Plastic Research Papers - Academia.edu (original) (raw)

The operations were performed with the patient under general anesthesia. For reconstruction, three different flaps adjacent to the defect were raised in a slopey tripod manner, with a base on one of the main arteries of the scalp (Fig 1).... more

The operations were performed with the patient under general anesthesia. For reconstruction, three different flaps adjacent to the defect were raised in a slopey tripod manner, with a base on one of the main arteries of the scalp (Fig 1). The flaps were ...

In order to assist researchers explore the full potential of distributed recycling of post-consumer polymer waste, this article describes a recyclebot, which is a waste plastic extruder capable of making commercial quality 3-D printing... more

In order to assist researchers explore the full potential of distributed recycling of post-consumer polymer waste, this article describes a recyclebot, which is a waste plastic extruder capable of making commercial quality 3-D printing filament. The device design takes advantage of both the open source hardware methodology and the paradigm developed by the open source self-replicating rapid prototyper (RepRap) 3-D printer community. Specifically, this paper describes the design, fabrication and operation of a RepRapable Recyclebot, which refers to the Recyclebot's ability to provide the filament needed to largely replicate the parts for the Recyclebot on any type of RepRap 3-D printer. The device costs less than $700 in mate rials and can be fabricated in about 24 h. Filament is produced at 0.4 kg/h using 0.24 kWh/kg with a diameter ±4.6%. Thus, filament can be manufactured from commercial pellets for <22% of commercial filament costs. In addition, it can fabricate recycled waste plastic into filament for 2.5 cents/kg, which is <1000X commercial filament costs. The system can fabricate filament from polymers with extrusion temperatures <250 °C and is thus capable of manufacturing custom filament over a wide range of thermopolymers and composites for material science studies of new materials and recyclability studies, as well as research on novel applications of fused filament based 3-D printing.

In the treatment of photoaged skin, glycolic acid works by removing superficial portions of the epidermis and stimulating dermis regeneration. Vitamins A, C, and E should stimulate collagen production and antioxidants should prevent free... more

In the treatment of photoaged skin, glycolic acid works by removing superficial portions of the epidermis and stimulating dermis regeneration. Vitamins A, C, and E should stimulate collagen production and antioxidants should prevent free radical damage and skin aging. However, the effectiveness of different therapies has often relied on subjective methods of assessment. Histologic analysis has seldom been used because of the drawback of permanent scarring. In the literature, the use of a quantitative method for the assessment of facial rejuvenation has been described: the silicone replica technique. The authors' aim was to promote and recommend the use of this technique and, in particular, to test the effect of glycolic acid and multivitamin- and antioxidant-based products on skin texture. The authors performed a prospective, randomized, double-blind, controlled study on 30 women treated topically in the outer canthal region (crow's-feet area). Patients were divided into thr...

Over the last two hundred years, the world has become dependent on synthetic plastics, from industrial applications to consumer use [1] plastics are among the prime products in many different applications, where huge masses are used. The... more

Over the last two hundred years, the world has become dependent on synthetic plastics, from industrial applications to consumer use [1] plastics are among the prime products in many different applications, where huge masses are used. The most important feature of plastics can be the flexibility, abundance and durability of the raw materials; however, this feature comes with a side effect.

PET plastic bottles are not only widely used in packaging carbonated beverages, drinking water, fruit juice, enzymes and tea drinks, is the largest use of today's beverage packaging, and widely used in food, chemicals, pharmaceutical... more

PET plastic bottles are not only widely used in packaging carbonated beverages, drinking water, fruit juice, enzymes and tea drinks, is the largest use of today's beverage packaging, and widely used in food, chemicals, pharmaceutical packaging and many other areas.

After studying this article, the participant should be able to discuss: 1. The terminology related to male-to-female gender dysphoria. 2. The different theories regarding cause, epidemiology, and treatment of gender dysphoria. 3. The... more

After studying this article, the participant should be able to discuss: 1. The terminology related to male-to-female gender dysphoria. 2. The different theories regarding cause, epidemiology, and treatment of gender dysphoria. 3. The surgical goals of sex reassignment surgery in male-to-female transsexualism. 4. The surgical techniques available for sex reassignment surgery in male-to-female transsexualism. Gender identity disorder (previously "transsexualism") is the term used for individuals who show a strong and persistent cross-gender identification and a persistent discomfort with their anatomical sex, as manifested by a preoccupation with getting rid of one's sex characteristics, or the belief of being born in the wrong sex. Since 1978, the Harry Benjamin International Gender Dysphoria Association (in honor of Dr. Harry Benjamin, one of the first physicians who made many clinicians aware of the potential benefits of sex reassignment surgery) has played a major ro...

