Surfactant systems for drag reduction: Physico-chemical properties and rheological behaviour

1986 ◽  
Vol 25 (5) ◽  
pp. 468-486 ◽  
Author(s):  
D. Ohlendorf ◽  
W. Interthal ◽  
H. Hoffmann
Keyword(s):  
Drag Reduction ◽  
Chemical Properties ◽  
Rheological Behaviour ◽  
Physico Chemical ◽  
Surfactant Systems

scholarly journals Micellar Catalysis of Chemical Reactions by Mixed Surfactant Systems and Gemini Surfactants

2021 ◽  
Vol 33 (7) ◽  
pp. 1471-1480
Author(s):  
Mohammed Hassan ◽  
Sadeq M. Al-Hazmi ◽  
Ibrahim A. Alhagri ◽  
Ahmed N. Alhakimi ◽  
Adnan Dahadha ◽  
...  
Keyword(s):  
Gemini Surfactants ◽  
Chemical Properties ◽  
Catalytic Efficiency ◽  
Micellar Catalysis ◽  
Head Group ◽  
Mixed Surfactant ◽  
Structure Control ◽  
Mixed Surfactant Systems ◽  
Physico Chemical ◽  
Surfactant Systems

Micellar catalysis exhibited by mixed surfactant systems and gemini surfactants was reviewed. The review focused on mixed surfactant systems and tried to correlate the changes in the physico-chemical properties of these systems to the variations of their catalytic activities. Mixed surfactant systems are promising as the catalytic efficiency of some single surfactants was significantly enhanced in the presence of other critically selected surfactants. The selection should consider the charge, size, and structures of the head group as well as an appropriate length of hydrocarbon tail. The overall conclusion has arrived the mixed surfactant systems could be a tool by which the reaction rate can be tuned by changing the composition and/or the components’ structures. The higher catalytic activity of gemini surfactants compared to conventional ones, their facile synthesis and liability for structure control made them of superior choice for micellar catalysis.

Physico-chemical properties and rheological behaviour ofPatella caerula paramyosin

1995 ◽  
Vol 201 (3) ◽  
pp. 230-235 ◽  
Author(s):  
V�ronique Verrez-Bagnis ◽  
Marc J�r�me
Keyword(s):  
Chemical Properties ◽  
Rheological Behaviour ◽  
Physico Chemical

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

PHYSICO CHEMICAL PROPERTIES OF NICKEL OXIDE AT HIGH TEMPERATURE

1976 ◽  
Vol 37 (C7) ◽  
pp. C7-438-C7-442 ◽  
Author(s):  
R. FARHI ◽  
G. PETOT-ERVAS
Keyword(s):  
High Temperature ◽  
Nickel Oxide ◽  
Chemical Properties ◽  
Physico Chemical

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

Physico-chemical properties of the rare-earth metals, scandium, and yttrium

1963 ◽  
Vol 79 (2) ◽  
pp. 263-293 ◽  
Author(s):  
E.M. Savitskii ◽  
V.F. Terekhova ◽  
O.P. Naumkin
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Chemical Properties ◽  
Physico Chemical ◽  
The Rare Earth

Physico chemical properties and gas adsorption separation characteristics of Itaya zeolite and its modified products.

1990 ◽  
Vol 39 (442) ◽  
pp. 996-1000 ◽  
Author(s):  
Ayao TAKASAKA ◽  
Hideyuki NEMOTO ◽  
Hirohiko KONO ◽  
Yoshihiro MATSUDA
Keyword(s):  
Gas Adsorption ◽  
Chemical Properties ◽  
Physico Chemical

Development of Ketchup from Sudanese Red karkade (Hibiscus sabdariffa L.) byproduct

Food Biology ◽  
1970 ◽  
pp. 19-23
Author(s):  
Nawal Abdel-Gayoum Abdel-Rahman
Keyword(s):  
Sensory Quality ◽  
Chemical Properties ◽  
Storage Period ◽  
Gum Arabic ◽  
Raw Material ◽  
Soluble Solids ◽  
Hibiscus Sabdariffa ◽  
Overall Acceptability ◽  
Physico Chemical ◽  
Tomato Ketchup

The aim of this study is to use of karkede (Hibiscus sabdariffa L.) byproduct as raw material to make ketchup instead of tomato. Ketchup is making of various pulps, but the best type made from tomatoes. Roselle having adequate amounts of macro and micro elements, and it is rich in source of anthocyanine. The ketchup made from pulped of waste of soaked karkede, and homogenized with starch, salt, sugar, ginger (Zingiber officinale), kusbara (Coriandrum sativum) and gum Arabic. Then processed and filled in glass bottles and stored at two different temperatures, ambient and refrigeration. The total solids, total soluble solids, pH, ash, total titratable acidity and vitamin C of ketchup were determined. As well as, total sugars, reducing sugars, colour density, and sodium chloride percentage were evaluated. The sensory quality of developed product was determined immediately and after processing, which included colour, taste, odour, consistency and overall acceptability. The suitability during storage included microbial growth, physico-chemical properties and sensory quality. The karkede ketchup was found free of contaminants throughout storage period at both storage temperatures. Physico-chemical properties were found to be significantly differences at p?0.05 level during storage. There were no differences between karkade ketchup and market tomato ketchup concerning odour, taste, odour, consistency and overall acceptability. These results are encouraging for use of roselle cycle as a raw material to make acceptable karkade ketchup.

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