scholarly journals On the stability of unimolecular films. Part I.—The conditions of equilibrium

1929 ◽  
Vol 124 (794) ◽  
pp. 322-333 ◽  
Keyword(s):  
Vapour Pressure ◽  
Film Formation ◽  
The State ◽  
Long Chain Fatty Acids ◽  
Phase Rule ◽  
Highly Dispersed ◽  
Temperature And Pressure ◽  
The Stability ◽  
Long Chain ◽  
Good Agreement

Of the factors which determine the state of equilibrium of a unimolecular film on the surface of water the two which have been subjected to the most exhaustive examination are the effects of changes in temperature and pressure. In previous communications a generalisation of the effects of kinetic agitation on the state of a film, and the conditions of equilibrium imposed by the phase rule on the various states of such films have been described. As pointed out originally by Hardy, in film formation the magnitude and direction of the adhesional forces between the surface and the polar "heads" of the spreading molecules is one of primary importance. The effects of replacement of one type of polar head by another have been examined in detail by numerous investigators; but the effect on the state of a film of one substance of changing the magnitude of this adhesion, a factor clearly as important as the conditions of temperature and pressure, has not hitherto been considered. In these communications the results of an investigation on the effects of such a change are described. Unimolecular films of long chain fatty acids on the surface of water can exist in three well-defined states, the highly dispersed or vaporous, the expanded and the condensed. The expanded state, first noted by Labrouste, was considered originally by Adam to be vaporous in character. Schofield and Rideal ( loc. cit .), however, from an examination of the isothermals of the force area curves for a series of acids concluded that expanded that the true vapour pressure of a film of myristic acid at ordinary temperatures should be about 0∙2 dynes per centimetre. A similar suggestion was made independently by Langmuir and later accepted by Adam, when with a sensitive apparatus he effected the measurement of the vapour pressure of expanded films, which proved to be in good agreement with that predicted by Schofield and Rideal. It seemed probable that expanded films consist of some arrangement of tilted molecules with the chains still enmeshed and the heads free, as suggested by Schofield and Rideal and Langmuir. Adam, however, has concluded that the heads adhere to one another with sufficient tenacity to render this view improbable.

scholarly journals Protective Langmuir–Blodgett coatings based on long-chain fatty acids

2021 ◽  
Vol 57 (4) ◽  
pp. 480-487
Author(s):  
V. M. Akulova ◽  
A. E. Salamianski ◽  
G. B. Melnikova ◽  
D. A. Nekrashevich ◽  
Yu. V. Sinkevich ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Wear Resistance ◽  
Silicon Surface ◽  
Steel Surface ◽  
Long Chain Fatty Acids ◽  
Langmuir Blodgett ◽  
Tribotechnical Properties ◽  
Monomolecular Films ◽  
The Stability ◽  
Long Chain

The morphology and tribotechnical properties of Langmuir–Blodgett (LB) monolayers and multilayers of some fatty acids, such as nervonic (NA), cerotic (CA) and montanic acids (OCA), was investigated. It was established that the wear resistance of silicon surface coated by LB monolayer of OCA is greater by 11 and 1.3 times in comparison with the LB monomolecular films of NA and CA, respectively. The multilayer of OCA, formed by 140 layers, increases the stability of steel surface by 35 times.

scholarly journals Study and monitoring of the stability of a rock mass at the Dar-El-Oued tunnel, wilaya of Jijel – Algeria

2018 ◽  
Vol 149 ◽  
pp. 02069
Author(s):  
Chahra Yellas ◽  
Riad Benzaid ◽  
Mustapha Tekkouk
Keyword(s):  
Numerical Model ◽  
The State ◽  
Underground Structures ◽  
Surface Displacements ◽  
The Face ◽  
The Stability ◽  
National Road ◽  
The City ◽  
Good Agreement

The construction of a civil engineering work requires many preliminary studies as well as various calculation methods to give an assessment or a forecast of the state of the rock in place and the behavior of the structure in its real environment and under various conditions (construction phase, service and operating phase). The present work concerns the access zone of the Dar-El-Oued tunnel, located on the national road n°43 about 40 km West of the city of Jijel (northeastern Algeria). The geotechnical study of this tunnel was carried out following the classification methods relating to underground structures. Through the results of this study we have determined the influence of land pressures on the mechanical behavior of the ground, which allowed us to measure the state of stress in the rock and to make a comparison between the results of the measurements of convergence and that of numerical modeling. On the other hand, the influence of the velocity of vibration induced by explosive shots has been discussed in order to check the stability of the face as the digging progresses. From the results obtained, it can be said that the surface displacements of the soil are relatively small compared to those determined by the numerical model at the level of the vault and the slab. Note the good agreement between the results provided by our numerical model and those obtained in-situ.

