secondary plastic
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2021 ◽  
pp. 0734242X2110308
Author(s):  
Hao Jin ◽  
Jeongsoo Yu ◽  
Kazuaki Okubo

In the last three decades, the increased use of plastics is rapidly becoming a global environmental issue, resulting in growing landfills, pollution of surrounding atmosphere, and possible greenhouse effect. The automotive industry, as a major demander of plastic materials, is starting to take responsibility on sustainable actions. Japan, as the world’s top tier car manufacturing and dealing country, has been taking attempts to the proper dealings of used auto-plastic. This research aims to find out current situation of auto-plastic recycling industry after these attempts. Furthermore, this research compares pros and cons of each treatment and methods under treatment environmentally as well as economically from the point of recycling operators using life cycle assessment. Bumper is chosen as the target to represent auto-plastic because of their homogeneity of composition and relatively large share of weight among all auto-plastic parts. The result shows that material recycling amount is decreasing along with recent promotion demonstration. Top reason is that material recycling even reduces carbon emissions, costs far more than energy recovery, and that subsidy is given to energy recovery but not material recycling worsens the situation. Besides that, lack of cooperation between stakeholders on the demand of secondary plastic is impeding material recycling. Also, better scheme on how to separate auto-plastic and what kind would be separated should be noticed by the policymaker.


Author(s):  
I.O. Mikulionok

Basic data on the volume and structure of solid waste in the world and Ukraine are presented. The need to improve the ways of handling plastic solid waste as one of the most dangerous for the environment and promising from the point of view of using their properties is shown. A detailed classification of methods for handling plastic solid waste is proposed and a critical analysis of each of them is given. Particular attention is paid to the methods of disposal of plastic solid waste, in particular, recycling, which makes it possible to effectively use secondary plastic raw materials directly for their intended purpose. The features of physical, chemical, biological and combined processing methods are also considered, in particular combustion, gasification, pyrolysis, plasma decomposition of plastic solid waste, as well as their decomposition under the influence of sunlight and microorganisms. The main ways of solving the problem of plastic solid waste in Ukraine are proposed. Bibl. 83, Fig. 3, Tab. 3.


2021 ◽  
pp. 0734242X2110112
Author(s):  
Stepan Polygalov ◽  
Galina Ilinykh ◽  
Vladimir Korotaev ◽  
Nemanja Stanisavljevic ◽  
Bojan Batinic

Efficient collection systems and information about the characteristics and quality of collected secondary plastic waste flows are of fundamental importance for the development of circular economies. In order to assess the effectiveness of the implementation of separate collection systems for plastic packaging, especially polyethylene terephthalate (PET) bottles, characteristic of the collected PET bottles in street mesh containers were studied in the city of Perm, Russia. The share of extraneous fractions was assessed and differentiation was carried out by volume, type of product, label presence, shape, content of solid and liquid impurities and colour. These results indicate that PET composition in different seasons is very similar, despite the assumption that the consumption of PET bottles in the spring and autumn seasons varies. In the mesh containers, up to 34% of the items were foreign objects, considering that only PET bottles should be collected. In each dimensional flow of PET bottles, the proportion of transparent bottles prevailed; it ranged from 31% to 70%. Based on the results of the experiment, almost all PET bottle categories had a standard shape, except packaging for food products and household chemicals, in which 26–27% of PET bottles had a non-standard shape. The results about charactersitic of source-separated PET bottles are fundamental for goal-oriented design and implementation of collection, recycling technologies, secondary separation facilities, the economics of recycling intitatives and reverse vending machines for collecting materials.


