Correlation between scratch healing and rheological behavior for terpyridine complex based metallopolymers

2015 ◽  
Vol 3 (44) ◽  
pp. 22145-22153 ◽  
Author(s):  
S. Bode ◽  
M. Enke ◽  
R. K. Bose ◽  
F. H. Schacher ◽  
S. J. Garcia ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Metal Salt ◽  
Life Time

The healing phenomenon of metallopolymers is studied in detail and the dependency of the chosen metal salt is provided. Furthermore, a correlation between the supramolecular bond life time and the healing behavior could be revealed.

scholarly journals Kinetic Interpretation of Rheological Behavior of High Polymers

1962 ◽  
Vol 35 (4) ◽  
pp. 1013-1027
Author(s):  
Junji Furukawa
Keyword(s):  
Polymer Chain ◽  
Rheological Behavior ◽  
Maximum Stress ◽  
Life Time ◽  
Polar Groups ◽  
Maximum Value ◽  
Stress Strain Relation ◽  
Constant Rate ◽  
Creep And Stress Relaxation ◽  
High Polymers

Abstract Rheological behavior of high polymers is interpreted in terms of the pseudo crosslinking hypothesis, i.e., polar groups in a polymer form a kind of pseudolink and contribute to the elastic property of the polymer, but such a crossbond as this is not so firm that plastic flow may not occur to some extent. The ratio of real elongation of polymer chain to overall elongation of specimen is demonstrated as the function of slippage of the polymer chain. Creep and stress relaxation are accounted for as the phenomena involving slippage of the chain accompanied by the elongation of the chain and the dissociation of the crossbond. The stress-strain relation in the ease of constant rate drawing is supposed to show the existence of maximum stress according to the hypothesis. Rupture of linear high polymer is also discussed supposing the breakdown of the second crossbond and the breakdown may be concluded when load applied is larger than the maximum value estimated from the equation for the equilibrium crosslinking. The rate of rupture is also discussed and the logarithmic life time in rupture is concluded to be correlated linearly to the load applied.

Anomalous Rheological Behavior of Complex Fluids (Nanofluids)

2011 ◽  
Author(s):  
Byeongnam Jo ◽  
Seunghwan Jung ◽  
Donghyun Shin ◽  
Debjyoti Banerjee
Keyword(s):  
Experimental Study ◽  
Rheological Behavior ◽  
Metal Salt ◽  
Complex Fluids ◽  
Shear Thinning ◽  
The Other ◽  
Metal Salts ◽  
Different Types ◽  
Before And After ◽  
Newtonian Behavior

The rheological behavior of various complex fluids was explored in this experimental study. Nanofluids were obtained by mixing nanoparticles with various solvents. The solvents consisted of metal salt eutectics that melt at high temperatures (exceeding 200 °C) depending on the composition of the metal salts in the eutectics. The rheological behaviors of these high temperature solvents were measured as a function of temperature before and after mixing with different types of nanoparticles (chemical composition, size, shape and concentration). These nanofluids exhibited non-Newtonian behavior (shear thinning behavior) while some of the other nanofluids were surprisingly found to have Newtonian behavior. It was observed that high aspect ratio nanoparticles (e.g., stick shaped carbon nanotubes) were more likely to cause shear thinning behavior of the resulting nanofluids.

Chemical modification of the bacterial wall to determine sites of metal deposition

1978 ◽  
Vol 36 (2) ◽  
pp. 350-351
Author(s):  
T. J. Beveridge
Keyword(s):  
Electron Scattering ◽  
Metal Salt ◽  
Metal Deposition ◽  
Suitable Model ◽  
X Ray Diffraction ◽  
Subtilis Cell ◽  
Thin Sections ◽  
X Ray ◽  
Section Data ◽  
Metal Impregnation

The Bacillus subtilis cell wall provides a protective sacculus about the vital constituents of the bacterium and consists of a collection of anionic hetero- and homopolymers which are mainly polysaccharidic. We recently demonstrated that unfixed walls were able to trap and retain substantial amounts of metal when suspended in aqueous metal salt solutions. These walls were briefly mixed with low concentration metal solutions (5mM for 10 min at 22°C), were well washed with deionized distilled water, and the quantity of metal uptake (atomic absorption and X-ray fluorescence), the type of staining response (electron scattering profile of thin-sections), and the crystallinity of the deposition product (X-ray diffraction of embedded specimens) determined.Since most biological material possesses little electron scattering ability electron microscopists have been forced to depend on heavy metal impregnation of the specimen before obtaining thin-section data. Our experience with these walls suggested that they may provide a suitable model system with which to study the sites of reaction for this metal deposition.