Postprandial Activation of Coagulant Factor VII by Long-chain Dietary Fatty Acids

1996 ◽  
Vol 76 (03) ◽  
pp. 369-371 ◽  
Author(s):  
T A B Sanders ◽  
G J Miller ◽  
Tamara de Grassi ◽  
Najat Yahia
Keyword(s):  
Fatty Acids ◽  
Dietary Fatty Acids ◽  
Factor Vii ◽  
Fat Intake ◽  
Long Chain Fatty Acids ◽  
Postprandial Lipaemia ◽  
Increased Risk ◽  
Coagulant Activity ◽  
Long Chain Triglycerides ◽  
Long Chain

SummaryFactor VII coagulant activity (FVIIc) is associated with an increased risk of fatal ischaemic heart disease (IHD). Several reports have suggested that dietary fat intake or hypertriglyceridaemia are associated with elevated levels of FVII. This study demonstrates that an intake of long-chain fatty acids sufficient to induce postprandial lipaemia in healthy subjects leads to a substantial elevation in both FVIIc and the concentration of FVII circulating in the activated form. Such an increase in FVIIc could not be induced by medium-chain triglycerides. These results suggest that the consumption of a sufficient amount of long-chain triglycerides to induce postprandial lipaemia induces the activation of FVII.

The working standard of the unit of power of electromagnetic waves in the frequency range from 37,5 to 220 GHz

2020 ◽  
pp. 53-58
Author(s):  
A. V. Koudelny ◽  
I. M. Malay ◽  
V. A. Perepelkin ◽  
I. P. Chirkov
Keyword(s):  
Microwave Power ◽  
Electromagnetic Waves ◽  
Primary Standard ◽  
The State ◽  
Frequency Range ◽  
Working Standard ◽  
Extended Frequency Range ◽  
Effective Efficiency ◽  
Extended Frequency ◽  
Good Agreement

The possibility of using bolometric converters of microwave power from the State primary standard of the unit of power of electromagnetic waves in waveguide and coaxial paths GET 167-2017, which has a frequency range from 37,5 to 78,33 GHz, in an extended frequency range up to 220 GHz, is shown. Studies of semiconductor bolometric converters of microwave power in an extended frequency range have confirmed good agreement and smooth frequency characteristics of the effective efficiency factor of the converters. Based on the research results, the State working standard of the unit of power of electromagnetic waves of 0,1–10 mW in the frequency range from 37,5 to 220 GHz 3.1.ZZT.0288.2018 was approved. The technical characteristics of the working standard of the unit of power of electromagnetic oscillations in an extended frequency range from 37,5 to 220 GHz are given.

Cracking national integration after the events (the Arab Spring) and its impact On regional stability

2019 ◽  
Vol 3 (6) ◽  
pp. 1
Author(s):  
Muhannad Al Janabi Al Janabi
Keyword(s):  
Arab Spring ◽  
The State ◽  
The Political ◽  
Prominent Feature ◽  
Regional Stability ◽  
National Integration ◽  
Arab Region ◽  
Political Media ◽  
The Stability ◽  
The Arab Spring

Since late 2010 and early 2011, the Arab region has witnessed mass protests in Tunisia, Egypt, Libya, Syria, Yemen, Iraq, Bahrain and other countries that have been referred to in the political, media and other literature as the Arab Spring. These movements have had a profound effect on the stability of the regimes Which took place against it, as leaders took off and contributed to radical reforms in party structures and public freedoms and the transfer of power, but it also contributed to the occurrence of many countries in an internal spiral, which led to the erosion of the state from the inside until it became a prominent feature of the Arab) as is the case in Syria, Libya, Yemen and Iraq.

