scholarly journals A preliminary study of the degradation of selected commercial packaging materials in compost and aqueous environments

2011 ◽  
Vol 13 (1) ◽  
pp. 55-57 ◽  
Author(s):  
Marta Musioł ◽  
Joanna Rydz ◽  
Wanda Sikorska ◽  
Piotr Rychter ◽  
Marek Kowalczuk
Keyword(s):  
Molecular Weight ◽  
Weight Loss ◽  
Terephthalic Acid ◽  
Packaging Materials ◽  
Distilled Water ◽  
Abiotic Degradation ◽  
Aqueous Environments ◽  
Preliminary Study ◽  
Industrial Composting ◽  
Surface Changes

A preliminary study of the degradation of selected commercial packaging materials in compost and aqueous environmentsThe paper presents the results of the degradation of two commercial packaging materials CONS-PET and BioPlaneta in the compost and distilled water at 70°C. The materials containing polylactide (PLA), CONS-PET 13% and BioPlaneta 20%, aliphatic-aromatic copolyester terephthalic acid/adipic acid/1,4-butanediol (BTA) and commercial additives degraded under the industrial composting conditions (composting pile or container) and in distilled water at 70°C in the laboratory holding oven. Distilled water provided the conditions for the hydrolytic (abiotic) degradation of the materials. Weight loss, changes of molecular weight, dispersity monitored via the GPC technique and the macroscopic surface changes of the tested materials were monitored during the experiments. The investigated systems show similar trends of degradation, however on the last day of the incubation the decrease of the molecular weight was higher in water than under the industrial composting conditions. The results indicate that commercial packaging materials can be degraded both while composting ((bio)degradation) and during the incubation in distilled water at 70°C (abiotic hydrolysis).

Reconstruction of Two-Dimensional Projections of GP 32*I

1981 ◽  
Vol 39 ◽  
pp. 38-39
Author(s):  
H.A. Cohen ◽  
W. Chiu ◽  
J. Hosoda
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Uranyl Acetate ◽  
Distilled Water ◽  
Acetate Solution ◽  
Two Dimensional ◽  
Parent Molecule ◽  
T4 Bacteriophage ◽  
Electron Imaging ◽  
Better Than

GP 32 (molecular weight 35000) is a T4 bacteriophage protein that destabilizes the DNA helix. The fragment GP32*I (77% of the total weight), which destabilizes helices better than does the parent molecule, crystallizes as platelets thin enough for electron diffraction and electron imaging. In this paper we discuss the structure of this protein as revealed in images reconstructed from stained and unstained crystals.Crystals were prepared as previously described. Crystals for electron microscopy were pelleted from the buffer suspension, washed in distilled water, and resuspended in 1% glucose. Two lambda droplets were placed on grids over freshly evaporated carbon, allowed to sit for five minutes, and then were drained. Stained crystals were prepared the same way, except that prior to draining the droplet, two lambda of aqueous 1% uranyl acetate solution were applied for 20 seconds. Micrographs were produced using less than 2 e/Å2 for unstained crystals or less than 8 e/Å2 for stained crystals.

Evaluation of the effect of cetrimide with edta on Microhardness and surface changes in root dentin – An invitro study

2019 ◽  
Vol 11 (1) ◽  
pp. 3-11
Author(s):  
Dr. Swarooparanil Patil ◽  
Dr. B.S. Keshava Prasad
Keyword(s):  
Surface Erosion ◽  
Distilled Water ◽  
Test Results ◽  
Chi Square ◽  
Chi Square Test ◽  
Root Dentin ◽  
Group 3 ◽  
Post Hoc ◽  
Hardness Values ◽  
Surface Changes

