Crystal plasticity in Cu damascene interconnect lines undergoing electromigration as revealed by synchrotron x-ray microdiffraction

Science.gov (United States)

Budiman, A. S.; Nix, W. D.; Tamura, N.; Valek, B. C.; Gadre, K.; Maiz, J.; Spolenak, R.; Patel, J. R.

2006-06-01

Plastic deformation was observed in damascene Cu interconnect test structures during an in situ electromigration experiment and before the onset of visible microstructural damage (voiding, hillock formation). We show here, using a synchrotron technique of white beam x-ray microdiffraction, that the extent of this electromigration-induced plasticity is dependent on the linewidth. In wide lines, plastic deformation manifests itself as grain bending and the formation of subgrain structures, while only grain rotation is observed in the narrower lines. The deformation geometry leads us to conclude that dislocations introduced by plastic flow lie predominantly in the direction of electron flow and may provide additional easy paths for the transport of point defects. Since these findings occur long before any observable voids or hillocks are formed, they may have direct bearing on the final failure stages of electromigration.

Man and his contribution to radiological protection -- a tribute to Wade Patterson

Energy Technology Data Exchange (ETDEWEB)

Thomas, R., LLNL

1998-07-01

Henry Wade Patterson died in Lakeview, Oregon, on 7 October 1997. With his passing, we lost not only one of the most significant figures of the health physics profession but a most personable colleague and friend. His career at the University of California, both at Berkeley and Livermore, spanned five decades and he was generally regarded to be the first professional accelerator health physicist.

Leaching of plasticizers from polyvinylchloride perfusion lines by different lipid emulsions for premature infants under clinical conditions.

Science.gov (United States)

Faessler, David; McCombie, Gregor; Biedermann, Maurus; Felder, Florian; Subotic, Ulrike

2017-03-30

Plasticizers migrate from polyvinylchloride (PVC) infusion systems into lipid emulsions. The aim of this study was to investigate the leaching of different plasticizers from PVC perfusion lines by a selection of lipid emulsions under clinical conditions. Seven PVC perfusion lines with an equal length of 150cm and three internal diameters were perfused with three lipid emulsions: Intralipid ® 20%, ClinOleic ® 20% and SMOFlipid ® 20%, mimicking clinical conditions. The concentrations of the plasticizers were measured directly in the emulsions by gas chromatography - mass spectrometry. Of the four plasticizers examined in this study, di (2-ethylhexyl) phthalate (DEHP) leached the most and was found, on average, at 46.5μg/ml in the emulsions - around one order of magnitude higher than the other plasticizers. This study demonstrates that the leaching of DEHP by lipid emulsions in conditions of total parenteral nutrition is many times higher than should be accepted and higher when compared to the other plasticizers. There was no significant difference in leaching of plasticizers in relation to the type of lipid emulsion. The influence of tube diameter on the leaching rate of plasticizers should be taken into account especially in particular exposed patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Selective Method for the Determination of Manganese in End-fitting of Spoolable Reinforced Plastic Line Pipe for Petroleum Industries

Science.gov (United States)

Shao, Xiaodong; Zhang, Dongna; Li, Houbu; Cai, Xuehua

2017-10-01

The fact that spoolable reinforced plastic line pipe is more flexible and spoolable than steel, and is also much lighter, means that it can becarried and deployedfrom smaller vessels and managed more easily. It was well known that manganese is an important element in end-fitting of spoolable reinforced plastic line pipe. In this paper, a simple spectrophotometric method was described for the determination of manganese in end-fitting of spoolable reinforced plastic line pipe. The method was based on the oxidation-reduction reaction between ammonium persulfate and manganese(II) producing manganese(VII) in the presence of silver nitrate as a catalyst. The characteristic wavelength of maximum absorption of manganese(VII) was obtained locating at 530 nm. Under the optimum reaction conditions the absorption value was proportional to the concentration of manganese in the range of 0.50%˜1.80% (R2 = 0.9997), and the relative standard deviation was less than 3.0% (n=5). The proposed method was applied successfully to determine manganese in end-fitting of spoolable reinforced plastic line pipe samples.

A Private Issue Becomes a Public Issue: A Rhetorical Analysis of "Roe v Wade."

Science.gov (United States)

Cooper, Martha

Supreme Court decisions tend to take the form of either (1) an act of justification or argumentation that defends the verdict of the communicator, or (2) a construction of a new symbolic reality that influences the world view of its audience. The "Roe vs. Wade" decision is an example of the merger of these two rhetorical functions. The…

Roe v. Wade. Ardently prochoice.

Science.gov (United States)

Baldwin, M

1998-01-01

In this commentary, a community activist who is also a retired educator describes how she became ardently in favor of women having the legal right to make abortion decisions. She had converted to Catholicism as an adult in the late 1940s and became a zealot. When the Supreme Court issued its decision in Roe vs. Wade, she tried to determine how she felt about abortion and read some of the publications of Catholics for a Free Choice. In 1980, she ran for office in Vermont and had to declare her views about abortion. She asserted that abortion was a matter to be decided between a woman and her doctor and lost the election to a man in a close race. In 1989, she became a co-founder of Vermont Catholics for Free Choice and served as the president of the organization for 7 years. The Vermont group considered many issues affecting Roman Catholics, including divorce, celibacy, the ordination of women, world population, the rights of homosexuals, contraception, due process, and the local election of bishops as well as abortion. In 1996, the group changed its name to Vermont Catholics for Free Conscience in order to provide an umbrella for all of the dissenting Catholic voices in Vermont.

Landscape factors and hydrology influence mercury concentrations in wading birds breeding in the Florida Everglades, USA.

Science.gov (United States)

Herring, Garth; Eagles-Smith, Collin A; Ackerman, Joshua T; Gawlik, Dale E; Beerens, James M

2013-08-01

The hydrology of wetland ecosystems is a key driver of both mercury (Hg) methylation and waterbird foraging ecology, and hence may play a fundamental role in waterbird exposure and risk to Hg contamination. However, few studies have investigated hydrological factors that influence waterbird Hg exposure. We examined how several landscape-level hydrological variables influenced Hg concentrations in great egret and white ibis adults and chicks in the Florida Everglades. The great egret is a visual "exploiter" species that tolerates lower prey densities and is less sensitive to hydrological conditions than is the white ibis, which is a tactile "searcher" species that pursues higher prey densities in shallow water. Mercury concentrations in adult great egrets were most influenced by the spatial region that they occupied in the Everglades (higher in the southern region); whereas the number of days a site was dry during the previous dry season was the most important factor influencing Hg concentrations in adult ibis (Hg concentrations increased with the number of days dry). In contrast, Hg concentrations in egret chicks were most influenced by calendar date (increasing with date), whereas Hg concentrations in ibis chicks were most influenced by chick age, region, and water recession rate (Hg concentrations decreased with age, were higher in the southern regions, and increased with positive water recession rates). Our results indicate that both recent (preceding two weeks) hydrological conditions, and those of the prior year, influence Hg concentrations in wading birds. Further, these results suggest that Hg exposure in wading birds is driven by complex relationships between wading bird behavior and life stage, landscape hydrologic patterns, and biogeochemical processes. Published by Elsevier B.V.

Raising of geo ecological safety of engineering collectors: the new method of assessment of water tightness of reinforced concrete blocks with basalt plastic lining

Directory of Open Access Journals (Sweden)

Lyapidevskaya Olga

2017-01-01

Full Text Available This work presents analytics ways to estimation and assessment of water tightness of reinforced concrete blocks with basalt plastic lining for increasing geo ecological safety of engineering collectors. It is proved the advisability of application basalt plastic lining instead secondary protection of concrete with hydraulic seal. The results of estimation filtration coefficient and assessment of water tightness of basalt plastic lining of engineering collectors are represented. It is carried out comparative analysis of filtration coefficient and water tightness data of basalt plastic lining and secondary protection. The geo ecological effect is proved at the expense of application of new materials and reducing breakdown events with collectors that may lead pollution of ground and subsoil water with sewage.

Predicting foraging wading bird populations in Everglades National Park from seasonal hydrologic statistics under different management scenarios

Science.gov (United States)

Kwon, Hyun-Han; Lall, Upmanu; Engel, Vic

2011-09-01

The ability to map relationships between ecological outcomes and hydrologic conditions in the Everglades National Park (ENP) is a key building block for their restoration program, a primary goal of which is to improve conditions for wading birds. This paper presents a model linking wading bird foraging numbers to hydrologic conditions in the ENP. Seasonal hydrologic statistics derived from a single water level recorder are well correlated with water depths throughout most areas of the ENP, and are effective as predictors of wading bird numbers when using a nonlinear hierarchical Bayesian model to estimate the conditional distribution of bird populations. Model parameters are estimated using a Markov chain Monte Carlo (MCMC) procedure. Parameter and model uncertainty is assessed as a byproduct of the estimation process. Water depths at the beginning of the nesting season, the average dry season water level, and the numbers of reversals from the dry season recession are identified as significant predictors, consistent with the hydrologic conditions considered important in the production and concentration of prey organisms in this system. Long-term hydrologic records at the index location allow for a retrospective analysis (1952-2006) of foraging bird numbers showing low frequency oscillations in response to decadal fluctuations in hydroclimatic conditions. Simulations of water levels at the index location used in the Bayesian model under alternative water management scenarios allow the posterior probability distributions of the number of foraging birds to be compared, thus providing a mechanism for linking management schemes to seasonal rainfall forecasts.

Excavations in 2014 at Wade Street, Bristol - a documentary and archaeological analysis

OpenAIRE

Nick Corcos; Kamal Badreshany; Alejandra Gutiérrez; Rachel Heaton; Lorrain Higbee; Sarah Newns; Rachel Tyson

2017-01-01

A staged programme of historical research and archaeological fieldwork, involving a desk-based assessment in 2000 (Smith and Erskine 2000), an evaluation in 2013 (Mason 2013), and an excavation followed by a watching brief in 2014, the latter two by Avon Archaeology Ltd, was undertaken in order to mitigate the archaeological impact of a proposed residential development on a site of 1,260m² at the corner and on the north-west side of Little Anne Street and Wade Street, St Jude’s, Bristol. The ...

The influence of plastic deformation and chemical environment on the resistively of al-alloy overhead lines

Directory of Open Access Journals (Sweden)

Nowak-Woźny D.

2005-01-01

Full Text Available The electrical resistively and intensity of X-ray diffraction reflexes were determined for overhead line wires deformed plastically and immersed at different solutions. Immersing (chemical ageing was performed by plastic deformation along the wire axis. During chemical ageing the samples were exposed to the action of the Cl-, SO4 2-, and SO3 2- ions. Resistively was measured at room temperature and at liquid nitrogen temperature. After the X-ray and resistively measurement data were compared, it was found that three processes could take place: the flow of ions through the boundary between a sample and environment; the mechanical relaxation of vacancies near a line of dislocations, and the ordering of microstructure. These effects can lead to the anisotropy of resistively.

Preliminary Use of Uric Acid as a Biomarker for Wading Birds on Everglades Tree Islands, Florida, United States

Science.gov (United States)

Bates, Anne L.; Orem, William H.; Newman, Susan; Gawlik, Dale E.; Lerch, Harry E.; Corum, Margo D.; Van Winkle, Monica

2010-01-01

Concentrations of organic biomarkers and concentrations of phosphorus in soil cores can potentially be used as proxies for historic population densities of wading birds on tree islands in the Florida Everglades. This report focuses on establishing a link between the organic biomarker uric acid found in wading bird guano and the high phosphorus concentrations in tree island soils in the Florida Everglades. Uric acid was determined in soil core sections, in surface samples, and in bird guano by using a method of high-performance liquid chromatography-mass spectrometry (HPLC-MS) developed for this purpose. Preliminary results show an overall correlation between uric acid and total phosphorus in three soil cores, with a general trend of decreasing concentrations of both uric acid and phosphorus with depth. However, we have also found no uric acid in a soil core having high concentrations of phosphorus. We believe that this result may be explained by different geochemical circumstances at that site.

A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

Energy Technology Data Exchange (ETDEWEB)

Webb, Carol F., E-mail: carol-webb@omrf.org [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK (United States); Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Ratliff, Michelle L., E-mail: michelle-ratliff@omrf.org [Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK (United States); Powell, Rebecca, E-mail: rebeccapowell@gmail.com [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Wirsig-Wiechmann, Celeste R., E-mail: celeste-wirsig@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Lakiza, Olga, E-mail: olga-lakiza@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Obara, Tomoko, E-mail: tomoko-obara@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

2015-08-07

Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.

A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

International Nuclear Information System (INIS)

Webb, Carol F.; Ratliff, Michelle L.; Powell, Rebecca; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

2015-01-01

Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development

Glass fiber -reinforced plastic tapered poles for transmission and distribution lines: development and experimental study

International Nuclear Information System (INIS)

Ibrahim, S.; Burachysnsky, V.; Polyzois, D.

1999-01-01

A research project to develop lightweight poles for use in power transmission and distribution lines and involving the use of glass fiber-reinforced plastic using the filament winding process is described. Twelve full scale specimen poles were designed, fabricated and subjected to cantilever bending to test failure modes. The test parameters included fiber orientation, ratio of longitudinal-to-circumferential fiber, and the number of layers. Results showed that local buckling was the most dominant failure mode, attributable to the high radius-to-thickness ratio of the specimen poles. Overall, however, these fiber-reinforced plastic poles compared favourably to wooden poles in carrying capacity with significant weight reduction. Lateral displacement at ultimate loads did not exceed the acceptable limit of 10 per cent of the specimen free length. 7 refs., 3 tabs., 2 figs

Hearing it again and again: on-line subcortical plasticity in humans.

Science.gov (United States)

Skoe, Erika; Kraus, Nina

2010-10-26

Human brainstem activity is sensitive to local sound statistics, as reflected in an enhanced response in repetitive compared to pseudo-random stimulus conditions [1]. Here we probed the short-term time course of this enhancement using a paradigm that assessed how the local sound statistics (i.e., repetition within a five-note melody) interact with more global statistics (i.e., repetition of the melody). To test the hypothesis that subcortical repetition enhancement builds over time, we recorded auditory brainstem responses in young adults to a five-note melody containing a repeated note, and monitored how the response changed over the course of 1.5 hrs. By comparing response amplitudes over time, we found a robust time-dependent enhancement to the locally repeating note that was superimposed on a weaker enhancement of the globally repeating pattern. We provide the first demonstration of on-line subcortical plasticity in humans. This complements previous findings that experience-dependent subcortical plasticity can occur on a number of time scales, including life-long experiences with music and language, and short-term auditory training. Our results suggest that the incoming stimulus stream is constantly being monitored, even when the stimulus is physically invariant and attention is directed elsewhere, to augment the neural response to the most statistically salient features of the ongoing stimulus stream. These real-time transformations, which may subserve humans' strong disposition for grouping auditory objects, likely reflect a mix of local processes and corticofugal modulation arising from statistical regularities and the influences of expectation. Our results contribute to our understanding of the biological basis of statistical learning and initiate a new investigational approach relating to the time-course of subcortical plasticity. Although the reported time-dependent enhancements are believed to reflect universal neurophysiological processes, future

Hearing it again and again: on-line subcortical plasticity in humans.

Directory of Open Access Journals (Sweden)

Erika Skoe

2010-10-01

Full Text Available Human brainstem activity is sensitive to local sound statistics, as reflected in an enhanced response in repetitive compared to pseudo-random stimulus conditions [1]. Here we probed the short-term time course of this enhancement using a paradigm that assessed how the local sound statistics (i.e., repetition within a five-note melody interact with more global statistics (i.e., repetition of the melody.To test the hypothesis that subcortical repetition enhancement builds over time, we recorded auditory brainstem responses in young adults to a five-note melody containing a repeated note, and monitored how the response changed over the course of 1.5 hrs. By comparing response amplitudes over time, we found a robust time-dependent enhancement to the locally repeating note that was superimposed on a weaker enhancement of the globally repeating pattern.We provide the first demonstration of on-line subcortical plasticity in humans. This complements previous findings that experience-dependent subcortical plasticity can occur on a number of time scales, including life-long experiences with music and language, and short-term auditory training. Our results suggest that the incoming stimulus stream is constantly being monitored, even when the stimulus is physically invariant and attention is directed elsewhere, to augment the neural response to the most statistically salient features of the ongoing stimulus stream. These real-time transformations, which may subserve humans' strong disposition for grouping auditory objects, likely reflect a mix of local processes and corticofugal modulation arising from statistical regularities and the influences of expectation. Our results contribute to our understanding of the biological basis of statistical learning and initiate a new investigational approach relating to the time-course of subcortical plasticity. Although the reported time-dependent enhancements are believed to reflect universal neurophysiological

Electromigration-induced plasticity and texture in Cu interconnects

International Nuclear Information System (INIS)

Advanced Light Source; Tamura, Nobumichi; Budiman, A. S.; Hau-Riege, C.S.; Besser, P. R.; Marathe, A.; Joo, Y.-C.; Tamura, N.; Patel, J. R.; Nix, W. D.

2007-01-01

Plastic deformation has been observed in damascene Cu interconnect test structures during an in-situ electromigration experiment and before the onset of visible microstructural damage (ie. voiding) using a synchrotron technique of white beam X-ray microdiffraction. We show here that the extent of this electromigration-induced plasticity is dependent on the texture of the Cu grains in the line. In lines with strong textures, the extent of plastic deformation is found to be relatively large compared to our plasticity results in the previous study [1] using another set of Cu lines with weaker textures. This is consistent with our earlier observation that the occurrence of plastic deformation in a given grain can be strongly correlated with the availability of a direction of the crystal in the proximity of the direction of the electron flow in the line (within an angle of 10 o ). In out-of-plane oriented grains in a damascene interconnect scheme, the crystal plane facing the sidewall tends to be a {110} plane,[2-4] so as to minimize interfacial energy. Therefore, it is deterministic rather than probabilistic that the grains will have a direction nearly parallel to the direction of electron flow. Thus, strong textures lead to more plasticity, as we observe

Electromigration-induced Plasticity and Texture in Cu Interconnects

Science.gov (United States)

Budiman, A. S.; Hau-Riege, C. S.; Besser, P. R.; Marathe, A.; Joo, Y.-C.; Tamura, N.; Patel, J. R.; Nix, W. D.

2007-10-01

Plastic deformation has been observed in damascene Cu interconnect test structures during an in-situ electromigration experiment and before the onset of visible microstructural damage (ie. voiding) using a synchrotron technique of white beam X-ray microdiffraction. We show here that the extent of this electromigration-induced plasticity is dependent on the texture of the Cu grains in the line. In lines with strong textures, the extent of plastic deformation is found to be relatively large compared to our plasticity results in the previous study[1] using another set of Cu lines with weaker textures. This is consistent with our earlier observation that the occurrence of plastic deformation in a given grain can be strongly correlated with the availability of a direction of the crystal in the proximity of the direction of the electron flow in the line (within an angle of 10°). In out-of-plane oriented grains in a damascene interconnect scheme, the crystal plane facing the sidewall tends to be a {110} plane,[2-4] so as to minimize interfacial energy. Therefore, it is deterministic rather than probabilistic that the grains will have a direction nearly parallel to the direction of electron flow. Thus, strong textures lead to more plasticity, as we observe.

Electromigration-induced plasticity and texture in Cu interconnects

Energy Technology Data Exchange (ETDEWEB)

Advanced Light Source; Tamura, Nobumichi; Budiman, A. S.; Hau-Riege, C.S.; Besser, P. R.; Marathe, A.; Joo, Y.-C.; Tamura, N.; Patel, J. R.; Nix, W. D.

2007-10-31

Plastic deformation has been observed in damascene Cu interconnect test structures during an in-situ electromigration experiment and before the onset of visible microstructural damage (ie. voiding) using a synchrotron technique of white beam X-ray microdiffraction. We show here that the extent of this electromigration-induced plasticity is dependent on the texture of the Cu grains in the line. In lines with strong <111> textures, the extent of plastic deformation is found to be relatively large compared to our plasticity results in the previous study [1] using another set of Cu lines with weaker textures. This is consistent with our earlier observation that the occurrence of plastic deformation in a given grain can be strongly correlated with the availability of a <112> direction of the crystal in the proximity of the direction of the electron flow in the line (within an angle of 10{sup o}). In <111> out-of-plane oriented grains in a damascene interconnect scheme, the crystal plane facing the sidewall tends to be a {l_brace}110{r_brace} plane,[2-4] so as to minimize interfacial energy. Therefore, it is deterministic rather than probabilistic that the <111> grains will have a <112> direction nearly parallel to the direction of electron flow. Thus, strong <111> textures lead to more plasticity, as we observe.

An Optimized Circuit in Plastic Meander Line Antenna for 2.45 GHz Applications

Directory of Open Access Journals (Sweden)

Farhat Majeed

2016-01-01

Full Text Available Researchers seek to design electrically small planar antennas for RFID applications. Using multiparameter optimization, various meander line antennas were designed for the lowest resonant frequency and maximum radiation efficiencies for a fixed grid size. One such design for highest radiation efficiency was optimized for microwave frequencies by including an impedance matching structure. The antenna was printed with silver ink on a plexiglass substrate using the circuit in plastic (CiP technique of embedded electrical components. The measured scattering parameter (S11 was −18.43 dB at resonance. The radiation efficiency of the antenna measured using simple and improved Wheeler cap method was 74.4/74.1%. The radiation pattern of electrically small CiP antenna was doughnut-shaped with main lobe magnitude of 0.453 dB and an angular width of 84.2° in elevation plane. The measured 10 dB fractional bandwidth of the antenna was 18.98%. The results are compared with silver/copper in air antennas optimized for achieving the highest radiation efficiency for a fixed grid size. Plastic antennas are viable at microwave frequencies.

Roe v. Wade, the next twenty-five years.

Science.gov (United States)

Kissling, F

1998-01-01

There is little left to be said about abortion in the US; most Americans are either bored with the issue or the issue has simply lost its immediacy. The world today is certainly different from the 1970s, when the US Supreme Court issued its Roe vs. Wade decision. That era was marked by societal and economic generosity manifest by greater acceptance of civil rights, liberal sexual mores, acceptance of divorce, ignorance of infertility, and a focus on alleviating the readily apparent suffering of women made desperate by an unwanted pregnancy. In the 25 intervening years, abortion has remained legal even as the US has become more conservative. It may be, therefore, that pro-choices forces are safe enough to attempt to regain the moral edge and lead the way out of the abortion wars. In order to do this, the values that informed early commitment to women's right to make the abortion decision must finally be clearly expressed, explained, and advocated. Also, pro-choice groups must initiate a more meaningful public dialogue about the morality of abortion and offer answers to the hard questions such as whether it is not better to encourage teenagers to talk to their parents about an unwanted pregnancy, what is the moral significance of developing life, is viability a significant threshold, are there better and worse reasons for abortion, and are some pro-abortion arguments morally dubious. While some may consider this course of action threatening, the visionary leadership that is desperately needed involves addressing both the underlying values and hard questions.

49 CFR 192.321 - Installation of plastic pipe.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Installation of plastic pipe. 192.321 Section 192... Transmission Lines and Mains § 192.321 Installation of plastic pipe. (a) Plastic pipe must be installed below ground level except as provided by paragraphs (g) and (h) of this section. (b) Plastic pipe that is...

On the theory of critical currents and flux flow in superconductors by the mechanism of plastic deformation of the flux-line lattice

International Nuclear Information System (INIS)

Welch, D.O.

1999-01-01

In this paper the author will discuss how the nature of the stress state in the flux-line lattice (FLL) of superconductors arises from the distribution, density, geometry, and strength of pinning centers. Under certain conditions this stress causes the onset of plastic deformation in the FLL for values of the current density below that required for flux-flow by general depinning. He will describe an analytic framework, based on a theory of plasticity of the FLL, which describes the flux-flow characteristics, including the possibility of thermally-activated flow and flux creep

Consumer Exposure to Bisphenol A from Plastic Bottles

Science.gov (United States)

Bidabadi, Fatemeh

2013-01-01

Bisphenol A (BPA) is a plastic monomer and plasticizer and is a chemical that has one of the highest volume production worldwide, with more than six billion pounds each year. Its primary use is the production of polycarbonate plastics, epoxy resins used to line metal cans in a host of plastic consumer products such as toys, water pipes, drinking…

Art and Plastic Surgery.

Science.gov (United States)

Fernandes, Julio Wilson; Metka, Susanne

2016-04-01

The roots of science and art of plastic surgery are very antique. Anatomy, drawing, painting, and sculpting have been very important to the surgery and medicine development over the centuries. Artistic skills besides shape, volume, and lines perception can be a practical aid to the plastic surgeons' daily work. An overview about the interactions between art and plastic surgery is presented, with a few applications to rhinoplasty, cleft lip, and other reconstructive plastic surgeries. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

49 CFR 192.311 - Repair of plastic pipe.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Repair of plastic pipe. 192.311 Section 192.311... Lines and Mains § 192.311 Repair of plastic pipe. Each imperfection or damage that would impair the serviceability of plastic pipe must be repaired or removed. [Amdt. 192-93, 68 FR 53900, Sept. 15, 2003] ...

Extruded plastic scintillator for MINERvA

International Nuclear Information System (INIS)

Pla-Dalmau, Anna; Bross, Alan D.; FermilabRykalin, Victor V.; Wood, Brian M.; NICADD, DeKalb

2005-01-01

An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here

Plasticity Approach to Shear Design

DEFF Research Database (Denmark)

Hoang, Cao Linh; Nielsen, Mogens Peter

1998-01-01

The paper presents some plastic models for shear design of reinforced concrete beams. Distinction is made between two shear failure modes, namely web crushing and crack sliding. The first mentioned mode is met in beams with large shear reinforcement degrees. The mode of crack sliding is met in non......-shear reinforced beams as well as in lightly shear reinforced beams. For such beams the shear strength is determined by the recently developed crack sliding model. This model is based upon the hypothesis that cracks can be transformed into yield lines, which have lower sliding resistance than yield lines formed...... in uncracked concrete. Good agree between theory and tests has been found.Keywords: dsign, plasticity, reinforced concrete, reinforcement, shear, web crushing....

Extruding plastic scintillator at Fermilab

International Nuclear Information System (INIS)

Pla-Dalmau, Anna; Bross, Alain D.; Rykalin, Viktor V.

2003-01-01

An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R andD program at Fermilab

Point and line defects which are common to both degraded light emitting diodes and plastically deformed GaAs

International Nuclear Information System (INIS)

Liliental, Z.

1983-01-01

Similar dipoles with Burger's vector b = a/2 [101] (also referred to as dark line defects) were found in the active layer of degraded light emitting diodes (LED's) and in plastically deformed GaAs. The dependence of characteristic x-ray production of electron channeling conditions has been used in an electron microscope to study point defects in the neighbourhood of these dipoles. Our results are consistent with the occurence of I/sub As/, I/sub As/ +V/sub Ga/, V/sub Ga/ and IAs in descending order of likelihood. Of these, I/sub As/ +V/sub Ga/ can explain the dislocation climb without any extra point defects involved in such process

Gamma spectrometry and plastic-scintillator inherent background

International Nuclear Information System (INIS)

Pomerantsev, V.V.; Gagauz, I.B.; Mitsai, L.I.; Pilipenko, V.S.; Solomonov, V.M.; Chernikov, V.V.; Tsirlin, Y.A.

1988-01-01

The authors measured the energy resolution for a linear dependence of light yield on gamma radiation energy of gamma spectrometers based on plastic scintillation detectors for several plastic scintillators. If there were several gamma lines from the source the line with the highest energy was used to eliminate distortion due to overlap from the Compton background from gamma radiation of higher energy. Attenuation lengths were calculated. The tests were based on three modes of interaction between the gamma radiation and the scintillator: Compton scattering, the photoelectric effect, and pair formation. The contribution from light collection was also considered. The scintillators tested included polystyrene, polymethyl methacrylate, cesium iodide, and sodium iodide. Gamma sources included cesium 137, sodium 22, potassium 40, yttrium 88, thorium 232, and plutonium-beryllium

A new hyperspectral imaging based device for quality control in plastic recycling

Science.gov (United States)

Bonifazi, G.; D'Agostini, M.; Dall'Ava, A.; Serranti, S.; Turioni, F.

2013-05-01

The quality control of contamination level in the recycled plastics stream has been identified as an important key factor for increasing the value of the recycled material by both plastic recycling and compounder industries. Existing quality control methods for the detection of both plastics and non-plastics contaminants in the plastic waste streams at different stages of the industrial process (e.g. feed, intermediate and final products) are currently based on the manual collection from the stream of a sample and on the subsequent off-line laboratory analyses. The results of such analyses are usually available after some hours, or sometimes even some days, after the material has been processed. The laboratory analyses are time-consuming and expensive (both in terms of equipment cost and their maintenance and of labour cost).Therefore, a fast on-line assessment to monitor the plastic waste feed streams and to characterize the composition of the different plastic products, is fundamental to increase the value of secondary plastics. The paper is finalized to describe and evaluate the development of an HSI-based device and of the related software architectures and processing algorithms for quality assessment of plastics in recycling plants, with particular reference to polyolefins (PO). NIR-HSI sensing devices coupled with multivariate data analysis methods was demonstrated as an objective, rapid and non-destructive technique that can be used for on-line quality and process control in the recycling process of POs. In particular, the adoption of the previous mentioned HD&SW integrated architectures can provide a solution to one of the major problems of the recycling industry, which is the lack of an accurate quality certification of materials obtained by recycling processes. These results could therefore assist in developing strategies to certify the composition of recycled PO products.

Plasticity size effects in voided crystals

DEFF Research Database (Denmark)

Hussein, M. I.; Borg, Ulrik; Niordson, Christian Frithiof

singularities in an elastic material. The lattice resistance to dislocation motion, dislocation nucleation, dislocation interaction with obstacles and annihilation are incorporated through a set of constitutive rules. Over the range of length scales investigated, both the discrete dislocation and strain......The shear and equi-biaxial straining responses of periodic voided single crystals are analysed using discrete dislocation plasticity and a continuum strain gradient crystal plasticity theory. In the discrete dislocation formulation the dislocations are all of edge character and are modelled as line...... predictions of the two formulations for all crystal types and void volume fractions considered when the material length scale in the non-local plasticity model chosen to be $0.325\\mu m$ (around ten times the slip plane spacing in the discrete dislocation models)....

Plasticity size effects in voided crystals

DEFF Research Database (Denmark)

Hussein, M.I.; Borg, Ulrik; Niordson, Christian Frithiof

2008-01-01

as line singularities in an elastic material. The lattice resistance to dislocation motion, dislocation nucleation, dislocation interaction with obstacles and annihilation are incorporated through a set of constitutive rules. Over the range of length scales investigated, both the discrete dislocation......The shear and equi-biaxial straining responses of periodic voided single crystals are analysed using discrete dislocation plasticity and a continuum strain gradient crystal plasticity theory. In the discrete dislocation formulation, the dislocations are all of edge character and are modelled...... between predictions of the two formulations for all crystal types and void volume fractions considered when the material length scale in the non-local plasticity model is chosen to be 0.325 mu m (about 10 times the slip plane spacing in the discrete dislocation models)....

Plastic debris in the coastal environment: The invincible threat? Abundance of buried plastic debris on Malaysian beaches.

Science.gov (United States)

Fauziah, S H; Liyana, I A; Agamuthu, P

2015-09-01

Studies on marine debris have gained worldwide attention since many types of debris have found their way into the food chain of higher organisms. Thus, it is crucial that more focus is given to this area in order to curb contaminations in sea food. This study was conducted to quantify plastic debris buried in sand at selected beaches in Malaysia. Marine debris was identified according to size range and distribution, and this information was related to preventive actions to improve marine waste issues. For the purpose of this study, comparison of plastic waste abundance between a recreational beach and fish-landing beaches was also carried out, since the different beach types represent different activities that produce debris. Six beaches along the Malaysian coastline were selected for this study. The plastic types in this study were related to the functions of the beach. While recreational beaches have abundant quantities of plastic film, foamed plastic including polystyrene, and plastic fragment, fish-landing beaches accumulated line and foamed plastic. A total of 2542 pieces (265.30 g m(-2)) of small plastic debris were collected from all six beaches, with the highest number from Kuala Terengganu, at 879 items m(-2) on Seberang Takir Beach, followed by Batu Burok Beach with 780 items m(-2). Findings from studies of Malaysian beaches have provided a clearer understanding of the distribution of plastic debris. This demonstrates that commitments and actions, such as practices of the 'reduce, reuse, recycle' (3R) approach, supporting public awareness programmes and beach clean-up activities, are essential in order to reduce and prevent plastic debris pollution. © The Author(s) 2015.

On the formulation of higher gradient single and polycrystal plasticity

International Nuclear Information System (INIS)

Menzel, A.; Steinmann, P.

1998-01-01

This contribution aims in a geometrically linear formulation of higher gradient plasticity of single and polycrystalline material based on the continuum theory of dislocations and incompatibilities. Thereby, general continuum dislocation densities and incompatibilities are introduced from the viewpoint of continuum mechanics by considering the spatial closure failure of arbitrary line integrals of the displacement differential. Then these findings are translated to the plastic parts of the displacement gradient, the so called plastic distortion, and the plastic strain, respectively, within an elasto-plastic solid thus defining tensor fields of plastic dislocation densities and plastic incompatibilities. Next, in the case of single crystalline material the plastic dislocation density and in the case of polycrystalline material the plastic incompatibility are considered within the exploitation of the thermodynamical principle of positive dissipation. As a result, a phenomenological but physically motivated description of hardening is obtained, which incorporates for single crystals second spatial derivatives of the plastic deformation gradient and for polycrystals fourth spatial derivatives of the plastic strains into the yield condition. Moreover, these modifications mimic the characteristic structure of kinematic hardening, whereby the backstress obeys a nonlocal evolution law. (orig.)

Plastic

International Nuclear Information System (INIS)

Jeong Gi Hyeon

1987-04-01

This book deals with plastic, which includes introduction for plastic, chemistry of high polymers, polymerization, speciality and structure of a high molecule property of plastic, molding, thermosetting plastic, such as polyethylene, polyether, polyamide and polyvinyl acetyl, thermal plastic like phenolic resins, xylene resins, melamine resin, epoxy resin, alkyd resin and poly urethan resin, new plastic like ionomer and PPS resin, synthetic laminated tape and synthetic wood, mixed materials in plastic, reprocessing of waste plastic, polymer blend, test method for plastic materials and auxiliary materials of plastic.

GREEN PLASTIC: A NEW PLASTIC FOR PACKAGING

OpenAIRE

Mr. Pankaj Kumar*, Sonia

2016-01-01

This paper gives a brief idea about a new type of plastic called as bio-plastic or green plastic. Plastic is used as a packaging material for various products, but this plastic is made up of non renewable raw materials. There are various disadvantages of using conventional plastic like littering, CO2 production, non-degradable in nature etc. To overcome these problems a new type of plastic is discovered called bio-plastic or green plastic. Bio-plastic is made from renewable resources and also...

Directional selection on cold tolerance does not constrain plastic capacity in a butterfly.

Science.gov (United States)

Franke, Kristin; Dierks, Anneke; Fischer, Klaus

2012-12-05

Organisms may respond to environmental change by means of genetic adaptation, phenotypic plasticity or both, which may result in genotype-environment interactions (G x E) if genotypes differ in their phenotypic response. We here specifically target the latter source of variation (i.e. G x E) by comparing plastic responses among lines of the tropical butterfly Bicyclus anynana that had been selected for increased cold tolerance and according controls. Our main aim here was to test the hypothesis that directional selection on cold tolerance will interfere with plastic capacities. Plastic responses to temperature and feeding treatments were strong, with e.g. higher compared to lower temperatures reducing cold tolerance, longevity, pupal mass, and development time. We report a number of statistically significant genotype-environment interactions (i.e. interactions between selection regime and environmental variables), but most of these were not consistent across treatment groups. We found some evidence though for larger plastic responses to different rearing temperatures in the selection compared to the control lines, while plastic responses to different adult temperatures and feeding treatments were overall very similar across selection regimes. Our results indicate that plastic capacities are not always constrained by directional selection (on cold tolerance) and therefore genetic changes in trait means, but may operate independently.

In vitro functional screening as a means to identify new plasticizers devoid of reproductive toxicity

Energy Technology Data Exchange (ETDEWEB)

Boisvert, Annie; Jones, Steven; Issop, Leeyah [The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Erythropel, Hanno C. [Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Papadopoulos, Vassilios [The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Culty, Martine, E-mail: martine.culty@mcgill.ca [The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Department of Medicine, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada); Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada H4A 3J1 (Canada)

2016-10-15

Plasticizers are indispensable additives providing flexibility and malleability to plastics. Among them, several phthalates, including di (2-ethylhexyl) phthalate (DEHP), have emerged as endocrine disruptors, leading to their restriction in consumer products and creating a need for new, safer plasticizers. The goal of this project was to use in vitro functional screening tools to select novel non-toxic plasticizers suitable for further in vivo evaluation. A panel of novel compounds with satisfactory plasticizer properties and biodegradability were tested, along with several commercial plasticizers, such as diisononyl-cyclohexane-1,2-dicarboxylate (DINCH®). MEHP, the monoester metabolite of DEHP was also included as reference compound. Because phthalates target mainly testicular function, including androgen production and spermatogenesis, we used the mouse MA-10 Leydig and C18-4 spermatogonial cell lines as surrogates to examine cell survival, proliferation, steroidogenesis and mitochondrial integrity. The most promising compounds were further assessed on organ cultures of rat fetal and neonatal testes, corresponding to sensitive developmental windows. Dose-response studies revealed the toxicity of most maleates and fumarates, while identifying several dibenzoate and succinate plasticizers as innocuous on Leydig and germ cells. Interestingly, DINCH®, a plasticizer marketed as a safe alternative to phthalates, exerted a biphasic effect on steroid production in MA-10 and fetal Leydig cells. MEHP was the only plasticizer inducing the formation of multinucleated germ cells (MNG) in organ culture. Overall, organ cultures corroborated the cell line data, identifying one dibenzoate and one succinate as the most promising candidates. The adoption of such collaborative approaches for developing new chemicals should help prevent the development of compounds potentially harmful to human health. - Highlights: • Phthalate plasticizers exert toxic effects on male reproduction

In vitro functional screening as a means to identify new plasticizers devoid of reproductive toxicity

International Nuclear Information System (INIS)

Boisvert, Annie; Jones, Steven; Issop, Leeyah; Erythropel, Hanno C.; Papadopoulos, Vassilios; Culty, Martine

2016-01-01

Plasticizers are indispensable additives providing flexibility and malleability to plastics. Among them, several phthalates, including di (2-ethylhexyl) phthalate (DEHP), have emerged as endocrine disruptors, leading to their restriction in consumer products and creating a need for new, safer plasticizers. The goal of this project was to use in vitro functional screening tools to select novel non-toxic plasticizers suitable for further in vivo evaluation. A panel of novel compounds with satisfactory plasticizer properties and biodegradability were tested, along with several commercial plasticizers, such as diisononyl-cyclohexane-1,2-dicarboxylate (DINCH®). MEHP, the monoester metabolite of DEHP was also included as reference compound. Because phthalates target mainly testicular function, including androgen production and spermatogenesis, we used the mouse MA-10 Leydig and C18-4 spermatogonial cell lines as surrogates to examine cell survival, proliferation, steroidogenesis and mitochondrial integrity. The most promising compounds were further assessed on organ cultures of rat fetal and neonatal testes, corresponding to sensitive developmental windows. Dose-response studies revealed the toxicity of most maleates and fumarates, while identifying several dibenzoate and succinate plasticizers as innocuous on Leydig and germ cells. Interestingly, DINCH®, a plasticizer marketed as a safe alternative to phthalates, exerted a biphasic effect on steroid production in MA-10 and fetal Leydig cells. MEHP was the only plasticizer inducing the formation of multinucleated germ cells (MNG) in organ culture. Overall, organ cultures corroborated the cell line data, identifying one dibenzoate and one succinate as the most promising candidates. The adoption of such collaborative approaches for developing new chemicals should help prevent the development of compounds potentially harmful to human health. - Highlights: • Phthalate plasticizers exert toxic effects on male reproduction

40 CFR Table 10 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Science.gov (United States)

2010-07-01

... Continuous Lamination Lines and Continuous Casting Lines Complying With a Percent Reduction Limit on a Per... SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic... Reduction Limit on a Per Line Basis As required in § 63.5865(a), in order to comply with a percent reduction...

A survey of endangered waterbirds on Maui and Oahu and assessment of potential impacts to waterbirds from the proposed Hawaii Geothermal Project transmission corridor. Final report

Energy Technology Data Exchange (ETDEWEB)

Evans, K.; Woodside, D.; Bruegmann, M. [Fish and Wildlife Service, Honolulu, HI (United States). Pacific Islands Office

1994-08-01

A survey of endangered waterbirds on Maui and Oahu was conducted during August and September 1993 to identify potential waterbird habitats within the general area of the proposed Hawaii Geothermal Project transmission corridor and to assess the potential impacts to endangered waterbird of installing and operating a high voltage transmission line from the Island of Hawaii to the islands of Oahu and Maui. Annual waterbird survey information and other literature containing information on specific wetland sites were summarized. Literature describing impacts of overhead transmission lines on birds was used to evaluate potential impacts of the proposed project on endangered waterbirds, resident wading birds, and migratory shorebirds and waterfowl. On Oahu, five wetland habitats supporting endangered Hawaiian waterbirds were identified within 2.5 miles of the proposed transmission line corridor. On Maui, three wetland habitats supporting endangered Hawaiian waterbirds were identified within the general area of the proposed transmission line corridor. Several of the wetlands identified on Oahu and Maui also supported resident wading birds and migratory shorebirds and waterfowl. Endangered waterbirds, resident wading birds, and migratory birds may collide with the proposed transmission lines wires. The frequency and numbers of bird collisions is expected to be greater on Oahu than on Maui because more wetland habitat exists and greater numbers of birds occur in the project area on Oahu. In addition, the endangered Hawaiian goose and the endangered Hawaiian petrel may be impacted by the proposed segment of the Hawaii Geothermal Project transmission line on Maui.

Durability of Capped Wood Plastic Composites

Science.gov (United States)

Mark Mankowski; Mark J. Manning; Damien P. Slowik

2015-01-01

Manufacturers of wood plastic composites (WPCs) have recently introduced capped decking to their product lines. These new materials have begun to take market share from the previous generation of uncapped products that possessed a homogenous composition throughout the thickness of their cross-section. These capped offerings have been introduced with claims that the...

Sleep and protein synthesis-dependent synaptic plasticity: impacts of sleep loss and stress

Science.gov (United States)

Grønli, Janne; Soulé, Jonathan; Bramham, Clive R.

