scholarly journals The thermal diffusion of radon gas mixtures

1942 ◽  
Vol 181 (984) ◽  
pp. 93-100 ◽  
Keyword(s):  
Force Field ◽  
Thermal Diffusion ◽  
Special Theory ◽  
Mean Value ◽  
Repulsive Force ◽  
Inert Gases ◽  
Inert Gas ◽  
Cold Side ◽  
The Mean ◽  
Gas Molecules

In continuation of earlier experiments (Harrison 1937) in which the thermal diffusion in radon-hydrogen and radon-helium mixtures was measured, the thermal diffusion of mixtures of radon-neon and radon-argon has now been studied. The mean value obtained for the ratio of the proportion by volume of radon on the cold side at 0° C to that on the hot side at 100° C, after thermal diffusion, was 1·074 for radon-neon mixtures, and 1·008 for radon-argon mixtures. In order to calculate the repulsive force field, F 12 , between these two pairs of molecules, the present results were combined with measurements of ordinary diffiisirm of radon into neon and radon into argon (Hirst & Harrison 1939), and viscosity determinations at various temperatures of neon and argon (Trautz & Binkele 1930). The special theory, due to Chapman (1929), of thermal diffusion of a rare constituent in a binary mixture was used to derive Flt. The values obtained for the repulsive force field between the dissimilar molecules at collision were: F 12 (radon-neon) = 1·9 x 10 -51 d -6·1 = ( d / d 0 ) -6·1 , d 0 = 4·8 x 10 -9 , F 12 (radon-argon) = 2·1 x 10 -43 d -5·1 = ( d 0 )-5·1 , d 0 = 4·3 x 10 -9 , d being the distance between the point centres of repulsive force and d 0 the value of d at which F 12 is 1 dyne. A comparison of the values obtained for the repulsive force index for radon-neon and radon-argon molecules with those obtained by Atkins, Bastick & Ibbs (1939) for binary mixtures of the first five inert gases shows that radon is the4 softest ’ of the inert gas molecules. Radon-argon molecules are the closest approach to the Maxwellian case yet studied experimentally.

scholarly journals The diffusion of radon gas mixtures

1939 ◽  
Vol 169 (939) ◽  
pp. 573-586 ◽  
Keyword(s):  
Thermal Diffusion ◽  
Special Theory ◽  
Gas Mixtures ◽  
Repulsive Force ◽  
Wide Range ◽  
Experimental Values ◽  
Coefficient Of Viscosity ◽  
The Given ◽  
Helium Neon ◽  
Coefficient Of Diffusion

The repulsive force, F 12 , between dissimilar molecules may be represented by the equation F 12 = μ 12 d - 8 12, where d is the distance between the dissimilar molecules which are regarded as point centres of repulsive force, while 8 12 represents the repulsive force index, and μ 12 the repulsive force constant between these molecules. Chapman (1929) has given a special theory of thermal diffusion in mixtures of two gases in which one component is rare and heavy. He has shown that F 12 may be determined provided that thermal diffusion measurements for the given gas mixture have been made, and the coefficient of viscosity of the lighter gas at various temperatures together with the coefficient of diffusion of the two gases is known. Thermal diffusion measurements for radon-hydrogen and radon-helium gas mixtures have already been made by one of us (Harrison 1937), radon being the rare and heavy constituent of these mixtures. The variation of the viscosity of hydrogen and helium over a wide range of temperature was known, but no experimental value of the coefficient of diffusion of radon into hydrogen or helium was available. In the previous investigation, approximate values of the latter were therefore calculated from a formula given by Chapman (1917). Owing to uncertainty in the accuracy of these calculated values, 8 12 was evaluated approximately for radon-hydrogen and radon-helium molecules, but μ 12 was not calculated, since the latter is much more sensitive to an error in the coefficient of diffusion than the former. The purpose of the present investigation was to obtain experimental values of the coefficient of diffusion of radon into hydrogen, helium, neon and argon, so that the repulsive force between radon-hydrogen and radonhelium molecules can be derived from existing experimental evidence, and that for radon-neon and radon-argon can be obtained when the thermal diffusion measurements for these two mixtures are completed. Information concerning the very massive, monatomic radon molecule obtained from diffusion experiments is of special interest, particularly as the molecular field cannot be obtained from viscosity measurements or the equation of state owing to the extremely small quantity of gas available.

