scholarly journals Fabrication of a High-Performance Bending Actuator Made with a PVC Gel

2018 ◽  
Vol 8 (8) ◽  
pp. 1284 ◽  
Author(s):  
Eun-Jae Shin ◽  
Won-Hyeong Park ◽  
Sang-Youn Kim
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
High Performance ◽  
Low Molecular Weight ◽  
Bending Angle ◽  
Bending Performance ◽  
Molecular Weights ◽  
Elapsed Time ◽  
Poly Vinyl Chloride ◽  
Bending Actuator

This paper proposes a small, transparent, electroactive and highly deformable poly vinyl chloride (PVC) gel-based bending actuator. The effect of the PVC molecular weight and plasticizer content on the performance of the bending actuator is investigated. Three PVCs are prepared with different molecular weights (low molecular weight: PVCL, 116,000; medium molecular weight: PVCM, 239,000; and high molecular weight: PVCH, 282,000) and mixed with plasticizers in various ratios to achieve the best performance of the bending actuator. Experiments are conducted to investigate the bending performance of the actuators based on the prepared PVC gels. Among the prepared actuators, the PVCH-based bending actuator shows the best performance (maximum bending angle: 180°, elapsed time: 3.15 s).

scholarly journals Biodegradation of low molecular weight polyacrylamide under aerobic and anaerobic conditions: effect of the molecular weight

2020 ◽  
Vol 81 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Wenzhe Song ◽  
Yu Zhang ◽  
Amir Hossein Hamidian ◽  
Min Yang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Carbon Chain ◽  
Anaerobic Treatment ◽  
Low Molecular Weight ◽  
Amino Groups ◽  
Molecular Weights ◽  
Weight One ◽  
Hydrolysis Of ◽  
Aerobic And Anaerobic

Abstract The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0–52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2–17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45–7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76–5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.

Comparison of exopolysaccharides from mucoid and nonmucoid strains of Clavibacter michiganensis subspecies sepedonicus

1993 ◽  
Vol 39 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Paul J. Henningson ◽  
Neil C. Gudmestad
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Size Exclusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Low Molecular Weight ◽  
Neutral Sugar ◽  
Clavibacter Michiganensis ◽  
Serological Reaction ◽  
Molecular Weights ◽  
Exclusion Chromatography

The exopolysaccharides produced by six strains of Clavibacter michiganensis ssp. sepedonicus were isolated and purified by liquid chromatography. Neutral sugar composition and molecular weights were determined for each polysaccharide fraction, using gas chromatography and high-performance size-exclusion chromatography. The serological reaction of each fraction was tested using enzyme-linked immunosorbent assay. Exopolysaccharide from nonmucoid strains contained only low molecular weight polysaccharides (1.5 × 103 to 1.1 × 104). Exopolysaccharide from mucoid and intermediate strains could be separated into low (4.0 × 103 to 1.1 × 104) molecular weight and high (5.0 × 105 to 1.6 × 106) molecular weight fractions. High molecular weight polysaccharides were composed almost exclusively of galactose, glucose, and fucose. The ratios of these sugars were highly variable among strains. Low molecular weight polysaccharides were primarily composed of galactose with significant and varying amounts of glucose, rhamnose, mannose, and ribose. All polysaccharide fractions except one, produced by a nonmucoid strain, reacted in the immunoassay test.Key words: exopolysaccharide, polysaccharide, Clavibacter, michiganensis, sepedonicus.

scholarly journals Effects Of Environmental Factors On The Dispersion Behavior Of Iron Oxide In Aqueous Solutions With Poly Acrylic Acid

2015 ◽  
Vol 60 (2) ◽  
pp. 1561-1564
Author(s):  
E.-H. Lee ◽  
K.-M. Kim ◽  
W.-Y. Maeng ◽  
D.-H. Hur
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
High Molecular Weight ◽  
Low Molecular Weight ◽  
Solution Ph ◽  
Molecular Weights ◽  
Aqueous Suspensions ◽  
Magnetite Particles ◽  
The Stability ◽  
Poly Acrylic Acid

Abstract After preparing aqueous suspensions from magnetite particles with a poly-acrylic acid, we investigated the effects of several experimental parameters. We characterized the stability of the suspensions using visual inspection, sedimentation, adsorption, and thermal stability of the dispersant. The dispersion stability is affected by the solution pH, the concentrations of magnetite particles, the molecular weight, the concentration of the dispersants, and the temperature. The stability of the suspensions increased as the concentration of the dispersant and the temperature increased. In terms of the molecular weights of the dispersant, the suspensions with dispersant of low-molecular weight (1800) were more stable than those of high-molecular weight (250000) at room temperature. However, at high temperature the suspensions with high-molecular weight showed stability. The adsorption efficiency of the dispersant was very low. The dispersant of high-molecular weight showed a higher thermal integrity than that of low-molecular weight. From this work, we obtained the optimum conditions for stable aqueous suspensions of magnetite particles.