2014-01-01

Sleep has been ascribed a critical role in cognitive functioning. Several lines of evidence implicate sleep in the consolidation of synaptic plasticity and long-term memory. Stress disrupts sleep while impairing synaptic plasticity and cognitive performance. Here, we discuss evidence linking sleep to mechanisms of protein synthesis-dependent synaptic plasticity and synaptic scaling. We then consider how disruption of sleep by acute and chronic stress may impair these mechanisms and degrade sleep function. PMID:24478645

Short-term plasticity in auditory cognition.

Science.gov (United States)

Jääskeläinen, Iiro P; Ahveninen, Jyrki; Belliveau, John W; Raij, Tommi; Sams, Mikko

2007-12-01

Converging lines of evidence suggest that auditory system short-term plasticity can enable several perceptual and cognitive functions that have been previously considered as relatively distinct phenomena. Here we review recent findings suggesting that auditory stimulation, auditory selective attention and cross-modal effects of visual stimulation each cause transient excitatory and (surround) inhibitory modulations in the auditory cortex. These modulations might adaptively tune hierarchically organized sound feature maps of the auditory cortex (e.g. tonotopy), thus filtering relevant sounds during rapidly changing environmental and task demands. This could support auditory sensory memory, pre-attentive detection of sound novelty, enhanced perception during selective attention, influence of visual processing on auditory perception and longer-term plastic changes associated with perceptual learning.

Computational Strain Gradient Crystal Plasticity

DEFF Research Database (Denmark)

Niordson, Christian Frithiof; Kysar, Jeffrey W.

2011-01-01

A model for strain gradient crystal visco-plasticity is formulated along the lines proposed by Fleck andWillis (2009) for isotropic plasticity. Size-effects are included in the model due to the addition of gradient terms in both the free energy as well as through a dissipation potential. A finite...... element solution method is presented, which delivers the slip-rate field and the velocity-field based on two minimum principles. Some plane deformation problems relevant for certain specific orientations of a face centered cubic crystal under plane loading conditions are studied, and effective in......-plane parameters are developed based on the crystallographic properties of the material. The problem of cyclic shear of a single crystal between rigid platens is studied as well as void growth of a cylindrical void....

Snippets from the past: the evolution of Wade Hampton Frost's epidemiology as viewed from the American Journal of Hygiene/Epidemiology.

Science.gov (United States)

Morabia, Alfredo

2013-10-01

Wade Hampton Frost, who was a Professor of Epidemiology at Johns Hopkins University from 1919 to 1938, spurred the development of epidemiologic methods. His 6 publications in the American Journal of Hygiene, which later became the American Journal of Epidemiology, comprise a 1928 Cutter lecture on a theory of epidemics, a survey-based study of tonsillectomy and immunity to Corynebacterium diphtheriae (1931), 2 papers from a longitudinal study of the incidence of minor respiratory diseases (1933 and 1935), an attack rate ratio analysis of the decline of diphtheria in Baltimore (1936), and a 1936 lecture on the age, time, and cohort analysis of tuberculosis mortality. These 6 American Journal of Hygiene /American Journal of Epidemiology papers attest that Frost's personal evolution mirrored that of the emerging "early" epidemiology: The scope of epidemiology extended beyond the study of epidemics of acute infectious diseases, and rigorous comparative study designs and their associated quantitative methods came to light.

Sub-keV x-ray calibration of plastic scintillators

International Nuclear Information System (INIS)

Lyons, P.B.; Day, R.H.; Lier, D.W.; Elsberry, T.L.

1976-01-01

Several types of x-ray detectors have found widespread use for plasma diagnostic applications in the energy range below a few keV. Silicon diodes, photoelectric diodes, and plastic scintillators have been used to obtain diagnostic information in this region. Sub-keV calibration data for plastic scintillator detectors are reported, and the advantages and limitations of these three detectors in diagnostic measurements are compared. In a previous paper calibration data for plastic scintillators from 1.5 to 20 keV were given. In this paper the data are extended to the C-K/sub α/ line (277 eV). These data represent one application of a new sub-keV x-ray calibration facility at the Los Alamos Scientific Laboratory

[Analysis of phthalate esters in plastic-packaging bags on-line sample stacking-microemulsion electrokinetic chromatography].

Science.gov (United States)

Xiao, Jia; Huang, Ying; Wang, Minyi; Chen, Guonan

2012-09-01

Two convenient, effective, and reproducible methods using microemulsion electrokinetic chromatography (MEEKC)-normal stacking mode (NSM) and reversed electrode polarity stacking mode (REPSM) were developed for the on-line sample stacking of phthalate esters (PAEs). REPSM coupled with MEEKC increased the sensitivity of 937.5 to 7,143 times for four PAEs compared to the conventional MEEKC. The separating conditions in the MEEKC method were studied, and many factors influencing the two sample stacking processes were investigated in detail. The optimum sample matrices for the two stacking methods were as follows: 30 mmol/L sodium cholate (SC) and 30.0 mmol/L borate (pH 8.5). Additionally, sample injections as large as 3.45 kPa x 40 s and 3.45 kPa x 90 s were applied for NSM-MEEKC and REPSM-MEEKC, respectively. The linear relationship and reproducibility were also examined. Under the optimum conditions, the detection limits (S/N = 3) of the PAEs were in the ranges of 0.021 - 0.33 mg/L and 0.7 - 4 microg/L for NSM-MEEKC and REPSM-MEEKC, respectively. The proposed REPSM-MEEKC has been successfully applied to determine PAEs in plastic-packaging bags, and the spiked recoveries were in the range of 89.1% - 105.6% with satisfactory results.

Method of solidifying radioactive waste by plastics

International Nuclear Information System (INIS)

Yasumura, Keijiro; Tomita, Toshihide.

1976-01-01

Purpose: To prevent leakage of radioactivity by providing corrosion-resistant layer on the inner surface of a waste container for radioactive waste. Constitution: The inner periphery and bottom of a drum can is lined with an non-flammable cloth of such material as asbestos. This drum is filled with a radioactive waste in the form of powder or pellets. Then, a mixture of a liquid plastic monomer and a polymerization starting agent is poured at a normal temperature, and the surface is covered with a non-flammable cloth. The plastic monomer and radioactive waste are permitted to impregnate the non-flammable cloth and are solidified there. Thus, even if the drum can is corroded at the sea bottom after disposal it in the ocean, it is possible to prevent the waste from permeating into the outer sea water because of the presence of the plastic layer on the inside. Styrene is used as the monomer. (Aizawa, K.)

Malfunctioning Plastic Biliary Endoprosthesis: Percutaneous Transhepatic Balloon Pulling Technique

Directory of Open Access Journals (Sweden)

Umberto G. Rossi

2013-01-01

Full Text Available Percutaneous transhepatic removal techniques for malfunctioning plastic biliary endoprosthesis are considered safe and efficient second-line strategies, when endoscopic procedures are not feasible. We describe the percutaneous transhepatic balloon pulling technique in a patient with an unresectable malignant hilar cholangiocarcinoma.

Towards predicting wading bird densities from predicted prey densities in a post-barrage Severn estuary

International Nuclear Information System (INIS)

Goss-Custard, J.D.; McGrorty, S.; Clarke, R.T.; Pearson, B.; Rispin, W.E.; Durell, S.E.A. le V. dit; Rose, R.J.; Warwick, R.M.; Kirby, R.

1991-01-01

A winter survey of seven species of wading birds in six estuaries in south-west England was made to develop a method for predicting bird densities should a tidal power barrage be built on the Severn estuary. Within most estuaries, bird densities correlated with the densities of widely taken prey species. A barrage would substantially reduce the area of intertidal flats available at low water for the birds to feed but the invertebrate density could increase in the generally more benign post-barrage environmental conditions. Wader densities would have to increase approximately twofold to allow the same overall numbers of birds to remain post-barrage as occur on the Severn at present. Provisional estimates are given of the increases in prey density required to allow bird densities to increase by this amount. With the exception of the prey of dunlin, these fall well within the ranges of densities found in other estuaries, and so could in principle be attained in the post-barrage Severn. An attempt was made to derive equations with which to predict post-barrage densities of invertebrates from easily measured, static environmental variables. The fact that a site was in the Severn had a significant additional effect on invertebrate density in seven cases. This suggests that there is a special feature of the Severn, probably one associated with its highly dynamic nature. This factor must be identified if the post-barrage densities of invertebrates are to be successful predicted. (author)

Plasticity theory

CERN Document Server

Lubliner, Jacob

2008-01-01

The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

A review of the welfare impact on Pinnipeds of plastic marine debris

Directory of Open Access Journals (Sweden)

Andrew Butterworth

2016-08-01

Full Text Available Uncounted, and usually unobserved, numbers of pinnipeds find themselves entangled in lost fishing gear, monofilament line, nets, rope, plastic packaging in the ocean or on the shoreline. These animals may carry debris wrapped around themselves for long periods, and often die as a result, sometimes from deep chronic wounds. The pinniped species most affected by this modern and manmade phenomenon are fur seals, monk seals, and California sea lions, and to a lesser extent grey, common and monk seals. Entanglement rates described range up to 7.9% of local populations annually, and the common entangling materials; packing bands, fragments of lost net, rope, monofilament line, fishery flashers and lures, long-line fishing gear, hooks and line, and bait hooks are discussed. Awareness of this issue is increasing, and local action is reported to have made measurable differences in entanglement rates, however, plastic material in the ocean is likely to be long lived, and will leave many entangled pinnpeds unreported and result in a hidden and potentially significant effect on wild animal welfare.

Analysis of acetal toilet fill valve supply line nut failure

Directory of Open Access Journals (Sweden)

Anthony Timpanaro

2017-10-01

Full Text Available In recent years, there has been a rise in the number of product liability cases involving the failure of toilet water supply line acetal plastic nuts. These nuts can fail in service, causing water leaks that result in significant property and financial losses. This study examines three possible failure modes of acetal plastic toilet water supply nuts. The three failure modes tested were all due to over load failure of the acetal nut and are as follows: (1 Overtightening of the supply line acetal nut, (2 Supply line lateral pull and, (3 Embrittled supply line lateral pull. Additionally, a “hand-tight” torque survey was conducted. The fracture surfaces and characteristics of these failure tests were examined with Stereo Microscopy and Scanning Electron Microscopy (SEM. The failure modes were compared and contrasted to provide guidance in determination of cause in these investigations.

Vocal plasticity in a reptile.

Science.gov (United States)

Brumm, Henrik; Zollinger, Sue Anne

2017-05-31

Sophisticated vocal communication systems of birds and mammals, including human speech, are characterized by a high degree of plasticity in which signals are individually adjusted in response to changes in the environment. Here, we present, to our knowledge, the first evidence for vocal plasticity in a reptile. Like birds and mammals, tokay geckos ( Gekko gecko ) increased the duration of brief call notes in the presence of broadcast noise compared to quiet conditions, a behaviour that facilitates signal detection by receivers. By contrast, they did not adjust the amplitudes of their call syllables in noise (the Lombard effect), which is in line with the hypothesis that the Lombard effect has evolved independently in birds and mammals. However, the geckos used a different strategy to increase signal-to-noise ratios: instead of increasing the amplitude of a given call type when exposed to noise, the subjects produced more high-amplitude syllable types from their repertoire. Our findings demonstrate that reptile vocalizations are much more flexible than previously thought, including elaborate vocal plasticity that is also important for the complex signalling systems of birds and mammals. We suggest that signal detection constraints are one of the major forces driving the evolution of animal communication systems across different taxa. © 2017 The Author(s).

Magical Engineering Plastic

Energy Technology Data Exchange (ETDEWEB)

Kim, Gwang Ung

1988-01-15

This book introduces engineering plastic about advantage of engineering plastic, plastic material from processing method, plastic shock, plastic until now, background of making of engineering plastic, wonderful engineering plastic science such as a high molecule and molecule, classification of high molecule, difference between metal and high molecule, heat and high molecule materials, and property of surface, engineering plastic of dream like from linseed oil to aramid, small dictionary of engineering plastic.

Magical Engineering Plastic

International Nuclear Information System (INIS)

Kim, Gwang Ung

1988-01-01

This book introduces engineering plastic about advantage of engineering plastic, plastic material from processing method, plastic shock, plastic until now, background of making of engineering plastic, wonderful engineering plastic science such as a high molecule and molecule, classification of high molecule, difference between metal and high molecule, heat and high molecule materials, and property of surface, engineering plastic of dream like from linseed oil to aramid, small dictionary of engineering plastic.

International policies to reduce plastic marine pollution from single-use plastics (plastic bags and microbeads): A review.

Science.gov (United States)

Xanthos, Dirk; Walker, Tony R

2017-05-15

Marine plastic pollution has been a growing concern for decades. Single-use plastics (plastic bags and microbeads) are a significant source of this pollution. Although research outlining environmental, social, and economic impacts of marine plastic pollution is growing, few studies have examined policy and legislative tools to reduce plastic pollution, particularly single-use plastics (plastic bags and microbeads). This paper reviews current international market-based strategies and policies to reduce plastic bags and microbeads. While policies to reduce microbeads began in 2014, interventions for plastic bags began much earlier in 1991. However, few studies have documented or measured the effectiveness of these reduction strategies. Recommendations to further reduce single-use plastic marine pollution include: (i) research to evaluate effectiveness of bans and levies to ensure policies are having positive impacts on marine environments; and (ii) education and outreach to reduce consumption of plastic bags and microbeads at source. Copyright © 2017 Elsevier Ltd. All rights reserved.

Numerical investigation of heat transfer in Plastic Leaded Chip ...

African Journals Online (AJOL)

Plastic Leaded Chip Carrier (PLCC) package has been emerged a promising option to tackle the thermal management issue of micro-electronic devices. In the present study, three dimensional numerical analysis of heat and fluid flow through PLCC packages oriented in-line and mounted horizontally on a printed circuit ...

comparison of elastic-plastic FE method and engineering method for RPV fracture mechanics analysis

International Nuclear Information System (INIS)

Sun Yingxue; Zheng Bin; Zhang Fenggang

2009-01-01

This paper described the FE analysis of elastic-plastic fracture mechanics for a crack in RPV belt line using ABAQUS code. It calculated and evaluated the stress intensity factor and J integral of crack under PTS transients. The result is also compared with that by engineering analysis method. It shows that the results using engineering analysis method is a little larger than the results using FE analysis of 3D elastic-plastic fracture mechanics, thus the engineering analysis method is conservative than the elastic-plastic fracture mechanics method. (authors)

An on-line tritium-in-water monitor

International Nuclear Information System (INIS)

Singh, A.N.; Ratnakaran, M.; Vohra, K.G.

1985-01-01

The paper describes the development and operation of a continuous on-line tritium-in-water monitor for the detection of heavy water leaks into the secondary coolant light water of a heavy water power reactor. The heart of the instrument is its plastic scintillator sponge detector, made from 5 μm thick plastic scintillator films. The sponge weighs only about 1 g and is in the form of disc of 48 mm diameter and 8 mm thickness. The total surface area of the films is about 3000 cm 2 . In the coincidence mode of counting, the detector gives 1000 cps for the passage of 3.7 x 10 4 Bq/cm 3 (1 μCi/cm 3 ) of tritiated water. The background in 6 cm thick lead shielding in the laboratory is 0.2 cps, and inside the reactor building it is below 1 cps. The monitor presently scans 18 sample lines in sequence for 5 min each and gives a printout for the activity in each line. (orig.)

An on-line tritium-in-water monitor

Science.gov (United States)

Singh, A. N.; Ratnakaran, M.; Vohra, K. G.

1985-05-01

The paper describes the development and operation of a continuous on-line tritium-in-water monitor for the detection of heavy water leaks into the secondary coolant light water of a heavy water power reactor. The heart of the instrument is its plastic scintillator sponge detector, made from 5 μm thick plastic scintillator films. The sponge weighs only about 1 g and is in the form of disc of 48 mm diameter and 8 mm thickness. The total surface area of the films is about 3000 cm 2. In the coincidence mode of counting, the detector gives 1000 cps for the passage of 3.7 × 10 4 Bq/cm 3 (1 μCi/cm 3) of tritiated water. The background in 6 cm thick lead shielding in the laboratory is 0.2 cps, and inside the reactor building it is below 1 cps. The monitor presently scans 18 sample lines in sequence for 5 min each and gives a printout for the activity in each line.

Effects of plastic anisotropy on crack-tip behaviour

DEFF Research Database (Denmark)

Legarth, Brian Nyvang; Tvergaard, Viggo; Kuroda, Mitsutoshi

2002-01-01

For a crack in a homogeneous material the effect of plastic anisotropy on crack-tip blunting and on the near-tip stress and strain fields is analyzed numerically. The full finite strain analyses are carried out for plane strain under small scale yielding conditions, with purely symmetric mode I...... loading remote from the crack-tip. In cases where the principal axes of the anisotropy are inclined to the plane of the crack it is found that the plastic zones as well as the stress and strain fields just around the blunted tip of the crack become non-symmetric. In these cases the peak strain...... on the blunted tip occurs off the center line of the crack, thus indicating that the crack may want to grow in a different direction. When the anisotropic axes are parallel to the crack symmetry is retained, but the plastic zones and the near-tip fields still differ from those predicted by standard isotropic...

Does autophagy work in synaptic plasticity and memory?

Science.gov (United States)

Shehata, Mohammad; Inokuchi, Kaoru

2014-01-01

Many studies have reported the roles played by regulated proteolysis in neural plasticity and memory. Within this context, most of the research focused on the ubiquitin-proteasome system and the endosome-lysosome system while giving lesser consideration to another major protein degradation system, namely, autophagy. Although autophagy intersects with many of the pathways known to underlie synaptic plasticity and memory, only few reports related autophagy to synaptic remodeling. These pathways include PI3K-mTOR pathway and endosome-dependent proteolysis. In this review, we will discuss several lines of evidence supporting a physiological role of autophagy in memory processes, and the possible mechanistic scenarios for how autophagy could fulfill this function.

A discrimination model in waste plastics sorting using NIR hyperspectral imaging system.

Science.gov (United States)

Zheng, Yan; Bai, Jiarui; Xu, Jingna; Li, Xiayang; Zhang, Yimin

2018-02-01

Classification of plastics is important in the recycling industry. A plastic identification model in the near infrared spectroscopy wavelength range 1000-2500 nm is proposed for the characterization and sorting of waste plastics using acrylonitrile butadiene styrene (ABS), polystyrene (PS), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC). The model is built by the feature wavelengths of standard samples applying the principle component analysis (PCA), and the accuracy, property and cross-validation of the model were analyzed. The model just contains a simple equation, center of mass coordinates, and radial distance, with which it is easy to develop classification and sorting software. A hyperspectral imaging system (HIS) with the identification model verified its practical application by using the unknown plastics. Results showed that the identification accuracy of unknown samples is 100%. All results suggested that the discrimination model was potential to an on-line characterization and sorting platform of waste plastics based on HIS. Copyright © 2017 Elsevier Ltd. All rights reserved.

The scope of plastic surgery | Rogers | South African Journal of ...

African Journals Online (AJOL)

... reconstructive procedures, they were not necessarily identified as primary surgeons for procedures that they commonly perform. A significant number of respondents believed that plastic surgeons are seldom the first line of referral, and are more involved in cases with aesthetic rather than functional sequelae. Discussion.

Contrasting patterns of transgenerational plasticity in ecologically distinct congeners.

Science.gov (United States)

Sultan, Sonia E; Barton, Kasey; Wilczek, Amity M

2009-07-01

Stressful parental environments can influence offspring size and development either adaptively or maladaptively, yet little is known about species' differences in this complex aspect of phenotypic plasticity. We performed a reciprocal split-brood experiment to compare transgenerational plasticity in response to drought stress in two closely related annual plant species. We raised inbred replicate parent plants of eight genotypes per species in dry vs. moist soil to generate offspring of each genetic line that differed only in parental environment, then monitored seedling development in both dry and moist conditions. Individuals of the two species expressed contrasting patterns of transgenerational plasticity for traits important to seedling drought tolerance. In Polygonum persicaria, a weedy generalist found in moist, dry, and variably dry sites, drought-stressed plants produced offspring with longer and more rapidly extending root systems and greater biomass when growing in dry soil. In contrast, in P. hydropiper, a non-weedy congener restricted to moist habitats, the offspring of drought-stressed parents had reduced root system development and seedling biomass in dry soil. In P. persicaria, transgenerational and immediate adaptive plasticity combined to produce drought-adapted seedling phenotypes. These results make clear that characteristic patterns of transgenerational plasticity can contribute to ecological diversity among species.

Preliminary analysis of construction of the test drift in boom clay at Mol using plasticity solutions and finite elements

International Nuclear Information System (INIS)

Mair, R.J.; Taylor, R.N.; Higgins, K.G.; Potts, D.M.

1989-01-01

Analyses have been undertaken on an advancing tunnel heading at great depth in a clay formation corresponding to the test drift construction at Mol. Belgium. Simplifying assumptions enable plasticity solutions to be used to model the behaviour of a tunnel heading in a linear elastic-perfectly plastic soil. Finite element analysis with the same soil model has been undertaken of the test drift construction, assuming axisymmetric conditions. The results are compared with the plasticity solutions and with the measurements of lining stresses, soil movements and pore pressures by SCK/CEN. Good agreement is obtained between the plasticity solutions and finite element analysis. The measured immediate build-up of stress on the linings is well-predicted and reasonable agreement is obtained between predicted and measured soil movements. The measured pore-pressure changes are poorly predicted by the analyses

Wading bird guano contributes to Hg accumulation in tree island soils in the Florida Everglades

International Nuclear Information System (INIS)

Zhu, Yingjia; Gu, Binhe; Irick, Daniel L.; Ewe, Sharon; Li, Yuncong; Ross, Michael S.; Ma, Lena Q.

2014-01-01

Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those in mid and tail region, and marsh soils. Hg concentrations in bird guano (286 μg kg −1 ) were significantly higher than those in mammal droppings (105 μg kg −1 ) and plant leaves (53 μg kg −1 ). In addition, Hg concentrations and δ 15 N values displayed positive correlation in soils influenced by guano. During 1998–2010, estimated annual Hg deposition by guano was 148 μg m −2 yr −1 and ∼8 times the atmospheric deposition. Highlights: • Hg concentrations in the head region of tree islands were the highest. • Hg concentrations in bird guano (286 μg kg −1 ) were significantly higher than those in mammal droppings and plant leaves. • Hg concentrations and δ 15 N values showed positive correlation in soils influenced by guano. • Estimated annual Hg deposition by guano was 148 μg m −2 yr −1 , ∼8 times the atmospheric deposition. -- The annual Hg deposition by bird guano to tree island soils in the Everglades was ∼8 times the atmospheric deposition

DNA methylation mediates genetic variation for adaptive transgenerational plasticity.

Science.gov (United States)

Herman, Jacob J; Sultan, Sonia E

2016-09-14

Environmental stresses experienced by individual parents can influence offspring phenotypes in ways that enhance survival under similar conditions. Although such adaptive transgenerational plasticity is well documented, its transmission mechanisms are generally unknown. One possible mechanism is environmentally induced DNA methylation changes. We tested this hypothesis in the annual plant Polygonum persicaria, a species known to express adaptive transgenerational plasticity in response to parental drought stress. Replicate plants of 12 genetic lines (sampled from natural populations) were grown in dry versus moist soil. Their offspring were exposed to the demethylating agent zebularine or to control conditions during germination and then grown in dry soil. Under control germination conditions, the offspring of drought-stressed parents grew longer root systems and attained greater biomass compared with offspring of well-watered parents of the same genetic lines. Demethylation removed these adaptive developmental effects of parental drought, but did not significantly alter phenotypic expression in offspring of well-watered parents. The effect of demethylation on the expression of the parental drought effect varied among genetic lines. Differential seed provisioning did not contribute to the effect of parental drought on offspring phenotypes. These results demonstrate that DNA methylation can mediate adaptive, genotype-specific effects of parental stress on offspring phenotypes. © 2016 The Author(s).

Developmental Plasticity and Language: A Comparative Perspective.

Science.gov (United States)

Griebel, Ulrike; Pepperberg, Irene M; Oller, D Kimbrough

2016-04-01

The growing field of evo-devo is increasingly demonstrating the complexity of steps involved in genetic, intracellular regulatory, and extracellular environmental control of the development of phenotypes. A key result of such work is an account for the remarkable plasticity of organismal form in many species based on relatively minor changes in regulation of highly conserved genes and genetic processes. Accounting for behavioral plasticity is of similar potential interest but has received far less attention. Of particular interest is plasticity in communication systems, where human language represents an ultimate target for research. The present paper considers plasticity of language capabilities in a comparative framework, focusing attention on examples of a remarkable fact: Whereas there exist design features of mature human language that have never been observed to occur in non-humans in the wild, many of these features can be developed to notable extents when non-humans are enculturated through human training (especially with intensive social interaction). These examples of enculturated developmental plasticity across extremely diverse taxa suggest, consistent with the evo-devo theme of highly conserved processes in evolution, that human language is founded in part on cognitive capabilities that are indeed ancient and that even modern humans show self-organized emergence of many language capabilities in the context of rich enculturation, built on the special social/ecological history of the hominin line. Human culture can thus be seen as a regulatory system encouraging language development in the context of a cognitive background with many highly conserved features. Copyright © 2016 Cognitive Science Society, Inc.

Analysis of stratification effects on mechanical integrity of pressurizer surge line

International Nuclear Information System (INIS)

Thomas-Solgadi, E.; Taupin, P.; Ensel, C.

1992-01-01

Unexpected thermal movements in pressurizer surge lines have been reported by several PWR operating utilities. Sometimes gaps between pipe and pipe whip restraints can become closed and plastic deformations could result. Moreover these movements, which have not been considered at conception, can induce additional stresses, and design limits on fatigue and stresses may be exceeded. These piping movements are caused by thermal stratification phenomenon in the horizontal part of the surge line (difference of temperature between hot leg and pressurizer varying from 30 C to above 160 C). To assess the mechanical consequences of this 3-dimensional phenomenon, FRAMATOME has developed a computer program using simplified models (1 and 2-dimensional). This method integrates past investigations on thermal-hydraulic variation of the stratification based on plant monitoring programs carried out by FRAMATOME since 1981, and based also on thermal-hydraulic tests and thermal-hydraulic computer code results. The methodology developed by FRAMATOME permits the following calculations: movements of the line in the elastic and plastic domains; stresses (Mises criterion -- calculations in compliance with ASME or RCC-M codes); usage factors in different components (elbows, welds, ...); crack propagation taking into account stratification and plastic shakedown

A plastic collapse method for evaluating rotation capacity of full-restrained steel moment connections

Directory of Open Access Journals (Sweden)

Lee Kyungkoo

2008-01-01

Full Text Available An analytical method to model failure of steel beam plastic hinges due to local buckling and low-cycle fatigue is proposed herein. This method is based on the plastic collapse mechanism approach and a yield-line plastic hinge (YLPH model whose geometry is based on buckled shapes of beam plastic hinges observed in experiments. Two limit states, strength degradation failure induced by local buckling and low-cycle fatigue fracture, are considered. The proposed YLPH model was developed for FEMA-350 WUF-W, RBS and Free Flange connections and validated in comparisons to experimental data. This model can be used to estimate the seismic rotation capacity of fully restrained beam-column connections in special steel moment-resisting frames under both monotonic and cyclic loading conditions.

Useful effectiveness of plastic pipes for gas pipelines operating at low pressure

Energy Technology Data Exchange (ETDEWEB)

Zayutsev, K I

1976-06-01

Because a significant portion of the feeder lines in the Soviet union operate at relatively low pressures up to 75 to 150 psi, it is economically feasible to replace the conventional pipeline material (steel) with plastic. Cost savings result from lower material costs and ease of laying plastic pipe. Because of stiffness and corrosion requirements, the steel pipe used for these low-pressure pipelines is much thicker than needed to withstand the pressure used. Data are tabulated on the comparative costs and manpower requirements for the construction of 1 km of steel, polyvinyl chloride, and polyethylene gas pipelines ranging in diameter from 3 to 14 in. Generally, the plastic pipelines required 15 to 30% less man-days and were 20 to 35% lower in cost to build. The plastic pipelines can operate at 150 to 175 psi pressure and at temperatures up to 100 to 140/sup 0/F. In research conducted at VNIIST (All-Union Research Institute for the Construction of Trunk Pipelines) on plastic pipelines, a 2.5-mile test section has been operating successfully for 2 years, and new techniques and equipment for joining plastic pipe up to 25-in. diameter are being developed.

Wading bird guano enrichment of soil nutrients in tree islands of the Florida Everglades

Energy Technology Data Exchange (ETDEWEB)

Irick, Daniel L. [University of Florida, Soil and Water Science Department, Tropical Research and Education Center, 18905 SW 280th St., Homestead, FL 33031 (United States); Gu, Binhe [University of Florida, Soil and Water Science Department, 2181 McCarty Hall, Gainesville, FL 32611 (United States); Li, Yuncong C., E-mail: yunli@ufl.edu [University of Florida, Soil and Water Science Department, Tropical Research and Education Center, 18905 SW 280th St., Homestead, FL 33031 (United States); Inglett, Patrick W. [University of Florida, Soil and Water Science Department, 2181 McCarty Hall, Gainesville, FL 32611 (United States); Frederick, Peter C. [University of Florida, Department of Wildlife Ecology and Conservation, 110 Newins-Ziegler Hall, PO Box 110430, Gainesville, FL 32611 (United States); Ross, Michael S. [Florida International University, Department of Earth and Environment, Southeast Environmental Research Center, 11200 SW 8th St, Miami, FL 33199 (United States); Wright, Alan L. [University of Florida, Soil and Water Science Department, Everglades Research and Education Center, 3200 E. Palm Beach Rd., Belle Glade, FL 33430 (United States); Ewe, Sharon M.L. [Ecology and Environment, Inc., 12300 South Shore Blvd, Wellington, FL 33414 (United States)

2015-11-01

Differential distribution of nutrients within an ecosystem can offer insight of ecological and physical processes that are otherwise unclear. This study was conducted to determine if enrichment of phosphorus (P) in tree island soils of the Florida Everglades can be explained by bird guano deposition. Concentrations of total carbon, nitrogen (N), and P, and N stable isotope ratio (δ{sup 15}N) were determined on soil samples from 46 tree islands. Total elemental concentrations and δ{sup 15}N were determined on wading bird guano. Sequential chemical extraction of P pools was also performed on guano. Guano contained between 53.1 and 123.7 g-N kg{sup −1} and 20.7 and 56.7 g-P kg{sup −1}. Most of the P present in guano was extractable by HCl, which ranged from 82 to 97% of the total P. Total P of tree islands classified as having low or high P soils averaged 0.71 and 40.6 g kg{sup −1}, respectively. Tree island soil with high total P concentration was found to have a similar δ{sup 15}N signature and total P concentration as bird guano. Phosphorus concentrations and δ{sup 15}N were positively correlated in tree island soils (r = 0.83, p < 0.0001). Potential input of guano with elevated concentrations of N and P, and {sup 15}N enriched N, relative to other sources suggests that guano deposition in tree island soils is a mechanism contributing to this pattern. - Highlights: • Tree island soil P concentration and δ{sup 15}N values exceed other Everglades soils. • Characteristics of Everglades tree island soil may indicate guano deposition. • Deposition of stable guano P can exceed other P sources to tree island soil.

On modeling of geometrically necessary dislocation densities in plastically deformed single crystals

DEFF Research Database (Denmark)

Niordson, Christian Frithiof; Kysar, Jeffrey W.

2013-01-01

) for isotropic plasticity. An effective 2Dsolution valid for certain orientations of face centered cubic crystals is presented, where effective in-plane material properties are derived based on the crystallographic properties. The problems of void growth, pure shear and 2D wedge indentation are analyzed......A computational method for strain gradient single crystal plasticity is presented. The method accounts for both recoverable and dissipative gradient effects. The mathematical solution procedure is predicated on two minimum principles along the lines of those devised by Fleck and Willis (2009...

Plastic Surgery

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Plastic Surgery KidsHealth / For Teens / Plastic Surgery What's in ... her forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word " ...

Plastic pollution in the South Pacific subtropical gyre.

Science.gov (United States)

Eriksen, Marcus; Maximenko, Nikolai; Thiel, Martin; Cummins, Anna; Lattin, Gwen; Wilson, Stiv; Hafner, Jan; Zellers, Ann; Rifman, Samuel

2013-03-15

Plastic marine pollution in the open ocean of the southern hemisphere is largely undocumented. Here, we report the result of a (4489 km) 2424 nautical mile transect through the South Pacific subtropical gyre, carried out in March-April 2011. Neuston samples were collected at 48 sites, averaging 50 nautical miles apart, using a manta trawl lined with a 333 μm mesh. The transect bisected a predicted accumulation zone associated with the convergence of surface currents, driven by local winds. The results show an increase in surface abundance of plastic pollution as we neared the center and decrease as we moved away, verifying the presence of a garbage patch. The average abundance and mass was 26,898 particles km(-2) and 70.96 g km(-2), respectively. 88.8% of the plastic pollution was found in the middle third of the samples with the highest value of 396,342 particles km(-2) occurring near the center of the predicted accumulation zone. Copyright © 2013 Elsevier Ltd. All rights reserved.

Plastic dosimeter

International Nuclear Information System (INIS)

Nagai, Shiro; Matsuda, Kohji.

1988-01-01

The report outlines major features and applications of plastic dosimeters. Some plastic dosimeters, including the CTA and PVC types, detect the response of the plastic material itself to radiations while others, such as pigment-added plastic dosimeters, contain additives as radiation detecting material. Most of these dosimeters make use of color centers produced in the dosimeter by radiations. The PMMA dosimeter is widely used in the field of radiation sterilization of food, feed and medical apparatus. The blue cellophane dosimeter is easy to handle if calibrated appropriately. The rad-color dosimeter serves to determine whether products have been irradiated appropriately. The CTA dosimeter has better damp proofing properties than the blue cellophane type. The pigment-added plastic dosimeter consists of a resin such as nylon, CTA or PVC that contains a dye. Some other plastic dosimeters are also described briefly. Though having many advantages, these plastic dosimeter have disadvantages as well. Some of their major disadvantages, including fading as well as large dependence on dose, temperature, humidity and anviroment, are discussed. (Nogami, K.)

Computational modeling of neural plasticity for self-organization of neural networks.

Science.gov (United States)

Chrol-Cannon, Joseph; Jin, Yaochu

2014-11-01

Self-organization in biological nervous systems during the lifetime is known to largely occur through a process of plasticity that is dependent upon the spike-timing activity in connected neurons. In the field of computational neuroscience, much effort has been dedicated to building up computational models of neural plasticity to replicate experimental data. Most recently, increasing attention has been paid to understanding the role of neural plasticity in functional and structural neural self-organization, as well as its influence on the learning performance of neural networks for accomplishing machine learning tasks such as classification and regression. Although many ideas and hypothesis have been suggested, the relationship between the structure, dynamics and learning performance of neural networks remains elusive. The purpose of this article is to review the most important computational models for neural plasticity and discuss various ideas about neural plasticity's role. Finally, we suggest a few promising research directions, in particular those along the line that combines findings in computational neuroscience and systems biology, and their synergetic roles in understanding learning, memory and cognition, thereby bridging the gap between computational neuroscience, systems biology and computational intelligence. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

plastic waste recycling

African Journals Online (AJOL)

Dr Ahmed

incinerators is increasing around the world. Discarded plastic products ... Agency (EPA) estimated that the amount of plastics throw away is. 50 % greater in the ... The waste plastics were identified using the Society of the Plastic. Industry (SPI) ...

Rigid-Plastic Post-Buckling Analysis of Columns and Quadratic Plates

DEFF Research Database (Denmark)

Jönsson, Jeppe

2008-01-01

the compressive load as a function of the transverse displacement. An estimate of the magnitude of the transverse displacement prior to the forming of the collapse mechanism is introduced into the compressive load function, determined by the virtual work equation, thereby revealing a qualified estimate...... yield lines accommodate differential rotations of rigid parts and the area “collapse” yield lines accommodate local area changes of the rigid parts thereby preserving compatibility of the rigid parts of a plate. The approach will be illustrated for rigid plastic column analysis and for a quadratic plate...

Direct liquefaction of plastics and coprocessing of coal with plastics

Energy Technology Data Exchange (ETDEWEB)

Huffman, G.P.; Feng, Z.; Mahajan, V. [Univ. of Kentucky, Lexington, KY (United States)

1995-12-31

The objectives of this work were to optimize reaction conditions for the direct liquefaction of waste plastics and the coprocessing of coal with waste plastics. In previous work, the direct liquefaction of medium and high density polyethylene (PE), polypropylene (PPE), poly(ethylene terephthalate) (PET), and a mixed plastic waste, and the coliquefaction of these plastics with coals of three different ranks was studied. The results established that a solid acid catalyst (HZSM-5 zeolite) was highly active for the liquefaction of the plastics alone, typically giving oil yields of 80-95% and total conversions of 90-100% at temperatures of 430-450 {degrees}C. In the coliquefaction experiments, 50:50 mixtures of plastic and coal were used with a tetralin solvent (tetralin:solid = 3:2). Using approximately 1% of the HZSM-5 catalyst and a nanoscale iron catalyst, oil yields of 50-70% and total conversion of 80-90% were typical. In the current year, further investigations were conducted of the liquefaction of PE, PPE, and a commingled waste plastic obtained from the American Plastics Council (APC), and the coprocessing of PE, PPE and the APC plastic with Black Thunder subbituminous coal. Several different catalysts were used in these studies.

Recycling of Plastic

DEFF Research Database (Denmark)

Christensen, Thomas Højlund; Fruergaard, Thilde

2011-01-01

Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like...

Plastic flexible films waste management - A state of art review.

Science.gov (United States)

Horodytska, O; Valdés, F J; Fullana, A

2018-04-21

Plastic flexible films are increasingly used in many applications due to their lightness and versatility. In 2014, the amount of plastic films represented 34% of total plastic packaging produced in UK. The flexible film waste generation rises according to the increase in number of applications. Currently, in developed countries, about 50% of plastics in domestic waste are films. Moreover, about 615,000 tonnes of agricultural flexible waste are generated in the EU every year. A review of plastic films recycling has been conducted in order to detect the shortcomings and establish guidelines for future research. This paper reviews plastic films waste management technologies from two different sources: post-industrial and post-consumer. Clean and homogeneous post-industrial waste is recycled through closed-loop or open-loop mechanical processes. The main differences between these methods are the quality and the application of the recycled materials. Further research should be focused on closing the loops to obtain the highest environmental benefits of recycling. This could be accomplished through minimizing the material degradation during mechanical processes. Regarding post-consumer waste, flexible films from agricultural and packaging sectors have been assessed. The agricultural films and commercial and industrial flexible packaging are recycled through open-loop mechanical recycling due to existing selective waste collection routes. Nevertheless, the contamination from the use phase adversely affects the quality of recycled plastics. Therefore, upgrading of current washing lines is required. On the other hand, household flexible packaging shows the lowest recycling rates mainly because of inefficient sorting technologies. Delamination and compatibilization methods should be further developed to ensure the recycling of multilayer films. Finally, Life Cycle Assessment (LCA) studies on waste management have been reviewed. A lack of thorough LCA on plastic films waste

Matrigel Basement Membrane Matrix influences expression of microRNAs in cancer cell lines

International Nuclear Information System (INIS)

Price, Karina J.; Tsykin, Anna; Giles, Keith M.; Sladic, Rosemary T.; Epis, Michael R.; Ganss, Ruth; Goodall, Gregory J.; Leedman, Peter J.

2012-01-01

Highlights: ► Matrigel alters cancer cell line miRNA expression relative to culture on plastic. ► Many identified Matrigel-regulated miRNAs are implicated in cancer. ► miR-1290, -210, -32 and -29b represent a Matrigel-induced miRNA signature. ► miR-32 down-regulates Integrin alpha 5 (ITGA5) mRNA. -- Abstract: Matrigel is a medium rich in extracellular matrix (ECM) components used for three-dimensional cell culture and is known to alter cellular phenotypes and gene expression. microRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and have roles in cancer. While miRNA profiles of numerous cell lines cultured on plastic have been reported, the influence of Matrigel-based culture on cancer cell miRNA expression is largely unknown. This study investigated the influence of Matrigel on the expression of miRNAs that might facilitate ECM-associated cancer cell growth. We performed miRNA profiling by microarray using two colon cancer cell lines (SW480 and SW620), identifying significant differential expression of miRNAs between cells cultured in Matrigel and on plastic. Many of these miRNAs have previously been implicated in cancer-related processes. A common Matrigel-induced miRNA signature comprised of up-regulated miR-1290 and miR-210 and down-regulated miR-29b and miR-32 was identified using RT-qPCR across five epithelial cancer cell lines (SW480, SW620, HT-29, A549 and MDA-MB-231). Experimental modulation of these miRNAs altered expression of their known target mRNAs involved in cell adhesion, proliferation and invasion, in colon cancer cell lines. Furthermore, ITGA5 was identified as a novel putative target of miR-32 that may facilitate cancer cell interactions with the ECM. We propose that culture of cancer cell lines in Matrigel more accurately recapitulates miRNA expression and function in cancer than culture on plastic and thus is a valuable approach to the in vitro study of miRNAs.

Plastic deformation and hysteresis for hydrogen storage in Pd–Rh alloys

Energy Technology Data Exchange (ETDEWEB)

Cappillino, P.J., E-mail: pcappil@sandia.gov [Sandia National Laboratories, PO Box 969, Mail Stop 9292, Livermore, CA 94551 (United States); Lavernia, E.J. [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616 (United States); Ong, M.D. [Department of Physics, Whitworth University, Spokane, WA 99251 (United States); Wolfer, W.G.; Yang, N.Y. [Sandia National Laboratories, PO Box 969, Mail Stop 9292, Livermore, CA 94551 (United States)

2014-02-15

Highlights: • Experimental evidence of plastic work resulting from hydriding of palladium is presented. • A model of this plastic work was generated and correlated to hysteresis losses. • This hysteresis is thought to be important to the lifetime of hydrogen storage materials. • Yield strength values predicted by this model agree with measured hardness. -- Abstract: The hysteresis observed when reversibly absorbing and desorbing hydrogen in metals is currently not fully understood. In general, a hysteresis represents energy that is dissipated during a cycle, but the underlying mechanism of dissipation is still uncertain. It has been suggested that the hysteresis arises either from plastic work, or from elastic strains associated with the accommodation of the hydride phase, or from both. We present here experimental evidence that implicates plastic deformation as the cause of the hysteresis in a Pd–Rh alloy. The plastic work is evident from the increased dislocation density, from the accumulation of surface steps from slip bands, from line broadening of X-ray diffraction peaks, and from an increase in hardness with the number of hydriding cycles. A model of this plastic work is developed that depends on an effective yield strength. When this model is correlated with the measured hysteresis losses, two values are found for the effective yield strength. The lower value is shown to agree with yield strength values derived from Vickers hardness measurements. The hysteresis areas for repeated cycles of absorption and desorption decrease little with the number of cycles which is reminiscent of the plastic deformation hysteresis during low-cycle fatigue of metals. This similarity further confirms the plastic nature of the hydriding hysteresis.