scholarly journals Thermal diffusion in mixtures of the inert gases

1947 ◽  
Vol 189 (1018) ◽  
pp. 402-414 ◽  
Keyword(s):  
Critical Temperature ◽  
Temperature Dependence ◽  
Thermal Diffusion ◽  
Force Fields ◽  
Repulsive Force ◽  
Inert Gases ◽  
Lennard Jones ◽  
Observed Behaviour ◽  
Theoretical Results ◽  
Thermal Diffusion Ratio

Measurements have been made of the separation produced by thermal diffusion in all the binary mixtures of the inert gases (except Kr-X and Rn mixtures) at temperatures ranging from -180 to 400° C. The temperature dependence of the thermal diffusion ratio, k T , and of R T ( R T = k T /[ k T (∞)] 1 , where [ k T (∞)] 1 is the theoretical value for molecules behaving like rigid elastic spheres) has been deduced. The results indicate that, in general, R T increases with the temperature in the lower range and becomes constant at high temperatures. The constant value is first attained at a temperature which varies from mixture to mixture, but its magnitude is nearly the same for all mixtures. It corresponds with a repulsive force index of 11, if the molecules are treated as centres of repulsive force only. The results have been compared with those calculated by R. Clark Jones (1940, 1941) for a gas mixture in which the two molecular species have identical force fields of the Lennard-Jones type, with repulsive force index v = 9 and attractive force index v' = 5. The theoretical results give R T as a function of T / T c , where T c is the critical temperature of the gas. This relation with the critical temperature is supported by the experimental results, though there are difficulties in the comparison due to the non-identical nature of the force fields in the experimental mixtures. It appears, however, that the observed behaviour could be explained by a Lennard-Jones model if the force indices were suitably chosen, and that a study of the temperature dependence of R T in isotopic mixtures would enable the indices to be determined with some precision.

The recombination of atoms II. Causes of variation in the observed rate constant for iodine atoms

1955 ◽  
Vol 231 (1187) ◽  
pp. 446-457 ◽  
Keyword(s):  
Rate Constant ◽  
Inert Gases ◽  
Inert Gas ◽  
Third Order ◽  
Experimental Conditions ◽  
The Third ◽  
M 10 ◽  
Linear Relationships ◽  
Real Increase ◽  
Gas Molecules

A re-investigation of the recombination of iodine atoms in presence of the inert gases over a wider range of experimental conditions has shown that the simple termolecular rate law — d(I)/d t = k (I) 2 ( M ) is not obeyed. For each of the inert gases k , the experimentally determined termolecular rate constant, increases with the ratio (I 2 )/( M ), where (I 2 ) and ( M ) are the concentrations of iodine m olecules and inert gas molecules respectively. The dependence of k on (I 2 )/( M ) was obscured in previous work by the fact that a thermal effect, which results in a lowering of the apparent value of k as recombination proceeds, increases as (I 2 )/( M ) increases and compensated for the real increase in k with (I 2 )/( M ). Except at low (I 2 )/( M ) values, k is a linear function of (I 2 )/( M ), the gradient being the same for all five inert gases. A rapid termolecular reaction I+I+I 2 =I 2 +I' 3 with a rate constant k = 470 x 10 -32 ml. 2 mol .-2 s -1 is postulated to explain the linear relationships. B y extrapolation the values of k M the third-order rate constants for the five inert gases are M 10 32 k M (ml. 2 mol. -2 s -1 ) He Ne A Kr Xe 0.67 0.92 1.84 2.25 2.99

