PRESSURE, VOLUME, TEMPERATURE RELATIONS OF ETHYLENE IN THE CRITICAL REGION. I.

1939 ◽  
Vol 17b (7) ◽  
pp. 206-213 ◽  
Author(s):  
J. Dacey ◽  
R. McIntosh ◽  
O. Maass
Keyword(s):  
Experimental Error ◽  
Heterogeneous System ◽  
Constant Pressure ◽  
Volume Ratio ◽  
Time Lags ◽  
Compressed Liquid ◽  
Region I ◽  
Flat Portion ◽  
Liquid States ◽  
Mass Volume

Pressure isothermals of the system were determined both above and below the temperature of disappearance of the meniscus. Regions of constant pressure with changing volume were observed with all isothermals, in agreement with the prediction of Mayer and Harrison (2, 3). The complete envelope of this region above the critical temperature has not as yet been determined. The pressure of the heterogeneous system at 9.50 °C. was found to correspond within experimental error to the pressure of the flat portion of the homogeneous isothermal at the same temperature. The pressure of this heterogeneous system was found to be independent of the mass-volume ratio; this is in agreement with the experimental behaviour previously discovered by the authors (5) for such a system at 9.80 °C. Moreover, the pressure of the heterogeneous system was found to be identical with that of the system which had been heated at constant volume to a temperature at which the density difference in the tube is known to have been destroyed, and then cooled to the same temperature of 9.50 °C.The isothermal at 9.60 °C. was studied, and shown to be the equilibrium curve at that temperature. A hysteresis was observed on reversing the direction of measurement, i.e., from "vapour" to compressed "liquid". This hysteresis was found to be caused by the time lags which are observed in passing from the "vapour" region of an isothermal to regions of high density. Certain apparent discrepancies between the work of the present authors and that of Geddes and Maass have been observed and cannot as yet be explained.The phenomena observed are interpreted on the basis of a difference between the gaseous and liquid states of aggregation, with a structure assigned to the latter.

P-238 Left Ventricular Mass volume Ratio and Hazard of Adverse Cardiovascular Events

2009 ◽  
Vol 4 ◽  
pp. S119
Author(s):  
Michael Chuang ◽  
Philimon Gona ◽  
Carol J. Salton ◽  
Christopher J. O'Donnell ◽  
Warren J. Manning
Keyword(s):  
Left Ventricular Mass ◽  
Cardiovascular Events ◽  
Volume Ratio ◽  
Left Ventricular ◽  
Ventricular Mass ◽  
Mass Volume

scholarly journals Left Ventricular Global Function Index and Left Ventricular Mass Volume Ratio By CMR: Relation with Heart Failure in Thalassemia Major Patients

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2688-2688
Author(s):  
Antonella Meloni ◽  
Lucia De Franceschi ◽  
Domenico Maddaloni ◽  
Sabrina Carollo ◽  
Roberto Sarli ◽  
...  
Keyword(s):  
Heart Failure ◽  
Iron Overload ◽  
Volume Ratio ◽  
Thalassemia Major ◽  
Left Ventricular ◽  
Myocardial Iron ◽  
Global Function ◽  
Function Index ◽  
Lv Mass ◽  
Mass Volume

Abstract Introduction: Recently two novels indicators of left ventricular (LV) performance assessed by Cardiovascular Magnetic Resonance (CMR) have been introduced: the LV global function index (LVGFI) and the LV mass/volume ratio (LVMVR). The LVGFI combines LV stroke volume, end-systolic and end diastolic volumes, as well as LV mass, integrating structural as well as mechanical behaviour. Elevated LVMVR is indicative of concentric remodelling. A LVGFI <37% and a LVMVR>1 were shown to be associated with the occurrence of cardiovascular events in no-thalassemic populations. This retrospective cohort study aimed to systematically evaluate in a large historical cohort of thalassemia major (TM) in the CMR era whether the LVGFI and the LVMVR were associated with a higher risk of heart failure. Methods: We considered 812 TM patients (391 M, 30.4±8.6 years), consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) network. LVGFI and LVMRI were quantitatively evaluated by SSFP cine images. The T2* value in all the 16 cardiac segments was evaluated and a global heart T2* value <20 ms was considered indicative of myocardial iron overload (MIO). Results: Eighty (9.9%) patients had a LVGFI<37% and, compared to the patients with a normal LVGFI, they showed a significant higher frequency of heart failure (43.8% vs 4.2%; P<0.0001). Patients with a LVGFI<37% had a significant higher risk of heart failure (odds-ratio-OR=17.59, 95%CI=9.95-21.09; P=<0.001). The risk remained significant also adjusting for the presence of MIO (OR=15.54, 95%CI=8.05-26.27; P=<0.001). Thirty (3.7%) patients had a LVMVR≥1% and, compared to the patients with a normal LVMRI, they showed a significant higher frequency of heart failure (20.0% vs 7.7%; P=0.015). Patients with a LVMVR≥1% had a significant higher risk of heart failure (OR=3.01, 95%CI=1.18-7.64; P=0.021). The risk remained significant also adjusting for the presence of MIO (OR=3.44, 95%CI=1.31-9.01; P=0.012). In a multivariate model including LVGFI, LVMVR and heart iron, the significant predictors of heart failure were a LVGFI<37% (OR=14.05, 95%CI=7.66-25.77; P=<0.001) and a global heart T2*<20 ms (OR=1.94, 95%CI=1.08-3.47; P=0.026). Conclusions: In TM patients a LVGFI<37% was associated with an higher risk of heart failure, independent by the presence of MIO. A widespread program using CMR exploiting its multi-parametric potential can have considerable power for the early identification and treatment of patients at risk for heart failure. Disclosures No relevant conflicts of interest to declare.

