THE EFFECT OF THE FORMATION OF POLYMER /SURFACTANT COMPLEXES ON SELECTED TRIBOLOGICAL PROPERTIES OF THEIR AQUEOUS SOLUTIONS

Tribologia ◽  
2018 ◽  
Vol 281 (5) ◽  
pp. 117-122 ◽  
Author(s):  
Marian W. SUŁEK ◽  
Radosław JEDYNAK
Keyword(s):  
Aqueous Solutions ◽  
High Load ◽  
Polymer Complexes ◽  
Alkyl Sulphate ◽  
Practical Applications ◽  
Motion Resistance ◽  
Sodium Alkyl Sulphate ◽  
Polymer Surfactant ◽  
Load Conditions ◽  
Lubricating Properties

Aqueous solutions of sodium alkyl sulphate (surfactant) and polyvinylpyrrolidone (polymer) whose physicochemical properties, including complexing ability, have been widely described in the literature were proposed as a model lubricant. It has been assumed that aqueous solutions of these compounds will favourably modify lubricating properties of water under high load conditions. For this purpose, measurements were made on a four-ball apparatus (T-02 Tester) for aqueous solutions of these compounds. Two kinds of tests were carried out: at constant loads (2, 3, and 4 kN) and variable loads within the range of 0 to 7.2 kN. Unexpectedly, high decreases in motion resistance and wear as well as an increase in antiseizure properties were found in relation to water as a base. The results obtained are so promising that solutions with an optimized composition can find practical applications. The surprisingly high effectiveness of the additives used results from the formation of surfactant/polymer complexes. These adducts adsorb at the interface, and, under friction conditions, they form a lubricant film capable of carrying high loads.

High Load Conditions Measured on a UH-60A in Maneuvering Flight

1998 ◽  
Vol 43 (3) ◽  
pp. 202-211 ◽  
Author(s):  
Robert M. Kufeld ◽  
William G. Bousman
Keyword(s):  
High Load ◽  
Maneuvering Flight ◽  
Load Conditions

Contractile dysfunction of cardiomyopathic hamster myocytes is pronounced under high load conditions

2005 ◽  
Vol 39 (2) ◽  
pp. 231-239 ◽  
Author(s):  
S NISHIMURA ◽  
H YAMASHITA ◽  
M KATOH ◽  
K YAMADA ◽  
K SUNAGAWA ◽  
...  
Keyword(s):  
High Load ◽  
Contractile Dysfunction ◽  
Cardiomyopathic Hamster ◽  
Load Conditions

Initial Results on a New Light-Duty 2.7L Opposed-Piston Gasoline Compression Ignition Multi-Cylinder Engine

2018 ◽  
Author(s):  
Ashwin Salvi ◽  
Reed Hanson ◽  
Rodrigo Zermeno ◽  
Gerhard Regner ◽  
Mark Sellnau ◽  
...  
Keyword(s):  
Pressure Rise ◽  
High Load ◽  
Combustion Stability ◽  
Residual Fraction ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Peak Cylinder Pressure ◽  
Low Load ◽  
Initial Results ◽  
Load Conditions

Gasoline compression ignition (GCI) is a cost-effective approach to achieving diesel-like efficiencies with low emissions. Traditional challenges with GCI arise at low-load conditions due to low charge temperatures causing combustion instability and at high-load conditions due to peak cylinder pressure and noise limitations. The fundamental architecture of the two-stroke Achates Power Opposed-Piston Engine (OP Engine) enables GCI by decoupling piston motion from cylinder scavenging, allowing for flexible and independent control of cylinder residual fraction and temperature leading to improved low load combustion. In addition, the high peak cylinder pressure and noise challenges at high-load operation are mitigated by the lower BMEP operation and faster heat release for the same pressure rise rate of the OP Engine. These advantages further solidify the performance benefits of the OP Engine and demonstrate the near-term feasibility of advanced combustion technologies, enabled by the opposed-piston architecture. This paper presents initial results from a steady state testing on a brand new 2.7L OP GCI multi-cylinder engine. A part of the recipe for successful GCI operation calls for high compression ratio, leading to higher combustion stability at low-loads, higher efficiencies, and lower cycle HC+NOx emissions. In addition, initial results on catalyst light-off mode with GCI are also presented. The OP Engine’s architectural advantages enable faster and earlier catalyst light-off while producing low emissions, which further improves cycle emissions and fuel consumption over conventional engines.

Perceptual Load Improves the Expression but not Learning of Relevant Sequence Information

2009 ◽  
Vol 56 (2) ◽  
pp. 84-91 ◽  
Author(s):  
Natacha Deroost ◽  
Daphné Coomans ◽  
Eric Soetens
Keyword(s):  
Learning Process ◽  
Sequence Learning ◽  
Perceptual Load ◽  
Relevant Information ◽  
High Load ◽  
Cognitive System ◽  
Perceptual Identification ◽  
Sequence Information ◽  
Low Load ◽  
Load Conditions

In two experiments, we investigated the hypothesis of Rowland and Shanks (2006a) that sequence learning of relevant information is resistant to variations in perceptual load. Under conditions of increased selection difficulty, participants incidentally learned a sequence of targets presented together with three distractors. Target and distractors were composed of pairs of letters and shared more or less features with each other, rendering perceptual identification of the target either more (high load) or less (low load) attention demanding. The expression of sequence learning improved significantly under high load conditions as compared to low load conditions. This could indicate that the cognitive system promotes the development of response-based sequence learning in order to cope with the attentional demands arising from high perceptual load. However, the learning process proved to be unaffected by perceptual load when tested under baseline conditions without distractors (Experiment 1) or under opposite load conditions as during training (Experiment 2). This demonstrates that sequence learning is not influenced by increasing selection demands and suggests that sequence learning runs independently of input attention.

scholarly journals Ca2+ and synaptotagmin VII–dependent delivery of lysosomal membrane to nascent phagosomes

2006 ◽  
Vol 174 (7) ◽  
pp. 997-1007 ◽  
Author(s):  
Cecilia Czibener ◽  
Nathan M. Sherer ◽  
Steven M. Becker ◽  
Marc Pypaert ◽  
Enfu Hui ◽  
...  
Keyword(s):  
Binding Sites ◽  
Cell Types ◽  
High Load ◽  
Lysosomal Membrane ◽  
Phagocytic Ability ◽  
Particle Uptake ◽  
Synaptotagmin Vii ◽  
Load Conditions

Synaptotagmin (Syt) VII is a ubiquitously expressed member of the Syt family of Ca2+ sensors. It is present on lysosomes in several cell types, where it regulates Ca2+-dependent exocytosis. Because [Ca2+]i and exocytosis have been associated with phagocytosis, we investigated the phagocytic ability of macrophages from Syt VII−/− mice. Syt VII−/− macrophages phagocytose normally at low particle/cell ratios but show a progressive inhibition in particle uptake under high load conditions. Complementation with Syt VII rescues this phenotype, but only when functional Ca2+-binding sites are retained. Reinforcing a role for Syt VII in Ca2+-dependent phagocytosis, particle uptake in Syt VII−/− macrophages is significantly less dependent on [Ca2+]i. Syt VII is concentrated on peripheral domains of lysosomal compartments, from where it is recruited to nascent phagosomes. Syt VII recruitment is rapidly followed by the delivery of Lamp1 to phagosomes, a process that is inhibited in Syt VII−/− macrophages. Thus, Syt VII regulates the Ca2+-dependent mobilization of lysosomes as a supplemental source of membrane during phagocytosis.

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