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

Partition Coefficient Ratios and Tumour Perfusion Studied with 85mKr and 133Xe

1987 ◽  
Vol 26 (06) ◽  
pp. 253-257
Author(s):  
M. Mäntylä ◽  
J. Perkkiö ◽  
J. Heikkonen
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Regional Blood Flow ◽  
Blood Perfusion ◽  
Compartmental Analysis ◽  
Malignant Tumour ◽  
Mean Value ◽  
Perfusion Rate ◽  
Biological Variables ◽  
The Mean

The relative partition coefficients of krypton and xenon, and the regional blood flow in 27 superficial malignant tumour nodules in 22 patients with diagnosed tumours were measured using the 85mKr- and 133Xe-clearance method. In order to minimize the effect of biological variables on the measurements the radionuclides were injected simultaneously into the tumour. The distribution of the radiotracers was assumed to be in equilibrium at the beginning of the experiment. The blood perfusion was calculated by fitting a two-exponential function to the measuring points. The mean value of the perfusion rate calculated from the xenon results was 13 ± 10 ml/(100 g-min) [range 3 to 38 ml/(100 g-min)] and from the krypton results 19 ± 11 ml/(100 g-min) [range 5 to 45 ml/(100 g-min)]. These values were obtained, if the partition coefficients are equal to one. The equations obtained by using compartmental analysis were used for the calculation of the relative partition coefficient of krypton and xenon. The partition coefficient of krypton was found to be slightly smaller than that of xenon, which may be due to its smaller molecular weight.

Detection of Soluble Fibrin Monomer Complexes in Blood by Means of Protamine Sulphate Test

1968 ◽  
Vol 20 (01/02) ◽  
pp. 044-049 ◽  
Author(s):  
B Lipiński ◽  
K Worowski
Keyword(s):  
Human Subjects ◽  
Coronary Thrombosis ◽  
Mean Value ◽  
Healthy Human ◽  
Protamine Sulphate ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
Dog Plasma ◽  
The Mean ◽  
Precipitable Protein

SummaryIn the present paper described is a simple test for detecting soluble fibrin monomer complexes (SFMC) in blood. The test consists in mixing 1% protamine sulphate with diluted oxalated plasma or serum and reading the optical density at 6190 Å. In experiments with dog plasma, enriched with soluble fibrin complexes, it was shown that OD read in PS test is proportional to the amount of fibrin recovered from the precipitate. It was found that SFMC level in plasma increases in rabbits infused intravenously with thrombin and decreases after injection of plasmin with streptokinase. In both cases PS precipitable protein in serum is elevated indicating enhanced fibrinolysis. In healthy human subjects the mean value of OD readings in plasma and sera were found to be 0.30 and 0.11, while in patients with coronary thrombosis they are 0.64 and 0.05 respectively. The origin of SFMC in circulation under physiological and pathological conditions is discussed.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Determination of Plasminogen in Clots and Thrombi

1966 ◽  
Vol 16 (01/02) ◽  
pp. 038-050 ◽  
Author(s):  
Ulla Hedner ◽  
Inga Marie Nilsson ◽  
B Robertson
Keyword(s):  
Mean Value ◽  
Main Mechanism ◽  
Clot Lysis ◽  
Post Mortem ◽  
Digestion Time ◽  
Normal Volunteers ◽  
Casein Solution ◽  
The Mean

SummaryThe plasminogen content was determined by a casein method in plasma and serum from 20 normal volunteers. The mean plasminogen content was found to be 10.1 ACU (the arbitrary caseinolytic unit defined in such a way that using a 3% casein solution and a digestion time of 20 min. at 37°C, 10 ACU gave an extinction of 0.300). No difference between serum and plasma regarding the plasminogen content was found.Plasminogen was determined in drained and drained plus washed clots prepared from 2 ml plasma. The highest values found in the drained clots were 0.9 ACU/clot and 0.2 ACU/clot in the drained plus washed clots.Plasminogen was also determined in drained and drained plus washed clots prepared from plasma with added purified plasminogen. The plasminogen was recovered in the washing fluid. According to these tests, then, purified added plasminogen is washed out of the clots.The plasminogen content of 20 thrombi obtained post mortem was also determined. The mean value was found to be 0.7 ACU/cm thrombus. Judging from our results, the “intrinsic clot lysis theory” is not the main mechanism of clot dissolution.