The aim of the study was to evaluate the effect of different concentrations of cetrimide with or without EDTA solution on the microhardness and surface changes in root dentin. Single rooted human mandibular premolar teeth were decoronated and sectioned longitudinally. The root segments were horizontally embedded in autopolymerizing resin. These specimens were randomly divided into 6 experimental groups according to the irrigating solution used. The irrigating solutions used were 5% EDTA, 5%EDTA + 0.25% Cetrimide, 5%EDTA + 0.50% Cetrimide, 0.25% Cetrimide, 0.50% Cetrimide and distilled water. Each group was further divided into two subgroups. First subgroup specimens were employed for microhardness testing using vicker’s indenter. Second subgroup specimens were used to evaluate the surface changes of root dentin under stereomicroscope. Comparison of the mean microhardness of test groups was done using ANOVA followed by post hoc Tukey’s test. Pre- and post- treatment hardness values were compared using student paired t test. The data obtained from surface erosion scoring was subjected to statistical analysis using Chi square test. Results of this study showed significant reduction in the microhardness of dentin for all the groups except for the distilled water (p<0.001). The greatest reduction in dentin microhardness was observed with Group-3 (5% EDTA + 0.50% CTR). Specimens in 5% EDTA group showed greater erosion than other groups. Within the limitations of this study it was concluded that all the tested irrigating solutions reduced the microhardness of root dentin except distilled water. Maximum reduction in microhardness was observed with addition of 0.50% cetrimide to EDTA. EDTA increased the surface roughness of root dentin irrespective of cetrimide association. Use of cetrimide at concentrations higher than 0.25% would be detrimental to the microhardness of dentin.

scholarly journals Severe central obesity or diabetes can replace weight loss in the detection of frailty in obese younger elderly – a preliminary study

2018 ◽  
Vol Volume 13 ◽  
pp. 1907-1918 ◽  
Author(s):  
Assaf Buch ◽  
Lital Keinan-Boker ◽  
Ofer Kis ◽  
Eli Carmeli ◽  
Elena Izkhakov ◽  
...  
Keyword(s):  
Weight Loss ◽  
Central Obesity ◽  
Preliminary Study

scholarly journals Effect of different packaging systems and chlorination on the quality and shelf life of green chili

2013 ◽  
Vol 37 (4) ◽  
pp. 729-736 ◽  
Author(s):  
Mohammad Mizanur Rahman ◽  
Md Miaruddin ◽  
Md. Golam Ferdous Chowdhury ◽  
Md. Hafizul Haque Khan ◽  
MA Matin
Keyword(s):  
Weight Loss ◽  
Moisture Content ◽  
Shelf Life ◽  
Substantial Reduction ◽  
Modified Atmosphere Packaging ◽  
Ambient Condition ◽  
Packaging Materials ◽  
Modified Atmosphere ◽  
Packaging System ◽  
Quality And Shelf Life

The experiment was conducted to evaluate the effect of packaging materials on the quality and shelf life of green chili (Capsicum annuum) using passive modification of modified atmosphere packaging system. The modified atmosphere was created by making perforation in the polypropylene packets. Green chili pre-treated with chlorine water and then packaging in 0.3% perforated polypropylene packet resulted substantial reduction of weight loss and rotting/shriveling. These treatment combinations also considerably retained vitamin C, ß-carotene, moisture content, etc. Under this condition the retention of quality and shelf life of green chili could be extended up to 10 days at ambient condition as compared to non-treated and without packaging. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14397 Bangladesh J. Agril. Res. 37(4): 729-736, December 2012

Effects of Molecular Weight of Chitosan on the Biodegradability and Thermal Properties of Polybutylene Succinate/Chitosan Composites

2018 ◽  
Vol 775 ◽  
pp. 26-31
Author(s):  
Sukantika Manatsittipan ◽  
Kamonthip Kuttiyawong ◽  
Kazuo Ito ◽  
Sunan Tiptipakorn
Keyword(s):  
Molecular Weight ◽  
Weight Loss ◽  
Thermal Properties ◽  
Water Absorption ◽  
Melting Temperature ◽  
Microbial Degradation ◽  
Decomposition Temperature ◽  
Molecular Weights ◽  
Significant Difference ◽  
Polybutylene Succinate

In this study, the biodegradability and thermal properties the composites of polybutylene succinate (PBS) and chitosan of different molecular weights (Mn = 104,105, and 106 Da) were prepared at chitosan contents of 0-10 wt%. After 10 days of microbial degradation, the results show that the amount of holes from degradation was increased with either decreasing Mn or increasing chitosan contents. However, the size of holes was increased with increasing Mn and chitosan contents. The results from Differential Scanning Calorimeter (DSC) present that the melting temperature (Tm) of PBS was decreased with increasing chitosan contents. Moreover, there was no significant difference between Tm of the composites with different Mn of chitosan. From the TGA thermograms, the decomposition temperature at 10% weight loss (Td10) was decreased with increasing chitosan contents. Moreover, the water absorption of PBS/chitosan composites was increased with increasing Mn and content of chitosan.