Quantification of mammalian tumor cell state plasticity with digital holographic cytometry

Science.gov (United States)

Hejna, Miroslav; Jorapur, Aparna; Zhang, Yuntian; Song, Jun S.; Judson, Robert L.

2018-02-01

Individual cells within isogenic tumor populations can exhibit distinct cellular morphologies, behaviors, and molecular profiles. Cell state plasticity refers to the propensity of a cell to transition between these different morphologies and behaviors. Elevation of cell state plasticity is thought to contribute to critical stages in tumor evolution, including metastatic dissemination and acquisition of therapeutic resistance. However, methods for quantifying general plasticity in mammalian cells remain limited. Working with a HoloMonitor M4 digital holographic cytometry platform, we have established a machine learning-based pipeline for high accuracy and label-free classification of adherent cells. We use twenty-six morphological and optical density-derived features for label-free identification of cell state in heterogeneous cultures. The system is housed completely within a mammalian cell incubator, permitting the monitoring of changes in cell state over time. Here we present an application of our approach for studying cell state plasticity. Human melanoma cell lines of known metastatic potential were monitored in standard growth conditions. The rate of feature change was quantified for each individual cell in the populations. We observed that cells of higher metastatic potential exhibited more rapid fluctuation of cell state in homeostatic conditions. The approach we demonstrate will be advantageous for further investigations into the factors that influence cell state plasticity.

Plastic surgical management of a cobra bite – a case study

Directory of Open Access Journals (Sweden)

Kuhbier, Jörn W.

2017-02-01

Full Text Available Cobra bites are quite rare in European countries as these snakes are not native there. Toxins are devastating for tissue resulting in massive necrosis, thus plastic surgery might play a role in reconstruction of the lost tissue. A case of a male patient bitten by a thai cobra in the left index finger is presented. Antitoxin administration was delayed due to secondary patient admission. Progressive tissue necrosis made radical debridement necessary, resulting in the need for plastic surgical defect coverage with a flap. While a radical debridement to prevent toxic necrosis due to lytic enzymes in cobra venom has been favoured beforehand, large case studies led to a more restrained initial surgical intervention. However, antitoxin administration should be first line therapy in management of these cases. If severe necrosis is present as it might occur in delayed admission, a plastic surgical management of the patient might be advantageous.

Plastic value chains

DEFF Research Database (Denmark)

Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

2014-01-01

Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example......, plastics from WEEE is chosen as a Nordic case study. The project aims to propose a number of improvements for this value chain together with representatives from Nordic stakeholders. Based on the experiences made, a guide for other plastic value chains shall be developed....

Our plastic age.

Science.gov (United States)

Thompson, Richard C; Swan, Shanna H; Moore, Charles J; vom Saal, Frederick S

2009-07-27

Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation.

Our plastic age

Science.gov (United States)

Thompson, Richard C.; Swan, Shanna H.; Moore, Charles J.; vom Saal, Frederick S.

2009-01-01

Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation. PMID:19528049

Impact of Bio-Based Plastics on Current Recycling of Plastics

Directory of Open Access Journals (Sweden)

Luc Alaerts

2018-05-01

Full Text Available Bio-based plastics are increasingly appearing in a range of consumption products, and after use they often end up in technical recycling chains. Bio-based plastics are different from fossil-based ones and could disturb the current recycling of plastics and hence inhibit the closure of plastic cycles, which is undesirable given the current focus on a transition towards a circular economy. In this paper, this risk has been assessed via three elaborated case studies using data and information retrieved through an extended literature search. No overall risks were revealed for bio-based plastics as a group; rather, every bio-based plastic is to be considered as a potential separate source of contamination in current recycling practices. For PLA (polylactic acid, a severe incompatibility with PET (polyethylene terephthalate recycling is known; hence, future risks are assessed by measuring amounts of PLA ending up in PET waste streams. For PHA (polyhydroxy alkanoate there is no risk currently, but it will be crucial to monitor future application development. For PEF (polyethylene furanoate, a particular approach for contamination-related issues has been included in the upcoming market introduction. With respect to developing policy, it is important that any introduction of novel plastics is well guided from a system perspective and with a particular eye on incompatibilities with current and upcoming practices in the recycling of plastics.

Plastic condoms.

Science.gov (United States)

1968-01-01

Only simple equipment, simple technology and low initial capital investment are needed in their manufacture. The condoms can be made by people who were previously unskilled or only semi-skilled workers. Plastic condoms differ from those made of latex rubber in that the nature of the plastic film allows unlimited shelf-life. Also, the plastic has a higher degree of lubricity than latex rubber; if there is a demand for extra lubrication in a particular market, this can be provided. Because the plastic is inert, these condoms need not be packaged in hermetically sealed containers. All these attributes make it possible to put these condoms on the distributors' shelves in developing countries competitively with rubber condoms. The shape of the plastic condom is based on that of the lamb caecum, which has long been used as luxury-type condom. The plastic condom is made from plastic film (ethylene ethyl acrilate) of 0.001 inch (0.0254 mm.) thickness. In addition, a rubber ring is provided and sealed into the base of the condom for retention during coitus. The advantage of the plastic condom design and the equipment on which it is made is that production can be carried out either in labour-intensive economy or with varying degrees of mechanization and automation. The uniform, finished condom if made using previously untrained workers. Training of workers can be done in a matter of hours on the two machines which are needed to produce and test the condoms. The plastic film is provided on a double wound roll, and condom blanks are prepared by means of a heat-sealing die on the stamping machine. The rubber rings are united to the condom blanks on an assembly machine, which consists of a mandrel and heat-sealing equipment to seal the rubber ring to the base of the condom. Built into the assembly machine is a simple air-testing apparatus that can detect the smallest pinhole flaw in a condom. The manufacturing process is completed by unravelling the condom from the assembly

Biodegradability of plastics.

Science.gov (United States)

Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

2009-08-26

Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

Low Abundance of Plastic Fragments in the Surface Waters of the Red Sea

KAUST Repository

Martí, Elisa

2017-11-08

The floating plastic debris along the Arabian coast of the Red Sea was sampled by using surface-trawling plankton nets. A total of 120 sampling sites were spread out over the near-shore waters along 1,500 km of coastline during seven cruises performed during 2016 and 2017. Plastic debris, dominated by millimeter-sized pieces, was constituted mostly of fragments of rigid objects (73%) followed by pieces of films (17%), fishing lines (6%), and foam (4%). These fragments were mainly made up by polyethylene (69%) and polypropylene (21%). Fibers, likely released from synthetic textiles, were ubiquitous and abundant, although were analyzed independently due to the risk of including non-plastic fibers and airborne contamination of samples in spite of the precautions taken. The plastic concentrations (excluding possible plastic fibers) contrasts with those found in other semi-closed seas, such as the neighboring Mediterranean. They were relatively low all over the Red Sea ( < 50,000 items km; mean ± SD = 3,546 ± 8,154 plastic item km, 1.1 ± 3.0 g km) showing no clear spatial relationship with the distribution of coastal population. Results suggests a low plastic waste input from land as the most plausible explanation for this relative shortage of plastic in the surface waters of the Red Sea; however, the additional intervention of particular processes of surface plastic removal by fish or the filtering activity of the extensive coral reefs along the coastline cannot be discarded. In addition, our study highlights the relevance of determining specific regional conversion rates of mismanaged plastic waste to marine debris, accounting for the role of near-shore activities (e.g., beach tourism, recreational navigation), in order to estimate plastic waste inputs into the ocean.

Low Abundance of Plastic Fragments in the Surface Waters of the Red Sea

Directory of Open Access Journals (Sweden)

Elisa Martí

2017-11-01

Full Text Available The floating plastic debris along the Arabian coast of the Red Sea was sampled by using surface-trawling plankton nets. A total of 120 sampling sites were spread out over the near-shore waters along 1,500 km of coastline during seven cruises performed during 2016 and 2017. Plastic debris, dominated by millimeter-sized pieces, was constituted mostly of fragments of rigid objects (73% followed by pieces of films (17%, fishing lines (6%, and foam (4%. These fragments were mainly made up by polyethylene (69% and polypropylene (21%. Fibers, likely released from synthetic textiles, were ubiquitous and abundant, although were analyzed independently due to the risk of including non-plastic fibers and airborne contamination of samples in spite of the precautions taken. The plastic concentrations (excluding possible plastic fibers contrasts with those found in other semi-closed seas, such as the neighboring Mediterranean. They were relatively low all over the Red Sea (<50,000 items km−2; mean ± SD = 3,546 ± 8,154 plastic item km−2, 1.1 ± 3.0 g km−2 showing no clear spatial relationship with the distribution of coastal population. Results suggests a low plastic waste input from land as the most plausible explanation for this relative shortage of plastic in the surface waters of the Red Sea; however, the additional intervention of particular processes of surface plastic removal by fish or the filtering activity of the extensive coral reefs along the coastline cannot be discarded. In addition, our study highlights the relevance of determining specific regional conversion rates of mismanaged plastic waste to marine debris, accounting for the role of near-shore activities (e.g., beach tourism, recreational navigation, in order to estimate plastic waste inputs into the ocean.

Characterization of plastic blends made from mixed plastics waste of different sources.

Science.gov (United States)

Turku, Irina; Kärki, Timo; Rinne, Kimmo; Puurtinen, Ari

2017-02-01

This paper studies the recyclability of construction and household plastic waste collected from local landfills. Samples were processed from mixed plastic waste by injection moulding. In addition, blends of pure plastics, polypropylene and polyethylene were processed as a reference set. Reference samples with known plastic ratio were used as the calibration set for quantitative analysis of plastic fractions in recycled blends. The samples were tested for the tensile properties; scanning electron microscope-energy-dispersive X-ray spectroscopy was used for elemental analysis of the blend surfaces and Fourier transform infrared (FTIR) analysis was used for the quantification of plastics contents.

Early developmental responses to seedling environment modulate later plasticity to light spectral quality.

Directory of Open Access Journals (Sweden)

Eric J B von Wettberg

Full Text Available Correlations between developmentally plastic traits may constrain the joint evolution of traits. In plants, both seedling de-etiolation and shade avoidance elongation responses to crowding and foliage shade are mediated by partially overlapping developmental pathways, suggesting the possibility of pleiotropic constraints. To test for such constraints, we exposed inbred lines of Impatiens capensis to factorial combinations of leaf litter (which affects de-etiolation and simulated foliage shade (which affects phytochrome-mediated shade avoidance. Increased elongation of hypocotyls caused by leaf litter phenotypically enhanced subsequent elongation of the first internode in response to low red:far red (R:FR. Trait expression was correlated across litter and shade conditions, suggesting that phenotypic effects of early plasticity on later plasticity may affect variation in elongation traits available to selection in different light environments.

Clonidine and Cortical Plasticity: Possible Evidence for Noradrenergic Involvement.

Science.gov (United States)

1984-10-31

Recording, MHPG, Development of CNS, Plasticity. INTRODUCTION Temporary closure of one eye for even a short duration during a three week to three...bottom line shows the daily schedule of injections along with the cycle of general illumination in the colony. EiLug.2- Composite ocular dominance...Neureaci., 4 (1984) 1354. 1360. 15. DEGRELL, I., VENNER , K., KUMMER, P., and STOCK, G., Monoamine metabolites in the CSF of conscious unrestrained cats

The Prevalence of Cosmetic Facial Plastic Procedures among Facial Plastic Surgeons.

Science.gov (United States)

Moayer, Roxana; Sand, Jordan P; Han, Albert; Nabili, Vishad; Keller, Gregory S

2018-04-01

This is the first study to report on the prevalence of cosmetic facial plastic surgery use among facial plastic surgeons. The aim of this study is to determine the frequency with which facial plastic surgeons have cosmetic procedures themselves. A secondary aim is to determine whether trends in usage of cosmetic facial procedures among facial plastic surgeons are similar to that of nonsurgeons. The study design was an anonymous, five-question, Internet survey distributed via email set in a single academic institution. Board-certified members of the American Academy of Facial Plastic and Reconstructive Surgery (AAFPRS) were included in this study. Self-reported history of cosmetic facial plastic surgery or minimally invasive procedures were recorded. The survey also queried participants for demographic data. A total of 216 members of the AAFPRS responded to the questionnaire. Ninety percent of respondents were male ( n  = 192) and 10.3% were female ( n  = 22). Thirty-three percent of respondents were aged 31 to 40 years ( n  = 70), 25% were aged 41 to 50 years ( n  = 53), 21.4% were aged 51 to 60 years ( n  = 46), and 20.5% were older than 60 years ( n  = 44). Thirty-six percent of respondents had a surgical cosmetic facial procedure and 75% has at least one minimally invasive cosmetic facial procedure. Facial plastic surgeons are frequent users of cosmetic facial plastic surgery. This finding may be due to access, knowledge base, values, or attitudes. By better understanding surgeon attitudes toward facial plastic surgery, we can improve communication with patients and delivery of care. This study is a first step in understanding use of facial plastic procedures among facial plastic surgeons. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Recycling of plastic waste: Presence of phthalates in plastics from households and industry.

Science.gov (United States)

Pivnenko, K; Eriksen, M K; Martín-Fernández, J A; Eriksson, E; Astrup, T F

2016-08-01

Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large volumes and are commonly used as plasticisers in plastics manufacturing. Potential impacts on human health require restricted use in selected applications and a need for the closer monitoring of potential sources of human exposure. Although the presence of phthalates in a variety of plastics has been recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP had the highest frequency of detection in the samples analysed, with 360μg/g, 460μg/g and 2700μg/g as the maximum measured concentrations, respectively. Among other, statistical analysis of the analytical results suggested that phthalates were potentially added in the later stages of plastic product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications is recommended if recycled plastics are to be used as raw material in production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recycling of plastic waste: Presence of phthalates in plastics from households and industry

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn; Eriksen, Marie Kampmann; Martín-Fernández, J. A.

2016-01-01

Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large...... recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP...

Biodegradability of Plastics

Directory of Open Access Journals (Sweden)

Yutaka Tokiwa

2009-08-01

Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

Elastic-plastic response of a piping system due to simulated double-ended guillotine break events

International Nuclear Information System (INIS)

Kussmaul, K.; Diem, H.; Hunger, H.; Katzenmeier, G.

1987-01-01

From the blowdown experiments performed on the HDR feedwater line with feedwater check valve the conclusion can be drawn that high transient loads of up to plastic strains of 3%, acting on an initially integer piping system, can be sustained without loss of integrity for a low number of load cycles due to the plasticizing capacity of the pipework materials nowadays used in reactor technology. In the experiments carried out with ferritic piping of ND 400 pressure peaks up to about 31,5 MPa were achieved which resulted in excessive strains of up to 3%. By nonlinear finite element computations (ABAQUS) it was possible to describe the elastic-plastic behaviour of the piping in a good approximation. (orig./GL)

Elastic-plastic behaviour of thick-walled containers considering plastic compressibility

International Nuclear Information System (INIS)

Betten, J.; Frosch, H.G.

1983-01-01

In this paper the elastic-plastic behaviour of thick-walled pressure vessels with internal and external pressure is studied. To describe the mechanical behaviour of isotropic, plastic compressible materials we use a plastic potential which is a single-valued function of the principle stresses. For cylinders and spheres an analytic expression for the computation of stresses and residual stresses is specified. Afterwards the strains are calculated by using the finite difference method. Some examples will high-light the influence of the plastic compressibility on the behaviour of pressure vessels. (orig.) [de

Mechanically equivalent elastic-plastic deformations and the problem of plastic spin

Directory of Open Access Journals (Sweden)

Steigmann David J.

2011-01-01

Full Text Available The problem of plastic spin is phrased in terms of a notion of mechanical equivalence among local intermediate configurations of an elastic/ plastic crystalline solid. This idea is used to show that, without further qualification, the plastic spin may be suppressed at the constitutive level. However, the spin is closely tied to an underlying undistorted crystal lattice which, once specified, eliminates the freedom afforded by mechanical equivalence. As a practical matter a constitutive specification of plastic spin is therefore required. Suppression of plastic spin thus emerges as merely one such specification among many. Restrictions on these are derived in the case of rate-independent response.

Plastics and health risks.

Science.gov (United States)

Halden, Rolf U

2010-01-01

By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP). Opinions on the safety of plastics vary widely, and despite more than five decades of research, scientific consensus on product safety is still elusive. This literature review summarizes information from more than 120 peer-reviewed publications on health effects of plastics and plasticizers in lab animals and humans. It examines problematic exposures of susceptible populations and also briefly summarizes adverse environmental impacts from plastic pollution. Ongoing efforts to steer human society toward resource conservation and sustainable consumption are discussed, including the concept of the 5 Rs--i.e., reduce, reuse, recycle, rethink, restrain--for minimizing pre- and postnatal exposures to potentially harmful components of plastics.

Acoustic emission from fiber reinforced plastic damaged hoop wrapped cylinders

Energy Technology Data Exchange (ETDEWEB)

Akhtar, A.; Kung, D.; Westbrook, D.R.

2000-03-01

Metal lined continuous fiber reinforced plastic (FRP) hoop wrapped cylinders with axial cuts to the FRP were modeled mathematically and tested experimentally. Steel lined and aluminum alloy lined glass FRP vessels were subjected to acoustic emission tests (AE) and hydraulic burst tests. The burst pressure decreased monotonically with the length of the axial cut. Acoustic emission increased initially with a decrease in burst pressure, and attained a maximum at an intermediate level of damage to the FRP. However, acoustic emission decreased when the level of damage was higher and the burst pressure was lower. Implications of the findings are discussed in the context of the search for an acoustic emission test method to inspect periodically the vessels used for the storage of compressed gaseous fuels on natural gas vehicles (NGV) and hydrogen vehicles.

A mathematical model of cancer cells with phenotypic plasticity

Directory of Open Access Journals (Sweden)

Da Zhou

2015-12-01

Full Text Available Purpose: The phenotypic plasticity of cancer cells is recently becoming a cutting-edge research area in cancer, which challenges the cellular hierarchy proposed by the conventional cancer stem cell theory. In this study, we establish a mathematical model for describing the phenotypic plasticity of cancer cells, based on which we try to find some salient features that can characterize the dynamic behavior of the phenotypic plasticity especially in comparison to the hierarchical model of cancer cells. Methods: We model cancer as population dynamics composed of different phenotypes of cancer cells. In this model, not only can cancer cells divide (symmetrically and asymmetrically and die, but they can also convert into other cellular phenotypes. According to the Law of Mass Action, the cellular processes can be captured by a system of ordinary differential equations (ODEs. On one hand, we can analyze the long-term stability of the model by applying qualitative method of ODEs. On the other hand, we are also concerned about the short-term behavior of the model by studying its transient dynamics. Meanwhile, we validate our model to the cell-state dynamics in published experimental data.Results: Our results show that the phenotypic plasticity plays important roles in both stabilizing the distribution of different phenotypic mixture and maintaining the cancer stem cells proportion. In particular, the phenotypic plasticity model shows decided advantages over the hierarchical model in predicting the phenotypic equilibrium and cancer stem cells’ overshoot reported in previous biological experiments in cancer cell lines.Conclusion: Since the validity of the phenotypic plasticity paradigm and the conventional cancer stem cell theory is still debated in experimental biology, it is worthy of theoretically searching for good indicators to distinguish the two models through quantitative methods. According to our study, the phenotypic equilibrium and overshoot

Recycling of plastic waste: Presence of phthalates in plastics from households and industry

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn; Eriksen, Marie Kampmann; Martín-Fernández, J. A.

2016-01-01

recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP...... product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications...

Independent genetic control of maize (Zea mays L.) kernel weight determination and its phenotypic plasticity.

Science.gov (United States)

Alvarez Prado, Santiago; Sadras, Víctor O; Borrás, Lucas

2014-08-01

Maize kernel weight (KW) is associated with the duration of the grain-filling period (GFD) and the rate of kernel biomass accumulation (KGR). It is also related to the dynamics of water and hence is physiologically linked to the maximum kernel water content (MWC), kernel desiccation rate (KDR), and moisture concentration at physiological maturity (MCPM). This work proposed that principles of phenotypic plasticity can help to consolidated the understanding of the environmental modulation and genetic control of these traits. For that purpose, a maize population of 245 recombinant inbred lines (RILs) was grown under different environmental conditions. Trait plasticity was calculated as the ratio of the variance of each RIL to the overall phenotypic variance of the population of RILs. This work found a hierarchy of plasticities: KDR ≈ GFD > MCPM > KGR > KW > MWC. There was no phenotypic and genetic correlation between traits per se and trait plasticities. MWC, the trait with the lowest plasticity, was the exception because common quantitative trait loci were found for the trait and its plasticity. Independent genetic control of a trait per se and genetic control of its plasticity is a condition for the independent evolution of traits and their plasticities. This allows breeders potentially to select for high or low plasticity in combination with high or low values of economically relevant traits. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

The insitu lining of cooling water piping

International Nuclear Information System (INIS)

Vaughan, W.K.; Oxner, K.B.

1994-01-01

The internal corrosion of cooling water piping as well as other industrial piping is becoming an increasing problem to system reliability. There are various alternatives being offered as solutions to the problem including water treatment, coatings, and piping replacement. The in-place lining of these pipes is becoming increasingly popular as a cost-effective method to control corrosion. A cured-in-place plastic composite system can be installed with minimal dismantling or excavation. This paper will examine case histories of the installations of this lining system in power plants at three (3) locations in the United States and one in France. It will also summarize testing that has been performed on the lining system and tests that are currently being performed

Challenges in plastics recycling

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann

2015-01-01

Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study...... was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

Individual differences in behavioural plasticities.

Science.gov (United States)

Stamps, Judy A

2016-05-01

Interest in individual differences in animal behavioural plasticities has surged in recent years, but research in this area has been hampered by semantic confusion as different investigators use the same terms (e.g. plasticity, flexibility, responsiveness) to refer to different phenomena. The first goal of this review is to suggest a framework for categorizing the many different types of behavioural plasticities, describe examples of each, and indicate why using reversibility as a criterion for categorizing behavioural plasticities is problematic. This framework is then used to address a number of timely questions about individual differences in behavioural plasticities. One set of questions concerns the experimental designs that can be used to study individual differences in various types of behavioural plasticities. Although within-individual designs are the default option for empirical studies of many types of behavioural plasticities, in some situations (e.g. when experience at an early age affects the behaviour expressed at subsequent ages), 'replicate individual' designs can provide useful insights into individual differences in behavioural plasticities. To date, researchers using within-individual and replicate individual designs have documented individual differences in all of the major categories of behavioural plasticities described herein. Another important question is whether and how different types of behavioural plasticities are related to one another. Currently there is empirical evidence that many behavioural plasticities [e.g. contextual plasticity, learning rates, IIV (intra-individual variability), endogenous plasticities, ontogenetic plasticities) can themselves vary as a function of experiences earlier in life, that is, many types of behavioural plasticity are themselves developmentally plastic. These findings support the assumption that differences among individuals in prior experiences may contribute to individual differences in behavioural

Durability of wood plastic composites manufactured from recycled plastic

Directory of Open Access Journals (Sweden)

Irina Turku

2018-03-01

Full Text Available The influence of accelerated weathering, xenon-arc light and freeze-thaw cycling on wood plastic composites extruded from a recycled plastic was studied. The results showed that, in general, weathering had a stronger impact on samples made from plastic waste compared to a sample made from virgin material. After weathering, the mechanical properties, tensile and flexural, were reduced by 2–30%, depending on the plastic source. Wettability of the samples was shown to play a significant role in their stability. Chemical analysis with infrared spectroscopy and surface observation with a scan electron microscope confirmed the mechanical test results. Incorporation of carbon black retained the properties during weathering, reducing the wettability of the sample, diminishing the change of mechanical properties, and improving color stability. Keywords: Environmental science, Mechanical engineering, Materials science

Phenotypic plasticity, costs of phenotypes, and costs of plasticity

DEFF Research Database (Denmark)

Callahan, Hilary S; Maughan, Heather; Steiner, Uli

2008-01-01

Why are some traits constitutive and others inducible? The term costs often appears in work addressing this issue but may be ambiguously defined. This review distinguishes two conceptually distinct types of costs: phenotypic costs and plasticity costs. Phenotypic costs are assessed from patterns...... of covariation, typically between a focal trait and a separate trait relevant to fitness. Plasticity costs, separable from phenotypic costs, are gauged by comparing the fitness of genotypes with equivalent phenotypes within two environments but differing in plasticity and fitness. Subtleties associated with both...... types of costs are illustrated by a body of work addressing predator-induced plasticity. Such subtleties, and potential interplay between the two types of costs, have also been addressed, often in studies involving genetic model organisms. In some instances, investigators have pinpointed the mechanistic...

Plastic waste as a resource. Strategies for reduction and utilization of plastic waste

OpenAIRE

Pasqual i Camprubí, Gemma

2010-01-01

Plastic materials have experienced a spectacular rate of growth in recent decades, consequently, production of plastics, and likewise their consumption, has increased markedly since 1950. Moreover, they are lightweight and durable, as well as can be moulded into a variety of products that can be manufactured in many different types of plastic and in a wide range of applications. Inevitably, continually increasing amounts of used plastic are originating daily, resulting in a plastic waste prob...

In line wood plastic composite pyrolyses and HZSM-5 conversion of the pyrolysis vapors

International Nuclear Information System (INIS)

Lin, Xiaona; Zhang, Zhijun; Tan, Shun; Wang, Fengqiang; Song, Yongming; Wang, Qingwen; Pittman, Charles U.

2017-01-01

Graphical abstract: HZSM-5 can be used to catalytic convert Wood Fiber-Polypropylene or Wood Fiber-Polypropylene pyrolysis vapors into aromatic compounds in reasonable selectivities. This provides a recycling utilization WPCs wastes method. - Highlights: • Converting wood/plastic composites (WPC) wastes into aromatics. • Recycling WPC by fast pyrolysis coupled with vapor catalytic cracking. • Selective production of aromatics from WPCs and their components over HZSM-5. • Acid site concentration inside zeolite was critical for maximizing aromatic yield. • Synergistic effects between wood and plastics enhanced aromatics production. - Abstract: Wood powder-high density polyethylene (WPE) and wood powder-polypropylene (WPP) composites were pyrolyzed at 550 °C in the presence of HZSM-5 catalysts using analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Immediately passing the pyrolysis vapors through the HZSM-5 changed the product distribution by producing aromatic hydrocarbons and eliminating tar formation. Zeolite HZSM-5 was employed with three different silica-to-alumina ratios (25, 50, 260). The influence of catalysts on the yields of aliphatic and aromatic hydrocarbons, furan derivatives, lignin-derived compounds and acetic acid was studied. High yields of aliphatic hydrocarbons formed in WPE or WPP pyrolysis alone. The highest yields of aromatic hydrocarbons from WPE or WPP pyrolysis vapors over HZSM-5 occurred with a zeolite framework Si/Al ratio of 25 (more acid sites), suggesting that the concentration of acid sites inside the zeolite was critical for maximizing aromatic yield. Exposing vapors to HZSM-5 increased the hydrocarbon yields and reduced the amount of acetic acid produced, resulting in increased calorific value. The yields of typical aromatics from catalytic pyrolysis of WPP mixture and composites were higher than those of the calculated values of poplar wood and PP catalytic pyrolysis individually, indicating that a

Thermal degradation and plasticizing mechanism of poly(vinyl chloride) plasticized with a novel cardanol derived plasticizer

Science.gov (United States)

Chen, J.; Nie, X. A.; Jiang, J. C.; Zhou, Y. H.

2018-01-01

A natural plasticizer cardanol derivatives glycidyl ether (CGE) was synthesized and employed as a plasticizer for the poly(vinyl chloride). The effect of CGE on thermal degradation of PVC films and its plasticizing mechanism were firstly reported. The molecular structure of CGE was characterized with Fourier transform infrared spectroscopy (FTIR). Thermal properties, degradation properties and compatibility of the PVC films were investigated by Differential scanning calorimeter analysis (DSC), Thermogravimetric analysis (TGA) and FTIR, respectively. Compared with the commercial plasticizers dioctylphthalate (DOP), CGE can endow PVC film with a decrease of 4.31 °C in glass transition temperature (Tg), an increase of 24.01 °C and 25.53 °C in 10% weight loss (T 10) and 50% weight loss (T 50) respectively, and a higher activetion energy of thermal degradation (Ea ).

Mixed plastics recycling technology

CERN Document Server

Hegberg, Bruce

1995-01-01

Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

Background matters: Minor vibratory stimulation during motor skill acquisition selectively reduces off-line memory consolidation.

Science.gov (United States)

Korman, Maria; Herling, Zohar; Levy, Ishay; Egbarieh, Nebal; Engel-Yeger, Batya; Karni, Avi

2017-04-01

Although a ubiquitous situation, it is not clear how effective is a learning experience when task-irrelevant, sensory noise occurs in the background. Here, young adults were trained on the finger opposition sequence task, in a well-established training and testing protocol affording measures for online as well as off-line learning. During the training session, one group experienced a minor background vibratory stimulation to the trunk by the means of vibrating cushion, while the second group experienced recorded sound vibrations. A control group was trained with no extra sensory stimulation. Sensory stimulation during training had no effect on the online within-session gains, but dampened the expression of the off-line, consolidation phase, gains in the two sensory stimulation groups. These results suggest that background sensory stimulation can selectively modify off-line, procedural memory consolidation processes, despite well-preserved on-line learning. Classical studies have shown that neural plasticity in sensory systems is modulated by motor input. The current results extend this notion and suggest that some types of task-irrelevant sensory stimulation, concurrent with motor training, may constitute a 'gating' factor - modulating the triggering of long-term procedural memory consolidation processes. Thus, vibratory stimulation may be considered as a behavioral counterpart of pharmacological interventions that do not interfere with short term neural plasticity but block long-term plasticity. Copyright © 2017 Elsevier Inc. All rights reserved.

Sub-nanosecond plastic scintillators

International Nuclear Information System (INIS)

Lyons, P.B.; Caldwell, S.E.; Hocker, L.P.; Crandall, D.G.; Zagarino, P.A.; Cheng, J.; Tirsell, G.; Hurlbut, C.R.

1977-01-01

Quenched plastic scintillators have been developed that yield much faster short decay components and greatly reduced long decay components compared to conventional plastic scintillators. The plastics are produced through the addition of selected quench agents to NE111 plastic scintillator that result in reduced total light output. Eight different agents have been studied. Benzophenone and piperidine are two of the most effective quench agents. Data are presented both for short and long decay components. The plastics are expected to make significant contributions in areas of plasma diagnostics

Sub-nanosecond plastic scintillators

International Nuclear Information System (INIS)

Lyons, P.B.; Caldwell, S.E.; Hocker, L.P.; Crandall, D.G.; Zagarino, P.A.; Cheng, J.; Tirsell, G.; Hurlbut, C.R.

1976-01-01

Quenched plastic scintillators have been developed that yield much faster short decay components and greatly reduced long decay components compared to conventional plastic scintillators. The plastics are produced through the addition of selected quench agents to NE111 plastic scintillator that result in reduced total light output. Eight different agents have been studied. Benzophenone and piperidine are two of the most effective quench agents. Data are presented both for short and long decay components. The plastics are expected to make significant contributions in areas of plasma diagnostics

Small-scale dislocation plasticity in strontium titanate

Energy Technology Data Exchange (ETDEWEB)

Stukowski, Alexander; Javaid, Farhan; Durst, Karsten; Albe, Karsten [Technische Universitaet Darmstadt (Germany)

2016-07-01

Strontium titanate (STO) is an optically transparent perovskite oxide ceramic material. In contrast to other ceramics, single crystal STO plastically deforms under ambient condition, without showing a phase transition or early fracture. This remarkable ductility makes it a prime candidate for different technological applications. However, while the mechanical behavior of bulk STO has been studied extensively using uniaxial compression testing techniques, little is known about the local, small-scale behavior and the details of dislocation-based nanoplasticity in this perovskite material. In this contribution we compare results obtained from new nanoindentation experiments and corresponding large-scale molecular dynamics simulations. The evolution of the plastic zone and dislocation structures that form underneath the indenter is investigated using etch-pit methods in experiments and a novel three-dimensional defect identification technique in atomistic computer models. The latter allows tracing the evolution of the complete dislocation line network as function of indentation depth, quantifying the activity of different slip systems, and correlating this information with the recorded load-displacement curves and hardness data.

Mixed-mode elastic-plastic fracture of 2024-T351 aluminium alloy

International Nuclear Information System (INIS)

Sakata, Masaru; Aoki, Shigeru; Kishimoto, Kikuo; Chikugo, Hiroshi; Takizawa, Masakazu.

1985-01-01

In order to evaluate accurately the strength and structural soundness of the structures made of high toughness materials, it is necessary to clarify the fracture behavior under the loading condition of mixed mode such as oblique cracks as well as the elasto-plastic fracture behavior of the materials in the case of single opening displacement type mode. About the fracture condition in the state of mixed mode, various theories based on the linear fracture mechanics have been proposed. In this study, the elasto-plastic fracture toughness test of mixed mode was carried out by using an aluminum alloy as the subject, and the behavior of dulling and development of cracks was observed with a scanning electron microscope. Moreover, the state of deformation of the test pieces was analyzed by elasto-plastic finite element method, thus the parameters controlling the elasto-plastic fracture of mixed mode were examined. In the range of this study, the limiting stretch zone width in the case of loading of mixed mode was 12 μm similarly to the case of single mode. Also in the case of mixed mode, there was distinct difference between the inclination of a dulling straight line and an R-curve, and the limit value of J intergral was determined by their intersection. (Kako, I.)

A new technology for automatic identification and sorting of plastics for recycling.

Science.gov (United States)

Ahmad, S R

2004-10-01

A new technology for automatic sorting of plastics, based upon optical identification of fluorescence signatures of dyes, incorporated in such materials in trace concentrations prior to product manufacturing, is described. Three commercial tracers were selected primarily on the basis of their good absorbency in the 310-370 nm spectral band and their identifiable narrow-band fluorescence signatures in the visible band of the spectrum when present in binary combinations. This absorption band was selected because of the availability of strong emission lines in this band from a commercial Hg-arc lamp and high fluorescence quantum yields of the tracers at this excitation wavelength band. The plastics chosen for tracing and identification are HDPE, LDPE, PP, EVA, PVC and PET and the tracers were compatible and chemically non-reactive with the host matrices and did not affect the transparency of the plastics. The design of a monochromatic and collimated excitation source, the sensor system are described and their performances in identifying and sorting plastics doped with tracers at a few parts per million concentration levels are evaluated. In an industrial sorting system, the sensor was able to sort 300 mm long plastic bottles at a conveyor belt speed of 3.5 m.sec(-1) with a sorting purity of -95%. The limitation was imposed due to mechanical singulation irregularities at high speed and the limited processing speed of the computer used.

Time between plastic displacements of elasto-plastic oscillators subject to Gaussian white noise

DEFF Research Database (Denmark)

Tarp-Johansen, Niels Jacob; Ditlevsen, Ove Dalager

2001-01-01

A one degree of freedom elasto-plastic oscillator subject to stationary Gaussian white noise has a plastic displacement response process of intermittent character. During shorter or longer time intervals the oscillator vibrates within the elastic domain without undergoing any plastic displacements...... between the clumps of plastic displacements. This is needed for a complete description of the plastic displacement process. A quite accurate fast simulation procedure is presented based on an amplitude model to determine the short waiting times in the transient regime of the elastic vibrations existing...

School Discipline in the Dark: Crippling Court Confusion Offers Mixed Messages for School Administrators Attempting to Discipline Students for Cyber Misconduct

Science.gov (United States)

Summers, Beth A.

2013-01-01

This dissertation examines the demarcation line of school authority between off campus conduct and on campus discipline involving student cyber speech. A lack of clear direction from the Supreme court has left school administrators wading through a quagmire of advice and disparate lower court rulings regarding their authority to punish students…

[Application of biodegradable plastic film to reduce plastic film residual pollution in Chinese agriculture].

Science.gov (United States)

Yan, Changrong; He, Wenqing; Xue, Yinghao; Liu, Enke; Liu, Qin

2016-06-25

Plastic film has become an important agriculture production material in recent years. Over the past three decades, the amount and application area of plastic film have increased steadily, and in 2014, which are 1.4 million tons and more than 180 million hm² respectively. It plays a key role for ensuring the supply of agricultural goods in China. Meanwhile, plastic film residual pollution becomes more and more serious, and in some regions, the amount of plastic film residues has reached over 250 kg/hm². In part of the Northwest region, soil structure of farmland has been destroyed by plastic film residues and then crop growth and farming operations were suppressed. It is recognized as a good choice to replace plastic film with biodegradable plastic film, an effective measure to solve the plastic film residue pollution. Now, it is in a critical stage of study and assessment of biodegradable plastic film in China and fortunately some biodegradable plastic films show effects in the production of potatoes, peanuts and tobacco. Overall, a series of challenges has still been faced by the biodegradable plastic film, mainly including improving the quality of biodegradable plastic products, such as tensile strength, flexibility, improving the controllability of rupture and degradation, enhancing the ability of increasing soil temperature and preserving soil moisture, and to satisfy the demand of crops production with mulching. In addition, it is essential to reduce the cost of the biodegradable film and promote the application of biodegradable film on large-scale. With the development of biodegradable plastic technology and agricultural production environment, the application of the biodegradable film will have a good future.

Plastic fish

CERN Multimedia

Antonella Del Rosso

2015-01-01

In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

Plastics in the Marine Environment.

Science.gov (United States)

Law, Kara Lavender

2017-01-03

Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence-albeit limited-of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

Plastics in the Marine Environment

Science.gov (United States)

Law, Kara Lavender

2017-01-01

Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence—albeit limited—of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

Selection of polychlorinated plastics in plastic waste by X-ray fluorescence method

International Nuclear Information System (INIS)

Kumasaki, H.; Shinozaki, Y.

1979-01-01

The X-ray fluorescence method using a small source of 55 Fe was examined and found to be applicable for the selection of polychlorinated plastics from plastic waste in model areas in Tokyo designated for investigating their content in the waste. The weight ratios of soft and hard polychlorinated plastics to the total plastic waste estimated by this method were found to be 15.6% and 0.29% respectively. These values agree well with the results obtained with the Beilstein method. (author)

Toxicological Threats of Plastic

Science.gov (United States)

Plastics pose both physical (e.g., entanglement, gastrointestinal blockage, reef destruction) and chemical threats (e.g., bioaccumulation of the chemical ingredients of plastic or toxic chemicals sorbed to plastics) to wildlife and the marine ecosystem.

Plasticity and beyond microstructures, crystal-plasticity and phase transitions

CERN Document Server

Hackl, Klaus

2014-01-01

The book presents the latest findings in experimental plasticity, crystal plasticity, phase transitions, advanced mathematical modeling of finite plasticity and multi-scale modeling. The associated algorithmic treatment is mainly based on finite element formulations for standard (local approach) as well as for non-standard (non-local approach) continua and for pure macroscopic as well as for directly coupled two-scale boundary value problems. Applications in the area of material design/processing are covered, ranging from grain boundary effects in polycrystals and phase transitions to deep-drawing of multiphase steels by directly taking into account random microstructures.

Vegetative and reproductive evaluation of hot peppers under different plastic mulches in poly/plastic tunnel

International Nuclear Information System (INIS)

Iqbal, Q.; Amjad, M.; Ahmad, R.

2009-01-01

Since the beginning of civilization, the man has developed technologies to increase the efficiency of food production. The use of plastic mulch in commercial vegetable production is one of these traditional techniques that have been used for centuries. Studies were conducted to assess the efficacy of plastic mulch on growth and yield of two hot pepper hybrids, viz. Sky Red and Maha in poly/plastic tunnel. The treatments were black plastic mulch, clear plastic mulch and bare soil as control. Both hot pepper hybrids mulched with black plastic showed significantly better vegetative growth (plant height, leaf area etc) and fruit yield. Clear plastic mulch significantly increased soil temperature and reduced the number of days to first flower than black plastic mulch and bare soil. However, fruit yield was higher by 39.56 and 36.49% respectively in both hybrids when they were grown on black and clear plastic mulch as compared to bare soil. Overall results indicated that the use of plastic mulch is an ideal option to maximize hot pepper productivity as well as to extend their production season in poly/plastic tunnels. (author)

Interaction between vegetable oil based plasticizer molecules and polyvinyl chloride, and their plasticization effect

Science.gov (United States)

Haryono, Agus; Triwulandari, Evi; Jiang, Pingping

2017-01-01

Plasticizer molecules are low molecular weight compounds that are widely used in polymer industries especially in polyvinyl chloride (PVC) resin. As an additive in PVC resin, the important role of plasticizer molecules is to improve the flexibility and processability of PVC by lowering the glass transition temperature (Tg). However, the commercial plasticizer like di(2-ethylhexyl)phthalate (DEHP) is known to cause liver cancer, at least in laboratory rats. DEHP can leach out from PVC into blood, certain drug solutions and fatty foods, which has been detected in the bloodstream of patients undergoing transfusion. Vegetable oil based plasticizers have some attractive properties such as non-toxic, bio-degradable, good heat and light stability, renewable resources, and environmentally friendly. Here we discussed the main results and development of vegetable oil based plasticizer, and especially palm oil based plasticizer. The interaction between plasticizer and polymer was discussed from the properties of the plasticized polymeric material.

Transformation induced plasticity in maraging steel: an experimental study

International Nuclear Information System (INIS)

Nagayama, K.; Kitajima, Y.; Kigami, S.; Tanaka, K.

2000-01-01

The deformation behavior of a maraging TRIP (transformation induced plasticity) steel (MAVAL X12) is studied experimentally under a constant load. The existence of the back stress in the axial direction is directly proved by investigating the dilatation curves. Martensite-start lines are given under tensile, compressive and shear stresses. The evolution of TRIP strain and the maximum TRIP strain are determined. The alloy response during isothermal tensile test is explained in terms of influences both by the composite and transformation. (orig.)

Auditory-Cortex Short-Term Plasticity Induced by Selective Attention

Science.gov (United States)

Jääskeläinen, Iiro P.; Ahveninen, Jyrki

2014-01-01

The ability to concentrate on relevant sounds in the acoustic environment is crucial for everyday function and communication. Converging lines of evidence suggests that transient functional changes in auditory-cortex neurons, “short-term plasticity”, might explain this fundamental function. Under conditions of strongly focused attention, enhanced processing of attended sounds can take place at very early latencies (~50 ms from sound onset) in primary auditory cortex and possibly even at earlier latencies in subcortical structures. More robust selective-attention short-term plasticity is manifested as modulation of responses peaking at ~100 ms from sound onset in functionally specialized nonprimary auditory-cortical areas by way of stimulus-specific reshaping of neuronal receptive fields that supports filtering of selectively attended sound features from task-irrelevant ones. Such effects have been shown to take effect in ~seconds following shifting of attentional focus. There are findings suggesting that the reshaping of neuronal receptive fields is even stronger at longer auditory-cortex response latencies (~300 ms from sound onset). These longer-latency short-term plasticity effects seem to build up more gradually, within tens of seconds after shifting the focus of attention. Importantly, some of the auditory-cortical short-term plasticity effects observed during selective attention predict enhancements in behaviorally measured sound discrimination performance. PMID:24551458

Handbook of Plastic Welding

DEFF Research Database (Denmark)

Islam, Aminul

The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve...

