Swelling and Solvation of Rubber in Different Solvents

1937 ◽  
Vol 10 (2) ◽  
pp. 235-241
Author(s):  
Ira Williams
Keyword(s):  
Molecular Weight ◽  
Relative Viscosity ◽  
Close Relation ◽  
The State ◽  
Equal Concentration ◽  
Chemical Attack ◽  
Dispersed Particles ◽  
Viscosity Characteristic ◽  
Degree Of Oxidation ◽  
Fractional Increase

Abstract The large variation of the fractional increase in viscosity of rubber sols and its lack of relation to the viscosity of the solvent indicates that the increase in viscosity is not due to rigid filiform molecules. The ability to interchange solvents and obtain a viscosity characteristic of the solvent shows the existence of a reversible equilibrium between solvent and rubber. The close relation between the maximum swelling and the fractional increase in viscosity of rubber in different solvents suggests that rubber sols contain swollen micelles of rubber. The extent of swelling and the viscosity depend on the equilibrium between solvent and rubber which, in turn, depends on the state of oxidation (or other suitable chemical attack) of the rubber. A rubber sol becomes a gel at the concentration which immobilizes essentially all the solvent. The relative viscosity of rubber sols of equal concentration in the same solvent is probably some function of the degree of solvation of the dispersed particles which is influenced by the degree of oxidation of the rubber. Viscosity is not a measure of the molecular weight.

Labour migration and its impact on employment in the Republic of Bashkortostan

2017 ◽  
Vol 31 (2) ◽  
pp. 67-74
Author(s):  
G. V. Yakshibaeva
Keyword(s):  
Migrant Workers ◽  
Close Relation ◽  
The State ◽  
Labour Migration ◽  
Rational Selection ◽  
Labor Migrants ◽  
Republic Of Bashkortostan ◽  
The Republic ◽  
External Migration

The problem of providing the most efficient and rational selection, distribution, use of migrant workers, with regard to both internal and external migration in close relation to socio-economic and demographic interests of the state are currently of particular relevance. Scientific novelty of work consists in the identification of factors and directions of flows as departing and arriving labor migrants in the Republic of Bashkortostan, the characteristics of the development of labour migration and its impact on employment, which allowed to identify problems and negative trends.

scholarly journals Identification of particulate organosulfates in three megacities at the middle and lower reaches of the Yangtze River

2015 ◽  
Vol 15 (15) ◽  
pp. 21415-21448 ◽  
Author(s):  
X. K. Wang ◽  
S. Rossignol ◽  
Y. Ma ◽  
L. Yao ◽  
M. Y. Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Yangtze River ◽  
High Performance ◽  
Average Molecular Weight ◽  
Photochemical Reactions ◽  
Degree Of Saturation ◽  
The Yangtze River ◽  
Seasonal And Diurnal Variations ◽  
Degree Of Oxidation ◽  
Kendrick Mass Defect

Abstract. PM2.5 filter samples have been collected in three megacities i.e., Wuhan (WH), Nanjing (NJ), and Shanghai (SH) at the middle and lower reaches of the Yangtze River, respectively. Analysis of those samples using an ultra-high performance liquid chromatography (UHPLC) coupled to an orbitrap mass spectrometer (MS) allowed detection of about two hundred particulate organosulfates (OSs), including dozens of nitrooxy-organosulfates, at each location. While aliphatic OSs represented more than 78 % of the detected OSs at the three locations, aromatic OSs were much less abundant. OSs with two to four isomers accounted for about 50 % of the total OSs on average in these megacities, and the percentage of OSs with six and more isomers in WH was more significant than those in SH and NJ. The average molecular weight, and the degrees of oxidation and saturation of OSs in the WH summer samples were greater than those in WH winter samples. In SH, the average molecular weight and the degree of oxidation of OSs in summer samples were greater than those in winter samples, but the degree of saturation was similar between the two seasons. In summer, the average molecular weight, and the degrees of oxidation and unsaturation of OSs were smallest in WH among the three cities. Between NJ and SH, the average molecular weight and the degree of saturation of OSs were close and the degree of oxidation of OSs in NJ was smaller. Kendrick mass defect diagrams and Van Krevelen diagrams indicated that the characteristics of identified OSs between in NJ and in SH shared better similarity. In addition, the identity and abundance of OSs in SH showed clear seasonal and diurnal variations. OSs in summer were more abundant than they were in winter due to stronger photochemical reactions in summer. The relative abundance of OSs at night was greater than that in the daytime and more nitrooxy-OSs existed at night, probably because of active NO3 radical chemistry at night. In SH summer samples, OSs with 5 and 10 carbons (C5 and C10) were the most abundant, indicating the importance of isoprene and monoterpenes as precursors of OSs, whereas the relative abundances of OSs with 8, 9, and more than 14 carbons (C8, C9, and C14+) were also high in SH winter samples, urging the need to further understand the precursors of OSs.

