system is in the order of 32 mm3 (or 0.04% volumetric strain for a triaxial specimen 38 mm in diameter and 76 mm in height) once the system is properly calibrated.Key words: unsaturated soils, volume-change measurement, open-ended, bottle-shaped, inner cell, differential pressure, calibration.

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