Analysis of proteins in rabbit pulmonary surfactant using monoclonal antibodies

1986 ◽  
Vol 250 (3) ◽  
pp. C460-C467 ◽  
Author(s):  
R. J. King ◽  
H. M. Martin ◽  
J. B. Baseman ◽  
J. Morrison-Plummer
Keyword(s):  
Molecular Weight ◽  
Monoclonal Antibodies ◽  
High Molecular Weight ◽  
Gel Electrophoresis ◽  
Pulmonary Surfactant ◽  
Polyacrylamide Gel Electrophoresis ◽  
Low Molecular Weight ◽  
Weight Group ◽  
Molecular Weights ◽  
Intermediate Group

We have used monoclonal antibodies developed against the apolipoproteins associated with pulmonary surfactant purified from rabbit lavage fluid to study the expression of epitopes common to these proteins. The pulmonary surfactant contained nearly 20 proteins, of which at least 10 were not derived from serum. Electrophoresis, with sulfhydryl reduction of these proteins indicated apparent molecular weights of approximately 155, 135, 125, and 115 X 10(3) (high-molecular-weight group); 80, 70, and 60 X 10(3) (intermediate group); and 18 through 10 X 10(3) (low-molecular-weight group). Two-dimensional polyacrylamide gel electrophoresis, in which the proteins were electrophoresed without reduction in the first dimension, but with sulfhydryl reduction in the second dimension, revealed that the 80, 70, and 60 X 10(3) proteins dissociated into proteins of nominal molecular weights of 40, 35, and 30 X 10(3), respectively. In contrast, the 125 and 115 X 10(3) proteins of the high-molecular-weight group contained a protein which could only be reduced to a minimum molecular weight of 55 to 60 X 10(3). Monoclonal antibodies generally were of three types: those that reacted strongly with the high-molecular-weight group and weakly with the intermediate group; those that reacted conversely; and those that reacted only with the low-molecular-weight group. Our results indicate that at least two different surfactant apolipoproteins, with differing minimum molecular weights in SDS-polyacrylamide gel electrophoresis, have common epitopes. Although these results cannot certify a physiological relationship between these proteins, they suggest that the intracellular synthesis or extracellular processing of surfactant apolipoproteins may be more complicated than predicted by the findings of previous experiments, perhaps involving the posttranslational assembly of one surfactant protein into oligomers which resist dissociation under the conditions used for the analyses.

Conditions Affecting the Molecular Weight of Factor VIII.

1979 ◽  
Author(s):  
G. Rock ◽  
E. Tackaberry ◽  
D. Palmer
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
High Molecular Weight ◽  
Calcium Concentration ◽  
Low Molecular Weight ◽  
Biochemical Purification ◽  
Molecular Weights ◽  
Will Self ◽  
And Storage ◽  
Molecular Weight Form

By purifying Factor VIII while maintaining physiological concentrations of calcium we have recently demonstrated that about 50% of the procoagulant activity is in a very low molecular weight (VLHW) form not associated with the carrier (VIII: RAG). The remainder is carrier associated and elutes at Vo as a high molecular weight (HMW) compound upon Sepharose 6B chromatography. Reduction of the calcium concentration by increasing the amount of citrate added to heparin results in decreasing the ratio of VLMW:HMW from 1:1 in pure heparin to 1:5 in pure citrate. If citrate is replaced with the more strongly chelating EDTA no VLMW is detectable in the plasma. It has also been found that most of the biochemical purification techniques which have been previously used to prepare Factor VIII for study actually result in the aggregation of this VLMW with the carrier to produce the high molecular weight form. This includes: cryoprecipitation, precipitation by polyethylene glycol and storage -80°C. As well, the VLMW material will self-associate upon freezing to produce an aggregate with a molecular weight of 106. However, this material does not cross-react with rabbit antibody directed against VIII: RAG. The data indicate that many of the previously reported biochemical characteristics, including molecular weights, actually describe species which are artifacts of the isolation process rather than those of the physiologically occuring Factor VIII.

