Role of the interface on charge build-up in a low-density polyethylene: Surface roughness and nature of the electrode

2009 ◽  
Author(s):  
M. Taleb ◽  
G. Teyssedre ◽  
S. Le Roy
Keyword(s):  
Surface Roughness ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Polyethylene Surface

A unique behavior of water drops induced by low-density polyethylene surface with a sharp wettability transition

2007 ◽  
Vol 311 (1) ◽  
pp. 186-193 ◽  
Author(s):  
Xiaoying Lu ◽  
Shuaixia Tan ◽  
Ning Zhao ◽  
Shuguang Yang ◽  
Jian Xu
Keyword(s):  
Low Density Polyethylene ◽  
Low Density ◽  
Water Drops ◽  
Polyethylene Surface

scholarly journals Vida útil de polpa congelada de araticum embalada ou não a vácuo

2019 ◽  
Vol 6 (1) ◽  
pp. 114-121
Author(s):  
Cristiane Maria Ascari Morgado ◽  
Ana Paula Silva Siqueira ◽  
Eli Regina Barboza de Souza ◽  
Annelisa Arruda de Brito ◽  
Luis Carlos Cunha Junior ◽  
...  
Keyword(s):  
Titratable Acidity ◽  
Soluble Solids ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Antioxidant Power ◽  
Total Antioxidant ◽  
Ferric Reducing Antioxidant Power ◽  
Annona Crassiflora

The objective of this work was to evaluate the role of two types of conditioning process in quality of frozen and stored araticum’s pulp at -18ºC. The fruits were collected at pre-maturing developmental stage, packed into boxes wrapped with bubble plastic, transported to the laboratory and stored for 7 days at 22ºC and 90% RH to complete the maturation. Afterwards, they were pulped and the pulp was stored in: 1) low-density polyethylene packages (LDPE) 60 micro, hermetically packed in a sealing machine or 2) low-density polyethylene packages (LDPE) 60 micro vacuum sealed. Those units were frozen at -18ºC for 402 days and were evaluated at processing day and at 30; 90; 150; 210 and 402 days of storage, for soluble solids contents (SS), titratable acidity (TA), SS/TA, ascorbic acid, total extractable polyphenols and total antioxidant activity using the Ferric Reducing Antioxidant Power (FRAP) method. The results were submitted to an analysis of variance and the means were each other compared using Tukey test with Sisvar software. It is conclued that is not necessary the use of vacuum to package the frozen araticum’s pulp for 402 days, at -18ºC. Keywords: Annona crassiflora Mart, freezing, vacuum.  

Influence of surface roughness and surface moisture of plastics on sensor-based sorting in the near infrared range

2019 ◽  
Vol 37 (8) ◽  
pp. 843-850 ◽  
Author(s):  
Bastian Küppers ◽  
Sabine Schloegl ◽  
Gernot Oreski ◽  
Roland Pomberger ◽  
Daniel Vollprecht
Keyword(s):  
Surface Roughness ◽  
Near Infrared ◽  
Thermoplastic Polyurethane ◽  
Low Density Polyethylene ◽  
Infrared Range ◽  
Low Density ◽  
Surface Moisture ◽  
Landfill Mining ◽  
Sensor Based Sorting

In the project ‘NEW-MINE’ the use of sensor-based sorting machinery in the field of ‘landfill mining’ is investigated. Defilements pose a particular challenge in the treatment and sorting of plastics contained in landfills. For this reason, the effects of various pollutants caused by the interactions in the landfill body or the mechanical treatment steps in landfill mining are examined. In the following elaboration, the focus is on the influences of surface moisture and surface roughness of plastics on sensor-based sorting by means of near-infrared technology. Near-infrared radiation (NIR) in a wavelength range of 990 nm to 1500 nm has been used for the detection and classification of plastic particles. The experiments demonstrate that increased surface roughness reduces signal noise and thereby improves the classification of both spectrally similar and transparent plastics, but reduces the yield of low-softening plastics because their sliding speed on a sensor-based chute sorter varies as a result of the heating of the chute. Surface moisture causes the absorption of radiation from 1115 nm (high density polyethylene [HDPE], linear low density polyethylene [LLDPE], polyethylen terephthalate [PET] and polyvinylchloride [PVC]) or from 1230 nm (low density polyethylene [LDPE], polypropylene [PP] and thermoplastic polyurethane [TPU]) up to at least 1680 nm, which causes amplification or attenuation of various extremes in the derivative. However, the influence of surface moisture on the yield of plastics is usually very low and depends on the spectral differences between the different plastics.

Surface damage characterization of photodegraded low-density polyethylene by means of friction measurements

2019 ◽  
Vol 39 (9) ◽  
pp. 805-812
Author(s):  
Toshio Igarashi ◽  
Soichiro Ohno ◽  
Sayaka Oda ◽  
Satoru Hirosawa ◽  
Yusuke Hiejima ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Irradiation Time ◽  
Polymeric Materials ◽  
Optical Measurements ◽  
Low Density Polyethylene ◽  
Mean Deviation ◽  
Low Density ◽  
Friction Coefficients ◽  
Brittle Transition ◽  
Friction Measurements

Abstract Friction measurements have been carried out to characterize surface damages during photodegradation of low-density polyethylene. The average and mean deviation of the friction coefficients increase with the irradiation time in the early stage of photodegradation processes, indicating the increase in the surface roughness, whereas the mechanical properties remain essentially unchanged. In the following stage, where the ductile-brittle transition takes place, the mean deviation of the friction coefficients shows an appreciable decrease with maintaining almost constant average values, suggesting that the surface becomes more homogeneous. Beyond the ductile-brittle transition, both of the average and mean deviation of the friction coefficients gradually increase with the irradiation time, indicating further enhancement of surface roughness, followed by formation of surface cracks. The soundness of the friction measurements is confirmed by comparing with optical measurements of the surface roughness, and it is suggested that the present method gives a convenient and sensitive method of detection for degradation in polymeric materials.

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