IMPACT OF GOVERNMENT DEBT ON FINANCIAL SECURITY OF UKRAINE

2017 ◽  
Author(s):  
Olena Pikaliuk ◽  
◽  
Dmitry Kovalenko ◽  
Keyword(s):  
Economic Development ◽  
Public Debt ◽  
Positive Impact ◽  
The State ◽  
Financial Security ◽  
State Budget ◽  
The Public ◽  
Debt Security ◽  
The Stability ◽  
The Impact

One of the main criteria for economic development is the size of the public debt and its dynamics. The article considers the impact of public debt on the financial security of Ukraine. The views of scientists on the essence of public debt and financial security of the state are substantiated. An analysis of the dynamics and structure of public debt of Ukraine for 2014-2019. It is proved that one of the main criteria for economic development is the size of public debt and its dynamics. State budget deficit, attracting and using loans to cover it have led to the formation and significant growth of public debt in Ukraine. The volume of public debt indicates an increase in the debt security of the state, which is a component of financial security. Therefore, the issue of the impact of public debt on the financial security of Ukraine is becoming increasingly relevant. The constant growth and large amounts of debt make it necessary to study it, which will have a positive impact on economic processes that will ensure the stability of the financial system and enhance its security.

scholarly journals Differential Effects of Fatty Acid Saturation and Chain Length on NASH in Juvenile Iberian Pigs

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 682-682 ◽  
Author(s):  
Kayla Dillard ◽  
Morgan Coffin ◽  
Gabriella Hernandez ◽  
Victoria Smith ◽  
Catherine Johnson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Body Weight ◽  
Fatty Acid ◽  
Liver Injury ◽  
Olive Oil ◽  
Coconut Oil ◽  
Long Chain Fatty Acids ◽  
Medium Chain ◽  
Long Chain ◽  
Chain Fatty Acids

Abstract Objectives Non-alcoholic fatty liver disease (NAFLD) represents the major cause of pediatric chronic liver pathology in the United States. The objective of this study was to compare the relative effect of inclusion of isocaloric amounts of saturated medium-chain fatty acids (hydrogenated coconut oil), saturated long-chain fatty acids (lard) and unsaturated long-chain fatty acids (olive oil) on endpoints of NAFLD and insulin resistance. Methods Thirty-eight 15-d-old Iberian pigs were fed 1 of 4 diets containing (g/kg body weight × d) 1) control (CON; n = 8): 0 g fructose, 10.5 g fat, and 187 kcal metabolizable energy (ME), 2) lard (LAR; n = 10): 21.6 g fructose, 17.1 g fat (100% lard) and 299 kcal ME, 3) hydrogenated coconut oil (COCO; n = 10): 21.6 g fructose, 16.9 g fat (42.5% lard and 57.5% coconut oil) and 299 kcal ME, and 4) olive oil (OLV, n = 10): 21.6 g fructose, 17.1 g fat (43.5% lard and 56.5% olive oil) and 299 kcal ME, for 9 consecutive weeks. Body weight was recorded every 3 d. Serum markers of liver injury and dyslipidemia were measured on d 60 at 2 h post feeding, with all other serum measures assessed on d 70. Liver tissue was collected on d 70 for histology, triacylglyceride (TG) quantification, and metabolomics analysis. Results Tissue histology indicated the presence of steatosis in LAR, COCO and OLV compared with CON (P ≤ 0.001), with a further increase in in non-alcoholic steatohepatitis (NASH) in OLV and COCO compared with LAR (P ≤ 0.01). Alanine and aspartate aminotransferases were higher in COCO and OLV (P ≤ 0.01) than CON. All treatment groups had lower liver concentrations of methyl donor's choline and betaine versus CON, while bile acids were differentially changed (P ≤ 0.05). COCO had higher levels of TGs with less carbons (Total carbons < 52) than all other groups (P ≤ 0.05). Several long-chain acylcarnitines involved in fat oxidation were higher in OLV versus all other groups (P ≤ 0.05). Conclusions Inclusion of fats enriched in medium-chain saturated and long-chain unsaturated fatty acids in a high-fructose high-fat diet increased liver injury, compared with fats with a long-chain saturated fatty acid profile. Further research is required to investigate the mechanisms causing this difference in physiological response to these dietary fat sources. Funding Sources ARI, AcornSeekers.

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