Experimental Study on Flow-Front Fingering Instabilities in Injection Molding of Polymer Solutions and Melts

2004 ◽  
Author(s):  
Kalonji K. Kabanemi ◽  
Jean-Franc¸ois He´tu ◽  
Samira H. Sammoun
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polymer Solutions ◽  
Low Molecular Weight ◽  
Flow Front ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Polymer Molecules ◽  
Molecular Weights ◽  
Solvent Molecules

An experimental investigation of the flow behavior of dilute, semi-dilute and concentrated polymer solutions has been carried out to gain a better understanding of the underlying mechanisms leading to the occurrence of instabilities at the advancing flow front during the filling of a mold cavity. Experiments were performed using various mass concentrations of low and high molecular weight polyacrylamide polymers in corn syrup and water. This paper reports a new type of elastic fingering instabilities at the advancing flow front that has been observed only in semi-dilute polymer solutions of high molecular weight polymers. These flow front elastic instabilities seem to arise as a result of a mixture of widely separated high molecular weight polymer molecules and low molecular weight solvent molecules, which gives rise to a largely non-uniform polydisperse solution, with respect to all the kinds of molecules in the resulting mixture (solvent molecules and polymer molecules). The occurrence of these instabilities appears to be independent of the injection flow rate and the cavity thickness. Moreover, these instabilities do not manifest themselves in dilute or concentrated regimes, where respectively, polymer molecules and solvent molecules are minor perturbation of the resulting solution. In those regimes, smooth flow fronts are confirmed from our experiments. Based on these findings, the experimental investigations have been extended to polymer melts. Different mixtures of polycarbonate melts of widely separated molecular weights (low and high molecular weights) were first prepared. The effect of the large polydispersity of the resulting mixtures on the flow front behavior was subsequently studied. The same instabilities at the flow front were observed only in the experiments where a very small amount of high molecular weight polycarbonate polymer has been mixed to a low molecular weight polycarbonate melt (oligomers).

The Removal of Chlorinated Organics from Conventional Pulp and Paper Wastewater Treatment Systems

1992 ◽  
Vol 26 (1-2) ◽  
pp. 417-425 ◽  
Author(s):  
C. W. Bryant ◽  
J. J. Avenell ◽  
W. A. Barkley ◽  
R. N. Thut
Keyword(s):  
Molecular Weight ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
High Molecular Weight ◽  
High Performance ◽  
Treatment Plant ◽  
Low Molecular Weight ◽  
Pulp Mills ◽  
Minimal Impact ◽  
Wastewater Treatment Systems

A two-year survey of adsorbable organic halide (AOX) removals was conducted for eight full-scale wastewater treatment systems operated at pulp mills in North America. The resulting AOX database, one of the most comprehensive currently available, supports several significant findings. AOX removals averaged 46% for the two activated sludge systems and 34% for the five aerated stabilization basins (ASBs). Both the activated sludge facilities and ASBs averaged removing over half of the influent low molecular weight AOX. The average removal of high molecular weight AOX varied among mill sites from 1% to 47% and was not correlated with the type of treatment process used. The best-performing treatment facility, located at a sulfite mill receiving nearly 100% hardwood furnish and using an activated sludge treatment system, was able to consistently remove 53% of the AOX, 62% of the low molecular weight AOX, and 47% of the high molecular weight AOX in bleaching wastewaters. Factors responsible for this high performance are not currently understood. Effluent AOX was strongly correlated (R2 = 0.90) to the influent loading for ASBs. In-mill improvements such as the use of oxygen and peroxide as well as chlorine dioxide substitution reduce influent AOX loading, apparently with minimal impact on treatment plant removal efficiency.

scholarly journals Fire Resistance, Thermal and Anti-Ageing Properties of Transparent Fire-Retardant Coatings Modified with Different Molecular Weights of Polyethylene Glycol Borate

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4206
Author(s):  
Long Yan ◽  
Xinyu Tang ◽  
Xiaojiang Xie ◽  
Zhisheng Xu
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
High Molecular Weight ◽  
Fire Resistance ◽  
Fire Retardant ◽  
Phosphate Ester ◽  
Low Molecular Weight ◽  
Molecular Weights ◽  
Flame Retarded ◽  
Residual Weight

