Summary
Plastic is made through a process called polymerization, in which molecules of monomers, such as ethylene and propylene, combine to form long polymer chains called polyethylenes and polypropylenes. The properties of plastics primarily depend on the length of the polymer chains and the patterns in which they are arranged. The production of plastics begins with the distillation and purification of crude oil, which provides hydrocarbons that are the fundamental building blocks for most plastics. The hydrocarbons are then cracked into hydrocarbon derivatives like ethylene and propylene, which are polymerized to form plastic resins. Additives such as plasticizers, stabilizers, and pigments are added to modify the properties of the plastics for specific applications. The plastics are then molded, extruded, or otherwise processed to form useful plastic products. More than 100 types of plastics with different resin identification codes and properties are manufactured for various applications ranging from food packaging to construction materials based on their durability, flexibility, heat tolerance, and recyclability. The most common plastics used today are polyethylene terephthalate(recycle code 1, used for bottled beverages),high density polyethylene(recycle code 2, used for milk jugs and detergent bottles),polyvinyl chloride(recycle code 3,used for plastic pipes),low density polyethylene(recycle code 4,used for plastic bags),polypropylene(recycle code 5,used for food containers and medical equipment), polystyrene(recycle code 6, used for food containers and plastic cutlery), polycarbonate (recycle code 7,used for impact-resistant applications). The production of plastics has increased exponentially over the past 70 years due to their low cost, durability, and versatility but improper waste management has led to a major pollution crisis. Most plastics are not biodegradable and pollute the environment, entering the oceans and waterways, harming and killing wildlife. Recycling and composting of plastics need to be scaled up to tackle this environmental challenge. Banning or restricting the use of some plastics and developing environmentally friendly and biodegradable alternatives can also help address the plastic pollution problem.
With the development unmanned aerial vehicle (UAV) systems real-time applications,3D printing technologies have developed make thermoplastic structures fusing filament Fused Deposition Modeling (FDM) Fused Filament Fabrication (FFF).We consider realization new technologies experimental models / technological demonstrators / prototypes becomes profitable using 3D printing technologies. The aim paper highlight use three types materials, processed differently, influences Von Mises stresses payload used UAV,mission photographing filming high altitude.
Published By:
L. Grigore - undefined
2021
Cited By:
1
A reanalysis shows river fluxes of microplastics into oceans overestimated by 2-3 orders of magnitude.Ocean surface microplasticsmay persist years, not days.
Published By:
Lisa Weiss - Science
2021
Cited By:
83
Engaging debates about re-emergence of race in science, this article examines expertise of racial phenotypes in facial plastic surgery. Drawing on fieldwork and analysis of medical discourse, it analyses how this expertise is made and used in US, Korea, and Brazil. Plastic surgery has used scientific knowledge of race from fields like anthropology and anthropometry to make racial features (nose, eyes) an object of medical intervention. Race has been enacted differently in three nations according to politics of difference and beauty ideals. While contemporary surgery tries to avoid ethical issues from scientific racism and whitening, it continues to pathologize non-white racial features by changing traits seen as “excessive” or typical, not beautiful.
Published By:
A. Edmonds - undefined
2020
Cited By:
1
Dumping lots of plastics into our oceans Considerable progress has been made determining plastic in seas, uncertain how much enters. Combine data on waste model population density, economic status estimate land-based plastic waste ocean.Unless waste management improve, plastic oceans increase order magnitude decade.Millions tons plastic waste oceans year. Plastic marine environment, quantity plastic entering ocean unknown. Linking worldwide data solid waste, population density, economic status, estimated mass land-based plastic waste entering ocean. Calculate 275 million metric tons (MT) plastic waste generated 192 coastal countries 2010, 4.8 12.7 million MT entering ocean. Population size quality waste management systems largely determine countries contribute greatest mass uncaptured waste available become plastic marine debris. Without waste management improvements, cumulative quantity plastic waste available enter ocean land predicted increase order magnitude 2025.
Published By:
J. Jambeck - Science
2015
Cited By:
6848
Plastic pollution is a global threat.To curb plastic waste,nations must cut single-use plastics,improve waste systems,and remove existing pollution.
Published By:
S. Borrelle - Science
2020
Cited By:
763
Bayfol HX photopolymer films are suitable for volume holographic optical elements. Recorded vHOEs in Bayfol HX films can be processed for embedding into final products.
Published By:
F. Bruder - undefined
2019
Cited By:
5
Due to increased industrial production, plastic waste threatens the environment.Plastic houses use waste and cut construction costs, time,labor and improve safety.
Published By:
S. Gulhane - undefined
2017
Cited By:
2
A study found less than 20% of social media posts in integrated plastic surgery residency programs were wellness-related. Despite burnout importance, residencies may lack or not promote enough wellness initiatives.
Published By:
Rose S. Maisner - Annals of Plastic Surgery
2022
Cited By:
1
We conducted a systematic review of plastic pollution studies. Effects depend on dose, shape, type, and size; microplastics effects are complex.
Published By:
K. Bucci - Ecological Applications
2019
Cited By:
239
The student society must network, schedule events, promote to intergrate and reform.Feedback helps improve engagement, exposure and progress.
Published By:
Yangmyung Ma - Indian Journal of Plastic Surgery
2022
Cited By:
0