Description of plastic remains found in the stomach contents of the jumbo squid Dosidicus gigas landed in Ecuador during 2014.

Science.gov (United States)

Rosas-Luis, Rigoberto

2016-12-15

Squids are active and opportunistic predators that feed on a wide range of prey. Their active movements in the water column and their voracity promote a high consumption of food. In the pelagic environment off Ecuador, marine pollution is characterized by plastic debris with a mainland origin, including plastics trash of fishing gears. The objective of this work was to describe the presence of plastic remains in the stomach contents of Dosidicus gigas caught off the coast of Ecuador. Results demonstrated that 12% of the stomachs contained plastic remains. These plastics were identified as multifilament of polyethylene lines and polyvinyl chloride remains. Findings of this work could be related to an increase in the discharge of solid materials in the water column, increasing the probability to be ingested by the jumbo squid. Copyright © 2016 Elsevier Ltd. All rights reserved.

Abiotic degradation of plastic films

Science.gov (United States)

Ángeles-López, Y. G.; Gutiérrez-Mayen, A. M.; Velasco-Pérez, M.; Beltrán-Villavicencio, M.; Vázquez-Morillas, A.; Cano-Blanco, M.

2017-01-01

Degradable plastics have been promoted as an option to mitigate the environmental impacts of plastic waste. However, there is no certainty about its degradability under different environmental conditions. The effect of accelerated weathering (AW), natural weathering (NW) and thermal oxidation (TO) on different plastics (high density polyethylene, HDPE; oxodegradable high density polyethylene, HDPE-oxo; compostable plastic, Ecovio ® metalized polypropylene, PP; and oxodegradable metalized polypropylene, PP-oxo) was studied. Plastics films were exposed to AW per 110 hours; to NW per 90 days; and to TO per 30 days. Plastic films exposed to AW and NW showed a general loss on mechanical properties. The highest reduction in elongation at break on AW occurred to HDPE-oxo (from 400.4% to 20.9%) and was higher than 90% for HDPE, HDPE-oxo, Ecovio ® and PP-oxo in NW. No substantial evidence of degradation was found on plastics exposed to TO. Oxo-plastics showed higher degradation rates than their conventional counterparts, and the compostable plastic was resistant to degradation in the studied abiotic conditions. This study shows that degradation of plastics in real life conditions will vary depending in both, their composition and the environment.

Plasticity characteristic obtained by indentation

International Nuclear Information System (INIS)

Mil'man, Yu.V.; Chugunova, S.I.; Goncharova, I.V.

2011-01-01

Methods for determination plasticity characteristic δH in the measurement of hardness and nanohardness are considered. Parameter δH characterizes the plasticity of a material by the part of plastic deformation in the total elastic-plastic deformation. The value of δH is defined for metals with different types of crystal lattice, covalent and partially covalent crystals, intermetallics, metallic glasses and quasicrystals. It is discussed the dependence of the plasticity characteristic δH on structural factors and temperature. Parameter δH allows to analyze and compare the plasticity of materials which are brittle at standard mechanical tests. The combination of hardness H, as the strength characteristic, and the plasticity characteristic δH makes possible the better characterization of mechanical behavior of materials than only the hardness H. The examples of plasticity characteristic δH application are represented.

Experiments with elasto-plastic oscillator

DEFF Research Database (Denmark)

Randrup-thomsen, Søren; Ditlevsen, Ove Dalager

1996-01-01

Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

Experiments with elasto-plastic oscillator

DEFF Research Database (Denmark)

Randrup-Thomsen, S.; Ditlevsen, Ove Dalager

1999-01-01

Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

ENVIRONMENTAL ISSUE-PLASTIC

OpenAIRE

Sunita Shakle

2017-01-01

Polythene is the most common plastic, the annual global production is approximately 60 million tones, and its primary use is in packing. Plastic bags pollute soil and waters and kill thousands of marine generalize plastic bags are not biodegradable they clog water ways, spoil the land scape and end up in landfills. Where they may take 1000 year or more to break down into ever smaller particals that continue to pollution the soil and water.

The Ethics of Sharing Plastic Surgery Videos on Social Media: Systematic Literature Review, Ethical Analysis, and Proposed Guidelines.

Science.gov (United States)

Dorfman, Robert G; Vaca, Elbert E; Fine, Neil A; Schierle, Clark F

2017-10-01

Recent videos shared by plastic surgeons on social media applications such as Snapchat, Instagram, and YouTube, among others, have blurred the line between entertainment and patient care. This has left many in the plastic surgery community calling for the development of more structured oversight and guidance regarding video sharing on social media. To date, no official guidelines exist for plastic surgeons to follow. Little is known about the ethical implications of social media use by plastic surgeons, especially with regard to video sharing. A systematic review of the literature on social media use in plastic surgery was performed on October 31, 2016, with an emphasis on ethics and professionalism. An ethical analysis was conducted using the four principles of medical ethics. The initial search yielded 87 articles. Thirty-four articles were included for analyses that were found to be relevant to the use of social media in plastic surgery. No peer-reviewed articles were found that mentioned Snapchat or addressed the ethical implications of sharing live videos of plastic surgery on social media. Using the four principles of medical ethics, it was determined that significant ethical concerns exist with broadcasting these videos. This analysis fills an important gap in the plastic surgery literature by addressing the ethical issues concerning live surgery broadcasts on social media. Plastic surgeons may use the guidelines proposed here to avoid potential pitfalls.

Experimental evolution across different thermal regimes yields genetic divergence in recombination fraction but no divergence in temperature associated plastic recombination.

Science.gov (United States)

Kohl, Kathryn P; Singh, Nadia D

2018-04-01

Phenotypic plasticity is pervasive in nature. One mechanism underlying the evolution and maintenance of such plasticity is environmental heterogeneity. Indeed, theory indicates that both spatial and temporal variation in the environment should favor the evolution of phenotypic plasticity under a variety of conditions. Cyclical environmental conditions have also been shown to yield evolved increases in recombination frequency. Here, we use a panel of replicated experimental evolution populations of D. melanogaster to test whether variable environments favor enhanced plasticity in recombination rate and/or increased recombination rate in response to temperature. In contrast to expectation, we find no evidence for either enhanced plasticity in recombination or increased rates of recombination in the variable environment lines. Our data confirm a role of temperature in mediating recombination fraction in D. melanogaster, and indicate that recombination is genetically and plastically depressed under lower temperatures. Our data further suggest that the genetic architectures underlying plastic recombination and population-level variation in recombination rate are likely to be distinct. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

Assessment of fatigue crack length via plastic deformation in compact tension specimens using magnetic Barkhausen noise

International Nuclear Information System (INIS)

Reyes-Rodriguez, F. de los; Diego-Velasco, G. de; Capo-Sanchez, J.; Franco-Fidalgo, E.

2013-01-01

In this paper the influence of different parameters on crack length is determined via plastic deformation using magnetic Barkhausen noise; the compact specimens steel used in this study were 12Cr1MoV and 11Cr1Mo, which are used for steam transportation on power plants. The main objective of this paper is to determine the crack length and its incubation time using magnetic Barkhausen noise, which lets to improve the pre-cracking process prior creep crack growth rate test simulating the real conditions of high pressure and temperature of main steam lines. Results showed that mean root square and maximum pick of voltage decrease with plastic deformation for each steel analyzed in this work, on the other hand, with the increasing of plastic deformation, a logic relationship between plastic deformation and spectrum density is observed for mid frequencies values, as well as, a variation of the amplitude, width and shape of the Barkhausen signal envelope. (Author)

Nano-Ceramic Coated Plastics

Science.gov (United States)

Cho, Junghyun

2013-01-01

Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (nano-ceramic coatings (TiO2, ZnO) on plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

Elastic-plastic analysis of AS4/PEEK composite laminate using a one-parameter plasticity model

Science.gov (United States)

Sun, C. T.; Yoon, K. J.

1992-01-01

A one-parameter plasticity model was shown to adequately describe the plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The elastic-plastic stress-strain relations of coupon specimens were measured and compared with those predicted by the finite element analysis using the one-parameter plasticity model. The results show that the one-parameter plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

Performance of molded plastic scintillators

International Nuclear Information System (INIS)

Gen, N.S.; Leman, V.E.; Solomonov, V.M.

1989-01-01

The performance of molded plastic scintillators is studied. The plastic scintillators studied were formed by transfer molding and intrusion from a scintillation composition consisting of polystyrene and a standard system of luminescent additives: 2 mass % of paraterphenyl + 0.06 mass % 1,4-di-/2-[5-phenyloxazoyly]/benzene and a plasticizer. The combined effect of mechanical load and temperature was studied. The effect of radiation on molded plastic scintillators was studied using gamma radiation from a 60 Co source. The studies show that the main operating characteristics of molded plastic scintillators are on a par with those of polymerized plastic scintillators. At the same time, molded plastic scintillators are superior in thermal stability at temperatures below the glass transition temperature and with respect to their working temperature range

Plastic food packaging and health

Directory of Open Access Journals (Sweden)

Raika Durusoy

2011-02-01

Full Text Available Plastics have a wide usage in our daily lives. One of their uses is for food packaging and food containers. The aim of this review is to introduce different types of chemicals that can leach from food packaging plastics into foods and cause human exposure and to mention their effects on health. The types of plastics were reviewed under the 13 headings in Turkish Codex Alimentarius and plastics recycling symbols were provided to enable the recognition of the type of plastic when applicable. Chemicals used during the production and that can cause health risks are investigated under the heading of the relevant type of plastic. The most important chemicals from plastic food packaging that can cause toxicity are styrene, 1,3-butadiene, melamine, formaldehyde, acrylamide, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate, vinyl chloride and bisphenol A. These chemicals have endocrine disrupting, carcinogenic and/or development disrupting effects. These chemicals may leach into foods depending on the chemical properties of the plastic or food, temperature during packaging, processing and storage, exposure to UV and duration of storage. Contact with fatty/oily or acidic foods, heating of the food inside the container, or drinking hot drinks from plastic cups, use of old and scratched plastics and some detergents increase the risk of leaching. The use of plastic containers and packaging for food and beveradges should be avoided whenever possible and when necessary, less harmful types of plastic should be preferred. [TAF Prev Med Bull 2011; 10(1.000: 87-96

From wetland specialist to hand-fed generalist: shifts in diet and condition with provisioning for a recently urbanized wading bird.

Science.gov (United States)

Murray, Maureen H; Kidd, Anjelika D; Curry, Shannon E; Hepinstall-Cymerman, Jeffrey; Yabsley, Michael J; Adams, Henry C; Ellison, Taylor; Welch, Catharine N; Hernandez, Sonia M

2018-05-05

Many wildlife species shift their diets to use novel resources in urban areas. The consequences of these shifts are not well known, and consumption of reliable-but low quality-anthropogenic food may present important trade-offs for wildlife health. This may be especially true for carnivorous species such as the American white ibis ( Eudocimus albus ), a nomadic wading bird which has been increasingly observed in urban parks in South Florida, USA. We tested the effects of anthropogenic provisioning on consumer nutrition (i.e. dietary protein), body condition and ectoparasite burdens along an urban gradient using stable isotope analysis, scaled mass index values and GPS transmitter data. Ibises that assimilated more provisioned food were captured at more urban sites, used more urban habitat, had lower mass-length residuals, lower ectoparasite scores, assimilated less δ 15N and had smaller dietary isotopic ellipses. Our results suggest that ibises in urban areas are heavily provisioned with anthropogenic food, which appears to offer a trade-off by providing low-quality, but easily accessible, calories that may not support high mass but may increase time available for anti-parasite behaviours such as preening. Understanding such trade-offs is important for investigating the effects of provisioning on infection risk and the conservation of wildlife in human-modified habitats.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'. © 2018 The Author(s).

Influence of process parameters on the weld lines of a micro injection molded component

DEFF Research Database (Denmark)

Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard

2007-01-01

The insufficient entanglement of the molecular chains and the stress amplification at the v-notch of a weld line compromise the mechanical strength of a plastic product, also in the micro scale. To investigate the influence of process parameters on the weld lines formation, a special micro cavity...... was designed and manufactured by µEDM (Electro Discharge Machining). Weld lines were quantitatively characterized both in the two-dimensional (direction and position) and three-dimensional range (surface topography characterization). Results showed that shape and position of weld lines are mainly influenced...

Our plastic age

OpenAIRE

Thompson, Richard C.; Swan, Shanna H.; Moore, Charles J.; vom Saal, Frederick S.

2009-01-01

Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste pl...

A Conservative Formulation for Plasticity

Science.gov (United States)

1992-01-01

concepts that apply to a broad class of macroscopic models: plastic deformation and plastic flow rule. CONSERVATIVE PLASTICITY 469 3a. Plastic Defrrnation...temperature. We illustrate these concepts with a model that has been used to describe high strain-rate plastic flow in metals [11, 31, 32]. In the case...JOURDREN, AND P. VEYSSEYRE. Un Modele ttyperelastique- Plastique Euldrien Applicable aux Grandes Dtformations: Que/ques R~sultats 1-D. preprint, 1991. 2. P

Wood-plastic combination

International Nuclear Information System (INIS)

Schaudy, R.

1978-02-01

A review on wood-plastic combinations is given including the production (wood and plastic component, radiation hardening, curing), the obtained properties, present applications and prospects for the future of these materials. (author)

Plastic deformation and contact area of an elastic-plastic contact of ellipsoid bodies after unloading

NARCIS (Netherlands)

Jamari, Jamari; Schipper, Dirk J.

2007-01-01

This paper presents theoretical and experimental results of the residual or plastic deformation and the plastic contact area of an elastic–plastic contact of ellipsoid bodies after unloading. There are three regime responses of the deformation and contact area: elastic, elastic–plastic and fully

Application of industrial robots in automatic disassembly line of waste LCD displays

Science.gov (United States)

Wang, Sujuan

2017-11-01

In the automatic disassembly line of waste LCD displays, LCD displays are disassembled into plastic shells, metal shields, circuit boards, and LCD panels. Two industrial robots are used to cut metal shields and remove circuit boards in this automatic disassembly line. The functions of these two industrial robots, and the solutions to the critical issues of model selection, the interfaces with PLCs and the workflows were described in detail in this paper.

Synaptic Plasticity and Nociception

Institute of Scientific and Technical Information of China (English)

ChenJianguo

2004-01-01

Synaptic plasticity is one of the fields that progresses rapidly and has a lot of success in neuroscience. The two major types of synaptie plasticity: long-term potentiation ( LTP and long-term depression (LTD are thought to be the cellular mochanisms of learning and memory. Recently, accumulating evidence suggests that, besides serving as a cellular model for learning and memory, the synaptic plasticity involves in other physiological or pathophysiological processes, such as the perception of pain and the regulation of cardiovascular system. This minireview will focus on the relationship between synaptic plasticity and nociception.

Experience during development triggers between-individual variation in behavioural plasticity.

Science.gov (United States)

Urszán, Tamás János; Garamszegi, László Zsolt; Nagy, Gergely; Hettyey, Attila; Török, János; Herczeg, Gábor

2018-05-12

1.Behavioural consistency within and across behaviours (animal personality and behavioural syndrome, respectively) have been vigorously studied in the last decade, leading to the emergence of 'animal personality' research. It has been proposed recently that not only mean behaviour (behavioural type), but the environmentally induced behavioural change (behavioural plasticity) might also differ between individuals within populations. 2.While case studies presenting between-individual variation in behavioural plasticity have started to accumulate, the mechanisms behind its emergence are virtually unknown. We have recently demonstrated that ecologically relevant environmental stimuli during ontogeny are necessary for the development of animal personality and behavioural syndromes. However, it is unknown whether between-individual variation in behavioural plasticity is hard-wired or induced. 3.Here, we tested whether experience with predation during development affected predator-induced behavioural plasticity in Rana dalmatina tadpoles. We ran a common garden experiment with two ontogenetic predation treatments: tadpoles developed from hatching in either the presence or absence of olfactory predator stimuli. Then, we assayed all tadpoles repeatedly for activity and risk-taking both in the absence and presence of olfactory predator stimuli. 4. We found that (i) between-individual variation in predator-induced behavioural plasticity was present only in the group that developed in the presence of olfactory stimuli from predators and (ii) previous experience with predatory stimuli resulted in lower plastic response at the group-level. The latter pattern resulted from increased between-individual variation and not from universally lower individual responses. We also found that experience with predation during development increased the predictability (i.e. decreased the within-individual variation unrelated to environmental change) of activity, but not risk-taking. In line

Life cycle assessment of hybrid vehicles recycling: Comparison of three business lines of dismantling.

Science.gov (United States)

Belboom, Sandra; Lewis, Grégory; Bareel, Pierre-François; Léonard, Angélique

2016-04-01

This paper undertakes an environmental evaluation of hybrid vehicles recycling, using industrial data from Comet Traitement SA in Belgium. Three business lines have been modelled and analysed. The first one is relative to the business as usual with a dismantling to recover batteries and engines followed by shredding and post shredding treatments. The second one considers, in addition, the removal of electronic control units (ECU) before shredding followed by same steps than in the first line and the last one is relative to the additional removal of big plastic parts before shredding and business as usual post shredding treatments. Results show non-significant environmental benefits when ECU or large parts of plastics are recovered before shredding. Improvements in terms of environmental benefits are lower than the uncertainty of the results. Indeed, the performing usual process for end-of-life vehicles (ELV) treatment reaches 97% of the ELV which is valorised in terms of metal and energy recoveries. Post shredding treatment units include metals, plastics and energy recovery of residues. Comet business as usual route for ELV valorisation is in accordance with the requirements of the European directive and recommendations for further improvement with dismantling of other parts (ECU or plastics) before shredding are non-relevant in this case. Copyright © 2016 Elsevier Ltd. All rights reserved.

Numerical estimate of fracture parameters under elastic and elastic-plastic conditions

International Nuclear Information System (INIS)

Soba, Alejandro; Denis, Alicia C.

2003-01-01

The importance of the stress intensity factor K in the elastic fracture analysis is well known. In this work three methods are developed to estimate the parameter K I , corresponding to the normal loading mode, employing the finite elements method. The elastic-plastic condition is also analyzed, where the line integral J is the relevant parameter. Two cases of interest are studied: sample with a crack in its center and tubes with internal pressure. (author)

Probing the limits of metal plasticity with molecular dynamics simulations

Science.gov (United States)

Zepeda-Ruiz, Luis A.; Stukowski, Alexander; Oppelstrup, Tomas; Bulatov, Vasily V.

2017-10-01

Ordinarily, the strength and plasticity properties of a metal are defined by dislocations--line defects in the crystal lattice whose motion results in material slippage along lattice planes. Dislocation dynamics models are usually used as mesoscale proxies for true atomistic dynamics, which are computationally expensive to perform routinely. However, atomistic simulations accurately capture every possible mechanism of material response, resolving every ``jiggle and wiggle'' of atomic motion, whereas dislocation dynamics models do not. Here we present fully dynamic atomistic simulations of bulk single-crystal plasticity in the body-centred-cubic metal tantalum. Our goal is to quantify the conditions under which the limits of dislocation-mediated plasticity are reached and to understand what happens to the metal beyond any such limit. In our simulations, the metal is compressed at ultrahigh strain rates along its [001] crystal axis under conditions of constant pressure, temperature and strain rate. To address the complexity of crystal plasticity processes on the length scales (85-340 nm) and timescales (1 ns-1μs) that we examine, we use recently developed methods of in situ computational microscopy to recast the enormous amount of transient trajectory data generated in our simulations into a form that can be analysed by a human. Our simulations predict that, on reaching certain limiting conditions of strain, dislocations alone can no longer relieve mechanical loads; instead, another mechanism, known as deformation twinning (the sudden re-orientation of the crystal lattice), takes over as the dominant mode of dynamic response. Below this limit, the metal assumes a strain-path-independent steady state of plastic flow in which the flow stress and the dislocation density remain constant as long as the conditions of straining thereafter remain unchanged. In this distinct state, tantalum flows like a viscous fluid while retaining its crystal lattice and remaining a strong

Synthesis of biodegradable plastic from tapioca with N-Isopropylacrylamid and chitosan using glycerol as plasticizer

Science.gov (United States)

Syaubari; Safwani, S.; Riza, M.

2018-04-01

One of natural polymers that can be used as raw material in the manufacture of biodegradable plastic is tapioca and chitosan. The addition of other compounds such as glycerol as plasticizer is to improve the characteristics of the plastic that already produced. N- Isopropylacrylamid (NIPAm) is an organic compound that can be synthesized into a polymer or polymer grafting which also biodegradable too. This research aims tostudy the synthesis of biodegradable plastics from tapioca with the addition of chitosan, NIPAm, poly(NIPAm) and analyze the characteristics of biodegradable plastics that already produced. This research was done in three stages, there are (1) polymerization NIPAm, (2) the grafting of chitosan-poly NIPAm and (3) the synthesis of biodegradable plastics from starch mixture with variation of addition chitosan, NIPAm, poly(NIPAm), chitosan-graft-poly(NIPAm) and also variations of glycerol as plasticizer. The results of this research is a thin sheet of plastic which is will get analyzed for the characteristics of functional groups, mechanical, morphological and its biodegradability. FTIR spectra showed the grafting process with the new group formation of CO single-bond at 850 cm-1. Plastic with the addition of NIPAm and 1 ml glycerol has the highest tensile strength value about 31.1 MPa. Plastic with poly(NIPAm) and 4 ml glycerol produces the highest elongation value about 153.72%. Plastic with Chitosan-graft-poly(NIPAm) with 1 ml glycerol has the longest biodegradation because of the small mass-loss for six weeks which is about 6.6%.

New perspectives in plastic biodegradation.

Science.gov (United States)

Sivan, Alex

2011-06-01

During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

Avalanches and plastic flow in crystal plasticity: an overview

Science.gov (United States)

Papanikolaou, Stefanos; Cui, Yinan; Ghoniem, Nasr

2018-01-01

Crystal plasticity is mediated through dislocations, which form knotted configurations in a complex energy landscape. Once they disentangle and move, they may also be impeded by permanent obstacles with finite energy barriers or frustrating long-range interactions. The outcome of such complexity is the emergence of dislocation avalanches as the basic mechanism of plastic flow in solids at the nanoscale. While the deformation behavior of bulk materials appears smooth, a predictive model should clearly be based upon the character of these dislocation avalanches and their associated strain bursts. We provide here a comprehensive overview of experimental observations, theoretical models and computational approaches that have been developed to unravel the multiple aspects of dislocation avalanche physics and the phenomena leading to strain bursts in crystal plasticity.

Melting the Plastic Ceiling: Overcoming Obstacles to Foster Leadership in Women Plastic Surgeons.

Science.gov (United States)

Silva, Amanda K; Preminger, Aviva; Slezak, Sheri; Phillips, Linda G; Johnson, Debra J

2016-09-01

The underrepresentation of women leaders in plastic surgery echoes a phenomenon throughout society. The importance of female leadership is presented, and barriers to gender equality in plastic surgery, both intrinsic and extrinsic, are discussed. Strategies for fostering women in leadership on an individual level and for the specialty of plastic surgery are presented.

46 CFR 160.040-4 - Equipment for impulse-projected rocket type line-throwing appliance.

Science.gov (United States)

2010-10-01

... be of either natural or synthetic fibers suitable for marine usage. The end of the line intended to... directions for loading and firing the appliance in service use shall be permanently engraved in plastic and...

Plastic and the nest entanglement of urban and agricultural crows.

Directory of Open Access Journals (Sweden)

Andrea K Townsend

Full Text Available Much attention has been paid to the impacts of plastics and other debris on marine organisms, but the effects of plastic on terrestrial organisms have been largely ignored. Detrimental effects of terrestrial plastic could be most pronounced in intensively human-modified landscapes (e.g., urban and agricultural areas, which are a source of much anthropogenic debris. Here, we examine the occurrence, types, landscape associations, and consequences of anthropogenic nest material in the American crow (Corvus brachyrhynchos, a North American species that breeds in both urban and agricultural landscapes. We monitored 195 nestlings in 106 nests across an urban and agricultural gradient in the Sacramento Valley, California, USA. We found that 85.2% of crow nests contained anthropogenic material, and 11 of 195 nestlings (5.6% were entangled in their nests. The length of the material was greater in nests in agricultural territories than in urban territories, and the odds of entanglement increased 7.55 times for each meter of anthropogenic material in the nest. Fledging success was significantly lower for entangled than for unentangled nestlings. In all environments, particularly urban, agricultural, and marine, careful disposal of potential hazards (string, packing and hay bale twine, balloon ribbon, wire, fishing line could reduce the occurrence of entanglement of nestling birds.

Plastic and the nest entanglement of urban and agricultural crows.

Science.gov (United States)

Townsend, Andrea K; Barker, Christopher M

2014-01-01

Much attention has been paid to the impacts of plastics and other debris on marine organisms, but the effects of plastic on terrestrial organisms have been largely ignored. Detrimental effects of terrestrial plastic could be most pronounced in intensively human-modified landscapes (e.g., urban and agricultural areas), which are a source of much anthropogenic debris. Here, we examine the occurrence, types, landscape associations, and consequences of anthropogenic nest material in the American crow (Corvus brachyrhynchos), a North American species that breeds in both urban and agricultural landscapes. We monitored 195 nestlings in 106 nests across an urban and agricultural gradient in the Sacramento Valley, California, USA. We found that 85.2% of crow nests contained anthropogenic material, and 11 of 195 nestlings (5.6%) were entangled in their nests. The length of the material was greater in nests in agricultural territories than in urban territories, and the odds of entanglement increased 7.55 times for each meter of anthropogenic material in the nest. Fledging success was significantly lower for entangled than for unentangled nestlings. In all environments, particularly urban, agricultural, and marine, careful disposal of potential hazards (string, packing and hay bale twine, balloon ribbon, wire, fishing line) could reduce the occurrence of entanglement of nestling birds.

Some Limitations in the Use of Plastic and Dyed Plastic Dosimeters

DEFF Research Database (Denmark)

Miller, Arne; Bjergbakke, Erling; McLaughlin, W. L.

1975-01-01

Several practical plastic and dyed plastic dosimeters were examined under irradiation conditions similar to those used for radiation processing of materials. Cellulose triacetate, polymethyl methacrylate, polyvinyl chloride, dyed polymethyl methacrylate, dyed Cellophane and dyed Nylon were given...

Plastic Fishes

CERN Multimedia

Trettnak, Wolfgang

2015-01-01

In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness. The slideshow below gives you a taste of the artworks by Wolfgang Trettnak and Margarita Cimadevila.

Plasticity resembling spike-timing dependent synaptic plasticity: the evidence in human cortex

Directory of Open Access Journals (Sweden)

Florian Müller-Dahlhaus

2010-07-01

Full Text Available Spike-timing dependent plasticity (STDP has been studied extensively in a variety of animal models during the past decade but whether it can be studied at the systems level of the human cortex has been a matter of debate. Only recently newly developed non-invasive brain stimulation techniques such as transcranial magnetic stimulation (TMS have made it possible to induce and assess timing dependent plasticity in conscious human subjects. This review will present a critical synopsis of these experiments, which suggest that several of the principal characteristics and molecular mechanisms of TMS-induced plasticity correspond to those of STDP as studied at a cellular level. TMS combined with a second phasic stimulation modality can induce bidirectional long-lasting changes in the excitability of the stimulated cortex, whose polarity depends on the order of the associated stimulus-evoked events within a critical time window of tens of milliseconds. Pharmacological evidence suggests an NMDA receptor mediated form of synaptic plasticity. Studies in human motor cortex demonstrated that motor learning significantly modulates TMS-induced timing dependent plasticity, and, conversely, may be modulated bidirectionally by prior TMS-induced plasticity, providing circumstantial evidence that long-term potentiation-like mechanisms may be involved in motor learning. In summary, convergent evidence is being accumulated for the contention that it is now possible to induce STDP-like changes in the intact human central nervous system by means of TMS to study and interfere with synaptic plasticity in neural circuits in the context of behaviour such as learning and memory.

Dense-body aggregates as plastic structures supporting tension in smooth muscle cells.

Science.gov (United States)

Zhang, Jie; Herrera, Ana M; Paré, Peter D; Seow, Chun Y

2010-11-01

The wall of hollow organs of vertebrates is a unique structure able to generate active tension and maintain a nearly constant passive stiffness over a large volume range. These properties are predominantly attributable to the smooth muscle cells that line the organ wall. Although smooth muscle is known to possess plasticity (i.e., the ability to adapt to large changes in cell length through structural remodeling of contractile apparatus and cytoskeleton), the detailed structural basis for the plasticity is largely unknown. Dense bodies, one of the most prominent structures in smooth muscle cells, have been regarded as the anchoring sites for actin filaments, similar to the Z-disks in striated muscle. Here, we show that the dense bodies and intermediate filaments formed cable-like structures inside airway smooth muscle cells and were able to adjust the cable length according to cell length and tension. Stretching the muscle cell bundle in the relaxed state caused the cables to straighten, indicating that these intracellular structures were connected to the extracellular matrix and could support passive tension. These plastic structures may be responsible for the ability of smooth muscle to maintain a nearly constant tensile stiffness over a large length range. The finding suggests that the structural plasticity of hollow organs may originate from the dense-body cables within the smooth muscle cells.

PLASTIC AND GLASS GREENHOUSES DETECTION AND DELINEATION FROM WORLDVIEW-2 SATELLITE IMAGERY

Directory of Open Access Journals (Sweden)

D. Koc-San

2016-06-01

Full Text Available Greenhouse detection using remote sensing technologies is an important research area for yield estimation, sustainable development, urban and rural planning and management. An approach was developed in this study for the detection and delineation of greenhouse areas from high resolution satellite imagery. Initially, the candidate greenhouse patches were detected using supervised classification techniques. For this purpose, Maximum Likelihood (ML, Random Forest (RF, and Support Vector Machines (SVM classification techniques were applied and compared. Then, sieve filter and morphological operations were performed for improving the classification results. Finally, the obtained candidate plastic and glass greenhouse areas were delineated using boundary tracing and Douglas Peucker line simplification algorithms. The proposed approach was implemented in the Kumluca district of Antalya, Turkey utilizing pan-sharpened WorldView-2 satellite imageries. Kumluca is the prominent district of Antalya with greenhouse cultivation and includes both plastic and glass greenhouses intensively. When the greenhouse classification results were analysed, it can be stated that the SVM classification provides most accurate results and RF classification follows this. The SVM classification overall accuracy was obtained as 90.28%. When the greenhouse boundary delineation results were considered, the plastic greenhouses were delineated with 92.11% accuracy, while glass greenhouses were delineated with 80.67% accuracy. The obtained results indicate that, generally plastic and glass greenhouses can be detected and delineated successfully from WorldView-2 satellite imagery.

Plastic and Non-plastic Debris Ingestion in Three Gull Species Feeding in an Urban Landfill Environment.

Science.gov (United States)

Seif, S; Provencher, J F; Avery-Gomm, S; Daoust, P-Y; Mallory, M L; Smith, P A

2018-04-01

Plastic debris is recognized as a widespread, common and problematic environmental pollutant. An important consequence of this pollution is the ingestion of plastic debris by wildlife. Assessing the degree to which different species ingest plastics, and the potential effects of these plastics on their health are important research needs for understanding the impacts of plastic pollution. We examined debris (plastic and other types) ingestion in three sympatric overwintering gull species (Herring gulls Larus smithsonianus, Great Black-backed Gulls Larus marinus, and Iceland Gulls Larus glaucoides) to understand how debris ingestion differs among species, age classes and sexes in gulls. We also assessed how plastic burdens were associated with body condition to investigate how gulls may be affected by debris ingestion. There were no differences among the species, age classes or sexes in the incidence of debris ingestion (plastic or otherwise), the mass or number of debris pieces ingested. We found no correlation between ingested plastics burdens and individual condition. Gulls ingested plastic debris, but also showed high levels of other debris types as well, including metal, glass and building materials, including a metal piece of debris found within an abscess in the stomach. Thus, when the health effects of debris ingestion on gulls, and other species that ingest debris, is of interest, either from a physical or chemical perspective, it may be necessary to consider all debris types and not just plastic burdens as is often currently done for seabirds.

Education on the Business of Plastic Surgery During Training: A Survey of Plastic Surgery Residents.

Science.gov (United States)

Ovadia, Steven A; Gishen, Kriya; Desai, Urmen; Garcia, Alejandro M; Thaller, Seth R

2018-06-01

Entrepreneurial skills are important for physicians, especially plastic surgeons. Nevertheless, these skills are not typically emphasized during residency training. Evaluate the extent of business training at plastic surgery residency programs as well as means of enhancing business training. A 6-question online survey was sent to plastic surgery program directors for distribution to plastic surgery residents. Responses from residents at the PGY2 level and above were included for analysis. Tables were prepared to present survey results. Hundred and sixty-six residents including 147 PGY2 and above residents responded to our survey. Only 43.5% reported inclusion of business training in their plastic surgery residency. A majority of residents reported they do not expect on graduation to be prepared for the business aspects of plastic surgery. Additionally, a majority of residents feel establishment of a formal lecture series on the business of plastic surgery would be beneficial. Results from our survey indicate limited training at plastic surgery programs in necessary business skills. Plastic surgery residency programs should consider incorporating or enhancing elements of business training in their curriculum. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Electromigration-induced Plasticity: Texture Correlation and Implications for Reliability Assessment

Energy Technology Data Exchange (ETDEWEB)

Budiman, A.S.; Besser, P.R.; Hau-Riege, C.S.; Marathe, A.; Joo, Y.-C.; Tamura, N.; Patel, J.R.; Nix, W.D.

2008-05-29

Plastic behavior has previously been observed in metallic interconnects undergoing high current density electromigration (EM) loading. In this study of Cu interconnects, using the synchrotron technique of white beam X-ray microdiffraction, we have further found preliminary evidence of a texture correlation. In lines with strong (111) textures, the extent of plastic deformation is found to be relatively large compared to that of weaker textures. We suggest that this strong (111) texture may lead to an extra path of mass transport in addition to the dominant interface diffusion in Cu EM. When this extra mass transport begins to affect the overall transport process, then the effective diffusivity, D{sub eff}, of the EM process is expected to deviate from that of interface diffusion only. This would have fundamental implications. We have some preliminary observations that this might be the case, and we report its implications for EM lifetime assessment in this manuscript.

The effects of plastic waves on the numerical convergence of the viscous-plastic and elastic-viscous-plastic sea-ice models

Science.gov (United States)

Williams, James; Tremblay, L. Bruno; Lemieux, Jean-François

2017-07-01

The plastic wave speed is derived from the linearized 1-D version of the widely used viscous-plastic (VP) and elastic-viscous-plastic (EVP) sea-ice models. Courant-Friedrichs-Lewy (CFL) conditions are derived using the propagation speed of the wave. 1-D numerical experiments of the VP, EVP and EVP* models successfully recreate a reference solution when the CFL conditions are satisfied, in agreement with the theory presented. The IMplicit-EXplicit (IMEX) method is shown to effectively alleviate the plastic wave CFL constraint on the timestep in the implicitly solved VP model in both 1-D and 2-D. In 2-D, the EVP and EVP* models show first order error in the simulated velocity field when the plastic wave is not resolved. EVP simulations are performed with various advective timestep, number of subcycles, and elastic-wave damping timescales. It is found that increasing the number of subcycles beyond that needed to resolve the elastic wave does not improve the quality of the solution. It is found that reducing the elastic wave damping timescale reduces the spatial extent of first order errors cause by the unresolved plastic wave. Reducing the advective timestep so that the plastic wave is resolved also reduces the velocity error in terms of magnitude and spatial extent. However, the parameter set required for convergence to within the error bars of satellite (RGPS) deformation fields is impractical for use in climate model simulations. The behavior of the EVP* method is analogous to that of the EVP method except that it is not possible to reduce the damping timescale with α = β.

Coliquefaction of coal, tar sand bitumen and plastic (interaction among coal, bitumen and plastic); Sekitan/tar sand bitumen/plastic no kyoekika ni okeru kyozon busshitsu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, H.; Okuyama, Y.; Matsubara, K. [NKK Corp., Tokyo (Japan); Kamo, T.; Sato, Y. [National Institute for Resources and Environment, Tsukuba (Japan)

1996-10-28

For the improvement of economy, coliquefaction of coal, tar sand bitumen and plastic was performed under low hydrogen pressure, to investigate the influence of interaction among these on the liquefaction characteristics. For comparison, coliquefaction was also performed under the hydrogen pressure same as the NEDOL process. In addition, for clarifying its reaction mechanism, coliquefaction of dibenzyl and plastic was performed as a model experiment, to illustrate the distribution of products and composition of oil, and to discuss the interaction between dibenzyl and various plastics, and between various plastics. Under direct coal liquefaction conditions, coprocessing of Tanito Harum coal, Athabasca tar sand and plastic was carried out under low hydrogen pressure with an autoclave. The observed value of oil yield was higher than the calculated value based on the values from separate liquefaction of coal and plastic, which suggested the interaction between coal and the mixed plastic. The results of coliquefaction of coal, tar sand bitumen and plastic could be explained from the obtained oil yield and its composition by the coliquefaction of dibenzyl and plastic. 2 refs., 3 tabs.

A review of plastic waste biodegradation.

Science.gov (United States)

Zheng, Ying; Yanful, Ernest K; Bassi, Amarjeet S

2005-01-01

With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

Analysis of temperature profiles and the mechanism of silicon substrate plastic deformation under epitaxial growth

International Nuclear Information System (INIS)

Mirkurbanov, H.A.; Sazhnev, S.V.; Timofeev, V.N.

2004-01-01

Full text: Thermal treatment of silicon wafers holds one of the major place in the manufacturing of semi-conductor devices. Thermal treatment includes wafer annealing, thermal oxidation, epitaxial growing etc. Quality of wafers in the high-temperature processes (900-1200 deg C) is estimated by the density of structural defects, including areas of plastic deformation, which are shown as the slip lines appearance. Such areas amount to 50-60 % of total wafer surface. The plastic deformation is caused by the thermal stresses. Experimental and theoretical researches allowed to determine thermal balance and to construct a temperature profiles throughout the plate surface. Thermal stresses are caused by temperature drop along the radius of a wafer and at the basic peripheral ring. The threshold temperature drop between center f a wafer and its peripherals (ΔT) for slip lines appearance, amounts to 15-17 deg. C. At the operating temperature of 900-1200 deg. C and ΔT>20 deg. C, the stresses reach the silicon yield point. According to the results of the researches of structure and stress profiles in a wafer, the mechanism of slip lines formation has been constructed. A source of dislocations is the rear broken layer of thickness 8-10 microns, formed after polishing. The micro-fissures with a density 10 5 -10 6 cm -2 are the sources of dislocations. Dislocations move on a surface of a wafer into a slip plane (111). On a wafer surface with orientation (111) it is possible to allocate zones where the tangential stress vector is most favorably directed with respect to a slip plane leaving on a surface, i.e. the shift stresses are maximal in the slip plane. The way to eliminate plastic deformation is to lower the temperature drop to a level of <15 deg. C and elimination of the broken layer in wafer

Recycling of plastics

Energy Technology Data Exchange (ETDEWEB)

Kaminsky, W; Menzel, J; Sinn, H

1976-01-01

Considering the shortage of raw materials and environmental pollution, the recycling of plastic waste is a very important topic. Pilot plants for research in Funabashi Japan, Franklin (Ohio) U.S.A., and the R 80-process of Krauss Maffei, W. Germany, have demonstrated the possibility of reclaiming plastics from refuse. Old tires and waste from the plastic producing and manufacturing industries are readily available. The pyrolysis of plastic yields gaseous and liquid products, and the exploitation of this cracking reaction has been demonstrated by pilot plants in Japan and Great Britain. Further laboratory scale experiments are taking place in W. Germany. In continuous fluidized beds and in molten salts, polyethylene, polypropylene, polyvinylchloride, polystyrene and rubber are pyrolysed and better than 98 percent conversion is obtained. Up to 40 percent of the feed can be obtained as aromatic compounds, and a pilot plant is under construction. As a first step PVC-containing material can be almost quantitatively dehydrochlorinated.

Plastics and environment

International Nuclear Information System (INIS)

Avenas, P.

1996-01-01

Synthetic organic polymers, such as plastics, PVC, polyamides etc are considered less ecological than natural materials such as wood. Other artificial materials such as metals, glass or biodegradable plastics have also a better image than petroleum products. This short paper demonstrates that the manufacturing or the transport of every material uses energy and that the complete energy balance sheet of a plastic bottle, for instance, is more favourable than the one of a glass bottle. Plastic materials are also easily valorized and recycled and part of the energy spent during manufacturing can be recovered during incineration for district heating. During the life-cycle of such a synthetic material, the same petroleum quantity can be used twice which leads to less negative effects on the environment. Finally, the paper focusses on the problem of biodegradable materials which are not degradable when buried under several meters of wastes and which are a nuisance to recycling. (J.S.)

Stem cell plasticity.

Science.gov (United States)

Lakshmipathy, Uma; Verfaillie, Catherine

2005-01-01

The central dogma in stem cell biology has been that cells isolated from a particular tissue can renew and differentiate into lineages of the tissue it resides in. Several studies have challenged this idea by demonstrating that tissue specific cell have considerable plasticity and can cross-lineage restriction boundary and give rise to cell types of other lineages. However, the lack of a clear definition for plasticity has led to confusion with several reports failing to demonstrate that a single cell can indeed differentiate into multiple lineages at significant levels. Further, differences between results obtained in different labs has cast doubt on some results and several studies still await independent confirmation. In this review, we critically evaluate studies that report stem cell plasticity using three rigid criteria to define stem cell plasticity; differentiation of a single cell into multiple cell lineages, functionality of differentiated cells in vitro and in vivo, robust and persistent engraft of transplanted cells.

75 FR 7563 - Certain Lined Paper Products from India: Notice of Final Results of Antidumping Duty...

Science.gov (United States)

2010-02-22

..., primarily suited for the recording of written numerical business data; lined business or office forms... polyolefin plastic material joined by 300 denier polyester, coated on the backside with PVC (poly vinyl...

Room temperature elastic--plastic response of thin-walled tubes subjected to nonradial combinations of axial and torsional loadings

International Nuclear Information System (INIS)

Liu, K.C.