scholarly journals Longevity of wild pansy flowers treated with growth regulators

2018 ◽  
Vol 24 (2) ◽  
pp. 103-108
Author(s):  
Tania Pires Da Silva ◽  
Fernanda Ferreira Araujo ◽  
Fernando Luiz Finger
Keyword(s):  
Weight Loss ◽  
Abscisic Acid ◽  
Growth Regulators ◽  
Water Status ◽  
Fluorescent Light ◽  
Distilled Water ◽  
Fresh Weight ◽  
Exogenous Ethylene ◽  
Fourth Experiment ◽  
And Control

The objective of this study was to evaluate the growth regulators action on the senescence of wild pansy flowers. In the first experiment, floral stems were treated with ethylene for 24 hours at concentrations of 0.1, 1.0, 10, 100 and 1000 μL L-1 and control without the hormone. In a second experiment, the flowers were immersed in solutions of abscisic acid (ABA) containing 5, 20, 50 and 100 μM for one minute and control with water. In a third experiment, 1-methylcyclopropene (1-MCP) was applied at concentrations of 0.5, 1.0 and 1.5 μL L-1 and control without the chemical. In a fourth experiment, 1-MCP and ethylene were applied, where 1-MCP was first applied followed by ethylene. After the treatments with 1-MCP and ethylene, the floral stems were removed from the hermetic chambers and kept in a vessel containing distilled water at 25 °C, 10 μmol m-2 s- 1 white fluorescent light and 50-70% relative humidity as for the ABA treatment. Flowers treated with ethylene did not present significant differences among the concentrations for visual senescence, showing evidence that this flower is not sensitive to ethylene. Treatment with 1000 μL L-1 of ethylene led to a slightly higher fresh weight loss than other treatments, which had a loss of about 33% at end of the experiment. For the ABA treatment, the flowers showed similar fresh weight loss among the different treatments; however, higher concentrations induced slight senescence of flowers. The use of 1-MCP increased the longevity of wild pansy flowers. These results show that 1-MCP is beneficial in maintaining the flower water status, even in the presence of exogenous ethylene, although ethylene may not be directly involved in the senescence of wild pansy flowers.

scholarly journals Tin Complexes Containing an Atenolol Moiety as Photostabilizers for Poly(Vinyl Chloride)

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2923
Author(s):  
Baneen Salam ◽  
Gamal A. El-Hiti ◽  
Muna Bufaroosha ◽  
Dina S. Ahmed ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Weight Loss ◽  
Infrared Spectroscopy ◽  
Surface Morphology ◽  
Vinyl Chloride ◽  
Poly Vinyl Chloride ◽  
Phenyl Rings ◽  
Tin Complexes ◽  
High Yields ◽  
Loss Determination ◽  
Surface Changes

The lifetime of poly(vinyl chloride) (PVC) can be increased through the addition of additives to provide protection against irradiation. Therefore, several new tin complexes containing atenolol moieties were synthesized and their photostabilizing effect on PVC was investigated. Reacting atenolol with a number of tin reagents in boiling methanol provided high yields of tin complexes. PVC was then mixed with the tin complexes at a low concentration, producing polymeric thins films. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and surface morphology techniques. Infrared spectroscopy and weight loss determination indicated that the films incorporating tin complexes incurred less damage and less surface changes compared to the blank film. In particular, the triphenyltin complex was very effective in enhancing the photostability of PVC, and this is due to its high aromaticity (three phenyl rings) compared to other complexes. Such an additive acts as a hydrogen chloride scavenger, radical absorber, and hydroperoxide decomposer.

scholarly journals A rugged, self-sterilizing antimicrobial copper coating on ultra-high molecular weight polyethylene: a preliminary study on the feasibility of an antimicrobial prosthetic joint material

2019 ◽  
Vol 7 (20) ◽  
pp. 3310-3318 ◽  
Author(s):  
Ke Wu ◽  
Samuel P. Douglas ◽  
Gaowei Wu ◽  
Alexander J. MacRobert ◽  
Elaine Allan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Copper Coating ◽  
Prosthetic Joint ◽  
Preliminary Study ◽  
First Time ◽  
Ultra High Molecular Weight ◽  
Joint Material

We report here for the first time how a copper coating bond to ultra-high molecular weight polyethylene (UHMWPE) via low temperature aerosol assisted chemical vapour deposition.

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