Perbedaan Pengetahuan Siswa Tentang Penyakit Hepatitis A Sebelum Dan Sesudah Penyuluhan Di MTsN 02 Bondowoso Tahun 2015

2017 ◽  
Vol 4 (2) ◽  
pp. 14
Author(s):  
Putri Megasari
Keyword(s):  
Hepatitis A ◽  
Hepatitis Virus ◽  
Sampling Technique ◽  
Mean Value ◽  
Test Design ◽  
The World ◽  
Before And After ◽  
Post Test ◽  
The Mean ◽  
Paired T Test

Hepatitis has become a health problem in the world. The hepatitis virus infected many people. According to the teacher of MTsN 02 Bondowoso more than 20 students have hepatitis A viral infection. The purpose of this research was to know the differences of students' knowledge about hepatitis A before and after counseling in MTsN 02 Bondowoso 2015. This study used pre-experimental (pre-post test design). This study used stratified random sampling technique, 127 students from 270 sample involved this research,and 143 students was excluded. We used questionnaires to collect data. The results showed that the mean value of the students 'knowledge about hepatitis A before counseling in MTsN 02 Bondowoso 2015 was 83.96 with the lowest value of 37.5 and the highest value was 100. The mean value of the students' knowledge about hepatitis A after counseling in MTsN 02 Bondowoso 2015 was 93.21 with the lowest value waf 62.5 and the highest value was 100. Paired t test showed that t (-9.07) > t table (1.98), the null hypothesis (H0) was rejected. There was a difference between students' knowledge about hepatitis A before and after counseling in MTsN 02 Bondowoso 2015. This study showed that routine counseling by healthcare provider was important to prevent hepatitis A infection.; Keywords: counseling, knowledge of students, hepatitis

SERUM THYROTROPHIN AND THE RESPONSE TO THYROTROPHIN RELEASING HORMONE IN SYMPTOMLESS AUTOIMMUNE THYROIDITIS AND IN BORDERLINE AND OVERT HYPOTHYROIDISM

1974 ◽  
Vol 75 (2) ◽  
pp. 274-285 ◽  
Author(s):  
A. Gordin ◽  
P. Saarinen ◽  
R. Pelkonen ◽  
B.-A. Lamberg
Keyword(s):  
Autoimmune Thyroiditis ◽  
Elevated Serum ◽  
Mean Value ◽  
Primary Hypothyroidism ◽  
Overt Hypothyroidism ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
The Mean ◽  
The Individual ◽  
Serum Tsh

ABSTRACT Serum thyrotrophin (TSH) was determined by the double-antibody radioimmunoassay in 58 patients with primary hypothyroidism and was found to be elevated in all but 2 patients, one of whom had overt and one clinically borderline hypothyroidism. Six (29%) out of 21 subjects with symptomless autoimmune thyroiditis (SAT) had an elevated serum TSH level. There was little correlation between the severity of the disease and the serum TSH values in individual cases. However, the mean serum TSH value in overt hypothyroidism (93.4 μU/ml) was significantly higher than the mean value both in clinically borderline hypothyroidism (34.4 μU/ml) and in SAT (8.8 μU/ml). The response to the thyrotrophin-releasing hormone (TRH) was increased in all 39 patients with overt or borderline hypothyroidism and in 9 (43 %) of the 21 subjects with SAT. The individual TRH response in these two groups showed a marked overlap, but the mean response was significantly higher in overt (149.5 μU/ml) or clinically borderline hypothyroidism (99.9 μU/ml) than in SAT (35.3 μU/ml). Thus a normal basal TSH level in connection with a normal response to TRH excludes primary hypothyroidism, but nevertheless not all patients with elevated TSH values or increased responses to TRH are clinically hypothyroid.

Sign in / Sign up

Export Citation Format

Share Document