1975-01-01

Two tubular specimens of type 304 stainless steel with uniform thin walls were subjected to a program of segmental combined tension/compression and torsion loadings at room temperature. A proportional, or radial, loading into the plastic range was initially applied to each specimen. Two nonproportional (nonradial) loadings along straight line segments for which neither the loading paths nor their linear extrapolations passed through the origin of the stress space were then applied. The axial and torsional stress-strain curves for these segmental prestress loadings were plotted. Hence, the stress-strain response characteristics for nonproportional loadings as well as for proportional loading can be studied. In addition, the axial and torsional plastic strain components were calculated, and the total plastic strain trajectories were plotted in a plastic strain space. Finally, using results from a detailed study of yield surfaces, which was performed for the first specimen, a spectrum of initial and subsequent yield curves corresponding to the segmental prestress loadings is presented. (U.S.)

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative

Directory of Open Access Journals (Sweden)

Domenico Sagnelli

2017-09-01

Full Text Available Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO, an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi© plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material.

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative

Science.gov (United States)

Sagnelli, Domenico; Kemmer, Gerdi Christine; Holse, Mette; Hebelstrup, Kim H.; Bao, Jinsong; Stelte, Wolfgang; Bjerre, Anne-Belinda; Blennow, Andreas

2017-01-01

Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi© plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material. PMID:28973963

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative.

Science.gov (United States)

Sagnelli, Domenico; Hooshmand, Kourosh; Kemmer, Gerdi Christine; Kirkensgaard, Jacob J K; Mortensen, Kell; Giosafatto, Concetta Valeria L; Holse, Mette; Hebelstrup, Kim H; Bao, Jinsong; Stelte, Wolfgang; Bjerre, Anne-Belinda; Blennow, Andreas

2017-09-30

Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi © plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material.

Plastics and beaches: A degrading relationship

International Nuclear Information System (INIS)

Corcoran, Patricia L.; Biesinger, Mark C.; Grifi, Meriem

2009-01-01

Plastic debris in Earth's oceans presents a serious environmental issue because breakdown by chemical weathering and mechanical erosion is minimal at sea. Following deposition on beaches, plastic materials are exposed to UV radiation and physical processes controlled by wind, current, wave and tide action. Plastic particles from Kauai's beaches were sampled to determine relationships between composition, surface textures, and plastics degradation. SEM images indicated that beach plastics feature both mechanically eroded and chemically weathered surface textures. Granular oxidation textures were concentrated along mechanically weakened fractures and along the margins of the more rounded plastic particles. Particles with oxidation textures also produced the most intense peaks in the lower wavenumber region of FTIR spectra. The textural results suggest that plastic debris is particularly conducive to both chemical and mechanical breakdown in beach environments, which cannot be said for plastics in other natural settings on Earth

Plastics recycling: challenges and opportunities.

Science.gov (United States)

Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

2009-07-27

Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3-4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

Plastics recycling: challenges and opportunities

Science.gov (United States)

Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

2009-01-01

Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

Plastic pollutants in water environment

OpenAIRE

Mrowiec Bożena

2017-01-01

Nowadays, wide applications of plastics result in plastic waste being present in the water environment in a wide variety of sizes. Plastic wastes are in water mainly as microplastics (the size range of 1 nm to < 5 mm). Microplastics have been recognized as an emerging threat, as well as ecotoxicological and ecological risk for water ecosystems. In this review are presented some of the physicochemical properties of plastic materials that determine their toxic effect on the aquatic environment....

DEVELOPMENT OF PLASTIC SURGERY.

Science.gov (United States)

Pećanac, Marija Đ

2015-01-01

Plastic surgery is a medical specialty dealing with corrections of defects, improvements in appearance and restoration of lost function. Ancient times. The first recorded account of reconstructive plastic surgery was found in ancient Indian Sanskrit texts, which described reconstructive surgeries of the nose and ears. In ancient Greece and Rome, many medicine men performed simple plastic cosmetic surgeries to repair damaged parts of the body caused by war mutilation, punishment or humiliation. In the Middle Ages, the development of all medical braches, including plastic surgery was hindered. New age. The interest in surgical reconstruction of mutilated body parts was renewed in the XVIII century by a great number of enthusiastic and charismatic surgeons, who mastered surgical disciplines and became true artists that created new forms. Modern era. In the XX century, plastic surgery developed as a modern branch in medicine including many types of reconstructive surgery, hand, head and neck surgery, microsurgery and replantation, treatment of burns and their sequelae, and esthetic surgery. Contemporary and future plastic surgery will continue to evolve and improve with regenerative medicine and tissue engineering resulting in a lot of benefits to be gained by patients in reconstruction after body trauma, oncology amputation, and for congenital disfigurement and dysfunction.

A work criterion for plastic collapse

International Nuclear Information System (INIS)

Muscat, Martin; Mackenzie, Donald; Hamilton, Robert

2003-01-01

A new criterion for evaluating limit and plastic loads in pressure vessel design by analysis is presented. The proposed criterion is based on the plastic work dissipated in the structure as loading progresses and may be used for structures subject to a single load or a combination of multiple loads. Example analyses show that limit and plastic loads given by the plastic work criterion are robust and consistent. The limit and plastic loads are determined purely by the inelastic response of the structure and are not influenced by the initial elastic response: a problem with some established plastic criteria

A Coupled Plastic Damage Model for Concrete considering the Effect of Damage on Plastic Flow

OpenAIRE

Zhou, Feng; Cheng, Guangxu

2015-01-01

A coupled plastic damage model with two damage scalars is proposed to describe the nonlinear features of concrete. The constitutive formulations are developed by assuming that damage can be represented effectively in the material compliance tensor. Damage evolution law and plastic damage coupling are described using the framework of irreversible thermodynamics. The plasticity part is developed without using the effective stress concept. A plastic yield function based on the true stress is ado...

Plastic solid waste utilization technologies: A Review

Science.gov (United States)

Awasthi, Arun Kumar; Shivashankar, Murugesh; Majumder, Suman

2017-11-01

Plastics are used in more number of applications in worldwide and it becomes essential part of our daily life. In Indian cities and villages people use the plastics in buying vegetable as a carry bag, drinking water bottle, use of plastic furniture in home, plastics objects uses in kitchen, plastic drums in packing and storage of the different chemicals for industrial use, use plastic utensils in home and many more uses. After usage of plastics it will become part of waste garbage and create pollution due to presence of toxic chemicals and it will be spread diseases and give birth to uncontrolled issues in social society. In current scenario consumption of plastic waste increasing day by day and it is very difficult to manage the plastic waste. There are limited methodologies available for reutilization of plastic waste again. Such examples are recycling, landfill, incineration, gasification and hydrogenation. In this paper we will review the existing methodologies of utilization of plastic waste in current scenario

Plastic Pollution from Ships

OpenAIRE

Čulin, Jelena; Bielić, Toni

2016-01-01

The environmental impact of shipping on marine environment includes discharge of garbage. Plastic litter is of particular concern due to abundance, resistance to degradation and detrimental effect on marine biota. According to recently published studies, a further research is required to assess human health risk. Monitoring data indicate that despite banning plastic disposal at sea, shipping is still a source of plastic pollution. Some of the measures to combat the problem are discussed.

Practical solution of plastic deformation problems in elastic-plastic range

Science.gov (United States)

Mendelson, A; Manson, S

1957-01-01

A practical method for solving plastic deformation problems in the elastic-plastic range is presented. The method is one of successive approximations and is illustrated by four examples which include a flat plate with temperature distribution across the width, a thin shell with axial temperature distribution, a solid cylinder with radial temperature distribution, and a rotating disk with radial temperature distribution.

Applications and societal benefits of plastics.

Science.gov (United States)

Andrady, Anthony L; Neal, Mike A

2009-07-27

This article explains the history, from 1600 BC to 2008, of materials that are today termed 'plastics'. It includes production volumes and current consumption patterns of five main commodity plastics: polypropylene, polyethylene, polyvinyl chloride, polystyrene and polyethylene terephthalate. The use of additives to modify the properties of these plastics and any associated safety, in use, issues for the resulting polymeric materials are described. A comparison is made with the thermal and barrier properties of other materials to demonstrate the versatility of plastics. Societal benefits for health, safety, energy saving and material conservation are described, and the particular advantages of plastics in society are outlined. Concerns relating to littering and trends in recycling of plastics are also described. Finally, we give predictions for some of the potential applications of plastic over the next 20 years.

Plastic pollutants in water environment

Directory of Open Access Journals (Sweden)

Mrowiec Bożena

2017-12-01

Full Text Available Nowadays, wide applications of plastics result in plastic waste being present in the water environment in a wide variety of sizes. Plastic wastes are in water mainly as microplastics (the size range of 1 nm to < 5 mm. Microplastics have been recognized as an emerging threat, as well as ecotoxicological and ecological risk for water ecosystems. In this review are presented some of the physicochemical properties of plastic materials that determine their toxic effect on the aquatic environment. Wastewater treatment plants (WWTPs are mentioned as one of main sources of microplastics introduced into fresh water, and rivers are the pathways for the transportation of the pollutants to seas and oceans. But, effluents from tertiary wastewater treatment facilities can contain only minimally microplastic loads. The issue of discharge reduction of plastic pollutants into water environment needs activities in the scope of efficient wastewater treatment, waste disposal, recycling of plastic materials, education and public involvement.

Track treeing mechanism and plastic zone in solid Part 1: Initial development of plastic zone

International Nuclear Information System (INIS)

Li Boyang

2008-01-01

After neutron exposure and chemical etching in advance, latent tracks of recoil nucleon develop into pits on CR39 surface. During electrochemical etching, plastic zone is formed at top of pits. Some pits develop into tree cracks in the initial stage of plastic zone development. Physical and mathematical model of crack and plastic zone is proposed; parameter of development free path of plastic zone is presented. Based on integration of elementary theories the stress analysis is build up; based on analyses of measured parameters, a set of common relations between parameters is obtained. Integrate parameter analysis and stress analysis, depth of plastic zone development, law and phenomenon in experimental data can be interpreted completely

Accumulation of plastic-derived chemicals in tissues of seabirds ingesting marine plastics.

Science.gov (United States)

Tanaka, Kosuke; Takada, Hideshige; Yamashita, Rei; Mizukawa, Kaoruko; Fukuwaka, Masa-aki; Watanuki, Yutaka

2013-04-15

We analyzed polybrominated diphenyl ethers (PBDEs) in abdominal adipose of oceanic seabirds (short-tailed shearwaters, Puffinus tenuirostris) collected in northern North Pacific Ocean. In 3 of 12 birds, we detected higher-brominated congeners (viz., BDE209 and BDE183), which are not present in the natural prey (pelagic fish) of the birds. The same compounds were present in plastic found in the stomachs of the 3 birds. These data suggested the transfer of plastic-derived chemicals from ingested plastics to the tissues of marine-based organisms. Copyright © 2012 Elsevier Ltd. All rights reserved.

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis.

Science.gov (United States)

Pflieger, Marilyne; Makorič, Petra; Kovač Viršek, Manca; Koren, Špela

2017-07-01

Plastic resin pellets, categorized as microplastics (≤5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Computational strain gradient crystal plasticity

DEFF Research Database (Denmark)

Niordson, Christian Frithiof; Kysar, Jeffrey W.

2014-01-01

A numerical method for viscous strain gradient crystal plasticity theory is presented, which incorporates both energetic and dissipative gradient effects. The underlying minimum principles are discussed as well as convergence properties of the proposed finite element procedure. Three problems...... of plane crystal plasticity are studied: pure shear of a single crystal between rigid platens as well as plastic deformation around cylindrical voids in hexagonal close packed and face centered cubic crystals. Effective in-plane constitutive slip parameters for plane strain deformation of specifically...... oriented face centered cubic crystals are developed in terms of the crystallographic slip parameters. The effect on geometrically necessary dislocation structures introduced by plastic deformation is investigated as a function of the ratio of void radius to plasticity length scale....

Imaging brain plasticity after trauma

Institute of Scientific and Technical Information of China (English)

Zhifeng Kou; Armin Iraji

2014-01-01

The brain is highly plastic after stroke or epilepsy;however, there is a paucity of brain plasticity investigation after traumatic brain injury (TBI). This mini review summarizes the most recent evidence of brain plasticity in human TBI patients from the perspective of advanced magnetic resonance imaging. Similar to other forms of acquired brain injury, TBI patients also demonstrat-ed both structural reorganization as well as functional compensation by the recruitment of other brain regions. However, the large scale brain network alterations after TBI are still unknown, and the ifeld is still short of proper means on how to guide the choice of TBI rehabilitation or treat-ment plan to promote brain plasticity. The authors also point out the new direction of brain plas-ticity investigation.

Constraints on the evolution of phenotypic plasticity

DEFF Research Database (Denmark)

Murren, Courtney J; Auld, Josh R.; Callahan, Hilary S

2015-01-01

Phenotypic plasticity is ubiquitous and generally regarded as a key mechanism for enabling organisms to survive in the face of environmental change. Because no organism is infinitely or ideally plastic, theory suggests that there must be limits (for example, the lack of ability to produce...... an optimal trait) to the evolution of phenotypic plasticity, or that plasticity may have inherent significant costs. Yet numerous experimental studies have not detected widespread costs. Explicitly differentiating plasticity costs from phenotype costs, we re-evaluate fundamental questions of the limits...... to the evolution of plasticity and of generalists vs specialists. We advocate for the view that relaxed selection and variable selection intensities are likely more important constraints to the evolution of plasticity than the costs of plasticity. Some forms of plasticity, such as learning, may be inherently...

Recycling of packing plastics

International Nuclear Information System (INIS)

Gintenreiter-Koegl, S.

2001-05-01

The ordinance on the avoidance of packaging waste was a serious intervention in the public and private waste management in Austria. Above all the high expenses for an overall packaging waste collection and the recycling of packaging plastics were criticized. The landfill ordinance comes into force in 2004 and this means another major change in the Austrian waste management system. In the course of this change the overall collection and the recycling and recovery of waste streams, especially of the high caloric plastics waste, have to be discussed again. The goal of this work was on the one hand to develop and adapt the hydrocracking process for the recovery of mixed plastics waste and to show a possible application in Austria. On the other hand the work shows the technical, ecological and economical conditions for packaging plastics recycling and recovery in order to find optimum applications for the processes and to examine their contribution to a sustainable development. A hydrocracking test plant for the processing of mixed plastic wastes was built and had been running for about three years. The tests were carried out successfully and the suitability of the technology for the recovery of packaging plastics could be shown. Results show at least a 35 % yield of fuel. The hydrocracking technology is quite common in the oil industries and therefore an integration on a refinery site is suggested. (author)

A reconfigurable on-line learning spiking neuromorphic processor comprising 256 neurons and 128K synapses.

Science.gov (United States)

Qiao, Ning; Mostafa, Hesham; Corradi, Federico; Osswald, Marc; Stefanini, Fabio; Sumislawska, Dora; Indiveri, Giacomo

2015-01-01

Implementing compact, low-power artificial neural processing systems with real-time on-line learning abilities is still an open challenge. In this paper we present a full-custom mixed-signal VLSI device with neuromorphic learning circuits that emulate the biophysics of real spiking neurons and dynamic synapses for exploring the properties of computational neuroscience models and for building brain-inspired computing systems. The proposed architecture allows the on-chip configuration of a wide range of network connectivities, including recurrent and deep networks, with short-term and long-term plasticity. The device comprises 128 K analog synapse and 256 neuron circuits with biologically plausible dynamics and bi-stable spike-based plasticity mechanisms that endow it with on-line learning abilities. In addition to the analog circuits, the device comprises also asynchronous digital logic circuits for setting different synapse and neuron properties as well as different network configurations. This prototype device, fabricated using a 180 nm 1P6M CMOS process, occupies an area of 51.4 mm(2), and consumes approximately 4 mW for typical experiments, for example involving attractor networks. Here we describe the details of the overall architecture and of the individual circuits and present experimental results that showcase its potential. By supporting a wide range of cortical-like computational modules comprising plasticity mechanisms, this device will enable the realization of intelligent autonomous systems with on-line learning capabilities.

Plastic debris in 29 Great Lakes tributaries: Relations to watershed attributes and hydrology

Science.gov (United States)

Baldwin, Austin K.; Corsi, Steven; Mason, Sherri A.

2016-01-01

Plastic debris is a growing contaminant of concern in freshwater environments, yet sources, transport, and fate remain unclear. This study characterized the quantity and morphology of floating micro- and macroplastics in 29 Great Lakes tributaries in six states under different land covers, wastewater effluent contributions, population densities, and hydrologic conditions. Tributaries were sampled three or four times each using a 333 μm mesh neuston net. Plastic particles were sorted by size, counted, and categorized as fibers/lines, pellets/beads, foams, films, and fragments. Plastics were found in all 107 samples, with a maximum concentration of 32 particles/m3 and a median of 1.9 particles/m3. Ninety-eight percent of sampled plastic particles were less than 4.75 mm in diameter and therefore considered microplastics. Fragments, films, foams, and pellets/beads were positively correlated with urban-related watershed attributes and were found at greater concentrations during runoff-event conditions. Fibers, the most frequently detected particle type, were not associated with urban-related watershed attributes, wastewater effluent contribution, or hydrologic condition. Results from this study add to the body of information currently available on microplastics in different environmental compartments, including unique contributions to quantify their occurrence and variability in rivers with a wide variety of different land-use characteristics while highlighting differences between surface samples from rivers compared with lakes.

Plastic Debris in 29 Great Lakes Tributaries: Relations to Watershed Attributes and Hydrology.

Science.gov (United States)

Baldwin, Austin K; Corsi, Steven R; Mason, Sherri A

2016-10-04

Plastic debris is a growing contaminant of concern in freshwater environments, yet sources, transport, and fate remain unclear. This study characterized the quantity and morphology of floating micro- and macroplastics in 29 Great Lakes tributaries in six states under different land covers, wastewater effluent contributions, population densities, and hydrologic conditions. Tributaries were sampled three or four times each using a 333 μm mesh neuston net. Plastic particles were sorted by size, counted, and categorized as fibers/lines, pellets/beads, foams, films, and fragments. Plastics were found in all 107 samples, with a maximum concentration of 32 particles/m 3 and a median of 1.9 particles/m 3 . Ninety-eight percent of sampled plastic particles were less than 4.75 mm in diameter and therefore considered microplastics. Fragments, films, foams, and pellets/beads were positively correlated with urban-related watershed attributes and were found at greater concentrations during runoff-event conditions. Fibers, the most frequently detected particle type, were not associated with urban-related watershed attributes, wastewater effluent contribution, or hydrologic condition. Results from this study add to the body of information currently available on microplastics in different environmental compartments, including unique contributions to quantify their occurrence and variability in rivers with a wide variety of different land-use characteristics while highlighting differences between surface samples from rivers compared with lakes.

Influence of preliminary plastic deformation on plasticity characteristics and structure of armco-iron

International Nuclear Information System (INIS)

Vergazov, A.N.; Rybin, V.V.; Meshkov, Yu.Ya.; Moskvina, V.A.; Serditova, T.N.

1990-01-01

Effect of preliminary plastic deformation (PPD) by drawing on the maximum plasticity characteristics (critical rupture strain) ε c , general δ and uniform δ p relative elongation and on the structure of armco-iron in a wide range of PPD degree change (e=0-4.6) is studied. It is ascertained that with e growth the metal plastic properties at T test =77 and 293 K change in a different way. In particular, the critical strain ε c increases monotonously at 77 K and reduces at 293 K. It is shown that all changes of mechanical characteristics observed with e increase are conditioned by the development of fragmentation process in armco-iron. The data obtained are discussed from the veiwpoint of the developed plastic deformation physics concepts

Plastic accumulation in the Mediterranean sea.

Directory of Open Access Journals (Sweden)

Andrés Cózar

Full Text Available Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2, as well as its frequency of occurrence (100% of the sites sampled, are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

Plastic Accumulation in the Mediterranean Sea

KAUST Repository

Có zar, André s; Sanz-Martí n, Marina; Martí , Elisa; Gonzá lez-Gordillo, J. Ignacio; Ubeda, Bá rbara; Gá lvez, José Á .; Irigoien, Xabier; Duarte, Carlos M.

2015-01-01

Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

Nano-plastics in the aquatic environment.

Science.gov (United States)

Mattsson, K; Hansson, L-A; Cedervall, T

2015-10-01

The amount of plastics released to the environment in modern days has increased substantially since the development of modern plastics in the early 1900s. As a result, concerns have been raised by the public about the impact of plastics on nature and on, specifically, aquatic wildlife. Lately, much attention has been paid to macro- and micro-sized plastics and their impact on aquatic organisms. However, micro-sized plastics degrade subsequently into nano-sizes whereas nano-sized particles may be released directly into nature. Such particles have a different impact on aquatic organisms than larger pieces of plastic due to their small size, high surface curvature, and large surface area. This review describes the possible sources of nano-sized plastic, its distribution and behavior in nature, the impact of nano-sized plastic on the well-being of aquatic organisms, and the difference of impact between nano- and micro-sized particles. We also identify research areas which urgently need more attention and suggest experimental methods to obtain useful data.

Integrating Hebbian and homeostatic plasticity: introduction.

Science.gov (United States)

Fox, Kevin; Stryker, Michael

2017-03-05

Hebbian plasticity is widely considered to be the mechanism by which information can be coded and retained in neurons in the brain. Homeostatic plasticity moves the neuron back towards its original state following a perturbation, including perturbations produced by Hebbian plasticity. How then does homeostatic plasticity avoid erasing the Hebbian coded information? To understand how plasticity works in the brain, and therefore to understand learning, memory, sensory adaptation, development and recovery from injury, requires development of a theory of plasticity that integrates both forms of plasticity into a whole. In April 2016, a group of computational and experimental neuroscientists met in London at a discussion meeting hosted by the Royal Society to identify the critical questions in the field and to frame the research agenda for the next steps. Here, we provide a brief introduction to the papers arising from the meeting and highlight some of the themes to have emerged from the discussions.This article is part of the themed issue 'Integrating Hebbian and homeostatic plasticity'. © 2017 The Author(s).

Plastic Accumulation in the Mediterranean Sea

KAUST Repository

Cózar, Andrés

2015-04-01

Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

Plastic accumulation in the Mediterranean sea.

Science.gov (United States)

Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J Ignacio; Ubeda, Bárbara; Gálvez, José Á; Irigoien, Xabier; Duarte, Carlos M

2015-01-01

Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

Plastic Accumulation in the Mediterranean Sea

Science.gov (United States)

Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

2015-01-01

Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

Ergonomic evaluation of a wearable assistive device for overhead work.

Science.gov (United States)

Rashedi, Ehsan; Kim, Sunwook; Nussbaum, Maury A; Agnew, Michael J

2014-01-01

Overhead work is an important risk factor for upper extremity (UE) musculoskeletal disorders. We examined the potential of a mechanical arm and an exoskeletal vest as a wearable assistive device (WADE) for overhead work. Twelve participants completed 10 minutes of simulated, intermittent overhead work, using each of three payloads (1.1, 3.4 and 8.1 kg) and with/without the WADE. Ratings of perceived discomfort (RPDs) and electromyography (EMG) were obtained for the upper arms, shoulders and low back. Using the WADE, UE RPDs decreased by ∼50% with the heavier payloads, whereas smaller (∼25%) and non-significant increases in low-back RPDs were found and were relatively independent of payload. Changes in RPDs with WADE use were consistent with physical demands indicated by EMG, though EMG-based differences in fatigue were less apparent. Participants generally preferred using the WADE, particularly with heavier payloads. These results supported the potential utility of a WADE as an intervention for overhead work.

Americium behaviour in plastic vessels

Energy Technology Data Exchange (ETDEWEB)

Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

2010-07-15

The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

Americium behaviour in plastic vessels

International Nuclear Information System (INIS)

Legarda, F.; Herranz, M.; Idoeta, R.; Abelairas, A.

2010-01-01

The adsorption of 241 Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of 241 Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of 241 Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

Consumer exposure to Bisphenol A from plastic bottles

Science.gov (United States)

Bidabadi, Fatemeh

Bisphenol A (BPA) is a plastic monomer and plasticizer and is a chemical that has one of the highest volume production worldwide, with more than six billion pounds each year. Its' primary use is the production of polycarbonate plastics, epoxy resins used to line metal cans in a host of plastic consumer products such as toys, water pipes, drinking containers, eyeglass lenses, sports safety equipment as well as consumer electronics. Studies have shown that BPA is leached from lacquer coated cans and baby feeding bottles due to hydrolysis of the Polymer during thermal treatment. Studies have also shown that even under normal use BPA may leach from food and beverage containers. For many years Bisphenol A was treated as neutral to human health. The detection of BPA in drinking water and food products has raised the interest of many researches since 1990. Thousands of studies have examined the impact of BPA to determine its effects in laboratory animals. Numerous toxicological and biochemical studies have supported that BPA has estrogenic properties. The effects of exposure to BPA can be harmful to fetus, infants and young children. BPA is used in products where traces of it can be found in every human at higher levels of concentration than that which causes problems in animals. The National Institute for Environmental Health Sciences (NIEHS) has defined "low dose" of endocrine disrupting chemicals as doses below no observable adverse effect (NOAE) for specific chemicals. In BPA, this dose is 50 mg/kg of body weight per day. Today there are more than 150 published results describing how low doses of BPA effects animals. A recent study reported that adult female mice, monkeys, and humans metabolized BPA at almost identical rates. Since the level of BPA and other endocrine chemicals appears to be increasing throughout the World, especially where plastics are prevalent, it is extremely important to study the effects of this chemical on man and wildlife. This research effort

Sustainable reverse logistics for household plastic waste

NARCIS (Netherlands)

Bing, X.

2014-01-01

Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste”

PhD Candidate: Xiaoyun Bing

Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower

Size effects in crystal plasticity

DEFF Research Database (Denmark)

Borg, Ulrik

2007-01-01

Numerical analyses of plasticity size effects have been carried out for different problems using a developed strain gradient crystal plasticiy theory. The theory employs higher order stresses as work conjugates to slip gradients and uses higher order boundary conditions. Problems on localization...... of plastic flow in a single crystal, grain boundary effects in a bicrystal, and grain size effects in a polycrystal are studied. Single crystals containing micro-scale voids have also been analyzed at different loading conditions with focus on the stress and deformation fields around the voids, on void...... growth and interaction between neighboring voids, and on a comparison between the developed strain gradient crystal plasticity theory and a discrete dislocation plasticity theory. Furthermore, voids and rigid inclusions in isotropic materials have been studied using a strain gradient plasticity theory...

Recent advances in continuum plasticity: phenomenological modeling and experimentation using X-ray diffraction

Science.gov (United States)

Edmiston, John Kearney

of the quantitative profitability of undertaking such a line of experimentation for the study of plastic deformation processes.

SYNTHESIS AND CHARACTERIZATION OF BIODEGRDABLE PLASTIC FROM CASAVA STARCH AND ALOE VERA EXTRACT WITH GLYCEROL PLASTICIZER

Directory of Open Access Journals (Sweden)

Mery Apriyani

2016-05-01

Full Text Available Synthesis and characterizations of Biodegradable Plastic made of Cassava Waste Starch, glycerol, acetic acid and Aloe vera extract has done. The aims of this research are to study the influence of addition of aloe vera extract in plastics mechanics properties, water vapor transmission rate and biodegradation. There are five main steps in this research, extraction of aloe vera, cassava starch preparation from cassava waste, preparations, characterization and biodegradability study of biodegradable plastic. The addition variations of aloe vera extract that used in this research are 0.01; 0.03; 0.05; 0.07 and 0.14 grams. Results showed that the addition of aloe Vera tends to increased biodegrable plastic thickness to 0.01 mm and elongation to 32.07%. However, biodegradable plastic tensile strength tends to decreased to 23.95 Mpa. Optimum tensile strength is 3.90 Mpa and elongation is 34.43%. Optimum water vapor transmission rate is 2.40 g/m2hours. Biodegradation study of biodegradable plastic showed that addition of aloe vera extract doesn’t significantly influence in plastic degradations.

Improvements of high-power diode laser line generators open up new application fields

Science.gov (United States)

Meinschien, J.; Bayer, A.; Bruns, P.; Aschke, L.; Lissotschenko, V. N.

2009-02-01

Beam shaping improvements of line generators based on high power diode lasers lead to new application fields as hardening, annealing or cutting of various materials. Of special interest is the laser treatment of silicon. An overview of the wide variety of applications is presented with special emphasis of the relevance of unique laser beam parameters like power density and beam uniformity. Complementary to vision application and plastic processing, these new application markets become more and more important and can now be addressed by high power diode laser line generators. Herewith, a family of high power diode laser line generators is presented that covers this wide spectrum of application fields with very different requirements, including new applications as cutting of silicon or glass, as well as the beam shaping concepts behind it. A laser that generates a 5m long and 4mm wide homogeneous laser line is shown with peak intensities of 0.2W/cm2 for inspection of railway catenaries as well as a laser that generates a homogeneous intensity distribution of 60mm x 2mm size with peak intensities of 225W/cm2 for plastic processing. For the annealing of silicon surfaces, a laser was designed that generates an extraordinary uniform intensity distribution with residual inhomogeneities (contrast ratio) of less than 3% over a line length of 11mm and peak intensities of up to 75kW/cm2. Ultimately, a laser line is shown with a peak intensity of 250kW/cm2 used for cutting applications. Results of various application tests performed with the above mentioned lasers are discussed, particularly the surface treatment of silicon and the cutting of glass.

Americium behaviour in plastic vessels.

Science.gov (United States)

Legarda, F; Herranz, M; Idoeta, R; Abelairas, A

2010-01-01

The adsorption of (241)Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of (241)Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of (241)Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification. Copyright 2009 Elsevier Ltd. All rights reserved.

Plastics control paraffin buildup

Energy Technology Data Exchange (ETDEWEB)

1965-06-01

Paraffin buildup in producing oil wells has been virtually eliminated by the use of plastic-coated sucker rods. The payout of the plasticing process is generally reached in less than a year, and the paraffin buildup may be inhibited for 10 yr or longer. Most of the plants applying plastic coatings to sucker rods are now fully automated, though a few still offer the hand-sprayed coating that some operators prefer. The several steps involved are described. The ideal plastic for the job is resistant to chemicals at high and low temperatures, flexible, has good adhesion, abrasion resistance, impact resistance, and a smooth glossy finish. The phenol aldehyde and epoxy resins presently offered by the industry fulfill these specifications very well; the multicoating and multibaking techniques improve their performance. Due to wide variations in the severity of the paraffin problem from one oil field to another, there is no general rule to estimate the possible savings from using plastic-coated sucker rods. The process, however, does appear to do a remarkable job in controlling paraffin buildup wherever it is a problem in producing oil by pump.

Plastics: Friend or foe?

Directory of Open Access Journals (Sweden)

O P Gupta

2018-01-01

Full Text Available Plastics has been playing a very significant role in our life. Being light weight, inexpensive and heving good insulating properties it is being used in all aspects of life, from clothes to contact lenses and from mobile phones to automobiles as well as in medical equipments, However it is not biodegradable, and while degrading to fragments it gets converted in to microplastics and nanoplastics The plastic waste is being recognized as an environmental hazard, since these micr- and nanoplastics find way from landfills to water and foods, It is said that we are not only using, but we are eating, drinking and even braething the plastics. These microplastics in body release certain hazardous chemicals and found to be disrupting functions of certain endocrine organs. Whether the rising prevalence of Diabetes, thyroid disorders or infirtility etc., are realated to the plastics?

Motor cortical plasticity in Parkinson's disease.

Science.gov (United States)

Udupa, Kaviraja; Chen, Robert

2013-09-04

In Parkinson's disease (PD), there are alterations of the basal ganglia (BG) thalamocortical networks, primarily due to degeneration of nigrostriatal dopaminergic neurons. These changes in subcortical networks lead to plastic changes in primary motor cortex (M1), which mediates cortical motor output and is a potential target for treatment of PD. Studies investigating the motor cortical plasticity using non-invasive transcranial magnetic stimulation (TMS) have found altered plasticity in PD, but there are inconsistencies among these studies. This is likely because plasticity depends on many factors such as the extent of dopaminergic loss and disease severity, response to dopaminergic replacement therapies, development of l-DOPA-induced dyskinesias (LID), the plasticity protocol used, medication, and stimulation status in patients treated with deep brain stimulation (DBS). The influences of LID and DBS on BG and M1 plasticity have been explored in animal models and in PD patients. In addition, many other factors such age, genetic factors (e.g., brain derived neurotropic factor and other neurotransmitters or receptors polymorphism), emotional state, time of the day, physical fitness have been documented to play role in the extent of plasticity induced by TMS in human studies. In this review, we summarize the studies that investigated M1 plasticity in PD and demonstrate how these afore-mentioned factors affect motor cortical plasticity in PD. We conclude that it is important to consider the clinical, demographic, and technical factors that influence various plasticity protocols while developing these protocols as diagnostic or prognostic tools in PD. We also discuss how the modulation of cortical excitability and the plasticity with these non-invasive brain stimulation techniques facilitate the understanding of the pathophysiology of PD and help design potential therapeutic possibilities in this disorder.

Process for remediation of plastic waste

Science.gov (United States)

Pol, Vilas G [Westmont, IL; Thiyagarajan, Pappannan [Germantown, MD

2012-04-10

A single step process for degrading plastic waste by converting the plastic waste into carbonaceous products via thermal decomposition of the plastic waste by placing the plastic waste into a reactor, heating the plastic waste under an inert or air atmosphere until the temperature of 700.degree. C. is achieved, allowing the reactor to cool down, and recovering the resulting decomposition products therefrom. The decomposition products that this process yields are carbonaceous materials, and more specifically egg-shaped and spherical-shaped solid carbons. Additionally, in the presence of a transition metal compound, this thermal decomposition process produces multi-walled carbon nanotubes.

B-MINE, the balloon-borne microcalorimeter nuclear line explorer

DEFF Research Database (Denmark)

Silver, E; Schnopper, H; Jones, C

2001-01-01

introduces the concept of focusing optics and microcalorimeter spectroscopy to nuclear line emission astrophysics. B-MINE has a thin, plastic foil telescope multilayered to maximize the reflectivity in a 20 keV band centered at 68 keV and a microcalorimeter array optimized for the same energy band....... This combination provides a reduced background, an energy resolution of 50 eV and a 3sigma sensitivity in 10(6) s of 3.3 x 10(-7) ph cm(-2) s(-1) at 68 keV. During the course of a long duration balloon flight, B-MINE could carry out a detailed study of the Ti-44 emission line centroid and width in CAS A....

B-MINE, the balloon-borne microcalorimeter nuclear line explorer

DEFF Research Database (Denmark)

Silver, E.; Schnopper, H.; Jones, C.

2002-01-01

introduces the concept of focusing optics and microcalorimeter spectroscopy to nuclear line emission astrophysics. B-MINE has a thin, plastic foil telescope multilayered to maximize the reflectivity in a 20 keV band centered at 68 keV and a microcalorimeter array optimized for the same energy band....... This combination provides a reduced background, an energy resolution of 50 eV and a 3σ sensitivity in 106 s of 3.3 × 10-7 ph cm-2 s-1 at 68 keV. During the course of a long duration balloon flight. B-MINE could carry out a detailed study of the 44Ti emission line centroid and width in CASA....

DESIGNERS’ KNOWLEDGE IN PLASTICS

DEFF Research Database (Denmark)

Eriksen, Kaare

2013-01-01

The Industrial designers’ knowledge in plastics materials and manufacturing principles of polymer products is very important for the innovative strength of the industry, according to a group of Danish plastics manufacturers, design students and practicing industrial designers. These three groups ...

A novel method to alleviate flash-line defects in coining process

KAUST Repository

Xu, Jiangping

2013-04-01

We employ a finite element framework based on a dynamic explicit algorithm to predict the flash-line defects in the coining process. The distribution of the flash-line is obtained by building a radial friction work model at the element level. The elasto-plastic behavior of porous materials undergoing large deformations is considered where the constitutive level updates are the result of a local variational minimization problem. We study the material flow at different strokes of the die across the entire coining process and observe that the change in the flow direction of the material in the rim region may contribute to the flash lines. Our proposed framework shows that a part of the rim region in which the flash-line defects appear is consistent with the reported experimental results. We also propose a novel method of redesigning the rim geometry of the workpiece to alleviate the flash-line defects which also shows good agreement with experiments. © 2012 Elsevier Inc. All rights reserved.

A Re-configurable On-line Learning Spiking Neuromorphic Processor comprising 256 neurons and 128K synapses

Directory of Open Access Journals (Sweden)

Ning eQiao

2015-04-01

Full Text Available Implementing compact, low-power artificial neural processing systems with real-time on-line learning abilities is still an open challenge. In this paper we present a full-custom mixed-signal VLSI device with neuromorphic learning circuits that emulate the biophysics of real spiking neurons and dynamic synapses for exploring the properties of computational neuroscience models and for building brain-inspired computing systems. The proposed architecture allows the on-chip configuration of a wide range of network connectivities, including recurrent and deep networks with short-term and long-term plasticity. The device comprises 128 K analog synapse and 256 neuron circuits with biologically plausible dynamics and bi-stable spike-based plasticity mechanisms that endow it with on-line learning abilities. In addition to the analog circuits, the device comprises also asynchronous digital logic circuits for setting different synapse and neuron properties as well as different network configurations. This prototype device, fabricated using a 180 nm 1P6M CMOS process, occupies an area of 51.4 mm 2 , and consumes approximately 4 mW for typical experiments, for example involving attractor networks. Here we describe the details of the overall architecture and of the individual circuits and present experimental results that showcase its potential. By supporting a wide range of cortical-like computational modules comprising plasticity mechanisms, this device will enable the realization of intelligent autonomous systems with on-line learning capabilities.

Grain Interactions in Crystal Plasticity

International Nuclear Information System (INIS)

Boyle, K.P.; Curtin, W.A.

2005-01-01

The plastic response of a sheet metal is governed by the collective response of the underlying grains. Intragranular plasticity depends on intrinsic variables such as crystallographic orientation and on extrinsic variables such as grain interactions; however, the role of the latter is not well understood. A finite element crystal plasticity formulation is used to investigate the importance of grain interactions on intragranular plastic deformation in initially untextured polycrystalline aggregates. A statistical analysis reveals that grain interactions are of equal (or more) importance for determining the average intragranular deviations from the applied strain as compared to the orientation of the grain itself. Furthermore, the influence of the surrounding grains is found to extend past nearest neighbor interactions. It is concluded that the stochastic nature of the mesoscale environment must be considered for a proper understanding of the plastic response of sheet metals at the grain-scale

Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

2013-01-01

Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

Directory of Open Access Journals (Sweden)

José Maria Rodrigues da Luz

Full Text Available Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

2013-01-01

Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate. PMID:23967057

Desorption modeling of hydrophobic organic chemicals from plastic sheets using experimentally determined diffusion coefficients in plastics.

Science.gov (United States)

Lee, Hwang; Byun, Da-Eun; Kim, Ju Min; Kwon, Jung-Hwan

2018-01-01

To evaluate rate of migration from plastic debris, desorption of model hydrophobic organic chemicals (HOCs) from polyethylene (PE)/polypropylene (PP) films to water was measured using PE/PP films homogeneously loaded with the HOCs. The HOCs fractions remaining in the PE/PP films were compared with those predicted using a model characterized by the mass transfer Biot number. The experimental data agreed with the model simulation, indicating that HOCs desorption from plastic particles can generally be described by the model. For hexachlorocyclohexanes with lower plastic-water partition coefficients, desorption was dominated by diffusion in the plastic film, whereas desorption of chlorinated benzenes with higher partition coefficients was determined by diffusion in the aqueous boundary layer. Evaluation of the fraction of HOCs remaining in plastic films with respect to film thickness and desorption time showed that the partition coefficient between plastic and water is the most important parameter influencing the desorption half-life. Copyright © 2017 Elsevier Ltd. All rights reserved.

Distributed cerebellar plasticity implements adaptable gain control in a manipulation task: a closed-loop robotic simulation

Directory of Open Access Journals (Sweden)

Jesus A Garrido Alcazar

2013-10-01

Full Text Available Adaptable gain regulation is at the core of the forward controller operation performed by the cerebro-cerebellar loops and it allows the intensity of motor acts to be finely tuned in a predictive manner. In order to learn and store information about body-object dynamics and to generate an internal model of movement, the cerebellum is thought to employ long-term synaptic plasticity. LTD at the PF-PC synapse has classically been assumed to subserve this function (Marr, 1969. However, this plasticity alone cannot account for the broad dynamic ranges and time scales of cerebellar adaptation. We therefore tested the role of plasticity distributed over multiple synaptic sites (Gao et al., 2012; Hansel et al., 2001 by generating an analog cerebellar model embedded into a control loop connected to a robotic simulator. The robot used a three-joint arm and performed repetitive fast manipulations with different masses along an 8-shape trajectory. In accordance with biological evidence, the cerebellum model was endowed with both LTD and LTP at the PF-PC, MF-DCN and PC-DCN synapses. This resulted in a network scheme whose effectiveness was extended considerably compared to one including just PF-PC synaptic plasticity. Indeed, the system including distributed plasticity reliably self-adapted to manipulate different masses and to learn the arm-object dynamics over a time course that included fast learning and consolidation, along the lines of what has been observed in behavioral tests. In particular, PF-PC plasticity operated as a time correlator between the actual input state and the system error, while MF-DCN and PC-DCN plasticity played a key role in generating the gain controller. This model suggests that distributed synaptic plasticity allows generation of the complex learning properties of the cerebellum. The incorporation of further plasticity mechanisms and of spiking signal processing will allow this concept to be extended in a more realistic

Liquid crystal displays with plastic substrates

Science.gov (United States)

Lueder, Ernst H.

1998-04-01

Plastic substrates for the cells of displays exhibit only 1/6 of the weight of glass substrates; they are virtually unbreakable; their flexibility allows the designer to give them a shape suppressing reflections, to realize a display board on a curved surface or meeting the requirements for an appealing styling; displays with plastics are thinner which provides a wider viewing angle. These features render them attractive for displays in portable systems such as mobile phones, pagers, smart cards, personal digital assistants (PDAs) and portable computers. Reflective displays are especially attractive as they don't need a back light. The most important requirements are the protection of plastics against gas permeation and chemical agents, the prevention of layers on plastics to crack or peel off when the plastic is bent and the development of low temperature thin film processes because the plastics, as a rule, only tolerate temperatures below 150 degrees Celsius. Bistable reflective FLC- and PSCT-displays with plastic substrates will be introduced. Special sputtered SiO2-orientation layers preserve the displayed information even if pressure or torsion is applied. MIM-addressed PDLC-displays require additional Al- or Ti-layers which provide the necessary ductility. Sputtered or PECVD-generated TFTs can be fabricated on plastics at temperatures below 150 degrees Celsius.

PLASTIC ANALYSIS OF STEEL FRAME STRUCTURE

Directory of Open Access Journals (Sweden)

M. Rogac

2013-05-01

Full Text Available This paper presents the plastic analysis of steel frame structure loaded by gravity loads. By applying the cinematic theorem of ultimate analysis, the ultimate load for the case of elastic - ideally plastic material is calculated. The identical structure was treated in the computer program SAP2000 where the zone of material reinforcement in the plastic area was covered. Keywords: Steel frame structure, plastic analysis, ultimate gravity load, material reinforcement.