The deep inferior epigastric artery perforator (DIEP) flap aims to reduce donor-site morbidity by minimizing rectus muscle damage; however, damage to motor nerves during perforator dissection may denervate rectus muscle. Although... more

The deep inferior epigastric artery perforator (DIEP) flap aims to reduce donor-site morbidity by minimizing rectus muscle damage; however, damage to motor nerves during perforator dissection may denervate rectus muscle. Although cadaveric research has demonstrated that individual nerves do not arise from single spinal cord segments and are not distributed segmentally, the functional distribution of individual nerves remains unknown. Using intraoperative nerve stimulation, the current study describes the motor distribution of individual nerves supplying the rectus abdominis, providing a guide to nerve dissection during DIEP flap harvest. Twenty rectus abdominis muscles in 17 patients undergoing reconstructive surgery involving rectus abdominis (DIEP, transverse rectus abdominis musculocutaneous, or vertical rectus abdominis musculocutaneous flaps) underwent intraoperative stimulation of nerves innervating the infraumbilical segment of the rectus. Nerve course and extent of rectus muscle contraction were recorded. In each case, three to seven nerves entered the infraumbilical segment of the rectus abdominis. Small nerves (type 1) innervated small longitudinal strips of rectus muscle, rather than transverse strips as previously described. There was significant overlap between adjacent type 1 nerves. In 18 of 20 cases, a single large nerve (type 2) at the level of the arcuate line supplied the entire width and length of rectus muscle. Nerves innervating the rectus abdominis are at risk during DIEP flap harvest. Small, type 1 nerves have overlapping innervation from adjacent nerves and may be sacrificed without functional detriment. However, large type 2 nerves at the level of the arcuate line innervate the entire width of rectus muscle without adjacent overlap and may contribute to donor-site morbidity if sacrificed.

We examined the occurrence of marine debris in the gastrointestinal tract of 54 loggerhead sea turtles (Caretta caretta) found stranded or incidentally captured dead by fisheries in the Adriatic Sea, with a curved carapace length of... more

We examined the occurrence of marine debris in the gastrointestinal tract of 54 loggerhead sea turtles (Caretta caretta) found stranded or incidentally captured dead by fisheries in the Adriatic Sea, with a curved carapace length of 25.0–79.2 cm. Marine debris was present in 35.2% of turtles and included soft plastic, ropes, Styrofoam and monofilament lines found in 68.4%, 42.1%, 15.8% and 5.3% of loggerheads that have ingested debris, respectively. The dry mass of debris per turtle was low, ranging from <0.01 to 0.71 g, and the ingestion was not significantly affected by sex or body size (all p > 0.05). Marine debris averaged 2.2 ± 8.0% of dry mass of gut content, with a maximum of 35% found in a juvenile turtle that most likely died due to debris ingestion. Considering the relatively high occurrence of debris intake and possible sub-lethal effects of even small quantities of marine debris, this can be an additional factor of concern for loggerheads in the Adriatic Sea.► Marine debris was ingested by 35.2% loggerheads foraging in neritic habitats of the Adriatic. ► Soft plastic was the most frequent type of debris found in digestive tract. ► Debris ingestion was not significantly affected by sex or body size of turtles. ► High occurrence of debris intake represents a factor of concern for loggerheads in the Adriatic Sea.

Microplastics are ubiquitous tiny plastic particles (< 5 mm) nonbiodegradable and have large surface area in the environment or the body of living things from anthropogenic activities or fragmentation of plastic debris. Though found in... more

Microplastics are ubiquitous tiny plastic particles (< 5 mm) nonbiodegradable and have large surface area in the environment or the body of living things from anthropogenic activities or fragmentation of plastic debris. Though found in sea food and human body, their health implications are still speculative. A major reason for dearth of information on this topical issue is the lack of standard methods for analyzing microplastics in more complex environmental matrices. In the present review some methodologies for analyzing microplastics reported in the period 2000 to 2018 have been documented with the aim of assessing which methods is most suitable and in what matrix. The following methods have been studied: CHN analyzers, pyrolysis-gas chromatography/mass spectroscopy (PyrGC/MS), optical microscopy, fourier transform infrared microspectroscopy (Micro-FTIR), raman microspectroscopy (RMS) and scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDS). Studies ...