2021 ◽  
Author(s):  
Mikael Kaandorp ◽  
Henk Dijkstra ◽  
Erik van Sebille

<p>Field studies have shown that plastic fragments make up the majority of plastic pollution in the oceans in terms of abundance. How quickly environmental plastics fragment is not well understood, however. Here, we study this process by considering a model which captures continuous fragmentation of particles over time in a cascading fashion. With this cascading fragmentation model, we simulate particle size distributions (PSDs), specifying the abundance or mass of particles for different size classes.</p><p> </p><p>The fragmentation model is coupled to an environmental box model, simulating the distributions of plastic particles in the ocean, coastal waters, and on the beach. Transport in the box model is based on a previous study regarding a previous study regarding sources and sinks of marine plastics in the Mediterranean Sea. We compare the modelled PSDs to available observations, and use the results to illustrate the effect of size-selective processes such as vertical mixing in the water column and resuspension of particles from the beach into coastal waters.</p><p> </p><p>Using the coupled fragmentation and environmental box model, we quantify the role of fragmentation on the marine plastic mass budget. While fragmentation is a major source of (secondary) plastic particles in terms of abundance, it seems to have a minor effect on the total mass of particles larger than 0.1 mm. Future comparison to observed PSD data should allow us to understand size-selective plastic transport in the environment, and potentially inform us on plastic longevity.</p>


2020 ◽  
Vol 54 (11) ◽  
pp. 6859-6868 ◽  
Author(s):  
Elvis Genbo Xu ◽  
Rachel S. Cheong ◽  
Lan Liu ◽  
Laura M. Hernandez ◽  
Agil Azimzada ◽  
...  

2020 ◽  
Vol 57 (7) ◽  
pp. 900-908 ◽  
Author(s):  
William M. Padovano ◽  
Alison K. Snyder-Warwick ◽  
Gary B. Skolnick ◽  
Kristin D. Pfeifauf ◽  
Maithilee D. Menezes ◽  
...  

Objective: To report the incidences of secondary lip and nose operations, otolaryngology procedures, speech-language therapy, neurodevelopmental concerns, and dental and orthodontic issues in children with isolated cleft lip to inform multidisciplinary cleft team protocols. Setting: An American Cleft Palate-Craniofacial Association–approved team at a tertiary academic children’s hospital. Design: Retrospective cohort study of patients evaluated through longitudinal clinic visits by a multidisciplinary cleft palate and craniofacial team between January 2000 and June 2018. Patients, Participants: Children with nonsyndromic cleft lip with or without cleft alveolus (n = 92). Results: Median age at final team visit was 4.9 years (interquartile range: 2.4-8.2 years). Secondary plastic surgery procedures were most common between ages 3 and 5 (135 per 1000 person-years), and the majority of these procedures were minor lip revisions. The rate of tympanostomy tube insertion was highest before age 3 (122 per 1000 person-years). By their final team visit, 88% of patients had normal hearing and 11% had only slight to mild conductive hearing loss. No patients had speech errors attributable to lip abnormalities. Psychological interventions, learning disabilities, and dental or orthodontic concerns were uncommon. Conclusions: Most patients with isolated cleft lip may not require long-term, longitudinal evaluation by cleft team specialists. Cleft teams should develop limited follow-up protocols for these children to improve resource allocation and promote value-based care in this patient population.


2020 ◽  
pp. 73-77
Author(s):  
V.A. Kim ◽  
CH.F. YAkubovich

By mathematical modeling it is determined, that when turning in the zone of secondary plastic deformations of the cut layer at increase of the friction coefficient, the length of the chip contact with the front surface of the cutting wedge increases. In this case, significant residual stresses are formed in the surface layer. Keywords cutting, metal, cutting wedge, friction coefficient, chip, quality, stress, residual stresses [email protected]


2018 ◽  
Vol 146 ◽  
pp. 02009 ◽  
Author(s):  
Radim Smolka ◽  
Jindřich Sobotka

The article describes and verifies the possibility of applying secondary plastic materials to construction details such as flat roofs. The created element is a placement considered both in the area and in the finishing detail. The secure connection of the embedded element with the waterproofing layer is an integral part of the detail functionality. This is verified by a peeling resistance test at joints. Peel resistance is the tensile force required to completely separate the prepared joints. During testing, the test piece is pulled at constant speed until complete separation.


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