SEM and Auger microanalysis studies of Cu-Be dynode surfaces at each activation condition

1978 ◽  
Vol 36 (1) ◽  
pp. 524-525
Author(s):  
T. Koshikawa ◽  
Y. Fujii ◽  
E. Sugata ◽  
F. Kanematsu
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Life Time ◽  
Activation Process ◽  
Beam Diameter ◽  
Activation Temperature ◽  
Electron Multiplier ◽  
Activation Condition ◽  
Activation Conditions

The Cu-Be alloys are widely used as the electron multiplier dynodes after the adequate activation process. But the structures and compositions of the elements on the activated surfaces were not studied clearly. The Cu-Be alloys are heated in the oxygen atmosphere in the usual activation techniques. The activation conditions, e.g. temperature and O2 pressure, affect strongly the secondary electron yield and life time of dynodes.In the present paper, the activated Cu-Be dynode surfaces at each condition are investigated with Scanning Auger Microanalyzer (SAM) (primary beam diameter: 3μmϕ) and SEM. The commercial Cu-Be(2%) alloys were polished with Cr2O3 powder, rinsed in the distilled water and set in the vacuum furnance.Two typical activation condition, i.e. activation temperature 730°C and 810°C in 5x10-3 Torr O2 pressure were chosen since the formation mechanism of the BeO film on the Cu-Be alloys was guessed to be very different at each temperature from the results of the secondary electron emission measurements.

Negative Life Events Associated With Deliberate Self-Harm in an African Population in Uganda

Crisis ◽  
2005 ◽  
Vol 26 (1) ◽  
pp. 4-11 ◽  
Author(s):  
E. Kinyanda ◽  
H. Hjelmeland ◽  
S. Musisi
Keyword(s):  
Life Events ◽  
Negative Life Events ◽  
Life Time ◽  
Later Life ◽  
Dose Effect ◽  
Deliberate Self Harm ◽  
Time Period ◽  
Significant Difference ◽  
Self Harm ◽  
Suicide Interventions

Abstract. Negative life events associated with deliberate self-harm (DSH) were investigated in an African context in Uganda. Patients admitted at three general hospitals in Kampala, Uganda were interviewed using a Luganda version (predominant language in the study area) of the European Parasuicide Study Interview Schedule I. The results of the life events and histories module are reported in this paper. The categories of negative life events in childhood that were significantly associated with DSH included those related to parents, significant others, personal events, and the total negative life events load in childhood. For the later-life time period, the negative life events load in the partner category and the total negative life events in this time period were associated with DSH. In the last-year time period, the negative life events load related to personal events and the total number of negative life events in this time period were associated with DSH. A statistically significant difference between the cases and controls for the total number of negative life events reported over the entire lifetime of the respondents was also observed, which suggests a dose effect of negative life events on DSH. Gender differences were also observed among the cases. In conclusion, life events appear to be an important factor in DSH in this cultural environment. The implication of these results for treatment and the future development of suicide interventions in this country are discussed.

Inactivation of Factor XIa in Vivo: Studies in Chimpanzees and in Humans

1996 ◽  
Vol 76 (04) ◽  
pp. 549-555 ◽  
Author(s):  
Walter A Wuillemin ◽  
C Erik Hack ◽  
Wim K Bleeker ◽  
Bart J Biemond ◽  
Marcel Levi ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Life Time ◽  
In Vivo Studies ◽  
Clinical Samples ◽  
Plasma Samples ◽  
C1 Inhibitor ◽  
Elimination Kinetics ◽  
Factor Xia ◽  
Best Parameter

SummaryC1-inhibitor (C1Inh), antithrombin III (ATIII), α1-antitrypsin (a1AT), and α2-antiplasmin (a2AP) are known inhibitors of factor XIa (FXIa). However, their precise contribution to FXIa inactivation in vivo is not known. We investigated FXIa inactivation in chimpanzees and assessed the contribution of these inhibitors to FXIa inactivation in patients with presumed FXI activation.Chimpanzees were infused with FXIa and the various FXIa-FXIa inhibitor complexes formed were measured. Most of FXIa was complexed to C1Inh (68%), followed by a2AP (13%), a1AT (10%), and ATIII (9%). Analysis of the plasma elimination kinetics revealed a half-life time of clearance (t1/2) for the FXIa-FXIa inhibitor complexes of 95 to 104 min, except for FXIa-a1AT, which had a t1/2 of 349 min. Due to this long t1/2, FXIa-a1AT complexes were predicted to show the highest levels in plasma samples from patients with activation of FXI. This was indeed shown in patients with disseminated intravascular coagulation, recent myocardial infarction or unstable angina pectoris. We conclude from this study that in vivo C1Inh is the predominant inhibitor of FXIa, but that FXIa-a1 AT complexes due to their relatively long t1/2 may be the best parameter to assess FXI activation in clinical samples.

Sign in / Sign up

Export Citation Format

Share Document