ELECTROCHEMISTRY OF THE NICKEL OXIDE ELECTRODE: PART IV. ELECTROCHEMICAL KINETIC STUDIES OF REVERSIBLE POTENTIALS AS A FUNCTION OF DEGREE OF OXIDATION

1962 ◽  
Vol 40 (10) ◽  
pp. 1933-1942 ◽  
Author(s):  
B. E. Conway ◽  
E. Gileadi
Keyword(s):  
Nickel Oxide ◽  
Kinetic Studies ◽  
The State ◽  
Total Charge ◽  
Oxide Material ◽  
Oxide Electrode ◽  
Reversible Potential ◽  
Wide Range ◽  
Degree Of Oxidation ◽  
Nickel Oxide Electrode

Electrochemical kinetic studies have been carried out at the nickel oxide electrode showing that the reversible potential for the NiII–NiIII system is independent of the state of oxidation of the bulk oxide in the electrode over a wide range of degrees of oxidation. The properties of the electrode are shown to be determined by the state of a surface phase, which is completely charged when the bulk oxide material in the electrode has been charged to 10% of its total charge capacity. Experiments on sparingly charged electrodes have proved that charging of the bulk oxide does not commence significantly until the electrode is charged to about 1.5%. Consecutive electrochemical reactions possibly involved in the charging process are discussed.

Measurement of the Isothermal Volume Dilation Accompanying the Unilateral Extension of Rubber

1959 ◽  
Vol 32 (2) ◽  
pp. 428-433
Author(s):  
Fred G. Hewitt ◽  
Robert L. Anthony
Keyword(s):  
Molecular Weight ◽  
Young’S Modulus ◽  
Experimental Results ◽  
Molecular Weights ◽  
Rubber Specimen ◽  
A Value ◽  
Fractional Increase ◽  
Internal Agreement ◽  
Good Agreement

Abstract The fractional increase in volume accompanying the isothermal extension of soft gum rubber was measured for four rubber samples at mean extensions of 14, 33, and 51%. The chain molecular weights Mc of the four samples were 5500, 5100, 4400, and 3000, with an estimated uncertainty of about 10% in each value of Mc. The observed fractional increase in volume ranged from 3.2×10−5 to 142×10−5, the latter value being observed for the sample of lowest chain molecular weight and at the extension of 51%. The experimental results for each sample have been represented by theoretical curves based on Gee's expression for the fractional increase in volume as a function of the sample extension. The theoretical curves exhibit good agreement with those of Gee, Stern, and Treloar. The process of fitting the theoretical curves to the experimental points constituted a determination of Young's modulus E for each rubber specimen. As a check on the experimental results, and also on the theory employed, determinations of E were also made by two additional methods, namely, from rough stess-strain curves, and from the relation E=3γρRT/Mc. With one exception, the internal agreement between the three determinations of E for the four different samples was satisfactory. The exception noted can probably be ascribed to the use of too small a value of Mc for the sample of lowest chain molecular weight.

Socialization and Process: a Methodological Problem

1982 ◽  
Vol 13 (2) ◽  
pp. 143-159
Author(s):  
Colin W. Pritchard
Keyword(s):  
Methodological Problem ◽  
Close Relation ◽  
Emergent Property ◽  
The State ◽  
Basic Form ◽  
Final State ◽  
The Core ◽  
Present Argument

AbstractThe basic form of experiencing process as such, then, lies in the apprehension of an object changing through an ordered sequence of states towards an end state. The sequence is grasped in the light of the final state of things which stands in close relation to the central noema of "changing object" in terms of which the phases of the sequence are recognized and related. The central noema is itself an emergent property of the identification of the sequence of states as "pertaining to the same something." This complex, not to say convoluted, constitution is iteratively established through polythetic acts in which change itself is grasped and sequence evidenced through the positing of possible sequences in the light of the intuition of succession. Eventually the whole sequence may be grasped monothetically and the process experienced as such as a whole. This prototype of process itself provides a basic form by which the events of intentional life may be ordered. The core experience, that objects do change in an ordered manner towards a defined and defining end may provide a way of meaningfully structuring experience. Thus for example, the succession Sii to Siii may be experienced as such. That succession may lead to a question like "towards what end does this succession tend?" More germane to the present argument, a particular state of things may lead to the question "by what process has this state of things come about?" In both these cases, the prototype of process leads to the attempt to interpret the succession or the state of things in terms of orderly change through time and in this way the intuition of process, in its own right, may provide a structure in which the phenomena of consciousness may be experienced and meaningfully related.