Preparation and Microstructure of Exfoliated Graphite with Large Expanding Volume by Two-Step Intercalation

2014 ◽  
Vol 852 ◽  
pp. 101-105 ◽  
Author(s):  
Ji Jin Zhao ◽  
Xiao Xia Li ◽  
Yu Xiang Guo ◽  
De Yue Ma
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Phosphoric Acid ◽  
Potassium Permanganate ◽  
Reaction Temperature ◽  
Volume Ratio ◽  
Exfoliated Graphite ◽  
Mass Ratio ◽  
Preparation Conditions ◽  
Mass Volume

Exfoliated graphite with large expanding volume (EV) was prepared by two-step intercalation, in which the mixture of nitric acid and phosphoric acid, and that of nitric acid and acetic acid were employed as intercalating agent step by step, and potassium permanganate was used as oxidant. Its preparation conditions were optimized by orthogonal experiment and parallel experiment, and its microstructure was analyzed by scanning electron microscope. The results show that the optimal preparation conditions for the first step intercalation are as follows: the mass-volume ratio of natural graphite (NG) to mixed acid is 1: 4, the volume ratio of nitric acid to phosphoric acid is 1: 2, the mass ratio of NG to potassium permanganate is 1: 0.2, and the reaction temperature is 20~30°C for 40~60 minutes. Those for the second step intercalation are as follows: the mass-volume ratio of acidized graphite (AG) to acetic acid is 1: 5, the mass-volume ratio of AG to nitric acid is 1: 1.5, the mass ratio of AG to potassium permanganate is 1: 0.15, and the reaction temperature is 20~30°C for 40~60 minutes, the EV is 450ml/g under the conditions listed above. The interlayers of graphite are fully opened and become a worm-like fluffy rope.

Abstract 5160: Obesity is Related to Concentric Left Ventricular Hypertrophy: Results from the Multi-Ethnic Study of Atherosclerosis (MESA)

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Evrim B Turkbey ◽  
Robyn L McClelland ◽  
Richard A Kronmal ◽  
Diane Bild ◽  
Gregory L Burke ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Cardiac Output ◽  
Ejection Fraction ◽  
Fat Mass ◽  
Volume Ratio ◽  
Left Ventricular ◽  
Additive Models ◽  
Lv Mass ◽  
Mass Volume

Obesity is a risk factor for cardiovascular disease but its association with left ventricular (LV) morphologic adaptations is debated because of obesity-associated co-morbidities. We evaluated the relationship of obesity to ventricular size and remodeling independent of other risk factors for LV hypertrophy. 5004 participants (age 45– 84 years; 52% female) of the MESA study free of clinical cardiovascular disease underwent cardiac MRI to assess LV size and function. The association of LV indices with measures of obesity, including fat mass (FM), body mass index (BMI) and waist circumference (WC), was determined using generalized additive models adjusted for established risk factors for LV hypertrophy and fat-free mass (FFM). FFM of participants was estimated based on height-weight models derived from bioelectrical impedance studies and FM was obtained by subtracting FFM from weight. LV mass and end diastolic volume were positively associated with FM, BMI and WC after adjustment for risk factors and FFM. For a given FFM, LV mass/volume ratio increased with FM up to approximately 50 kg FM (Figure ). Cardiac output and stroke volume were also positively associated with FM (slopes: CO 0.02 L/min per kg FM, SV 0.16 ml per kg FM, p<0.001 for each). Ejection fraction showed no significant association with FM. The associations of fat mass to increased LV mass and LV mass/volume were similar in patients with and without obesity associated co-morbidities. Obesity is associated with concentric LV hypertrophy, marked by increased LV mass/volume ratio, increased cardiac output and preserved ejection fraction.