Plastik Ambalaj
İş Akış Şemaları
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Modern lifestyles have popularised the use of food containers, also known as food savers or Tupperware. However, their environmental impacts are currently unknown. To fill this knowledge gap, this paper presents the first comprehensive... more

Modern lifestyles have popularised the use of food containers, also known as food savers or Tupperware. However, their environmental impacts are currently unknown. To fill this knowledge gap, this paper presents the first comprehensive assessment of the life cycle environmental sustainability of reusable plastic and glass food savers and evaluates different options for improvements, focusing on European conditions. Taking a cradle-to-grave approach, the paper considers twelve environmental impacts, including global warming potential (GWP), acidification, eutrophication, human and ecotoxicities. The results suggest that, for example, the total GWP of using both types of food saver in the European Union (EU) amounts to 653 kt CO2 eq./year, equivalent to the annual greenhouse gas emissions of Bermuda. The use stage is the main contributor to the impacts (>40%), related to the washing of containers. Glass food savers have 12%–64% higher impacts than the plastic and should have up to 3.5 times greater lifespan to match the environmental footprint of plastic containers. Three improvement scenarios have been considered at the EU level for the year 2020: low-carbon electricity mix; implementation of the EU eco-design regulation for dishwashers; and adoption of more resource-efficient hand dishwashing techniques. The results suggest that the implementation of all three improvement options would reduce the impacts by 12%–47%. The option with the greatest potential for reducing the impacts (12%–27%) is improved hand dishwashing to reduce the amount of water, energy and detergents used. Thus, policy makers and manufacturers should devise strategies to raise awareness and guide consumers in adopting these techniques with the aim of reducing the environmental impacts associated with reusable food savers used by millions of people worldwide.

Matti Suuronen presentó en 1968 el prototipo de casa “Futuro”, un proyecto de cabaña realizada en poliéster reforzado con fibra de vidrio y cuya forma ovalada se enmarca dentro de la corriente artística de los años 70. Con un tamaño de 8... more

Matti Suuronen presentó en 1968 el prototipo de casa “Futuro”, un proyecto de cabaña realizada en poliéster reforzado con fibra de vidrio y cuya forma ovalada se enmarca dentro de la corriente artística de los años 70. Con un tamaño de 8 metros de diámetro por 4 metros de altura, la casa podía ser transportada fácilmente gracias a su reducido peso, llegando a ser distribuida a varios de sus destinos mediante helicóptero. De igual manera, las 16 piezas modulares que la componían podían ser cargadas en un camión o tren para ser ensambladas posteriormente en su destino.
El artículo analiza la casa Futuro como paradigma de la arquitectura sin lugar cuya relación con el entorno, tanto por su forma cuasi extraterrestre como por la levedad con la que sus patas se posan en el terreno, es mínima. Su cuerpo de níveo plástico brillante destaca entre el paisaje que la rodea como una nave aterrizada, a veces literalmente, en medio del bosque. Las unidades que a día de hoy siguen en pie son testigos vivos de la primera casa de plástico vendida alrededor del planeta.

Over the last two hundred years, the world has become dependent on synthetic plastics, from industrial applications to consumer use [1] plastics are among the prime products in many different applications, where huge masses are used. The... more

Over the last two hundred years, the world has become dependent on synthetic plastics, from industrial applications to consumer use [1] plastics are among the prime products in many different applications, where huge masses are used. The most important feature of plastics can be the flexibility, abundance and durability of the raw materials; however, this feature comes with a side effect.

Spec of Material PC (Polycarbonate)

Plastic molds and plastic molding information

Levels of marine debris, including microplastics, are largely un-documented in the Northeast Atlantic Ocean. Broad scale monitoring efforts are required to understand the distribution, abundance and ecological implications of microplastic... more

Levels of marine debris, including microplastics, are largely un-documented in the Northeast Atlantic Ocean. Broad scale monitoring efforts are required to understand the distribution, abundance and ecological implications of microplastic pollution. A method of continuous sampling was developed to be conducted in conjunction with a wide range of vessel operations to maximise vessel time. Transects covering a total of 12,700 km were sampled through continuous monitoring of open ocean sub-surface water resulting in 470 samples. Items classified as potential plastics were identified in 94% of samples. A total of 2315 particles were identified, 89% were less than 5mm in length classifying them as microplastics. Average plastic abundance in the Northeast Atlantic was calculated as 2.46 particles m(-3). This is the first report to demonstrate the ubiquitous nature of microplastic pollution in the Northeast Atlantic Ocean and to present a potential method for standardised monitoring of mic...