Water Vapor Permeation in Plastics

Energy Technology Data Exchange (ETDEWEB)

Keller, Paul E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-01-01

Polyvinyl toluene (PVT) and polystyrene (PS) (referred to as “plastic scintillator”) are used for gamma ray detectors. A significant decrease in radiation detection performance has been observed in some PVT-based gamma-ray detectors in systems in outdoor environments as they age. Recent studies have revealed that plastic scintillator can undergo an environmentally related material degradation that adversely affects gamma ray detection performance under certain conditions and histories. A significant decrease in sensitivity has been seen in some gamma-ray detectors in some systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. The objective of this report is to document the phenomenon of permeability of plastic scintillator to water vapor and to derive the relationship between time, temperature, humidity and degree of water penetration in plastic. Several conclusions are documented about the properties of water permeability of plastic scintillator.

The plasticity of clays

Science.gov (United States)

Group, F.F.

1905-01-01

(1) Sand injures plasticity little at first because the grains are suspended in a plastic mass. It is only when grains are abundant enough to come in contact with their neighbors, that the effect becomes serious, and then both strength and amount of possible flow are injured. (2) Certain rare organic colloids increase the plasticity by rendering the water viscous. (3) Fineness also tends to increase plasticity. (4) Plane surfaces (plates) increase the amount of possible flow. They also give a chance for lubrication by thinner films, thus increasing the friction of film, and the strength of the whole mass. The action of plates is thus twofold ; but fineness may be carried to such an extent as to break up plate-like grains into angular fragments. The beneficial effects of plates are also decreased by the fact that each is so closely surrounded by others in the mass. (5) Molecular attraction is twofold in increasing plasticity. As the attraction increases, the coherence and strength of the mass increase, and the amount of possible deformation before crumbling also increases. Fineness increases this action by requiring more water. Colloids and crystalloids in solution may also increase the attraction. It is thus seen to be more active than any other single factor.

25 years later, US abortion war still drags on.

Science.gov (United States)

Rovner, J

1998-01-31

In the 25 years since the US Supreme Court's landmark Roe vs. Wade decision legalizing abortion, activists on both sides of the issue have drawn further apart as they have vied for the support of the majority of US voters who express ambivalence towards the law. These voters believe that abortion may be murder but that it must be legal. The Roe vs. Wade anniversary has sparked new legislative priorities on both sides. Abortion-rights activists will seek legislation that attempts to decrease the need for abortion by increasing funding for family planning services in the US and abroad, supporting funding for contraceptive research, and requiring health insurers to pay for contraceptives. Abortion opponents will continue to press for "partial birth" abortion bans and will support efforts to make it a federal crime for an adult to transport a minor across state lines to evade state parental notification or consent laws.

Review of the partitioning of chemicals into different plastics: Consequences for the risk assessment of marine plastic debris

International Nuclear Information System (INIS)

O'Connor, Isabel A.; Golsteijn, Laura; Hendriks, A. Jan

2016-01-01

Marine plastic debris are found worldwide in oceans and coastal areas. They degrade only slowly and contain chemicals added during manufacture or absorbed from the seawater. Therefore, they can pose a long-lasting contaminant source and potentially transfer chemicals to marine organisms when ingested. In order to assess their risk, the contaminant concentration in the plastics needs to be estimated and differences understood. We collected from literature plastic water partition coefficients of various organic chemicals for seven plastic types: polydimethylsiloxane (PDMS), high-density, low-density and ultra-high molecular weight polyethylene (LDPE, HDPE, UHMWPE), polystyrene (PS), polypropylene (PP), and polyvinyl chloride (PVC). Most data was available for PDMS (1060) and LDPE (220), but much less for the remaining plastics (73). Where possible, regression models were developed and the partitioning was compared between the different plastic types. The partitioning of chemicals follows the order of LDPE ≈ HDPE ≥ PP > PVC ≈ PS. Data describing the impact of weathering are urgently needed. - Highlights: • Comparison of organic chemicals partitioning into seven plastic types • Linear correlation between plastic-water partition coefficient K pw and K ow • More data is needed for polypropylene, polystyrene and polyvinyl chloride. • In all plastic types, most K pw were similar to/smaller than the corresponding K ow .

Plasticity of pressure-sensitive materials

CERN Document Server

Ochsner, Andreas

2014-01-01

Classical plasticity theory of metals is independent of the hydrostatic pressure. However, if the metal contains voids or pores or if the structure is composed of cells, this classical assumption is no more valid and the influence of the hydrostatic pressure must be incorporated in the constitutive description. Looking at the microlevel, metal plasticity is connected with the uniform planes of atoms organized with long-range order. Planes may slip past each other along their close-packed directions. The result is a permanent change of shape within the crystal and plastic deformation. The presence of dislocations increases the likelihood of planes slipping. Nowadays, the theory of pressure sensitive plasticity is successfully applied to many other important classes of materials (polymers, concrete, bones etc.) even if the phenomena on the micro-level are different to classical plasticity of metals. The theoretical background of this phenomenological approach based on observations on the macro-level is describe...

Seabirds, gyres and global trends in plastic pollution

International Nuclear Information System (INIS)

Franeker, Jan A. van; Law, Kara Lavender

2015-01-01

Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters. Since the 1980s, pre-production plastic pellets in North Sea fulmars have decreased by ∼75%, while user plastics varied without a strong overall change. Similar trends were found in net-collected floating plastic debris in the North Atlantic subtropical gyre, with a ∼75% decrease in plastic pellets and no obvious trend in user plastic. The decreases in pellets suggest that changes in litter input are rapidly visible in the environment not only close to presumed sources, but also far from land. Floating plastic debris is rapidly “lost” from the ocean surface to other as-yet undetermined sinks in the marine environment. - Highlights: • Seabirds are effective biological monitors of floating plastic marine debris. • Plastics in fulmar stomachs and in the North Atlantic gyre show similar trends. • Pre-production plastic pellets show strong decreases in fulmars and in the gyre. • These data show that floating plastics rapidly disappear from the ocean surface. - Long term studies give evidence that reduced input of plastic debris into the ocean becomes rapidly visible. Floating plastics disappear to as-yet undetermined sinks

Emission characteristics of PBDEs during flame-retardant plastics extruding process: field investigation and laboratorial simulation.

Science.gov (United States)

Deng, Chao; Li, Ying; Li, Jinhui; Chen, Yuan; Li, Huafen

2017-10-01

Though mechanical recycling of WEEE plastics is supposed to be a promising method, PBDEs release and the resulting contamination during its processing remain unclear yet. The distribution of PBDEs pollution in production lines was investigated from two flame-retardant plastic modification plants in Southern China. This was followed by laboratory simulation experiments to characterize the emission processes. PBDEs concentrations ranged from 37 to 31,305 ng/L in cooling water and from 40,043 to 216,653 ng/g dry wt in solid samples taken during the field investigation. In the laboratory simulation, concentrations ranged from 146 to 433 ng/L in cooling water and from 411,436 to 747,516 ng/Nm 3 in flue gas. All samples were dominated by BDE-209 among the congeners. Temperatures and impurities in plastic substrate can significantly affect PBDEs release. Special attention should be paid to the risks of water directly discharge from the cooling system, especially for the biological sludge and sediments, as well as flue gas emissions to the environment.

Elastic-plastic response of a piping system due to simulated double-ended guillotine break events

International Nuclear Information System (INIS)

Kussmaul, K.; Diem, H.; Hunger, H.; Katzenmeier, G.

1987-01-01

From the blowdown experiments performed on the HDR feedwater line with feedwater check valve the conclusion can be drawn that high transient loads of up to plastic strains of 3%, acting on an initially integer piping system, can be sustained without loss of integrity for a low number of load cycles due to the plasticizing capacity of the pipework materials nowadays used in the reactor technology. In the experiments carried out with ferritic piping of ND 400 pressure peaks up to about 31,5 mPA were achieved which resulted in excessive strains of up to 3%. By nonlinear finite element computations (ABAQUS) it was possible to describe the elastic-plastic behaviour of the piping in a good approximation. On account of the safety margins proved in the experiments, potential inaccuracies in theoretical structure analyses are recommended so as to be on the safe side. On the other hand, it appears that designing pipework with reference to elastic stress categories does not adequately take into account the actual reserves of the pipework material

Phenotypic plasticity in the range-margin population of the lycaenid butterfly Zizeeria maha

Directory of Open Access Journals (Sweden)

Otaki Joji M

2010-08-01

Full Text Available Abstract Background Many butterfly species have been experiencing the northward range expansion and physiological adaptation, probably due to climate warming. Here, we document an extraordinary field case of a species of lycaenid butterfly, Zizeeria maha, for which plastic phenotypes of wing color-patterns were revealed at the population level in the course of range expansion. Furthermore, we examined whether this outbreak of phenotypic changes was able to be reproduced in a laboratory. Results In the recently expanded northern range margins of this species, more than 10% of the Z. maha population exhibited characteristic color-pattern modifications on the ventral wings for three years. We physiologically reproduced similar phenotypes by an artificial cold-shock treatment of a normal southern population, and furthermore, we genetically reproduced a similar phenotype after selective breeding of a normal population for ten generations, demonstrating that the cold-shock-induced phenotype was heritable and partially assimilated genetically in the breeding line. Similar genetic process might have occurred in the previous and recent range-margin populations as well. Relatively minor modifications expressed in the tenth generation of the breeding line together with other data suggest a role of founder effect in this field case. Conclusions Our results support the notion that the outbreak of the modified phenotypes in the recent range-margin population was primed by the revelation of plastic phenotypes in response to temperature stress and by the subsequent genetic process in the previous range-margin population, followed by migration and temporal establishment of genetically unstable founders in the recent range margins. This case presents not only an evolutionary role of phenotypic plasticity in the field but also a novel evolutionary aspect of range expansion at the species level.

Plastic zonder olie : lesmodule voor nieuwe scheikunde

OpenAIRE

Langejan, B.; Klein Douwel, C.; Horst, ter, J.J.; Tijdink, K.; Marle, van, N.; Klaasen, P.; Coolen, R.; Assenbergh, van, P.; Sijbers, J.P.J.; Mast, A.

2013-01-01

Lesmodule voor nieuwe scheikunde voor leerlingen uit 5 en 6 vwo. Bioplastics worden gemaakt uit natuurlijke grondstoffen. Als ze de synthetische plastics vervangen kan de voorraad aardolie ontzien worden. Omdat veel bioplastics afbreekbaar zijn, kan ook de berg plastic afval krimpen. Maar zijn bioplastics in staat om ons de reguliere plastics te doen vergeten? Hoe maken we bioplastics met dezelfde veelzijdige eigenschappen als plastic? Waar komen de uiteenlopende eigenschappen van plastics ei...

Elimination of Plastic Polymers in Natural Environments

OpenAIRE

Ramirez-Ekner, Sofia; Bidstrup, Marie Juliane Svea; Brusen, Nicklas Hald; Rugaard-Morgan, Zsa-Zsa Sophie Oona Ophelia

2017-01-01

Plastic production and consumption continues to rise and subsequently plastic waste continues to accumulates in natural environments, causing harm to ecosystems.The aim of this paper was to come up with a way to utilize organisms, that have been identified to produce plastic degrading enzymes, as a waste disposal technology. This review includes accounts of plastic production rates, the occurrence of plastic in natural environments and the current waste management systems to create an underst...

The evolution of age-dependent plasticity

NARCIS (Netherlands)

Fischer, Barbara; van Doorn, G. Sander; Dieckmann, Ulf; Taborsky, Barbara

2014-01-01

When organisms encounter environments that are heterogeneous in time, phenotypic plasticity is often favored by selection. The degree of such plasticity can vary during an organism''s lifetime, but the factors promoting differential plastic responses at different ages or life stages remain poorly

Biodegradability of Plastics: Challenges and Misconceptions.

Science.gov (United States)

Kubowicz, Stephan; Booth, Andy M

2017-11-07

Plastics are one of the most widely used materials and, in most cases, they are designed to have long life times. Thus, plastics contain a complex blend of stabilizers that prevent them from degrading too quickly. Unfortunately, many of the most advantageous properties of plastics such as their chemical, physical and biological inertness and durability present challenges when plastic is released into the environment. Common plastics such as polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) are extremely persistent in the environment, where they undergo very slow fragmentation (projected to take centuries) into small particles through photo-, physical, and biological degradation processes 1 . The fragmentation of the material into increasingly smaller pieces is an unavoidable stage of the degradation process. Ultimately, plastic materials degrade to micron-sized particles (microplastics), which are persistent in the environment and present a potential source of harm for organisms.

Synaptic plasticity in drug reward circuitry.

Science.gov (United States)

Winder, Danny G; Egli, Regula E; Schramm, Nicole L; Matthews, Robert T

2002-11-01

Drug addiction is a major public health issue worldwide. The persistence of drug craving coupled with the known recruitment of learning and memory centers in the brain has led investigators to hypothesize that the alterations in glutamatergic synaptic efficacy brought on by synaptic plasticity may play key roles in the addiction process. Here we review the present literature, examining the properties of synaptic plasticity within drug reward circuitry, and the effects that drugs of abuse have on these forms of plasticity. Interestingly, multiple forms of synaptic plasticity can be induced at glutamatergic synapses within the dorsal striatum, its ventral extension the nucleus accumbens, and the ventral tegmental area, and at least some of these forms of plasticity are regulated by behaviorally meaningful administration of cocaine and/or amphetamine. Thus, the present data suggest that regulation of synaptic plasticity in reward circuits is a tractable candidate mechanism underlying aspects of addiction.

Pregnancy and the Plastic Surgery Resident.

Science.gov (United States)

Garza, Rebecca M; Weston, Jane S; Furnas, Heather J

2017-01-01

Combining pregnancy with plastic surgery residency has historically been difficult. Two decades ago, 36 percent of plastic surgery program directors surveyed actively discouraged pregnancy among residents, and 33 percent of women plastic surgeons suffered from infertility. Most alarmingly, 26 percent of plastic surgery trainees had had an elective abortion during residency. With increasing numbers of women training in plastic surgery, this historical lack of support for pregnancy deserves further attention. To explore the current accommodations made for the pregnant plastic surgery resident, an electronic survey was sent to 88 plastic surgery program directors in the United States. Fifty-four responded, for a response rate of 61.36 percent. On average, a director trained a total of 7.91 women among 17.28 residents trained over 8.19 years. Of the women residents, 1.43 were pregnant during a director's tenure, with 1.35 of those residents taking maternity leave. An average 1.75 male residents took paternity leave. Approximately one-third of programs had a formal maternity/paternity leave policy (36.54 percent) which, in most cases, was limited to defining allowed weeks of leave, time required to fulfill program requirements, and remuneration during leave. This survey of plastic surgery directors is a first step in defining the challenges training programs face in supporting the pregnant resident. Directors provided comments describing their challenges accommodating an absent resident in a small program and complying with the American Board of Plastic Surgery's required weeks of training per year. A discussion of these challenges is followed by suggested solutions.

Functional nanostructures on injection molded plastic

DEFF Research Database (Denmark)

Johansson, Alicia Charlotte; Søgaard, Emil; Andersen, Nis Korsgaard

Nanotechnology can be used to make inexpensive plastic parts with functional surfaces. The plastic parts can be molded using a standard injection molding process. The nanostructures are directly transferred from the surface of the molding tool to the surface of the molded plastic part during...

7 CFR 58.326 - Plastic cream.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Plastic cream. 58.326 Section 58.326 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.326 Plastic cream. To produce plastic cream eligible for official certification, the quality...

Simulation of X-ray diffraction-line broadening due to dislocations in a model composite material

NARCIS (Netherlands)

Bor, Teunis Cornelis; Cleveringa, H.H.M.; Delhez, R; van der Giessen, E.

2001-01-01

X-ray diffraction-line profiles of two-dimensional, plastically deformed model composite materials are calculated and analysed in detail. The composite consists of elastic reinforcements in a crystalline solid and is subjected to macroscopic shear. Slip occurs in the matrix only due to the

Environment friendly solutions of plastics waste management

International Nuclear Information System (INIS)

Pirzada, F.N.; Riffat, T.; Pirzada, M.D.S.

1997-01-01

The use of plastics is growing worldwide. Consequently, the volume of plastic waste is also increasing. Presently, more than 100 million tons per year of plastic is being produced globally. In U.S. alone more than 10 million tons of plastic is being dumped in landfills as waste, where it can persist for decades. This has resulted in exhausting old landfills. Public awareness on environment is also making it difficult to find new sites for landfills. This has led to increased emphasis on treatment and recycling of plastic wastes. Volume reduction of plastic waste has some unique problems. They arise from the intrinsic chemical inertness of polymeric materials and toxic nature of their degradation byproducts. The paper reviews the present state of plastic waste management including land filling, incineration and recycling technologies. The technical problems associated with each of these processes have been discussed. There is also brief description of ongoing R and D for finding improved methods of plastic waste handling with their promises and problems. The role of tougher legislation in developing better recycling methods and degradable plastics has also been evaluated. The claims made by the proponents of degradable polymers have also been critically reviewed. (authors)

Plastic in surface waters of the Inside Passage and beaches of the Salish Sea in Washington State.

Science.gov (United States)

Davis, Wallace; Murphy, Anne G

2015-08-15

We summarize results of two independent studies on plastic pollution in the marine environment that overlap in time and space. One study evaluated the abundance of anthropogenic debris on 37 sandy beaches bordering the Salish Sea in Washington State while the other characterized plastic debris in surface waters of the Salish Sea and the Inside Passage to Skagway, Alaska. Both studies concluded that foam, primarily expanded polystyrene was the dominant pollutant. Plastic was found in surface waters the full length of the Inside Passage but was concentrated near harbors. At the wrack line, an average square meter of Washington's 1180km of sandy beaches in the Salish Sea had 61 pieces of anthropogenic debris weighing approximately 5g. The total loading for the entire 1m wide band is estimated to be 72,000,000 pieces and 5.8metric tons. Most anthropogenic debris on beaches is generated within the region. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modeling plasticity by non-continuous deformation

Science.gov (United States)

Ben-Shmuel, Yaron; Altus, Eli

2017-10-01

Plasticity and failure theories are still subjects of intense research. Engineering constitutive models on the macroscale which are based on micro characteristics are very much in need. This study is motivated by the observation that continuum assumptions in plasticity in which neighbour material elements are inseparable at all-time are physically impossible, since local detachments, slips and neighbour switching must operate, i.e. non-continuous deformation. Material microstructure is modelled herein by a set of point elements (particles) interacting with their neighbours. Each particle can detach from and/or attach with its neighbours during deformation. Simulations on two- dimensional configurations subjected to uniaxial compression cycle are conducted. Stochastic heterogeneity is controlled by a single "disorder" parameter. It was found that (a) macro response resembles typical elasto-plastic behaviour; (b) plastic energy is proportional to the number of detachments; (c) residual plastic strain is proportional to the number of attachments, and (d) volume is preserved, which is consistent with macro plastic deformation. Rigid body displacements of local groups of elements are also observed. Higher disorder decreases the macro elastic moduli and increases plastic energy. Evolution of anisotropic effects is obtained with no additional parameters.

Plastic debris in the open ocean

KAUST Repository

Cozar, Andres

2014-06-30

There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.

Plastic debris in the open ocean.

Science.gov (United States)

Cózar, Andrés; Echevarría, Fidel; González-Gordillo, J Ignacio; Irigoien, Xabier; Ubeda, Bárbara; Hernández-León, Santiago; Palma, Alvaro T; Navarro, Sandra; García-de-Lomas, Juan; Ruiz, Andrea; Fernández-de-Puelles, María L; Duarte, Carlos M

2014-07-15

There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.

Plastic debris in the open ocean

Science.gov (United States)

Cózar, Andrés; Echevarría, Fidel; González-Gordillo, J. Ignacio; Irigoien, Xabier; Úbeda, Bárbara; Hernández-León, Santiago; Palma, Álvaro T.; Navarro, Sandra; García-de-Lomas, Juan; Ruiz, Andrea; Fernández-de-Puelles, María L.; Duarte, Carlos M.

2014-01-01

There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean. PMID:24982135

Plastic Accumulation in the Mediterranean Sea

OpenAIRE

C?zar, Andr?s; Sanz-Mart?n, Marina; Mart?, Elisa; Gonz?lez-Gordillo, J. Ignacio; Ubeda, B?rbara; G?lvez, Jos? ?.; Irigoien, Xabier; Duarte, Carlos M.

2015-01-01

Copyright: © 2015 Cózar et al. Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by ...

High-temperature discrete dislocation plasticity

Science.gov (United States)

Keralavarma, S. M.; Benzerga, A. A.

2015-09-01

A framework for solving problems of dislocation-mediated plasticity coupled with point-defect diffusion is presented. The dislocations are modeled as line singularities embedded in a linear elastic medium while the point defects are represented by a concentration field as in continuum diffusion theory. Plastic flow arises due to the collective motion of a large number of dislocations. Both conservative (glide) and nonconservative (diffusion-mediated climb) motions are accounted for. Time scale separation is contingent upon the existence of quasi-equilibrium dislocation configurations. A variational principle is used to derive the coupled governing equations for point-defect diffusion and dislocation climb. Superposition is used to obtain the mechanical fields in terms of the infinite-medium discrete dislocation fields and an image field that enforces the boundary conditions while the point-defect concentration is obtained by solving the stress-dependent diffusion equations on the same finite-element grid. Core-level boundary conditions for the concentration field are avoided by invoking an approximate, yet robust kinetic law. Aspects of the formulation are general but its implementation in a simple plane strain model enables the modeling of high-temperature phenomena such as creep, recovery and relaxation in crystalline materials. With emphasis laid on lattice vacancies, the creep response of planar single crystals in simple tension emerges as a natural outcome in the simulations. A large number of boundary-value problem solutions are obtained which depict transitions from diffusional to power-law creep, in keeping with long-standing phenomenological theories of creep. In addition, some unique experimental aspects of creep in small scale specimens are also reproduced in the simulations.

21 CFR 872.5470 - Orthodontic plastic bracket.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Orthodontic plastic bracket. 872.5470 Section 872...) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5470 Orthodontic plastic bracket. (a) Identification. An orthodontic plastic bracket is a plastic device intended to be bonded to a tooth to apply...

Dimensioning of lining galleries in deep clays

International Nuclear Information System (INIS)

Bernaud, D.; Rousset, G.

1991-01-01

The aim of the work presented in this report is to study the mechanical behaviour of lining galleries in deep clays. This text constitutes a part of the researches on the feasibility of a geological disposal of radioactive waste, which the scope is to assure the gallery long term stabilization and also to optimize its dimensioning. In particular, we are interested here in the study of a closure controlled lining, that constitutes a direct application of the convergence-confinement method, especially well fitted to deep clays. The presentation and interpretation of the convergence controlled lining test, which was performed in the experimental gallery of Mol in Belgium, is given in this report. The instrumentation was conceived in order to find out the stress field exerced by the rockmass on the lining, the internal stress field inside the lining and the gallery closure. The analysis of all measurements results, obtained between november 1987 and December 1989, shows that they are all in good agreement and that the lining design was well chosen. Two years after the gallery construction, the average closure is of the order of 2% and the average confinement pressure is about 1.6 MPa (the third of the lithostatic pressure). The time dependent effects of the rockmass are very well modelled by the non linear elasto-viscoplastic law developed at L.M.S. with the laboratory tests. The elastic-plastic model of the lining are shown to be well fitted to simulate the sliding of the ribs. Finally, the numerical results have shown a very good agreement with the measurements results

Circular economy of plastic packaging: Current practice and perspectives in Austria.

Science.gov (United States)

Van Eygen, Emile; Laner, David; Fellner, Johann

2018-02-01

Plastics, especially from packaging, have gained increasing attention in waste management, driving many policy initiatives to improve the circularity of these materials in the economy to increase resource efficiency. In this context, the EU has proposed increasing targets to encourage the recycling of (plastic) packaging. To accurately calculate the recycling rates, detailed information on the flows of plastic packaging is needed. Therefore, the aim of this paper is to quantitatively and qualitatively investigate the waste management system for plastic packaging in Austria in 2013 using material flow analysis, taking into account the used product types and the polymer composition. The results show that 300,000 ± 3% t/a (35 kg/cap·a) of waste plastic packaging were produced, mainly composed of large and small films and small hollow bodies, including PET bottles. Correspondingly, the polymer composition of the waste stream was dominated by LDPE (46% ± 6%), PET (19% ± 4%) and PP (14% ± 6%). 58% ± 3% was collected separately, and regarding the final treatment, 26% ± 7% of the total waste stream was recovered as re-granulates, whereas the rest was thermally recovered in waste-to-energy plants (40% ± 3%) and the cement industry (33% ± 6%). The targets set by the EU and Austria were reached comfortably, although to reach the proposed future target major technological steps regarding collection and sorting will be needed. However, the current calculation point of the targets, i.e. on the input side of the recycling plant, is not deemed to be fully in line with the overall objective of the circular economy, namely to keep materials in the economy and prevent losses. It is therefore recommended that the targets be calculated with respect to the actual output of the recycling process, provided that the quality of the output products is maintained, to accurately assess the performance of the waste management system. Copyright © 2017

Plastic photochromic eyewear: a status report

Science.gov (United States)

Crano, John C.; Elias, Richard C.

1991-12-01

An estimated 10 million pairs of photochromic prescription lenses were dispensed in the United States in 1989, essentially all based on a silver halide system suspended in an inorganic glass. A significant trend within the ophthalmic industry has been the growth of light-weight plastic lenses. In the United States market, the percentage of prescription eyewear made of plastic is now greater than 70%. With this increasing market penetration of plastic lenses, the desire for an acceptable plastic photochromic lens has also increased. As with any commercial product, in order to achieve consumer acceptance there exist several technical requirements for a plastic photochromic lens. These include the light transmission and color of the lens in both the unactivated and activated states, the speeds of darkening and fading, and the fatigue resistance or lifetime of the photochromic system. These requirements will be defined along with approaches to achieving them. The properties of the commercially available plastic photochromic lenses will be compared with the defined requirements.

[From the French Society of Plastic and Reconstructive Surgery to the French Society of Plastic Reconstructive and Aesthetic Surgery].

Science.gov (United States)

Glicenstein, J

2004-04-01

(The) 3rd December 1952, 11 surgeons and other specialists found the French Society of Plastic and Reconstructive Surgery (SFCPR) which was officially published on (the) 28 September 1953. The first congress was during October 1953 and the first president as Maurice Aubry. The first secretary was Daniel Morel Fatio. The symposiums were after about three of four times each year and the thematic subjects were initially according the reconstructive surgery. The review "Annales de chirurgie plastique" was free in 1956. The members of the Society were about 30 initially, but their plastic surgery in the big hospitals at Paris and other big towns in France. The "specialty" of plastic surgery was created in 1971. On "syndicate", one French board of plastic reconstructive and aesthetic surgery, the increasing of departments of plastic surgery were the front of increasing of the plastic surgery in French and of the number of the French Society of Plastic Reconstructive surgery (580 in 2003). The French Society organized the International Congress of Plastic Surgery in 1975. The society SFCPR became the French Society of plastic reconstruction and Aesthetic Surgery (SFCPRE) in 1983 and the "logo" (front view) was in the 1994 SOF.CPRE.

Plastic ingestion by Flesh-footed Shearwaters (Puffinus carneipes): Implications for fledgling body condition and the accumulation of plastic-derived chemicals

International Nuclear Information System (INIS)

Lavers, Jennifer L.; Bond, Alexander L.; Hutton, Ian

2014-01-01

To provide much needed quantitative data on the lethal and sublethal effects of plastic pollution on marine wildlife, we sampled breast feathers and stomach contents from Flesh-footed Shearwater (Puffinus carneipes) fledglings in eastern Australia. Birds with high levels of ingested plastic exhibited reduced body condition and increased contaminant load (p < 0.05). More than 60% of fledglings exceed international targets for plastic ingestion by seabirds, with 16% of fledglings failing these targets after a single feeding (range: 0.13–3.21 g of plastic/feeding). As top predators, seabirds are considered sentinels of the marine environment. The amount of plastic ingested and corresponding damage to Flesh-footed Shearwater fledglings is the highest reported for any marine vertebrate, suggesting the condition of the Australian marine environment is poor. These findings help explain the ongoing decline of this species and are worrying in light of increasing levels of plastic pollution in our oceans. - Highlights: • Proportion of the shearwater population ingesting plastic increased over four years. • Shearwater body condition is negatively influenced by the amount of ingested plastic. • Shearwater contaminant load is positively related to the amount of ingested plastic. • Many chicks exceed international targets for ingested plastic after a single feeding. • Plastic ingestion in this study is the highest reported for any marine vertebrate. - Flesh-footed Shearwaters ingest large quantities of marine plastic, which is correlated with poor body condition and increased concentrations of trace metals such as chromium

Effect of waste plastic as modifier on thermal stability and degradation kinetics of bitumen/waste plastics blend

Energy Technology Data Exchange (ETDEWEB)

Naskar, M. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India); Chaki, T.K., E-mail: tapan@rtc.iitkgp.ernet.in [Rubber Technology Centre, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India); Reddy, K.S. [Department of Civil Engineering, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India)

2010-09-20

Different modified bituminous binders are used in pavement construction for improved durability and for enhanced performance in resisting cracking and permanent deformation of bituminous layers. Waste plastics, whose disposal is a matter of concern, have been used successfully for modifying bitumen. This paper reports the thermogravimetric studies conducted on waste plastic modified bituminous binders. Modified bituminous binders prepared using different plastic contents (0-7 wt% by weight of bitumen) were investigated. The activation energies were determined from thermogravimetric analysis (TGA) data using Kissinger and the Flynn-Wall-Ozawa methods, which do not require knowledge of the reaction mechanism. Modified bitumen (WPMB5) with 5 wt% plastic was found to have the highest thermal stability compared to other binders investigated. Differential scanning calorimetry (DSC) studies were carried out to find crystalline melting temperature and fusion enthalpy. Rheological parameters of modified binders prepared with different plastic contents also suggest that the 5 wt% plastic content is expected to yield optimal performance.

Effect of waste plastic as modifier on thermal stability and degradation kinetics of bitumen/waste plastics blend

International Nuclear Information System (INIS)

Naskar, M.; Chaki, T.K.; Reddy, K.S.

2010-01-01

Different modified bituminous binders are used in pavement construction for improved durability and for enhanced performance in resisting cracking and permanent deformation of bituminous layers. Waste plastics, whose disposal is a matter of concern, have been used successfully for modifying bitumen. This paper reports the thermogravimetric studies conducted on waste plastic modified bituminous binders. Modified bituminous binders prepared using different plastic contents (0-7 wt% by weight of bitumen) were investigated. The activation energies were determined from thermogravimetric analysis (TGA) data using Kissinger and the Flynn-Wall-Ozawa methods, which do not require knowledge of the reaction mechanism. Modified bitumen (WPMB5) with 5 wt% plastic was found to have the highest thermal stability compared to other binders investigated. Differential scanning calorimetry (DSC) studies were carried out to find crystalline melting temperature and fusion enthalpy. Rheological parameters of modified binders prepared with different plastic contents also suggest that the 5 wt% plastic content is expected to yield optimal performance.

Neuronal cytoskeleton in synaptic plasticity and regeneration.

Science.gov (United States)

Gordon-Weeks, Phillip R; Fournier, Alyson E

2014-04-01

During development, dynamic changes in the axonal growth cone and dendrite are necessary for exploratory movements underlying initial axo-dendritic contact and ultimately the formation of a functional synapse. In the adult central nervous system, an impressive degree of plasticity is retained through morphological and molecular rearrangements in the pre- and post-synaptic compartments that underlie the strengthening or weakening of synaptic pathways. Plasticity is regulated by the interplay of permissive and inhibitory extracellular cues, which signal through receptors at the synapse to regulate the closure of critical periods of developmental plasticity as well as by acute changes in plasticity in response to experience and activity in the adult. The molecular underpinnings of synaptic plasticity are actively studied and it is clear that the cytoskeleton is a key substrate for many cues that affect plasticity. Many of the cues that restrict synaptic plasticity exhibit residual activity in the injured adult CNS and restrict regenerative growth by targeting the cytoskeleton. Here, we review some of the latest insights into how cytoskeletal remodeling affects neuronal plasticity and discuss how the cytoskeleton is being targeted in an effort to promote plasticity and repair following traumatic injury in the central nervous system. © 2013 International Society for Neurochemistry.

Mechanisms of GABAergic Homeostatic Plasticity

Directory of Open Access Journals (Sweden)

Peter Wenner

2011-01-01

Full Text Available Homeostatic plasticity ensures that appropriate levels of activity are maintained through compensatory adjustments in synaptic strength and cellular excitability. For instance, excitatory glutamatergic synapses are strengthened following activity blockade and weakened following increases in spiking activity. This form of plasticity has been described in a wide array of networks at several different stages of development, but most work and reviews have focussed on the excitatory inputs of excitatory neurons. Here we review homeostatic plasticity of GABAergic neurons and their synaptic connections. We propose a simplistic model for homeostatic plasticity of GABAergic components of the circuitry (GABAergic synapses onto excitatory neurons, excitatory connections onto GABAergic neurons, cellular excitability of GABAergic neurons: following chronic activity blockade there is a weakening of GABAergic inhibition, and following chronic increases in network activity there is a strengthening of GABAergic inhibition. Previous work on GABAergic homeostatic plasticity supports certain aspects of the model, but it is clear that the model cannot fully account for some results which do not appear to fit any simplistic rule. We consider potential reasons for these discrepancies.

Plasticity characteristic obtained by indentation

International Nuclear Information System (INIS)

Milman, Yu V

2008-01-01

A dimensionless parameter δ H = ε p /ε t (where ε p and ε t are the average values of plastic and total deformation of material on the contact area indenter-specimen) may be used as the plasticity characteristic of materials, which made it possible to characterize the plasticity of materials that are brittle in standard mechanical tests. δ H may be calculated from the values of microhardness HM, Young's modulus E and Poisson's ratio ν. In instrumented indentation the plasticity characteristic δ A = A p /A t (A p and A t are the work of plastic and total deformation during indentation) may be calculated. δ A ∼ δ H for materials with δ H > 0.5, i.e. for all metals and the majority of ceramic materials. In this case, the theoretical equation δ A ∼ δ H = 1-10.2 · (1 - ν - 2ν 2 )(HM/E) is satisfied in experiments with the Berkovich indenter. The influence of the temperature and structural parameters (dislocation density and grain size including nanostructured materials) on δ H is discussed

Smartphones and the plastic surgeon.

Science.gov (United States)

Al-Hadithy, Nada; Ghosh, Sudip

2013-06-01

Surgical trainees are facing limited training opportunities since the introduction of the European Working Time Directive. Smartphone sales are increasing and have usurped computer sales for the first time. In this context, smartphones are an important portable reference and educational tool, already in the possession of the majority of surgeons in training. Technology in the palm of our hands has led to a revolution of accessible information for the plastic surgery trainee and surgeon. This article reviews the uses of smartphones and applications for plastic surgeons in education, telemedicine and global health. A comprehensive guide to existing and upcoming learning materials and clinical tools for the plastic surgeon is included. E-books, podcasts, educational videos, guidelines, work-based assessment tools and online logbooks are presented. In the limited resource setting of modern clinical practice, savvy plastic surgeons can select technological tools to democratise access to education and best clinical care. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Effect of Covered Metallic Stents Compared With Plastic Stents on Benign Biliary Stricture Resolution

Science.gov (United States)

Coté, Gregory A.; Slivka, Adam; Tarnasky, Paul; Mullady, Daniel K.; Elmunzer, B. Joseph; Elta, Grace; Fogel, Evan; Lehman, Glen; McHenry, Lee; Romagnuolo, Joseph; Menon, Shyam; Siddiqui, Uzma D.; Watkins, James; Lynch, Sheryl; Denski, Cheryl; Xu, Huiping; Sherman, Stuart

2017-01-01

IMPORTANCE Endoscopic placement of multiple plastic stents in parallel is the first-line treatment for most benign biliary strictures; it is possible that fully covered, self-expandable metallic stents (cSEMS) may require fewer endoscopic retrograde cholangiopancreatography procedures (ERCPs) to achieve resolution. OBJECTIVE To assess whether use of cSEMS is noninferior to plastic stents with respect to stricture resolution. DESIGN, SETTING, AND PARTICIPANTS Multicenter (8 endoscopic referral centers), open-label, parallel, randomized clinical trial involving patients with treatment-naive, benign biliary strictures (N = 112) due to orthotopic liver transplant (n = 73), chronic pancreatitis (n = 35), or postoperative injury (n = 4), who were enrolled between April 2011 and September 2014 (with follow-up ending October 2015). Patients with a bile duct diameter less than 6 mm and those with an intact gallbladder in whom the cystic duct would be overlapped by a cSEMS were excluded. INTERVENTIONS Patients (N = 112) were randomized to receive multiple plastic stents or a single cSEMS, stratified by stricture etiology and with endoscopic reassessment for resolution every 3 months (plastic stents) or every 6 months (cSEMS). Patients were followed up for 12 months after stricture resolution to assess for recurrence. MAIN OUTCOMES AND MEASURES Primary outcome was stricture resolution after no more than 12 months of endoscopic therapy. The sample size was estimated based on the noninferiority of cSEMS to plastic stents, with a noninferiority margin of −15%. RESULTS There were 55 patients in the plastic stent group (mean [SD] age, 57 [11] years; 17 women [31%]) and 57 patients in the cSEMS group (mean [SD] age, 55 [10] years; 19 women [33%]). Compared with plastic stents (41/48, 85.4%), the cSEMS resolution rate was 50 of 54 patients (92.6%), with a rate difference of 7.2% (1-sided 95% CI, −3.0% to ∞; P stents was rejected. The mean number of ERCPs to achieve resolution

Smart film actuators using biomass plastic

International Nuclear Information System (INIS)

Yoneyama, Satoshi; Tanaka, Nobuo

2011-01-01

This paper presents a novel smart film actuator based on the use of a biomass plastic as a piezoelectric film. Conventional polymeric smart sensors and actuators have been based upon synthetic piezoelectric polymer films such as PVDF. Almost all synthetic polymers are made from nearly depleted oil resources. In addition combustion of their materials releases carbon dioxide, thereby contributing to global warming. Thus at least two important sustainability principles are violated when employing synthetic polymers: avoiding depletable resources and avoiding ecosystem destruction. To overcome such problems, industrial plastic products made from synthetic polymers were developed to replace oil-based plastics with biomass plastics. This paper applies a biomass plastic with piezoelectricity such as poly-L-lactic acid (PLLA). As a result, PLLA film becomes a distributed parameter actuator per se, hence an environmentally conscious smart film actuator is developed. Firstly, this paper overviews the fundamental properties of piezoelectric synthetic polymers and biopolymers. The concept of carbon neutrality using biopolymers is mentioned. Then a two-dimensional modal actuator for exciting a specific structural mode is proposed. Furthermore, a biomass plastic-based cantilever beam with the capability of modal actuation is developed, the validity of the proposed smart film actuator based upon a biomass plastic being analytically as well as experimentally verified

Finding the missing plastic -resolving the global mass (im)balance for plastic pollution in the ocean

Science.gov (United States)

Wilcox, C.; van Sebille, E.

2016-02-01

Several global studies have attempted to estimate the standing stock of plastic debris in the oceans at the global scale. However, recent work estimating the amount lost from land on an annual basis suggests that the standing stock should be several orders of magnitude larger than the global estimates. We investigate the role of coastal deposition within the first few weeks after plastic enters the ocean and very near its sources, one of the hypothesized sinks for the missing plastic in this mass balance. We utilize a continental scale dataset of plastics collected along Australia's coast and in the offshore regions together with models of plastic release and transport based on Lagrangian tracking to investigate the role of local deposition in the coastal environment. Our models predict that the vast majority of positively buoyant plastic is deposited within a very short distance from its release point, with only a small fraction escaping into the open ocean. These predictions match our coastal and offshore observations, providing clear evidence that this mechanism of immediate coastal deposition is, at least in part, driving the apparent mismatch between coastal emissions and the standing stock in the ocean.

Long-term sorption of metals is similar among plastic types: implications for plastic debris in aquatic environments.

Directory of Open Access Journals (Sweden)

Chelsea M Rochman

Full Text Available Concerns regarding plastic debris and its ability to accumulate large concentrations of priority pollutants in the aquatic environment led us to quantify relationships between different types of mass-produced plastic and metals in seawater. At three locations in San Diego Bay, we measured the accumulation of nine targeted metals (aluminum, chromium, manganese, iron, cobalt, nickel, zinc, cadmium and lead sampling at 1, 3, 6, 9 and 12 months, to five plastic types: polyethylene terephthalate (PET, high-density polyethylene (HDPE, polyvinyl chloride (PVC, low-density polyethylene (LDPE, and polypropylene (PP. Accumulation patterns were not consistent over space and time, and in general all types of plastic tended to accumulate similar concentrations of metals. When we did observe significant differences among concentrations of metals at a single sampling period or location in San Diego Bay, we found that HDPE typically accumulated lesser concentrations of metals than the other four polymers. Furthermore, over the 12-month study period, concentrations of all metals increased over time, and chromium, manganese, cobalt, nickel, zinc and lead did not reach saturation on at least one plastic type during the entire 12-month exposure. This suggests that plastic debris may accumulate greater concentrations of metals the longer it remains at sea. Overall, our work shows that a complex mixture of metals, including those listed as priority pollutants by the US EPA (Cd, Ni, Zn and Pb, can be found on plastic debris composed of various plastic types.

Long-term sorption of metals is similar among plastic types: implications for plastic debris in aquatic environments.

Science.gov (United States)

Rochman, Chelsea M; Hentschel, Brian T; Teh, Swee J

2014-01-01

Concerns regarding plastic debris and its ability to accumulate large concentrations of priority pollutants in the aquatic environment led us to quantify relationships between different types of mass-produced plastic and metals in seawater. At three locations in San Diego Bay, we measured the accumulation of nine targeted metals (aluminum, chromium, manganese, iron, cobalt, nickel, zinc, cadmium and lead) sampling at 1, 3, 6, 9 and 12 months, to five plastic types: polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), and polypropylene (PP). Accumulation patterns were not consistent over space and time, and in general all types of plastic tended to accumulate similar concentrations of metals. When we did observe significant differences among concentrations of metals at a single sampling period or location in San Diego Bay, we found that HDPE typically accumulated lesser concentrations of metals than the other four polymers. Furthermore, over the 12-month study period, concentrations of all metals increased over time, and chromium, manganese, cobalt, nickel, zinc and lead did not reach saturation on at least one plastic type during the entire 12-month exposure. This suggests that plastic debris may accumulate greater concentrations of metals the longer it remains at sea. Overall, our work shows that a complex mixture of metals, including those listed as priority pollutants by the US EPA (Cd, Ni, Zn and Pb), can be found on plastic debris composed of various plastic types.