Hypertrophy signaling during peripartum cardiac remodeling

2007 ◽  
Vol 293 (5) ◽  
pp. H3008-H3013 ◽  
Author(s):  
A. M. D. Gonzalez ◽  
J. C. Osorio ◽  
C. Manlhiot ◽  
D. Gruber ◽  
S. Homma ◽  
...  
Keyword(s):  
Cardiac Remodeling ◽  
Volume Ratio ◽  
Mapk Signaling ◽  
Molecular Signaling ◽  
Sprague Dawley ◽  
Western Blots ◽  
Physiological Cardiac Hypertrophy ◽  
Lv Mass ◽  
Pregnancy And Postpartum ◽  
Mass Volume

Molecular signaling pathways that regulate peripartum cardiac remodeling are not well understood. Our objectives were to study the role of mitogen-activated protein kinases (MAPKs), protein kinase B (Akt), and endothelial nitric oxide synthase (eNOS) in mediating pregnancy and postpartum (PP) cardiac remodeling. Methods: Adult female Sprague-Dawley rats were divided into nonpregnant ( n = 5), 18 days pregnant ( n = 5), 0 days PP ( n = 7), and 14 days PP ( n = 8). Rats underwent echocardiography under sedation to measure left ventricle (LV) size and function, and Western blots were performed to measure myocardial protein expression of MAPKs (p38, JNK, ERK), Akt, and eNOS. Results: 1) During pregnancy, there was an increase in LV mass (0.62 ± 0.03 to 1.1 ± 0.04 g, P < 0.001), mass/volume ratio (0.7 ± 0.02 to 1.28 ± 0.02 g/ml, P < 0.0001), and ejection fraction (EF) (64 ± 3 to 74 ± 2%). Whereas LV mass and mass/volume ratio returned to prepregnancy values in the PP period, EF remained below normal range (53 ± 3%, P < 0.05). 2) The expression of anti-hypertrophic factors (p38, JNK, Akt) decreased during pregnancy and normalized PP, except JNK, which increased to higher than normal levels. eNOS also increased to higher than baseline levels PP. 3) Activation of p38 and JNK was directly correlated with lower LV mass/volume ratio ( r = −0.81 and −0.71, respectively; P < 0.05). Conclusion: Pregnancy is associated with physiological cardiac hypertrophy. There is rapid reversal of hypertrophy in the PP period while recovery of cardiac function is delayed, possibly related to PP upregulation of JNK. A dysregulation of MAPK signaling may be an important determinant of PP cardiac dysfunction.

scholarly journals COMPARATIVE ANALYSIS OF THE IAPWS-IF97 FORMULATION PERFORMANCE FOR THERMODYNAMIC PROPERTIES OF WATER ON A RANKINE CYCLE

2004 ◽  
Vol 3 (1) ◽  
pp. 52 ◽  
Author(s):  
J. G. Fonseca Jr. ◽  
P. S. Schneider
Keyword(s):  
Comparative Analysis ◽  
Thermodynamic Properties ◽  
General Public ◽  
Constant Pressure ◽  
International Association ◽  
Rankine Cycle ◽  
Specific Enthalpy ◽  
Specific Entropy ◽  
Compressed Liquid ◽  
Computational Implementation

The present paper presents the computational implementation of the industrial formulation of the thermodynamic properties of water at liquid and steam phases, proposed by the International Association for the Properties of Water and Steam, known as IAPWS-IF97. The validity field extends over to temperatures T between 0ºC and 800°C, for pressures p up to 100 MPa. Temperature T, specific volume v, specific enthalpy h, specific entropy s, specific heat at constant pressure cp and constant volume cv, besides saturation pressure ps, are calculated having a pair of known input values (p,T), (p,h) or (p,s). A comparative analysis between the IAPWS-IF97 routines and others, based on foregoing propositions, from an application on Rankine cycle, is made. IAPWS-IF97 has proved to be more precise, mainly because it accounts for the region of compressed liquid, besides requiring less processing time. The development is carried out as FORTRAN90 subroutines and functions and is available for public use according to a General Public License.

Dilatometric Determination of Polymer Compatibility

1963 ◽  
Vol 36 (3) ◽  
pp. 668-674 ◽  
Author(s):  
G. M. Bartenev ◽  
G. S. Kongarov
Keyword(s):  
Experimental Error ◽  
Linear Expansion ◽  
Volume Ratio ◽  
Glass Temperature ◽  
Polymer Mixtures ◽  
Polymer Compatibility ◽  
Coefficient Of Linear Expansion

Abstract 1. The temperature contraction curves for rubbery polymer mixtures define the degree of compatibility of these polymers only when the glass temperatures are not close to the same. 2. Mixtures of obviously incompatible polymers display several glass temperatures (according to the number of polymers in the mixture). The values of these temperatures coincide with the glass temperatures of the pure polymers and do not depend on the ratio of the polymers in the mixture. 3. Mixtures of compatible polymers have a single glass temperature which changes linearly with the volume ratio of the polymers. 4. The coefficient of linear expansion (contraction) of all polymer mixtures follows the additivity law within the visible limits of experimental error from sample to sample.

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