The theme of this year's World Environment Day is "Beat Plastic Pollution". This title story about menace of Plastic pollution was published way back in April 1994 issue of Urdu Science Monthly (urduscience.org ).It is translated into... more

The theme of this year's World Environment Day is "Beat Plastic Pollution". This title story about menace of Plastic pollution was published way back in April 1994 issue of Urdu Science Monthly (urduscience.org ).It is translated into Arabic for a wider circulation.

Several hundred million tons of plastics are produced every year. Previous studies suggest that people have contrasting behavior and perception on plastics. This study analyzes the perception of Grade 12 Marist students on plastics. One... more

Several hundred million tons of plastics are produced every year. Previous studies suggest that people have contrasting behavior and perception on plastics. This study analyzes the perception of Grade 12 Marist students on plastics. One hundred thirty-two Grade 12 Marist students were asked to participate in a survey. An analysis of the results shows that plastic use is common amongst Grade 12 Marist students. Results also show that Grade 12 Marist students are highly aware and concerned about plastic use. Moreover, our findings suggest that the students have divided opinions on school policies and programs concerning plastics use while half of them think that the government is not giving enough attention to plastic pollution in the country. Likewise, responses show that there a high level of awareness and a positive view on bioplastics is widespread amongst students. The results suggest that Grade 12 Marist students have an opposing view and behavior with regards to plastics. This trend may be caused by several factors such as social desirability bias, lack of accessible plastic alternatives, or failed school programs or policies. Further studies, however, are required to genuinely identify the factors that affect the trend.

Now a day, the 3D printing is an increasingly commercially used technology. A crucial section of 3D printing is for providing the printer with printable content if possible, which is achieved by using reels of plastic filament, the most... more

Now a day, the 3D printing is an increasingly commercially used technology. A crucial section of 3D printing is for providing the printer with printable content if possible, which is achieved by using reels of plastic filament, the most common is PLA, but it is the final product which is sold separately. For this situation, the other option arises that plastic material can be recycled and reused through bottles which are disposable which were discarded in order to be used as printable material. 3D Printing Technology is also defined as rapid prototyping, where a 3-dimensional structure is formed by laying the specific material layers. Three phases such as design, printing & finishing are included here in this process. They use any CAD software in the first step to create 3d design. Use this template to build an object in the 2nd stage 3D printer. And the finished item of the third step is extracted from the printer. This technology saves time and money. This avoids material waste. It is very useful to give the demo of any product in industries.

Plastic is one of the daily increasing useful as well as a hazardous material. At the time of need plastic is found to be very useful, but after its use, its simply thrown away, creating all kinds of hazards. Plastic is not bio... more

Plastic is one of the daily increasing useful as well as a hazardous material. At the time of need plastic is found to be very useful, but after its use, its simply thrown away, creating all kinds of hazards. Plastic is not bio degradable, so it will continue to be hazardous for more than centuries.The idea of this paper is to find a use for this waste plastic scrap into something beautiful. The mixing of plastic with sand to create a new type of brick was put into thought. Since it is uneconomical to approach a local brick manufacturer for lending the machine, we designed and fabricated a brick manufacturing machine in the nearby engineering workshop. The machine was designed so as to fulfil our need for manufacturing brick in small quantity. The plastic scrap used was leftover pieces of bottles, cans etc. So, as a trial the plastic was chopped into small pieces and heat was supplied from below. Into the molten plastic paste, M-sand was added in suitable proportions. The paste contained noting more than M-sand, plastic and thermocol. After thorough mixing, the paste was poured into a rectangular mould with standard brick dimensions.The paste took only 20 minutes to settle and harden. Cooling of the set was done by water cooling and after 5 more minutes the brick was extracted from the mould. It had a dark grey texture and increased weight by the initial analysis. Local brick testing methods were conducted such as free fall of the brick and scratch test. In both of those tests, our brick showed increased strength.The brick was subjected to compressive test, water absorption test and efflorescence test. The results showed promise, that the Plastic Composite Brick was efficient than the clay brick and cement brick.