Plastics recycling: challenges and opportunities

OpenAIRE

Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

2009-01-01

Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to pro...

ARE PLASTIC GROCERY BAGS SACKING THE ENVIRONMENT?

OpenAIRE

Mangal Gogte

2009-01-01

This paper is oriented on analysis impacts of plastic bags on environment. In this paper is analyzed did plastic bags are so harmful, and what are the main ingredients of it. One part of this paper is oriented on effects of plastic bags and management of their usage. There is also made comparative analysis between impacts of plastic and paper bags on environment.

Plastic surgery and global health: how plastic surgery impacts the global burden of surgical disease.

Science.gov (United States)

Semer, Nadine B; Sullivan, Stephen R; Meara, John G

2010-08-01

The global burden of surgical disease is estimated as being 11% of the total global burden of disease. In this article we discuss the portion of this burden which could be ameliorated with plastic surgical expertise. Although not necessarily seen as a major player in issues related to global health, plastic surgeons are uniquely qualified to decrease the burden of surgical disease afflicting people in the developing world. Burns, traumatic injuries, and congenital anomalies are some of the areas where the presence of plastic surgical expertise can make a significant difference in patient outcomes and thereby decrease the years of life lost due to disability due to these highly treatable conditions. In light of the severe shortage of plastic surgeons throughout the developing world, it falls to those concentrated in the developed world to harness their skills and address the vast unmet needs of the developing world so as to enhance global health. Copyright 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Translation-rotation plasticity as basic mechanism of plastic deformation in macro-, micro- and nanoindentation processes

International Nuclear Information System (INIS)

Grabco, D; Shikimaka, O; Harea, E

2008-01-01

This paper presents a brief review of multilateral examinations for the purpose of detection of interrelation between processes occuring in solids at different levels of action of exterior loading, namely, at macro-, micro- and nanoindentation. Convincing arguments supporting the rotation deformation mechanism alongside the recognized dislocation one are adduced. It has been shown that the decrease in dislocation mobility leads at all scales to the intensification of rotation plasticity and to the involvement of other plastic deformation mechanisms, such as appearance and interaction of disclinations, twinning, phase transition and compression of material. The conversion from translation plasticity to the rotation-translation one means transition to the higher level of plastic deformation, the mesolevel, when the possibilities of the previous microscopic level are exhausted. It was established that the plastic deformation zone in the vicinity of indentations could be separated into two main specific regions: (i) peripheral region predominantly with the dislocation deformation mechanism; otherwise, translation mechanism: microlevel, and (ii) quasidestructured region mainly with the disclination or the intergranular sliding mechanism: rotation mechanism, mesolevel

Use of recycled plastics in concrete: A critical review.

Science.gov (United States)

Gu, Lei; Ozbakkaloglu, Togay

2016-05-01

Plastics have become an essential part of our modern lifestyle, and the global plastic production has increased immensely during the past 50years. This has contributed greatly to the production of plastic-related waste. Reuse of waste and recycled plastic materials in concrete mix as an environmental friendly construction material has drawn attention of researchers in recent times, and a large number of studies reporting the behavior of concrete containing waste and recycled plastic materials have been published. This paper summarizes the current published literature until 2015, discussing the material properties and recycling methods of plastic and the influence of plastic materials on the properties of concrete. To provide a comprehensive review, a total of 84 studies were considered, and they were classified into sub categories based on whether they dealt with concrete containing plastic aggregates or plastic fibers. Furthermore, the morphology of concrete containing plastic materials is described in this paper to explain the influence of plastic aggregates and plastic fibers on the properties of concrete. The properties of concretes containing virgin plastic materials were also reviewed to establish their similarities and differences with concrete containing recycled plastics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Plasticized chitosan/polyolefin films produced by extrusion.

Science.gov (United States)

Matet, Marie; Heuzey, Marie-Claude; Ajji, Abdellah; Sarazin, Pierre

2015-03-06

Plasticized chitosan and polyethylene blends were produced through a single-pass extrusion process. Using a twin-screw extruder, chitosan plasticization was achieved in the presence of an acetic acid solution and glycerol, and directly mixed with metallocene polyethylene, mPE, to produce a masterbatch. Different dilutions of the masterbatch (2, 5 and 10 wt% of plasticized chitosan), in the presence of ethylene vinyl acetate, EVA, were subsequently achieved in single screw film extrusion. Very small plasticized chitosan domains (number average diameter <5 μm) were visible in the polymeric matrix. The resulting films presented a brown color and increasing haze with chitosan plasticized content. Mechanical properties of the mPE films were affected by the presence of plasticized chitosan, but improvement was observed as a result of some compatibility between mPE and chitosan in the presence of EVA. Finally the incorporation of plasticized chitosan affected mPE water vapor permeability while oxygen permeability remained constant. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rigid-Plastic Approximations for Predicting Plastic Deformation of Cylindrical Shells Subject to Dynamic Loading

Directory of Open Access Journals (Sweden)

Michelle S. Hoo Fatt

1996-01-01

Full Text Available A theoretical approach was developed for predicting the plastic deformation of a cylindrical shell subject to asymmetric dynamic loads. The plastic deformation of the leading generator of the shell is found by solving for the transverse deflections of a rigid-plastic beam/string-on-foundation. The axial bending moment and tensile force in the beam/string are equivalent to the longitudinal bending moments and membrane forces of the shell, while the plastic foundation force is equivalent to the shell circumferential bending moment and membrane resistances. Closed-form solutions for the transient and final deformation profile of an impulsive loaded shell when it is in a “string” state were derived using the eigenfunction expansion method. These results were compared to DYNA 3D predictions. The analytical predictions of the transient shell and final centerline deflections were within 25% of the DYNA 3D results.

Leaching of plastic additives to marine organisms

International Nuclear Information System (INIS)

Koelmans, Albert A.; Besseling, Ellen; Foekema, Edwin M.

2014-01-01

It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of Arenicola marina (lugworm) and Gadus morhua (North Sea cod). We use a biodynamic model that allows calculations of the relative contribution of plastic ingestion to total exposure of aquatic species to chemicals residing in the ingested plastic. Uncertainty in the most crucial parameters is accounted for by probabilistic modeling. Our conservative analysis shows that plastic ingestion by the lugworm yields NP and BPA concentrations that stay below the lower ends of global NP and BPA concentration ranges, and therefore are not likely to constitute a relevant exposure pathway. For cod, plastic ingestion appears to be a negligible pathway for exposure to NP and BPA. - Highlights: • Uptake of plastic additives after plastic ingestion was modeled for worms and fish. • This was done for bisphenol A and nonylphenol. • Uncertainty was accounted for by Monte Carlo simulations. • It appeared that exposure by plastic ingestion was negligible for fish. • Plastic ingestion may occasionally be relevant for marine worms. - Leaching of nonylphenol and bisphenol A from ingested microplastic may be relevant for the lugworm, but is irrelevant for fish like cod

When three traits make a line: evolution of phenotypic plasticity and genetic assimilation through linear reaction norms in stochastic environments.

Science.gov (United States)

Ergon, T; Ergon, R

2017-03-01

Genetic assimilation emerges from selection on phenotypic plasticity. Yet, commonly used quantitative genetics models of linear reaction norms considering intercept and slope as traits do not mimic the full process of genetic assimilation. We argue that intercept-slope reaction norm models are insufficient representations of genetic effects on linear reaction norms and that considering reaction norm intercept as a trait is unfortunate because the definition of this trait relates to a specific environmental value (zero) and confounds genetic effects on reaction norm elevation with genetic effects on environmental perception. Instead, we suggest a model with three traits representing genetic effects that, respectively, (i) are independent of the environment, (ii) alter the sensitivity of the phenotype to the environment and (iii) determine how the organism perceives the environment. The model predicts that, given sufficient additive genetic variation in environmental perception, the environmental value at which reaction norms tend to cross will respond rapidly to selection after an abrupt environmental change, and eventually becomes equal to the new mean environment. This readjustment of the zone of canalization becomes completed without changes in genetic correlations, genetic drift or imposing any fitness costs of maintaining plasticity. The asymptotic evolutionary outcome of this three-trait linear reaction norm generally entails a lower degree of phenotypic plasticity than the two-trait model, and maximum expected fitness does not occur at the mean trait values in the population. © 2016 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

Plastics and environmental health: the road ahead.

Science.gov (United States)

North, Emily J; Halden, Rolf U

2013-01-01

Plastics continue to benefit society in innumerable ways, even though recent public focus on plastics has centered mostly on human health and environmental concerns, including their endocrine-disrupting properties and the long-term pollution they represent. The benefits of plastics are particularly apparent in medicine and public health. Plastics are versatile, cost-effective, require less energy to produce than alternative materials like metal or glass, and can be manufactured to have many different properties. Due to these characteristics, polymers are used in diverse health applications like disposable syringes and intravenous bags, sterile packaging for medical instruments as well as in joint replacements, tissue engineering, etc. However, not all current uses of plastics are prudent and sustainable, as illustrated by the widespread, unwanted human exposure to endocrine-disrupting bisphenol A (BPA) and di-(2-ethylhexyl)phthalate (DEHP), problems arising from the large quantities of plastic being disposed of, and depletion of non-renewable petroleum resources as a result of the ever-increasing mass production of plastic consumer articles. Using the health-care sector as example, this review concentrates on the benefits and downsides of plastics and identifies opportunities to change the composition and disposal practices of these invaluable polymers for a more sustainable future consumption. It highlights ongoing efforts to phase out DEHP and BPA in the health-care and food industry and discusses biodegradable options for plastic packaging, opportunities for reducing plastic medical waste, and recycling in medical facilities in the quest to reap a maximum of benefits from polymers without compromising human health or the environment in the process.

Plastics and Environmental Health: The Road Ahead

Science.gov (United States)

North, Emily J.; Halden, Rolf U.

2013-01-01

Plastics continue to benefit society in innumerable ways, even though recent public focus on plastics has centered mostly on human health and environmental concerns, including endocrine-disrupting properties and long-term pollution. The benefits of plastics are particularly apparent in medicine and public health. Plastics are versatile, cost-effective, require less energy to produce than alternative materials – such as metal or glass – and can be manufactured to have many different properties. Due to these characteristics, polymers are used in diverse health applications, such as disposable syringes and intravenous bags, sterile packaging for medical instruments as well as in joint replacements, tissue engineering, etc. However, not all current uses of plastics are prudent and sustainable, as illustrated by widespread, unwanted human exposure to endocrine-disrupting bisphenol-A (BPA) and di-(2-ethylhexyl)phthalate (DEHP), problems arising from the large quantities of plastic being disposed of, and depletion of non-renewable petroleum resources as a result of ever increasing mass-production of plastic consumer articles. By example of the healthcare sector, this review concentrates on benefits and downsides of plastics and identities opportunities to change the composition and disposal practices of these invaluable polymers for a more sustainable future consumption. It highlights ongoing efforts to phase out DEHP and BPA in the healthcare and food industry, and discusses biodegradable options for plastic packaging, opportunities for reducing plastic medical waste, and recycling in medical facilities in the quest to reap a maximum of benefits from polymers without compromising human health or the environment in the process. PMID:23337043

ARE PLASTIC GROCERY BAGS SACKING THE ENVIRONMENT?

Directory of Open Access Journals (Sweden)

Mangal Gogte

2009-12-01

Full Text Available This paper is oriented on analysis impacts of plastic bags on environment. In this paper is analyzed did plastic bags are so harmful, and what are the main ingredients of it. One part of this paper is oriented on effects of plastic bags and management of their usage. There is also made comparative analysis between impacts of plastic and paper bags on environment.

Motor cortical plasticity in Parkinson’s disease

Directory of Open Access Journals (Sweden)

Kaviraja eUdupa

2013-09-01

Full Text Available In Parkinson’s disease (PD, there are alterations of the basal ganglia (BG thalamo-cortical networks, primarily due to degeneration of nigrostrial dopaminergic neurons. These changes in subcortical networks lead to plastic changes in primary motor cortex (M1, which mediates cortical motor output and is a potential target for treatment of PD. Studies investigating the motor cortical plasticity using non-invasive transcranial magnetic stimulation (TMS have found altered plasticity in PD, but there are inconsistencies among these studies. This is likely because plasticity depends on many factors such as the extent of dopaminergic loss and disease severity, response to dopaminergic replacement therapies, development of L-dopa-induced dyskinesias (LID, the plasticity protocol used, medication and stimulation status in patients treated with deep brain stimulation (DBS. The influences of LID and DBS on BG and M1 plasticity have been explored in animal models and in PD patients. In addition, many other factors such age, genetic factors (e.g. brain derived neurotropic factor and other neurotransmitters or receptors polymorphism, emotional state, time of the day, physical fitness have been documented to play role in the extent of plasticity induced by TMS in human studies. In this review, we summarize the studies that investigated M1 plasticity in PD and demonstrate how these afore-mentioned factors affect motor cortical plasticity in PD. We conclude that it is important to consider the clinical, demographic and technical factors that influence various plasticity protocols while developing these protocols as diagnostic or prognostic tools in PD. We also discuss how the modulation of cortical excitability and the plasticity with these non-invasive brain stimulation techniques facilitate the understanding of the pathophysiology of PD and help design potential therapeutic possibilities in this disorder.

Managing plastic waste in East Africa: Niche innovations in plastic production and solid waste

NARCIS (Netherlands)

Ombis, L.O.; Vliet, van B.J.M.; Mol, A.P.J.

2015-01-01

This paper assesses the uptake of environmental innovation practices to cope with plastic waste in Kenyan urban centres at the interface of solid waste management and plastic production systems. The Multi Level Perspective on Technological Transitions is used to evaluate 7 innovation pathways of

Catherine Malabou’s Hegel: One or several plasticities?

Directory of Open Access Journals (Sweden)

Moder Gregor

2015-01-01

Full Text Available Through an original and extraordinarily fruitful reading of the Hegelian conception of negativity, Catherine Malabou developed the concept of plasticity which she keeps working on as one of her cardinal concepts even to this day. Engaging in the problematic of unity in Hegel, the paper takes on the task of trying to answer the question whether plasticity is one or are there several plasticities. The author argues that one must be careful not to reduce the inherent multiple of plasticity to a single plasticity which becomes plasticity par excellence: the plasticity of plastic explosion, of an abrupt and absolute break, to be distinguished from a creative or productive plasticity of habit. Malabou claimed that Hegel was - contrary to what Deleuz read in him - a philosopher of conceptual multitude as a multitude which cannot be reduced to only one image, the image of unity. If this is true, then the concept of plasticity itself with which she grasped the essence of Hegel’s dialectics, should be understood at least as a “unity in conflict”, if not as an inorganic, inhomogeneous, composed unity - and perhaps even as a unity of the pack.

Degradation of plastic carrier bags in the marine environment

International Nuclear Information System (INIS)

O'Brine, Tim; Thompson, Richard C.

2010-01-01

Research highlights: → There is considerable concern about the hazards that plastic debris presents to wildlife. → Here we investigate breakdown of oxodegradable, compostable and conventional plastic bags. → Compostable plastic disappeared from our test rig between 16 and 24 weeks. → Approximately 98% of the other plastics remained after 40 weeks. → Fouling by marine organisms substantially reduced the amount of UV-light reaching the plastic. - Abstract: There is considerable concern about the hazards that plastic debris presents to wildlife. Use of polymers that degrade more quickly than conventional plastics presents a possible solution to this problem. Here we investigate breakdown of two oxo-biodegradable plastics, compostable plastic and standard polyethylene in the marine environment. Tensile strength of all materials decreased during exposure, but at different rates. Compostable plastic disappeared from our test rig between 16 and 24 weeks whereas approximately 98% of the other plastics remained after 40 weeks. Some plastics require UV light to degrade. Transmittance of UV through oxo-biodegradable and standard polyethylene decreased as a consequence of fouling such that these materials received ∼90% less UV light after 40 weeks. Our data indicate that compostable plastics may degrade relatively quickly compared to oxo-biodegradable and conventional plastics. While degradable polymers offer waste management solutions, there are limitations to their effectiveness in reducing hazards associated with plastic debris.

Dictionary of plastics. 7. rev. ed. Kunststoff-Lexikon

Energy Technology Data Exchange (ETDEWEB)

Stoeckhert, K [ed.

1981-01-01

The book starts with a list of about 400 acronyms for plastic materials and additives, caoutchouc types, and synthetic fibers. This is followed by a 500-page glossary of plastics and a 200-page appendix listing producers of plastic feedstocks, chemical substances and additives, recoverable materials, processing systems, semi-finished plastic products and end products, machinery, tools and further aids for plastics processing. (HK).

A METHOD OF RAPID CULTIVATION OF RADISH SEED PLANTS IN PLASTIC POTS OF SMALL-VOLUME

Directory of Open Access Journals (Sweden)

V. A. Stepanov

2017-01-01

Full Text Available The development of cheap and rapid breeding methods to breed  the lines used for  hybrid  F1  production  is a very actual task. The study was carried out with a use of radish varieties originated at VNIISSOK and breeding lines obtained by crossing components of different origin with male  sterility  in  winter  glass  greenhouse.  The  mother plants were grown  on the trays Plantec 64, while seedplants were grown in plastic pots of 1 liter capacity. The some morphobiological features such as the small habitus of see-plant; smaller number of secondary branching and absence of following branches; and consequently, the low yield of seeds were revealed in seed-plants of radish being grown in plastic pots. The period of ontogenesis in radish at first winter-spring rotation with this cultivation approach was reduced to 92 days. At the second summer-autumn rotation with additional lighting the duration of period of ontogenesis was essentially shorter than in the first rotation.  The utilization of  small-volume capacities in winter glass greenhouse to grow the radish seed-plants has permitted to produce two generations a year.

Analysis of a ceramic filled bio-plastic composite sandwich structure

International Nuclear Information System (INIS)

Habib Ullah, M.; Islam, M. T.

2013-01-01

Design and analysis of a ceramic-filled bio-plastic composite sandwich structure is presented. This proposed high-dielectric structure is used as a substrate for patch antennas. A meandered-strip line-fed fractal-shape patch antenna is designed and fabricated on a copper-laminated sandwich-structured substrate. Measurement results of this antenna show 44% and 20% of bandwidths with maximum gains of 3.45 dBi and 5.87 dBi for the lower and upper bands, respectively. The half-power beam widths of 104° and 78° have been observed from the measured radiation pattern at the two resonance frequencies 0.9 GHz and 2.5 GHz

Analysis of a ceramic filled bio-plastic composite sandwich structure

Energy Technology Data Exchange (ETDEWEB)

Habib Ullah, M. [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia); Department of Electrical, Electronic and System Engineering, Universiti Kebangsaan Malaysia, Bangi 43600 (Malaysia); Islam, M. T. [Institute of Space Science (ANGKASA), Universiti Kebangsaan Malaysia, Bangi Selangor 43600 (Malaysia)

2013-11-25

Design and analysis of a ceramic-filled bio-plastic composite sandwich structure is presented. This proposed high-dielectric structure is used as a substrate for patch antennas. A meandered-strip line-fed fractal-shape patch antenna is designed and fabricated on a copper-laminated sandwich-structured substrate. Measurement results of this antenna show 44% and 20% of bandwidths with maximum gains of 3.45 dBi and 5.87 dBi for the lower and upper bands, respectively. The half-power beam widths of 104° and 78° have been observed from the measured radiation pattern at the two resonance frequencies 0.9 GHz and 2.5 GHz.

Neurogenomic mechanisms of social plasticity.

Science.gov (United States)

Cardoso, Sara D; Teles, Magda C; Oliveira, Rui F

2015-01-01

Group-living animals must adjust the expression of their social behaviour to changes in their social environment and to transitions between life-history stages, and this social plasticity can be seen as an adaptive trait that can be under positive selection when changes in the environment outpace the rate of genetic evolutionary change. Here, we propose a conceptual framework for understanding the neuromolecular mechanisms of social plasticity. According to this framework, social plasticity is achieved by rewiring or by biochemically switching nodes of a neural network underlying social behaviour in response to perceived social information. Therefore, at the molecular level, it depends on the social regulation of gene expression, so that different genomic and epigenetic states of this brain network correspond to different behavioural states, and the switches between states are orchestrated by signalling pathways that interface the social environment and the genotype. Different types of social plasticity can be recognized based on the observed patterns of inter- versus intra-individual occurrence, time scale and reversibility. It is proposed that these different types of social plasticity rely on different proximate mechanisms at the physiological, neural and genomic level. © 2015. Published by The Company of Biologists Ltd.

Special transfer lines for the spallation neutron source

International Nuclear Information System (INIS)

Lucas, A.T.; Schippl, K.

1986-01-01

Special transfer lines were required to transport supercritical hydrogen gas at 20 0 K and 1.5 MPa and liquid methane at 800 0 K and 0.4 MPa over a distance of about 18 m, to moderator vessels sited within a concrete shielded area. The moderator vessels (1 L and 1/2 L volume respectively) are built into shielding material surrounding the uranium target which produces high energy pulsed neutrons. Energies up to 400 W can be deposited in the cryogenic fluid, which the control system must be capable of handling within less than one minute. The flow rates were designed to be 500 cm 3 /sec for hydrogen and 220 cms 3 /sec for methane. In order to maintain biological shielding integrity the lines had to be as compact in cross section as possible, and replacable using remote handling techniques. As commonly used plastic materials could not be used for spacers etc, on account of their poor radiation resistance, new techniques had to be developed to meet the long term requirements of the lines

Charge carrier dynamics in PMMA-LiClO4 based polymer electrolytes plasticized with different plasticizers

Science.gov (United States)

Pal, P.; Ghosh, A.

2017-07-01

We have studied the charge carrier dynamics in poly(methylmethacrylate)-LiClO4 polymer electrolytes plasticized with different plasticizers such as ethylene carbonate (EC), propylene carbonate (PC), polyethylene glycol (PEG), and dimethyl carbonate (DMC). We have measured the broadband complex conductivity spectra of these electrolytes in the frequency range of 0.01 Hz-3 GHz and in the temperature range of 203 K-363 K and analyzed the conductivity spectra in the framework of the random barrier model by taking into account the contribution of the electrode polarization observed at low frequencies and/or at high temperatures. It is observed that the temperature dependences of the ionic conductivity and relaxation time follow the Vogel-Tammann-Fulcher relation for all plasticized electrolytes. We have also performed the scaling of the conductivity spectra, which indicates that the charge carrier dynamics is almost independent of temperature and plasticizers in a limited frequency range. The existence of nearly constant loss in these electrolytes has been observed at low temperatures and/or high frequencies. We have studied the dielectric relaxation in these electrolytes using electric modulus formalism and obtained the stretched exponent and the decay function. We have observed less cooperative ion dynamics in electrolytes plasticized with DMC compared to electrolytes plasticized with EC, PC, and PEG.

UTILIZATION OF WASTE PLASTIC BOTTLES IN ASPHALT MIXTURE

Directory of Open Access Journals (Sweden)

TAHER BAGHAEE MOGHADDAM

2013-06-01

Full Text Available Nowadays, large amounts of waste materials are being produced in the world. One of the waste materials is plastic bottle. Generating disposable plastic bottles is becoming a major problem in many countries. Using waste plastic as a secondary material in construction projects would be a solution to overcome the crisis of producing large amount of waste plastics in one hand and improving the structure’s characteristics such as resistance against cracking on the other hand. This study aimed to investigate the effects of adding plastic bottles in road pavement. Marshall properties as well as specific gravity of asphalt mixture containing different percentages of plastic bottles were evaluated. Besides, Optimum Asphalt Content (OAC was calculated for each percentages of plastic bottles used in the mix. The stiffness and fatigue characteristics of mixture were assessed at OAC value. Results showed that the stability and flow values of asphalt mixture increased by adding waste crushed plastic bottle into the asphalt mixture. Further, it was shown that the bulk specific gravity and stiffness of mixtures increased by adding lower amount of plastic bottles; however, adding higher amounts of plastic resulted in lower specific gravity and mix stiffness. In addition, it was concluded that the mixtures containing waste plastic bottles have lower OAC values compared to the conventional mixture, and this may reduce the amount of asphalt binder can be used in road construction projects. Besides, the mixtures containing waste plastic showed significantly greater fatigue resistance than the conventional mixture.

77 FR 14729 - Certain Lined Paper Products From India: Notice of Final Results of Antidumping Duty...

Science.gov (United States)

2012-03-13

... covers, primarily suited for the recording of written numerical business data; Lined business or office... polyolefin plastic material joined by 300 denier polyester, coated on the backside with PVC (poly vinyl... Records Unit, main Commerce Building, Room 7046. In addition, a complete version of the Issues and...

Behavioral Response to Plastic Bag Legislation in Botswana

OpenAIRE

Dikgang, Johane; Visser, Martine

2010-01-01

This paper investigates the use of charges and standards in dealing with a common externality, plastic litter from shopping bags in Botswana. The country passed a plastic bag tax (effective 2007) to curb the plastic bag demand. Interestingly, the legislation did not force retailers to charge for plastic bags, which they did voluntarily at different prices. We assessed the environmental effectiveness and efficiency of the plastic bag legislation by analyzing consumers’ sensitivity to the impro...

PENGARUH PLASTICIZER PADA KARAKTERISTIK EDIBLE FILM DARI PEKTIN

Directory of Open Access Journals (Sweden)

Sang Kompiang Wirawan

2012-05-01

Full Text Available EFFECT OF PLASTICIzER ON THE PECTINIC EDIBLE FILM CHARACTERISTICS. The peel of Balinese Citrus contains high concentration of pectin which can be further processed to be edible films. The edible films can be utilized as a food coating which protects the food from any external mass transports such as humid, oxygen, and soluble material and can be served as a carrier to improve the mechanical-handing properties of the food. Edible films made of organic polymers tend to be brittle and thus addition of a plasticizer is required during the process. The work studies the effect of the type and the concentration of plasticizers on the tensile strength, the elongation of break, and the water vapor permeabilty of the edible film. Sorbitol and glycerol were used as plasticizers. Albedo from the citrus was hydrolized with hydrochloride acid 0.1 N to get pectinate substance. Pectin was then dissolved in water dan mixed with the plasticizers and CaCl2.2H2O solution. The concentrations of the plasticizers were 0, 0.03, 0.05, 0.1, and 0.15 mL/mL of solution. The results showed that increasing the concentration of plasticizers will decrease the tensile strength, but increase the elongation and film permeability. Sorbitol-plasticized films are more brittle, however exhibited higher tensile strength and water vapor permeability than of glycerol-plasticized film. The results suggested that glycerol is better plasticizer than sorbitol.  Kulit jeruk bali banyak mengandung pektin yang dapat dimanfaatkan sebagai bahan baku edible film. Edible film bisa digunakan untuk melapisi bahan makanan, melindungi makanan dari transfer massa eksternal seperti kelembaban, oksigen, dan zat terlarut, serta dapat digunakan sebagai carrier untuk meningkatkan penanganan mekanik produk makanan. Film yang terbuat dari bahan polimer organik ini cenderung rapuh sehingga diperlukan penambahan plasticizer. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh kadar dan jenis

Plastic waste associated with disease on coral reefs.

Science.gov (United States)

Lamb, Joleah B; Willis, Bette L; Fiorenza, Evan A; Couch, Courtney S; Howard, Robert; Rader, Douglas N; True, James D; Kelly, Lisa A; Ahmad, Awaludinnoer; Jompa, Jamaluddin; Harvell, C Drew

2018-01-26

Plastic waste can promote microbial colonization by pathogens implicated in outbreaks of disease in the ocean. We assessed the influence of plastic waste on disease risk in 124,000 reef-building corals from 159 reefs in the Asia-Pacific region. The likelihood of disease increases from 4% to 89% when corals are in contact with plastic. Structurally complex corals are eight times more likely to be affected by plastic, suggesting that microhabitats for reef-associated organisms and valuable fisheries will be disproportionately affected. Plastic levels on coral reefs correspond to estimates of terrestrial mismanaged plastic waste entering the ocean. We estimate that 11.1 billion plastic items are entangled on coral reefs across the Asia-Pacific and project this number to increase 40% by 2025. Plastic waste management is critical for reducing diseases that threaten ecosystem health and human livelihoods. Copyright © 2018, The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Can plastic mulching replace irrigation in dryland agriculture?

Science.gov (United States)

Wang, L.; Daryanto, S.; Jacinthe, P. A.

2017-12-01

Increasing water use efficiency (WUE) is a key strategy to maintaining crops yield without over-exploiting the scarce water resource. Plastic mulching technology for wheat and maize has been commonly used in China, but their effect on yield, soil moisture, evapotranspiration (ET), and WUE has not been compared with traditional irrigation method. Using a meta-analysis approach, we quantitatively examined the efficacy of plastic mulching in comparison with traditional irrigation in dryland agriculture. Our results showed that plastic mulching technique resulted in yield increase comparable to irrigated crops but used 24% less water. By covering the ridges with plastic and channeling rainwater into a very narrow planting zone (furrow), plastic mulching increased WUE and available soil moisture. Higher WUE in plastic-mulched croplands was likely a result of greater proportion of available water being used for transpiration than evaporation. If problems related to production costs and residual plastic pollution could be managed, plastic mulching technology would become a promising strategy for dryland farming in other regions.

Seabirds, gyres and global trends in plastic pollution.

Science.gov (United States)

van Franeker, Jan A; Law, Kara Lavender

2015-08-01

Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters. Since the 1980s, pre-production plastic pellets in North Sea fulmars have decreased by ∼75%, while user plastics varied without a strong overall change. Similar trends were found in net-collected floating plastic debris in the North Atlantic subtropical gyre, with a ∼75% decrease in plastic pellets and no obvious trend in user plastic. The decreases in pellets suggest that changes in litter input are rapidly visible in the environment not only close to presumed sources, but also far from land. Floating plastic debris is rapidly "lost" from the ocean surface to other as-yet undetermined sinks in the marine environment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Linking plastic ingestion research with marine wildlife conservation.

Science.gov (United States)

Avery-Gomm, Stephanie; Borrelle, Stephanie B; Provencher, Jennifer F

2018-05-16

Plastic is an increasingly pervasive marine pollutant. Concomitantly, the number of studies documenting plastic ingestion in wildlife is accelerating. Many of these studies aim to provide a baseline against which future levels of plastic ingestion can be compared, and are motivated by an underlying interest in the conservation of their study species and ecosystems. Although this research has helped to raise the profile of plastic as a pollutant of emerging concern, there is a disconnect between research examining plastic pollution and wildlife conservation. We present ideas to further discussion about how plastic ingestion research could benefit wildlife conservation by prioritising studies that elucidates the significance of plastic pollution as a population-level threat, identifies vulnerable populations, and evaluates strategies for mitigating impacts. The benefit of plastic ingestion research to marine wildlife can be improved by establishing a clearer understanding of how discoveries will be integrated into conservation and policy actions. Copyright © 2018. Published by Elsevier B.V.

Adaptive transgenerational plasticity in an annual plant: grandparental and parental drought stress enhance performance of seedlings in dry soil.

Science.gov (United States)

Herman, Jacob J; Sultan, Sonia E; Horgan-Kobelski, Tim; Riggs, Charlotte

2012-07-01

Stressful parental (usually maternal) environments can dramatically influence expression of traits in offspring, in some cases resulting in phenotypes that are adaptive to the inducing stress. The ecological and evolutionary impact of such transgenerational plasticity depends on both its persistence across generations and its adaptive value. Few studies have examined both aspects of transgenerational plasticity within a given system. Here we report the results of a growth-chamber study of adaptive transgenerational plasticity across two generations, using the widespread annual plant Polygonum persicaria as a naturally evolved model system. We grew five inbred Polygonum genetic lines in controlled dry vs. moist soil environments for two generations in a fully factorial design, producing replicate individuals of each genetic line with all permutations of grandparental and parental environment. We then measured the effects of these two-generational stress histories on traits critical for functioning in dry soil, in a third (grandchild) generation of seedling offspring raised in the dry treatment. Both grandparental and parental moisture environment significantly influenced seedling development: seedlings of drought-stressed grandparents or parents produced longer root systems that extended deeper and faster into dry soil compared with seedlings of the same genetic lines whose grandparents and/or parents had been amply watered. Offspring of stressed individuals also grew to a greater biomass than offspring of nonstressed parents and grandparents. Importantly, the effects of drought were cumulative over the course of two generations: when both grandparents and parents were drought-stressed, offspring had the greatest provisioning, germinated earliest, and developed into the largest seedlings with the most extensive root systems. Along with these functionally appropriate developmental effects, seedlings produced after two previous drought-stressed generations had

Studies of elastic-plastic instabilities

DEFF Research Database (Denmark)

Tvergaard, Viggo

1999-01-01

Analyses of plastic instabilities are reviewed, with focus on results in structural mechanics as well as continuum mechanics. First the basic theories for bifurcation and post-bifurcation behavior are briefly presented. Then, localization of plastic flow is discussed, including shear band formati...

Neuromodulation, development and synaptic plasticity.

Science.gov (United States)

Foehring, R C; Lorenzon, N M

1999-03-01

We discuss parallels in the mechanisms underlying use-dependent synaptic plasticity during development and long-term potentiation (LTP) and long-term depression (LTD) in neocortical synapses. Neuromodulators, such as norepinephrine, serotonin, and acetylcholine have also been implicated in regulating both developmental plasticity and LTP/LTD. There are many potential levels of interaction between neuromodulators and plasticity. Ion channels are substrates for modulation in many cell types. We discuss examples of modulation of voltage-gated Ca2+ channels and Ca(2+)-dependent K+ channels and the consequences for neocortical pyramidal cell firing behaviour. At the time when developmental plasticity is most evident in rat cortex, the substrate for modulation is changing as the densities and relative proportions of various ion channels types are altered during ontogeny. We discuss examples of changes in K+ and Ca2+ channels and the consequence for modulation of neuronal activity.

Aktau Plastics Plant Explosives Material Report

Energy Technology Data Exchange (ETDEWEB)

CASE JR.,ROGER S.

1999-12-01

The U.S. Department of Energy (DOE) has been cooperating with the Republic of Kazakhstanin Combined Threat Reduction (CTR) activities at the BN350 reactor located at the Mangyshlak Atomic Energy Complex (MAEC) in the city of Aktau, Kazakhstan since 1994. DOE contract personnel have been stationed at this facility for the last two years and DOE representatives regularly visit this location to oversee the continuing cooperative activities. Continued future cooperation is planned. A Russian news report in September 1999 indicated that 75 metric tons of organic peroxides stored at the Plastics Plant near Aktau were in danger of exploding and killing or injuring nearby residents. To ensure the health and safety of the personnel at the BN350 site, the DOE conducted a study to investigate the potential danger to the BN350 site posed by these materials at the Plastics Plant. The study conclusion was that while the organic peroxides do have hazards associated with them, the BN350 site is a safe distance from the Plastics Plant. Further, because the Plastics Plant and MAEC have cooperative fire-fighting agreements,and the Plastics Plant had exhausted its reserve of fire-fighting foam, there was the possibility of the Plastics Plant depleting the store of fire-fighting foam at the BN350 site. Subsequently, the DOE decided to purchase fire-fighting foam for the Plastics Plant to ensure the availability of free-fighting foam at the BN350 site.

Microbial Enzymatic Degradation of Biodegradable Plastics.

Science.gov (United States)

Roohi; Bano, Kulsoom; Kuddus, Mohammed; Zaheer, Mohammed R; Zia, Qamar; Khan, Mohammed F; Ashraf, Ghulam Md; Gupta, Anamika; Aliev, Gjumrakch

2017-01-01

The renewable feedstock derived biodegradable plastics are important in various industries such as packaging, agricultural, paper coating, garbage bags and biomedical implants. The increasing water and waste pollution due to the available decomposition methods of plastic degradation have led to the emergence of biodegradable plastics and biological degradation with microbial (bacteria and fungi) extracellular enzymes. The microbes utilize biodegradable polymers as the substrate under starvation and in unavailability of microbial nutrients. Microbial enzymatic degradation is suitable from bioremediation point of view as no waste accumulation occurs. It is important to understand the microbial interaction and mechanism involved in the enzymatic degradation of biodegradable plastics under the influence of several environmental factors such as applied pH, thermo-stability, substrate molecular weight and/or complexity. To study the surface erosion of polymer film is another approach for hydrolytic degradation characteristion. The degradation of biopolymer is associated with the production of low molecular weight monomer and generation of carbon dioxide, methane and water molecule. This review reported the degradation study of various existing biodegradable plastics along with the potent degrading microbes (bacteria and fungi). Patents available on plastic biodegradation with biotechnological significance is also summarized in this paper. This paper assesses that new disposal technique should be adopted for the degradation of polymers and further research is required for the economical production of biodegradable plastics along with their enzymatic degradation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Views of college students on plastic surgery.

Science.gov (United States)

Ahmad, Muhammad; Mohmand, Humayun; Ahmad, Nabila

2013-06-01

Various studies have been conducted in many countries to determine the perception/awareness about plastic surgery. The present study assessed the views of college students about plastic surgery. A questionnaire consisted of nine questions regarding the basic knowledge about plastic surgery was randomly distributed among college students. The students were given 20 minutes to fill out the forms. A total of 250 male and 250 female college students were randomly included in the study. The mean age of the male students was 21.1 years as compared to 20.7 years of female students. The top five conditions named were related to hair (89.8%) followed by face scars (88%). The most common procedure named by the students was liposuction (88.2%) followed by hair transplantation. 80.2% of the students opted not to be a plastic surgeon if given an opportunity to select the profession. 33.8% of the students had seen some kinds of plastic surgery operation. Only 5.6% of the students (3.4% male and 2.2% female) had seen some kinds of plastic surgery procedure. 68% of male students and 48% of female students wished to have a plastic surgery procedure sometime in their lives. Majority of the students (88%) got the information from the internet. The second most common source was magazines (85.2%). Majority of the students (53.4%) had an idea of an invisible scar as a result of having a plastic surgery procedure. Only 22% thought to have no scar. Late Michael Jackson was at the top of the list of celebrities having a plastic surgery procedure (97.8%) followed by Nawaz Shariff (92.4%). Despite the rapid growth of plastic surgery in the last two decades, a large portion of population remains unaware of the spatiality. It is essential to institute programs to educate healthcare consumers and providers about the plastic surgery.

River plastic emissions to the world's oceans

Science.gov (United States)

Lebreton, Laurent C. M.; van der Zwet, Joost; Damsteeg, Jan-Willem; Slat, Boyan; Andrady, Anthony; Reisser, Julia

2017-06-01

Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies.

Structural Plasticity Denoises Responses and Improves Learning Speed

Directory of Open Access Journals (Sweden)

Robin Spiess

2016-09-01

Full Text Available Despite an abundance of computational models for learning of synaptic weights, there has been relatively little research on structural plasticity, i.e. the creation and elimination of synapses. Especially, it is not clear how structural plasticity works in concert with spike-timing-dependent plasticity (STDP and what advantages their combination offers.Here we present a fairly large-scale functional model that uses leaky integrate-and-fire neurons, STDP, homeostasis, recurrent connections, and structural plasticity to learn the input encoding, the relation between inputs, and to infer missing inputs. Using this model, we compare the error and the amount of noise in the network's responses with and without structural plasticity and the influence of structural plasticity on the learning speed of the network.Using structural plasticity during learning shows good results for learning the representation of input values, i.e. structural plasticity strongly reduces the noise of the response by preventing spikes with a high error.For inferring missing inputs we see similar results, with responses having less noise if the network was trained using structural plasticity.Additionally, using structural plasticity with pruning significantly decreased the time to learn weights suitable for inference.Presumably, this is due to the clearer signal containing less spikes that misrepresent the desired value. Therefore, this work shows that structural plasticity is not only able to improve upon the performance using STDP without structural plasticity but also speeds up learning.Additionally, it addresses the practical problem of limited resources for connectivity that is not only apparent in the mammalian neocortex but also in computer hardware or neuromorphic (brain-inspired hardware by efficiently pruning synapses without losing performance.

Case study: Is the 'catch-all-plastics bin' useful in unlocking the hidden resource potential in the residual waste collection system?

Science.gov (United States)

Kranzinger, Lukas; Schopf, Kerstin; Pomberger, Roland; Punesch, Elisabeth

2017-02-01

Austria's performance in the collection of separated waste is adequate. However, the residual waste still contains substantial amounts of recyclable materials - for example, plastics, paper and board, glass and composite packaging. Plastics (lightweight packaging and similar non-packaging materials) are detected at an average mass content of 13% in residual waste. Despite this huge potential, only 3% of the total amount of residual waste (1,687,000 t y -1 ) is recycled. This implies that most of the recyclable materials contained in the residual waste are destined for thermal recovery and are lost for recycling. This pilot project, commissioned by the Land of Lower Austria, applied a holistic approach, unique in Europe, to the Lower Austrian waste management system. It aims to transfer excess quantities of plastic packaging and non-packaging recyclables from the residual waste system to the separately collected waste system by introducing a so-called 'catch-all-plastics bin'. A quantity flow model was constructed and the results showed a realistic increase in the amount of plastics collected of 33.9 wt%. This equals a calculated excess quantity of 19,638 t y -1 . The increased plastics collection resulted in a positive impact on the climate footprint (CO 2 equivalent) in line with the targets of EU Directive 94/62/EG (Circular Economy Package) and its Amendments. The new collection system involves only moderate additional costs.

Denervation-induced homeostatic dendritic plasticity in morphological granule cell models

Directory of Open Access Journals (Sweden)

Hermann Cuntz

2014-03-01

Full Text Available Neuronal death and subsequent denervation of target areas are major consequences of several neurological conditions such asischemia or neurodegeneration (Alzheimer's disease. The denervation-induced axonal loss results in reorganization of the dendritic tree of denervated neurons. The dendritic reorganization has been previously studied using entorhinal cortex lesion (ECL. ECL leads to shortening and loss of dendritic segments in the denervated outer molecular layer of the dentate gyrus. However, the functional importance of these long-term dendritic alterations is not yet understood and their impact on neuronal electrical properties remains unclear. Here we analyzed what happens to the electrotonic structure and excitability of dentate granule cells after lesion-induced alterations of their dendritic morphology, assuming all other parameters remain equal. We performed comparative electrotonic analysis in anatomically and biophysically realistic compartmental models of 3D-reconstructed healthy and denervated granule cells. Using the method of morphological modeling based on optimization principles minimizing the amount of wiring and maximizing synaptic democracy, we built artificial granule cells which replicate morphological features of their real counterparts. Our results show that somatofugal and somatopetal voltage attenuation in the passive cable model are strongly reduced in denervated granule cells. In line with these predictions, the attenuation both of simulated backpropagating action potentials and forward propagating EPSPs was significantly reduced in dendrites of denervated neurons. Intriguingly, the enhancement of action potential backpropagation occurred specifically in the denervated dendritic layers. Furthermore, simulations of synaptic f-I curves revealed a homeostatic increase of excitability in denervated granule cells. In summary, our morphological and compartmental modeling indicates that unless modified by changes of

Statistical reliability analyses of two wood plastic composite extrusion processes

International Nuclear Information System (INIS)

Crookston, Kevin A.; Mark Young, Timothy; Harper, David; Guess, Frank M.