Four kinds of polyethylene glycol borate (PEG-BA) with different molecular weights were grafted into cyclic phosphate ester (PEA) to obtain flexible phosphate esters (PPBs), and then applied in amino resin to obtain a series of transparent intumescent fire-retardant coatings. The comprehensive properties of the transparent coatings containing different molecular weights of PEG-BA were investigated by various analytical instruments. The transparency and mechanical analyses indicate that the presence of PEG-BA slightly decreases the optical transparency of the coatings but improves the flexibility and adhesion classification of the coatings. The results from fire protection and cone calorimeter tests show that low molecular weight of PEG-BA exerts a positive flame-retarded effect in the coatings, while high molecular weight of PEG800-BA behaves against flame-retarded effect. Thermogravimetric and char residue analyses show that the incorporation of low molecular weight of PEG-BA clearly increases the thermal stability and residual weight of the coatings and generates a more compact and stable intumescent char on the surface of the coatings, thus resulting in superior synergistic flame-retarded effect. In particular, MPPB1 coating containing PEG200-BA exerts the best flame-retarded effect and highest residual weight of 36.3% at 700 °C, which has 57.6% reduction in flame spread rate and 23.9% reduction in total heat release compared to those of MPPB0 without PEG-BA. Accelerated ageing test shows that low molecular weight of PEG-BA promotes to enhance the durability of structural stability and fire resistance of the coatings, while PEG800-BA with high molecular weight weakens the ageing resistance. In summary, the fire-resistant and anti-ageing efficiencies of PEG-BA in the coatings depend on its molecular weight, which present the order of PEG200-BA > PEG400-BA > PEG600-BA > PEG800-BA.

Variability of Low-Molecular-Weight, Heat-Modifiable Outer Membrane Proteins of Neisseria meningitidis

1980 ◽  
Vol 30 (3) ◽  
pp. 642-648
Author(s):  
J. T. Poolman ◽  
S. De Marie ◽  
H. C. Zanen
Keyword(s):  
Molecular Weight ◽  
Outer Membrane ◽  
High Molecular Weight ◽  
Outer Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Low Molecular Weight ◽  
Molecular Weights ◽  
Sds Page ◽  
Index Cases

Analysis of major outer membrane protein (MOMP) profiles of various meningococci by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of 0 to 2 low-molecular-weight, heat-modifiable MOMPs (molecular weight, 25,000 to 32,000) and 1 to 3 high-molecular-weight MOMPs (molecular weight, 32,000 to 46,000). Heat modifiability was investigated by comparing MOMP profiles after heating in SDS solutions at 100°C for 5 min or at 40°C for 1 h. Low-molecular-weight MOMPs shifted to higher apparent molecular weights after being heated at 100°C. Heat modifiability of high-molecular-weight MOMPs varied among strains; whenever modified these proteins shifted to lower apparent molecular weights after complete denaturation. Variability of low-molecular-weight, heat-modifiable MOMPs was demonstrated when MOMP profiles were compared of (i) isolates from index cases and associated cases and carriers among contacts, (ii) different isolates from the same individual, and (iii) isolates from a small epidemic caused by serogroup W-135. In some cases high-molecular-weight MOMPs revealed quantitative differences among related strains. The observed variability and quantitative differences indicate that MOMP serotyping and typing on the basis of SDS-PAGE profiles (PAGE typing) need careful reevaluation.

Molecular Weight Measurements of Low Molecular Weight Heparins by Gel Permeation Chromatography

1997 ◽  
Vol 77 (04) ◽  
pp. 668-674 ◽  
Author(s):  
B Mulloy ◽  
C Gee ◽  
S F Wheeler ◽  
R Wait ◽  
E Gray ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Molecular Weights ◽  
Calibration Table ◽  
Gel Permeation ◽  
Degraded Material

SummaryThe molecular weight profiles of low molecular weight heparin samples have been measured by high-performance gel permeation chromatography using as calibrant the heparinase-degraded material (90/686) now established as the 1st International Reference Preparation (IRP) Low Molecular Weight Heparin for Molecular Weight Calibration. Use of the calibrant as a broad molecular weight standard is described and a calibration table provided based on data collected over several years in one laboratory.In order to confirm the assignment of degree of polymerisation to resolved oligosaccharide peaks in the calibrant, molecular weights of oligosaccharides fractionated from the 1st IRP were independently determined by fast atom bombardment mass spectrometry (FAB MS).The molecular weight distributions of commercial low molecular weight heparins have been characterized. Measurements of molecular weight parameters of heparin molecular weight standards from several sources provide comparisons between the molecular weight scales of this and other studies.

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