scholarly journals INVESTIGATION OF EXTERNAL RESPIRATORY FUNCTION AND HEMOSTASIS SYSTEM’S STATUS IN PATIENTS WITH CHRONIC OBSTRUCTIVE LUNG DISEASE WITH CONCOMITANT CHRONIC PANCREATITIS

2020 ◽  
Vol 1 ◽  
pp. 48-52
Author(s):  
Yulia Karliychuk ◽  
Inna Dudka ◽  
Vitaliy Smandych ◽  
Taisiia Krasnova ◽  
Petro Varkhomiy
Keyword(s):  
Molecular Weight ◽  
Chronic Pancreatitis ◽  
Pulmonary Fibrosis ◽  
Proteinase Inhibitors ◽  
The State ◽  
Coagulation System ◽  
Collagenolytic Activity ◽  
External Respiration ◽  
Copd Patients ◽  
Frequent Relapses

INTRODUCTION: It can be assumed that the comorbidity course of сhronic obstructive pulmonary disease (COPD) and chronic pancreatitis (CP) can enhance the clinical symptoms of both diseases and lead to frequent relapses of the pathological process due to changes in the proteolysis intensity of high and low molecular weight plasma proteins and the state of the hemocoagulation. OBJECTIVE: To establish the features of hemocoagulation and proteolytic hemostasis at COPD with concomitant CP. METHODS: 120 patients with COPD and CP were examined. The function of external respiration, total coagulation potential of blood plasma, the state of enzymatic and non-enzymatic fibrinolysis, total fibrinolytic activity were investigated. RESULTS: CP contributes to the development of broncho-obstructive syndrome, and the maximum indicators of reduction of FEV1 relative to the proper values are observed in patients with a comorbid course of COPD and CP. Reducing the intensity of collagenolysis in patients of groups 1-2 contributed to the development of diffuse pulmonary fibrosis in response to chronic inflammation. The imbalanced increase in the intensity of proteolysis due to reduced expression of its inhibitors in COPD patients with CP led to progressive destruction of the cell membranes of alveolocytes, acinar epithelium of pancreas and epithelium of the bronchial mucosa, acceleration of their apoptosis and development of desquamation, atrophic changes, metaplasia, and the like. The above factors are active as inducers of inflammation, and the formation of pulmonary fibrosis and fibrosis of the pancreas. CONCLUSIONS: In COPD patients with accompanying CP are an increase in the lysis rate of low and high molecular weight proteins and a decrease in blood collagenolytic activity on the background of a significant imbalance in the activity of plasma proteinase inhibitors. Defined suppression of the activity of the anti-coagulation system factors and enzymatic, Hageman-factor-dependent fibrinolysis indicates the formation of hypercoagulation syndrome in these patients.

Method for measuring the concentration of urinary proteins according to their molecular size category.

1976 ◽  
Vol 22 (5) ◽  
pp. 667-672 ◽  
Author(s):  
A J Pesce ◽  
A Hsu ◽  
C Kornhauser ◽  
K Sethi ◽  
B S Ooi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Low Molecular Weight ◽  
Tubular Proteinuria ◽  
Equal Concentration ◽  
Glomerular Proteinuria ◽  
Low Molecular Weight Proteins

Abstract We combined the use of a concentrating device (Minicon) and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate to semi-quantitate the concentration of (a) the collective low-molecular-weight proteins and (b) of albumin excreted in the urine of patients after renal transplantation. Analytical recovery of many serum proteins from samples concentrated 100-fold in the Minicon apparatus was about 70%. It was possible to examine many urine samples by polyacrylamide gel electrophoresis after concentration with this device. The reproducibility (CV) of the technique was on the order of 20% when albumin and low-molecular-weight protein were in about equal concentration. The method was adequate to differntiate glomerular and tubular proteinuria, because in glomerular proteinuria the ratio of albumin to low-molecular-weight proteins is about 20/1, whereas in tubular proteinuria the ratio is about 1/1.

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