2011-01-01

Estimates of the reliability of wood plastic composites (WPC) are explored for two industrial extrusion lines. The goal of the paper is to use parametric and non-parametric analyses to examine potential differences in the WPC metrics of reliability for the two extrusion lines that may be helpful for use by the practitioner. A parametric analysis of the extrusion lines reveals some similarities and disparities in the best models; however, a non-parametric analysis reveals unique and insightful differences between Kaplan-Meier survival curves for the modulus of elasticity (MOE) and modulus of rupture (MOR) of the WPC industrial data. The distinctive non-parametric comparisons indicate the source of the differences in strength between the 10.2% and 48.0% fractiles [3,183-3,517 MPa] for MOE and for MOR between the 2.0% and 95.1% fractiles [18.9-25.7 MPa]. Distribution fitting as related to selection of the proper statistical methods is discussed with relevance to estimating the reliability of WPC. The ability to detect statistical differences in the product reliability of WPC between extrusion processes may benefit WPC producers in improving product reliability and safety of this widely used house-decking product. The approach can be applied to many other safety and complex system lifetime comparisons.

Occurrence of polycyclic aromatic hydrocarbons (PAHs in beached plastic pellets from Mumbai coast, India

Directory of Open Access Journals (Sweden)

HB Jayasiri

2014-06-01

Full Text Available PAHs are a class of ubiquitous pollutants which consist of two or more fused benzene rings in various arrangements. A number of PAH compounds are known carcinogens and bioaccumulate and biomagnify. These compounds originate naturally as well as anthropogenically through oil spills, incineration of waste and combustion of fossil fuels and wood. The environmental consequence of Plastic pellets is the sorption organic pollutants on their surface from the sea surface microlayer (SML where the hydrophobic contaminants are known to be enriched. The plastic pellets were collected along the recent high tide line from four beaches of Mumbai coast bimonthly during May 2011 - March 2012. A total of 72 pools of plastic pellets were extracted, fractionated and analysed by Gas Chromatograph coupled to a mass spectrometer to evaluate the extent and sources of 16 PAHs. The mean ΣPAH concentration in pellets was 9202.30±114.89 ng g-1 with a wide range (35.4-46191.58 ng g-1. The concentration of fluorene was found to be the highest (1606.30±251.54 ng g-1 followed by anthracene, chrysene and phenanthrene. The ΣPAH concentration was significantly varied among months and there was no significant difference among sites at  p=0.05. The 2-3 aromatic ring compounds accounted for 60% of the total PAHs in pellets of Mumbai coast while 4 rings and 5-6 rings compounds accounted for 26 and 14%, respectively. The ratio of low and high molecular weight PAHs indicated that the contamination by petrogenic sources was predominant over the pyrogenic ones in plastic pellets suggesting oil pollution in coastal area of Mumbai.Keywords: plastic pellets, PAHs, Mumbai, sources

Degradation of plastic carrier bags in the marine environment.

Science.gov (United States)

O'Brine, Tim; Thompson, Richard C

2010-12-01

There is considerable concern about the hazards that plastic debris presents to wildlife. Use of polymers that degrade more quickly than conventional plastics presents a possible solution to this problem. Here we investigate breakdown of two oxo-biodegradable plastics, compostable plastic and standard polyethylene in the marine environment. Tensile strength of all materials decreased during exposure, but at different rates. Compostable plastic disappeared from our test rig between 16 and 24 weeks whereas approximately 98% of the other plastics remained after 40 weeks. Some plastics require UV light to degrade. Transmittance of UV through oxo-biodegradable and standard polyethylene decreased as a consequence of fouling such that these materials received ∼ 90% less UV light after 40 weeks. Our data indicate that compostable plastics may degrade relatively quickly compared to oxo-biodegradable and conventional plastics. While degradable polymers offer waste management solutions, there are limitations to their effectiveness in reducing hazards associated with plastic debris. Copyright © 2010 Elsevier Ltd. All rights reserved.

Use of genotype-environment interactions to elucidate the pattern of maize root plasticity to nitrogen deficiency.

Science.gov (United States)

Li, Pengcheng; Zhuang, Zhongjuan; Cai, Hongguang; Cheng, Shuai; Soomro, Ayaz Ali; Liu, Zhigang; Gu, Riliang; Mi, Guohua; Yuan, Lixing; Chen, Fanjun

2016-03-01

Maize (Zea mays L.) root morphology exhibits a high degree of phenotypic plasticity to nitrogen (N) deficiency, but the underlying genetic architecture remains to be investigated. Using an advanced BC4 F3 population, we investigated the root growth plasticity under two contrasted N levels and identified the quantitative trait loci (QTLs) with QTL-environment (Q × E) interaction effects. Principal components analysis (PCA) on changes of root traits to N deficiency (ΔLN-HN) showed that root length and biomass contributed for 45.8% in the same magnitude and direction on the first PC, while root traits scattered highly on PC2 and PC3. Hierarchical cluster analysis on traits for ΔLN-HN further assigned the BC4 F3 lines into six groups, in which the special phenotypic responses to N deficiency was presented. These results revealed the complicated root plasticity of maize in response to N deficiency that can be caused by genotype-environment (G × E) interactions. Furthermore, QTL mapping using a multi-environment analysis identified 35 QTLs for root traits. Nine of these QTLs exhibited significant Q × E interaction effects. Taken together, our findings contribute to understanding the phenotypic and genotypic pattern of root plasticity to N deficiency, which will be useful for developing maize tolerance cultivars to N deficiency. © 2015 Institute of Botany, Chinese Academy of Sciences.

Plastic Recycling Experiments in Materials Education

Science.gov (United States)

Liu, Ping; Waskom, Tommy L.

1996-01-01

The objective of this project was to introduce a series of plastic recycling experiments to students in materials-related courses such as materials science, material technology and materials testing. With the plastic recycling experiments, students not only can learn the fundamentals of plastic processing and properties as in conventional materials courses, but also can be exposed to the issue of materials life cycle and the impact on society and environment.

Use of Plastic Mulch for Vegetable Production

OpenAIRE

Maughan, Tiffany; Drost, Dan

2016-01-01

Plastic mulches are used commercially for both vegetables and small fruit crops. Vegetable crops well suited for production with plastic mulch are typically high value row crops. This fact sheet describes the advantages, disadvantages, installation, and planting considerations. It includes sources for plastic and equipment.

Biological degradation of plastics: a comprehensive review.

Science.gov (United States)

Shah, Aamer Ali; Hasan, Fariha; Hameed, Abdul; Ahmed, Safia

2008-01-01

Lack of degradability and the closing of landfill sites as well as growing water and land pollution problems have led to concern about plastics. With the excessive use of plastics and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers. The interest in environmental issues is growing and there are increasing demands to develop material which do not burden the environment significantly. Biodegradation is necessary for water-soluble or water-immiscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. This requires understanding of the interactions between materials and microorganisms and the biochemical changes involved. Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. This paper reviews the current research on the biodegradation of biodegradable and also the conventional synthetic plastics and also use of various techniques for the analysis of degradation in vitro.

The heritability of mating behaviour in a fly and its plasticity in response to the threat of sperm competition.

Directory of Open Access Journals (Sweden)

Amanda Bretman

Full Text Available Phenotypic plasticity is a key mechanism by which animals can cope with rapidly changeable environments, but the evolutionary lability of such plasticity remains unclear. The socio-sexual environment can fluctuate very rapidly, affecting both the frequency of mating opportunities and the level of competition males may face. Males of many species show plastic behavioural responses to changes in social environment, in particular the presence of rival males. For example, Drosophila pseudoobscura males respond to rivals by extending mating duration and increasing ejaculate size. Whilst such responses are predicted to be adaptive, the extent to which the magnitude of response is heritable, and hence selectable, is unknown. We investigated this using isofemale lines of the fruit fly D. pseudoobscura, estimating heritability of mating duration in males exposed or not to a rival, and any genetic basis to the change in this trait between these environments (i.e. degree of plasticity. The two populations differed in population sex ratio, and the presence of a sex ratio distorting selfish chromosome. We find that mating duration is heritable, but no evidence of population differences. We find no significant heritability of plasticity in mating duration in one population, but borderline significant heritability of plasticity in the second. This difference between populations might be related to the presence of the sex ratio distorting selfish gene in the latter population, but this will require investigation in additional populations to draw any conclusions. We suggest that there is scope for selection to produce an evolutionary response in the plasticity of mating duration in response to rivals in D. pseudoobscura, at least in some populations.

Methodology for plastic fracture - a progress report

International Nuclear Information System (INIS)

Wilkinson, J.P.D.; Smith, R.E.E.

1977-01-01

This paper describes the progress of a study to develop a methodology for plastic fracture. Such a fracture mechanics methodology, having application in the plastic region, is required to assess the margin of safety inherent in nuclear reactor pressure vessels. The initiation and growth of flaws in pressure vessels under overload conditions is distinguished by a number of unique features, such as large scale yielding, three-dimensional structural and flaw configurations, and failure instabilities that may be controlled by either toughness or plastic flow. In order to develop a broadly applicable methodology of plastic fracture, these features require the following analytical and experimental studies: development of criteria for crack initiation and growth under large scale yielding; the use of the finite element method to describe elastic-plastic behaviour of both the structure and the crack tip region; and extensive experimental studies on laboratory scale and large scale specimens, which attempt to reproduce the pertinent plastic flow and crack growth phenomena. This discussion centers on progress to date on the selection, through analysis and laboratory experiments, of viable criteria for crack initiation and growth during plastic fracture. (Auth.)

Recycling plastic bottles in a creative way

OpenAIRE

Pavlin, Suzana

2016-01-01

Beside other plastic products, plastic bottles represent a true environmental disaster in the last few years. We assume that hardly anyone asks what happens after they drink that last drop of water out of it. Just like most municipal waste, a plastic bottle can be reused, recycled, burned or deposited into landfill. When the Environment Protection Act is not respected, plastic bottle ends up in the nature, very often in the sea, where it decomposes very slowly and has negative influence on th...

Chemoreception drives plastic consumption in a hard coral.

Science.gov (United States)

Allen, Austin S; Seymour, Alexander C; Rittschof, Daniel

2017-11-15

The drivers behind microplastic (up to 5mm in diameter) consumption by animals are uncertain and impacts on foundational species are poorly understood. We investigated consumption of weathered, unfouled, biofouled, pre-production and microbe-free National Institute of Standards plastic by a scleractinian coral that relies on chemosensory cues for feeding. Experiment one found that corals ingested many plastic types while mostly ignoring organic-free sand, suggesting that plastic contains phagostimulents. Experiment two found that corals ingested more plastic that wasn't covered in a microbial biofilm than plastics that were biofilmed. Additionally, corals retained ~8% of ingested plastic for 24h or more and retained particles appeared stuck in corals, with consequences for energetics, pollutant toxicity and trophic transfer. The potential for chemoreception to drive plastic consumption in marine taxa has implications for conservation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Plastic Debris Is a Human Health Issue

NARCIS (Netherlands)

Vethaak, A.D.; Leslie, H.A.

2016-01-01

The global threat of highly persistent plastic waste accumulating and fragmenting in the world’s oceans, inland waters and terrestrial environments is becoming increasingly evident.1−3 Humans are being exposed to both plastic particles and chemical additives being released from the plastic debris of

Architecture of European Plastic Surgery

NARCIS (Netherlands)

Nicolai, J. -P. A.; Banic, A.; Molea, G.; Mazzola, R.; Poell, J. G.

2006-01-01

The architecture of European Plastic Surgery was published in 1996 [Nicolai JPA, Scuderi N. Plastic surgical Europe in an organogram. Eur J Plast Surg 1996; 19: 253-6.] It is the objective of this paper to update information of that article. Continuing medical education (CME), science, training,

75 FR 34170 - Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium Automotive Exteriors, LLC...

Science.gov (United States)

2010-06-16

... Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium Automotive Exteriors, LLC, Troy, MI... the Anderson, South Carolina location of Plastic Omnium Automotive Exteriors, LLC, working out of Troy... certification to include workers in support of the Anderson, South Carolina facility working out of Troy...

Maximizing the life cycle of plastics. Final report

Energy Technology Data Exchange (ETDEWEB)

Hawkins, W. L.

1980-02-01

The Plastics Research Institute has conducted a coordinated research program designed to extend the useful life of plastics. Since feedstock for practically all synthetic plastics is derived from fossil fuel, every effort should be made to obtain the maximum useful life from these materials. Eventually, plastic scrap may be used as a fuel supplement, but this disposal route should be followed only after the scrap is no longer reusable in its polymeric form. The extent to which plastic scrap will be recovered and reused will be affected by the economic situation as well as the available supply of fossil fuel. The Institute's program was conducted at five major universities. Dedicated faculty members were assembled into a research team and met frequently with members of the Institute's Board of Trustees to review progress of the program. The research was conducted by graduate students in partial fulfillment of degree requirements. Summaries are presented of the following research projects: Improved Stabilization; Separation of Mixed Plastic Scrap; Compatibilizing Agents for Mixed Plastic Scrap; Controlled Degradation of Plastic Scrap; and Determination of Compatibility.

Space Plastic Recycling System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Techshot's proposed Space Plastic Recycler (SPR) is an automated closed loop plastic recycling system that allows the automated conversion of disposable ISS...

Plastics in the North Atlantic garbage patch: A boat-microbe for hitchhikers and plastic degraders.

Science.gov (United States)

Debroas, Didier; Mone, Anne; Ter Halle, Alexandra

2017-12-01

Plastic is a broad name given to different polymers with high molecular weight that impact wildlife. Their fragmentation leads to a continuum of debris sizes (meso to microplastics) entrapped in gyres and colonized by microorganisms. In the present work, the structure of eukaryotes, bacteria and Archaea was studied by a metabarcoding approach, and statistical analysis associated with network building was used to define a core microbiome at the plastic surface. Most of the bacteria significantly associated with the plastic waste originated from non-marine ecosystems, and numerous species can be considered as hitchhikers, whereas others act as keystone species (e.g., Rhodobacterales, Rhizobiales, Streptomycetales and Cyanobacteria) in the biofilm. The chemical analysis provides evidence for a specific colonization of the polymers. Alphaproteobacteria and Gammaproteobacteria significantly dominated mesoplastics consisting of poly(ethylene terephthalate) and polystyrene. Polyethylene was also dominated by these bacterial classes and Actinobacteria. Microplastics were made of polyethylene but differed in their crystallinity, and the majorities were colonized by Betaproteobacteria. Our study indicated that the bacteria inhabiting plastics harboured distinct metabolisms from those present in the surrounding water. For instance, the metabolic pathway involved in xenobiotic degradation was overrepresented on the plastic surface. Copyright © 2017 Elsevier B.V. All rights reserved.

49 CFR 178.517 - Standards for plastic boxes.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for plastic boxes. 178.517 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.517 Standards for plastic boxes. (a) The following are identification codes for plastic boxes: (1) 4H1 for an expanded plastic box; and (2) 4H2 for a...

Characterization and analysis of weld lines on micro-injection moulded parts using atomic force microscopy (AFM)

DEFF Research Database (Denmark)

Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard

2009-01-01

In recent years plastic moulding techniques, such as injection moulding, have been developed to fulfil the needs of micro-components fabrication. Micro-injection moulding (SLIM) is the process which enables the mass production of polymer micro-systems such as micro-mechanical parts, micro...... the two original flows will generate and a weld line is formed on the surface of the micro-moulded part. This phenomenon has to be avoided or at least reduced, since in the weld line area the mechanical properties are poorer than in the bulk part, creating strength problems on the final part. Although...... injection moulding parameters on the weld lines' dimensions is presented, using an atomic force microscope (AFM). Depth and width of weld lines were chosen as parameters to be optimized....

Preparing Attitude Scale to Define Students' Attitudes about Environment, Recycling, Plastic and Plastic Waste

Science.gov (United States)

Avan, Cagri; Aydinli, Bahattin; Bakar, Fatma; Alboga, Yunus

2011-01-01

The aim of this study is to introduce an attitude scale in order to define students? attitudes about environment, recycling, plastics, plastic waste. In this study, 80 attitude sentences according to 5-point Likert-type scale were prepared and applied to 492 students of 6th grade in the Kastamonu city center of Turkey. The scale consists of…

Plastic crystal phases of simple water models

International Nuclear Information System (INIS)

Aragones, J. L.; Vega, C.

2009-01-01

We report the appearance of two plastic crystal phases of water at high pressure and temperature using computer simulations. In one of them the oxygen atoms form a body centered cubic structure (bcc) and in the other they form a face centered cubic structure (fcc). In both cases the water molecules were able to rotate almost freely. We have found that the bcc plastic crystal transformed into a fcc plastic crystal via a Martensitic phase transition when heated at constant pressure. We have performed the characterization and localization in the phase diagram of these plastic crystal phases for the SPC/E, TIP4P, and TIP4P/2005 water potential models. For TIP4P/2005 model free energy calculations were carried out for the bcc plastic crystal and fcc plastic crystal using a new method (which is a slight variation of the Einstein crystal method) proposed for these types of solid. The initial coexistence points for the SPC/E and TIP4P models were obtained using Hamiltonian Gibbs–Duhem integration. For all of these models these two plastic crystal phases appear in the high pressure and temperature region of the phase diagram. It would be of interest to study if such plastic crystal phases do indeed exist for real water. This would shed some light on the question of whether these models can describe satisfactorily the high pressure part of the phase diagram of water, and if not, where and why they fail.

Homeostatic role of heterosynaptic plasticity: Models and experiments

Directory of Open Access Journals (Sweden)

Marina eChistiakova

2015-07-01

Full Text Available Homosynaptic Hebbian-type plasticity provides a cellular mechanism of learning and refinement of connectivity during development in a variety of biological systems. In this review we argue that a complimentary form of plasticity - heterosynaptic plasticity - represents a necessary cellular component for homeostatic regulation of synaptic weights and neuronal activity. The required properties of a homeostatic mechanism which acutely constrains the runaway dynamics imposed by Hebbian associative plasticity have been well-articulated by theoretical and modeling studies. Such mechanism(s should robustly support the stability of operation of neuronal networks and synaptic competition, include changes at non-active synapses, and operate on a similar time scale to Hebbian-type plasticity. The experimentally observed properties of heterosynaptic plasticity have introduced it as a strong candidate to fulfill this homeostatic role. Subsequent modeling studies which incorporate heterosynaptic plasticity into model neurons with Hebbian synapses (utilizing an STDP learning rule have confirmed its ability to robustly provide stability and competition. In contrast, properties of homeostatic synaptic scaling, which is triggered by extreme and long lasting (hours and days changes of neuronal activity, do not fit two crucial requirements for a hypothetical homeostatic mechanism needed to provide stability of operation in the face of on-going synaptic changes driven by Hebbian-type learning rules. Both the trigger and the time scale of homeostatic synaptic scaling are fundamentally different from those of the Hebbian-type plasticity. We conclude that heterosynaptic plasticity, which is triggered by the same episodes of strong postsynaptic activity and operates on the same time scale as Hebbian-type associative plasticity, is ideally suited to serve homeostatic role during on-going synaptic plasticity.

Leaching of plastic polymers by plastic vials used for storing homoeopathic medicines: A preliminary study

Directory of Open Access Journals (Sweden)

Neeraj Gupta

2014-01-01

Full Text Available Background: In Homoeopathy, plastic containers/vials are used for the storing/dispensing of ethanol-based medicines instead of glass. Various studies have suggested that plastic components that leach out in stored substances tend to cause contamination and may produce adverse effects in living systems. The present study was aimed to find out chemical composition and leaching behaviour of commonly used plastic vials (PVs if any during the storage of ethanol-based homoeopathic medicines in optimal environment. Material and Methods: The experiments were conducted on two sample sets of PVs. Chemical properties of PV were assessed by Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR spectroscopy. PV were cut separately [sample-1 (S-1 and sample-2 (S-2] and immersed in Homoeopathic Grade Ethanol (HGE in conical flask and stored for 7 days at ambient temperature (25° ± 5C with constant rotary shaking. After 7 days, S-1 and S-2 of PV in Homoeopathic Grade Ethanol (HGE were decanted and filtered. Aliquots (A1 and A2 were analysed by proton nuclear magnetic resonance spectroscopy (H 1 NMR. The spectral graph obtained by FTIR-ATR spectroscopy for PV compositions and spectral graph obtained by H 1 NMR spectroscopy for PV ethanol aliquots were examined for PVs material and PV leaching effect in HGE. Results: FTIR-ATR spectra showed that PV are made up of two types of polyolefin′s compounds i.e. Low Density Polyethylene (LDPE and Linear Low Density Polyethylene (LLDPE. Aliquots of PV in HGE showed the presence benzophenone and its methyl derivative, heat and light stabiliser (2, 2, 6, 6-tetramethylpiperidine and amino derivative, antioxidant (4, 4′- thiobis and 2-tertbutyl-5-methylphenol and plasticizer bis 2-Diethylhexyl phthalate (DEHP or Dioctyl phthalate (DOP. Results of study suggest that PVs leach out plastic polymers in HGE. Conclusion: This preliminary experiment suggests that it is not safe to use LDPE/LLDPE plastic for storing

Developmental plasticity: Friend or foe?

Science.gov (United States)

Michels, Karin B

2017-01-01

Developmental plasticity - the concept that adaptation to changing and unfavorable environmental conditions are possible but may come at the price of compromised health potentials - has evolutionary grounding as it facilitates survival but dissents with fundamental evolutionary principles in that it may advance the lesser fit. It is an important cornerstone of the Developmental Origins of Health and Disease (DOHaD). Unlike evolutionary adaptation developmental plasticity may be short-lived and restricted to one or few generations and inheritance is uncertain. Potential mechanisms include epigenetic modifications adopted in utero which may not transmit to the next generation; future insights may allow adjustments of the outcomes of developmental plasticity.

Radiation damage in plastic scintillators

International Nuclear Information System (INIS)

Majewski, S.

1990-01-01

Results of radiation damage studies in plastic scintillators are reviewed and critically analyzed from the point of view of applications of plastic scintillators in calorimetric detectors for the SSC. Damage to transmission and to fluorescent yield in different conditions is discussed. New directions in R ampersand D are outlined. Several examples are given of the most recent data on the new scintillating materials made with old and new plastics and fluors, which are exhibiting significantly improved radiation resistance. With a present rate of a vigorous R D programme, the survival limits in the vicinity of 100 MRad seem to be feasible within a couple of years

Waste product profile: Plastic film and bags

Energy Technology Data Exchange (ETDEWEB)

Miller, C. [Environmental Industry Associations, Washington, DC (United States)

1996-10-01

Plastic film is recycled by being pelletized following a granulation or densifying process. Manufacturing and converting plants are the major sources of plastic film for recycling because they can supply sufficient amounts of clean raw material of a known resin type. Post-consumer collection programs are more recent. They tend to focus on businesses such as grocery stores that are large generators of plastic bags. In this case, the recycling process is more complex, requiring sorting, washing, and removal of contaminants as a first step. Curbside collection of plastic bags is rare.

Photodegradable plastics useful for global environment conservation. Chikyu ni yasashii hikaribunkaisei plastic

Energy Technology Data Exchange (ETDEWEB)

Iwasa, T. (Harima Kasei K.K., Osaka (Japan))

1991-10-11

Photodegradable plastics and their additives were explained.Two methods are used to manufacture photodegradable plastics.The first method is made by using a copolymer and a monomer containing a functional group and the second method is made by adding a photodegradable agent to an undecomposable plastics.The copolymer based on ethylene and carbon monoxide is included in the first type. The copolymer based on the vinyl ketone to which the carboxyl group is introduced, and ethylene or styrene is also included in this type. A metal dithiocarbamate is included in the second additive type, for which several methods to improve weak points of the pigment compounding system have been proposed later. Benzophenone derivatives, transition metal salts of organic acids and anatase type titanium dioxide are also included in the second type. Any additives are usually supplied as the masterbatch. The performance evaluation and degrading mechanism of ferric tri(2-(methylbenzoyl)benzoate) of adittion type additives were explained. 8 refs., 3 figs., 1 tab.

Benthic plastic debris in marine and fresh water environments.

Science.gov (United States)

Corcoran, Patricia L

2015-08-01

This review provides a discussion of the published literature concerning benthic plastic debris in ocean, sea, lake, estuary and river bottoms throughout the world. Although numerous investigations of shoreline, surface and near-surface plastic debris provide important information on plastic types, distribution, accumulation, and degradation, studies of submerged plastic debris have been sporadic in the past and have become more prominent only recently. The distribution of benthic debris is controlled mainly by combinations of urban proximity and its association with fishing-related activities, geomorphology, hydrological conditions, and river input. High density plastics, biofouled products, polymers with mineral fillers or adsorbed minerals, and plastic-metal composites all have the potential to sink. Once deposited on the bottoms of water basins and channels, plastics are shielded from UV light, thus slowing the degradation process significantly. Investigations of the interactions between benthic plastic debris and bottom-dwelling organisms will help shed light on the potential dangers of submerged plastic litter.

The plastic brain: neoliberalism and the neuronal self.

Science.gov (United States)

Pitts-Taylor, Victoria

2010-11-01

Neuroscience-based representations and practices of the brain aimed at lay populations present the brain in ways that both affirm biological determinism and also celebrate plasticity, or the brain's ability to change structure and function. Popular uses of neuroscientific theories of brain plasticity are saturated with a neoliberal vision of the subject. Against more optimistic readings of plasticity, I view the popular deployment of plasticity through the framework of governmentality. I describe how popular brain discourse on plasticity opens up the brain to personal techniques of enhancement and risk avoidance, and how it promotes a neuronal self. I situate brain plasticity in a context of biomedical neoliberalism, where the engineering and modification of biological life is positioned as essential to selfhood and citizenship.

Fast Simulation of 3-D Surface Flanging and Prediction of the Flanging Lines Based On One-Step Inverse Forming Algorithm

International Nuclear Information System (INIS)

Bao Yidong; Hu Sibo; Lang Zhikui; Hu Ping

2005-01-01

A fast simulation scheme for 3D curved binder flanging and blank shape prediction of sheet metal based on one-step inverse finite element method is proposed, in which the total plasticity theory and proportional loading assumption are used. The scheme can be actually used to simulate 3D flanging with complex curve binder shape, and suitable for simulating any type of flanging model by numerically determining the flanging height and flanging lines. Compared with other methods such as analytic algorithm and blank sheet-cut return method, the prominent advantage of the present scheme is that it can directly predict the location of the 3D flanging lines when simulating the flanging process. Therefore, the prediction time of flanging lines will be obviously decreased. Two typical 3D curve binder flanging including stretch and shrink characters are simulated in the same time by using the present scheme and incremental FE non-inverse algorithm based on incremental plasticity theory, which show the validity and high efficiency of the present scheme

Radiation crosslinking of highly plasticized PVC

Science.gov (United States)

Mendizabal, E.; Cruz, L.; Jasso, C. F.; Burillo, G.; Dakin, V. I.

1996-02-01

To improve the physical properties of highly plasticized PVC, the polymer was crosslinked by gamma irradiation using a dose rate of 91 kGy/h. The effect of plasticizer type was studied by using three different plasticizers, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), di(2-ethyl hexyl) phthalate (DOP), and di(2-ethylhexyl terephthalate) (DOTP), and varying irradiation doses. Gel content was determined by soxhlet extraction, tensile measurements were made on a universal testing machine and the mechano-dynamic measurements were made in a dynamic rheometer. It was found that a considerable bonding of plasticizer molecules to macromolelcules takes place along with crosslinking, so that the use of the solvent extraction method for measuring the degree of crosslinking can give erroneous information. Radiation-chemical crosslinking yield ( Gc) and molecular weight of interjunctions chains ( Mc), were calculated for different systems studied. Addition of ethylene glycol dimethacrylate (EGDM) as a crosslinking coagent and dioctyl tin oxide (DOTO) as a stabilizer was also studied. Plasticizers extraction resistance was increased by irradiation treatment.

Radiation crosslinking of highly plasticized PVC

International Nuclear Information System (INIS)

Mendizabal, E.; Cruz, L.; Jasso, C.F.; Burillo, G.; Dakin, V.I.

1996-01-01

To improve the physical properties of highly plasticized PVC, the polymer was crosslinked by gamma irradiation using a dose rate of 91 kGy/h. The effect of plasticizer type was studied by using three different plasticizers, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), di(2-ethyl hexyl) phthalate (DOP), and di(2-ethylhexyl terephthalate) (DOTP), and varying irradiation doses. Gel content was determined by soxhlet extraction, tensile measurements were made on a universal testing machine and the mechano-dynamic measurements were made in a dynamic rheometer. It was found that a considerable bonding of plasticizer molecules to macromolecules takes place along with crosslinking, so that the use of the solvent extraction method for measuring the degree of crosslinking can give erroneous information. Radiation-chemical crosslinking yield (G c ) and molecular weight of interjunctions chains (M c ), were calculated for different systems studied. Addition of ethylene glycol dimethyacrylate (EGDM) as a crosslinking coagent and dioctyl tin oxide (DOTO) as a stabilizer was also studied. Plasticizers extraction resistance was increased by irradiation treatment. (author)

Plastic Surgery Response in Natural Disasters.

Science.gov (United States)

Chung, Susan; Zimmerman, Amanda; Gaviria, Andres; Dayicioglu, Deniz

2015-06-01

Disasters cause untold damage and are often unpredictable; however, with proper preparation, these events can be better managed. The initial response has the greatest impact on the overall success of the relief effort. A well-trained multidisciplinary network of providers is necessary to ensure coordinated care for the victims of these mass casualty disasters. As members of this network of providers, plastic surgeons have the ability to efficiently address injuries sustained in mass casualty disasters and are a valuable member of the relief effort. The skill set of plastic surgeons includes techniques that can address injuries sustained in large-scale emergencies, such as the management of soft-tissue injury, tissue viability, facial fractures, and extremity salvage. An approach to disaster relief, the types of disasters encountered, the management of injuries related to mass casualty disasters, the role of plastic surgeons in the relief effort, and resource management are discussed. In order to improve preparedness in future mass casualty disasters, plastic surgeons should receive training during residency regarding the utilization of plastic surgery knowledge in the disaster setting.

The neurophysiologist perspective into MS plasticity

Directory of Open Access Journals (Sweden)

Elise eHoudayer

2015-09-01

Full Text Available Multiple sclerosis (MS is a frequent, highly debilitating inflammatory demyelinating disease, starting to manifest in early adulthood and presenting a wide variety of symptoms which are often resistant to pharmacological treatments. Cortical dysfunctions have been demonstrated to be key components of MS condition, and plasticity of the corticospinal motor system is highly involved in major MS symptoms, such as fatigue, spasticity or pain. Cortical dysfunction in MS can be studied with neurophysiological tools such as electroencephalography (EEG and related techniques (evoked potentials – EPs or transcranial magnetic stimulation (TMS. These techniques are now widely used to provide essential elements of MS diagnosis and can also be used to modulate plasticity. Indeed the recent development of non-invasive brain stimulation (NIBS techniques able to induce cortical plasticity, such as repetitive TMS or transcranial direct current stimulation (tDCS, has brought promising results as add-on treatments.In this review we will focus on the use of these tools (EEG, TMS to study plasticity in MS and on the major techniques used to modulate plasticity in MS.

The Neurophysiologist Perspective into MS Plasticity.

Science.gov (United States)

Houdayer, Elise; Comi, Giancarlo; Leocani, Letizia

2015-01-01

Multiple sclerosis (MS) is a frequent, highly debilitating inflammatory demyelinating disease, starting to manifest in early adulthood and presenting a wide variety of symptoms, which are often resistant to pharmacological treatments. Cortical dysfunctions have been demonstrated to be key components of MS condition, and plasticity of the corticospinal motor system is highly involved in major MS symptoms, such as fatigue, spasticity, or pain. Cortical dysfunction in MS can be studied with neurophysiological tools, such as electroencephalography (EEG) and related techniques (evoked potentials) or transcranial magnetic stimulation (TMS). These techniques are now widely used to provide essential elements of MS diagnosis and can also be used to modulate plasticity. Indeed, the recent development of non-invasive brain stimulation techniques able to induce cortical plasticity, such as repetitive TMS or transcranial direct current stimulation, has brought promising results as add-on treatments. In this review, we will focus on the use of these tools (EEG and TMS) to study plasticity in MS and on the major techniques used to modulate plasticity in MS.

Replacing fossil based plastic performance products by bio-based plastic products-Technical feasibility.

Science.gov (United States)

van den Oever, Martien; Molenveld, Karin

2017-07-25

Larger scale market introduction of new bio-based products requires a clear advantage regarding sustainability, as well as an adequate techno-economic positioning relative to fossil based products. In a previous paper [Broeren et al., 2016], LCA results per kg and per functionality equivalent of bio-based plastics were presented, together with economic considerations. The present paper discusses the mechanical and thermal properties of a range of commercially available bio-based plastics based on polylactic acid (PLA), cellulose esters, starch and polyamides, and the feasibility of replacing fossil-based counterparts based on performance. The evaluation is approached from an end user perspective. First, potentially suitable bio-based plastics are selected based on manufacturers' specifications in technical data sheets, then a first experimental evaluation is performed on injection moulded ISO specimens, and finally a further selection of plastics is tested on large 50×70cm panels. This technical feasibility study indicates that so far bio-based plastics do not completely match the properties of high performance materials like flame retardant V-0 PC/ABS blends used in electronic devices. The performance gap is being decreased by the development of stereocomplex PLA and hybrid PLA blends with polycarbonate, which offer clearly improved properties with respect to maximum usage temperature and toughness. In addition, several materials meet the V-0 flammability requirements needed in specific durable applications. On the other hand, improving these properties so far has negative consequences for the bio-based content. This study also shows that replacement of bulk polymers like PS is feasible using PLA compounds with a bio-based content as high as 85%. Copyright © 2016 Elsevier B.V. All rights reserved.

Nonlinear analysis of rc members using hardening plasticity and arc-length method

International Nuclear Information System (INIS)

Memon, B.A.; Su, X.

2005-01-01

A general framework for three-dimensional nonlinear finite element analysis of reinforced concrete is done. To make computations robust, reliable and make analysis more realistic hardening plasticity with arc-length method as path following technique is used to model material-nonlinear behavior of reinforced concrete. Hardening plasticity has the advantage over other plasticity formulations that it allows extension of framework for the analysis of softening region. Concrete is treated as eight-node isoparametric element and reinforcement is modeled as line element embedded in the body of isoparametric concrete element. Different methods of stress-scaling back to yield surfaces are tested and their performance is compared. Severe convergence problems are encountered as solution process approaches singularity points; specially limit points; along load displacement curve in nonlinear analysis. To overcome the problem, cylindrical arc-length method is used. The use of the method not only tackles the issue of singularity points but also deals with load-step size problem. While marching along load-displacement path identification of singularity points is done by using singularity indicator, for the purpose various singularity test functions are implemented. Although most of the individual techniques are already well established, the framework is completely new one. A computer implementation of the proposed frame work is written in FORTRAN. Numerical examples are solved to illustrate the validity of proposed framework. Comparison of the outcome of proposed framework is made with experimental observations. two sets of the results are found in good agreement. (author)

Transgenerational plasticity in Silene vulgaris in response to three types of stress.

Science.gov (United States)

Sandner, T M; van Braak, J L; Matthies, D

2018-03-23

The environment experienced by plants can influence the phenotype of their offspring. Such transgenerational plasticity can be adaptive when it results in higher fitness of the offspring under conditions correlated with those experienced by the mother plant. However, it has rarely been tested if such anticipatory parental effects may be induced with different environments. We grew clonal replicates of Silene vulgaris under control conditions and three types of stress (nutrient deficiency, copper addition and drought), which are known from natural populations of the species. We then subjected offspring from differently treated mother plants to each of the different stress treatments to analyse the influence of maternal and offspring environment on performance and several functional traits. Current stress treatments strongly influenced biomass and functional traits of the plants, mostly in line with responses predicted by the theory of functional equilibrium. Plant performance was also influenced by maternal stress treatments, and some effects independent of initial size differences remained until harvest. In particular, stressed mothers produced offspring of higher fitness than control plants. However, there was no evidence for treatment-specific adaptive transgenerational plasticity, as offspring from a mother plant that had grown in a specific environment did not grow better in that environment than other plants. Our results indicate that the maternal environment may affect offspring traits and performance, but also that this transgenerational plasticity is not necessarily adaptive. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

History of plastic surgery: Art, philosophy, and rhinoplasty.

Science.gov (United States)

Macionis, Valdas

2018-03-23

The 200th anniversary of K. F. Graefe's "Rhinoplasty," E. Zeis' naming of the specialty of plastic surgery in 1838, and the continuing discussion on what is plastic surgery have prompted this historical-conceptual review with a semantic insight into the meaning of the word "plastic." A literature search has revealed that this term contains dual aspects: artistic and philosophical. The progressive development of these two connotations can be traced from their origin in the ceramics and the myths of ancient Greeks to their metamorphoses in fine arts, science, and philosophy of plasticity of the modern day. Although the names of plastic procedures and the title of the specialty carry both the artistic and philosophical features, the philosophical notion is less evident. This article underlines the importance of etymology in the interpretation of the concept of plastic surgery. Copyright © 2018 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

An alternative to conventional babbitt metal-lined generator pads

Energy Technology Data Exchange (ETDEWEB)

Puuska, H. [Imatra Hydroelectric Power Plant (Finland)

1996-08-01

The generator refurbishment of the Imatra Hydroelectric Power Plant Unit 1 in Finland is described. The generator work called for installation of a new cooling system for the generator thrust bearing. The considerations leading to the decision to replace the conventional babbitt metal-lined pads with elastic metal-plastic coated thrust bearing pads and the installation of the new pads are outlined in the article. Results of the trial run are summarized; the end temperature of the unit was more than 20C lower than for units equipped with conventional babbitted bearings.

[Survey of plasticizers in polyvinyl chloride toys].

Science.gov (United States)

Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Hirahara, Yoshichika; Kawamura, Yoko

2012-01-01

Plasticizers in 101 samples of polyvinyl chloride (PVC) toys on the Japanese market were surveyed. No phthalates were detected in designated toys, though bis(2-ethylhexyl)phthalate, diisononyl phthalate, diisobutyl phthalate, dibutyl phthalate, diisodecyl phthalate and benzyl butyl phthalate were detected in more than half of other toys. 2,2,4-Tributyl-1,3-pentanediol diisobutylate, o-acetyl tributyl citrate, adipates and diacetyl lauroyl glycerol, which are alternative plasticizers to phthalates, were detected. The results of structural analysis confirmed the presence of di(2-ethylhexyl)terephthalate, tributyl citrate, diisononyl 1,2-cyclohexanedicarboxylate and neopentyl glycol esters; these have not previonsly been reported in Japan. There appears to be a shift in plasticizers used for designated toys from phthalates to new plasticizers, and the number of different plasticizers is increasing.

PLASTIC SURGERY

African Journals Online (AJOL)

Department of Plastic and Reconstructive Surgery Sefako Makgatho Health Science University, ... We report on a pilot study on the use of a circumareolar excision and the use of .... and 1 gynecomastia patient) requested reduction in NAC size.

Discoloration of plasticized PVC upon irradiation

International Nuclear Information System (INIS)

Kojima, Keiichi; Ueno, Keiji; Kumafuji, Hisao.

1981-01-01

The effects of the factors on the discoloration of PVC cross-linked by electron irradiation, such as irradiation dose, the polymerization degree of PVC resin, plasticizers and stabilizers, were studied. The composition of the plasticized PVC used for the experiment was 100 PHR of PVC, 50 PHR of plasticizer, 5 PHR of stabilizer and 5 PHR of cross-linking agent (TMPMA). Three samples with the different degree of polymerization of the PVC resin were used, namely 750, 1050 and 2600. As the plasticizers, phthalic acid esters (DBP, DOP, DIDP), trimellitic acid esters (TOTM, n-TOTM), fatty acid esters (DOS, DOZ), polyester and epoxy group plasticizers were used. The irradiation dose for the test was 3, 6 and 12 Mrad. The experimental results are summarized as follows. As the electron irradiation dose was higher, the resultant discoloration was more remarkable, and the optimum irradiation dose was below 6 Mrad. The degree of polymerization of the PVC resin did not affect the irradiation discoloration. However it was noticed that the cross-linking efficiency was better as the degree of polymerization was higher. The cross-linking efficiency was better as the content of plasticizer was more. The fatty acid esters and epoxy groups showed less discoloration and better cross-linking efficiency. Tin and barium-zinc stabilizers were good. (Kako, I.)

Nigerian Journal of Plastic Surgery

African Journals Online (AJOL)

The Nigerian Journal of Plastic Surgery has its objectives in publishing original articles about developments in all areas related to plastic and reconstructive surgery as well as to trauma surgery. It also serves as a means of providing a forum for correspondence, information and discussion. It also accepts review articles that ...

Direct electroplating of plastic for advanced electrical applications

DEFF Research Database (Denmark)

Islam, Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

2017-01-01

Electrodeposition or electroplating is predominantly applied to metallic components. Electroplating of plastics is possible in some cases where an initial electroless plating layer of nickel or copper is made to provide a conductive surface on the plastic part. This paper proposes a method...... for direct electroplating of plastic eliminating the need for slow and expensive processes like electroless metal deposition, PVD coating, painting with conductive inks etc. The results obtained from the test demonstrate the potential of direct electroplating of plastic to enhance the electrical conductivity...... and the use of electroplated plastics for advanced applications like Moulded Interconnect Devices (MIDs)....

Plastic surgery in Nigeria-Scope and challenges

Directory of Open Access Journals (Sweden)

TOG Chukwuanukwu

2011-01-01

Full Text Available Background Plastic surgery as a major subspecialty of surgery has existed in Nigeria for several decades but the populace including medical practitioners are yet to fully appreciate its scope. This leads to very late presentation/referral of cases and management of cases that should have been referred by less qualified practitioners with attendant poor outcomes and complications. Most people still regard plastic surgery as being synonymous with cosmetic/aesthetic surgery but the scope goes far beyond this entity. It is therefore important that the public including medical practitioners who are the main sources of referral to the subspecialty are aware of the range of cases handled by plastic surgery units. The plastic surgeon in Nigeria is also faced with a lot of challenges ranging from the arduous task of one having to manage very many different and complicated cases to being very poorly equipped and appreciated. Objectives To educate the populace especially the medical practitioners on the scope of plastic surgery and the extent of development of the subspecialty in Nigeria and solicit for colleague′s cooperation in order to move plastic surgery forward. To also highlight the difficulties faced by the plastic surgeon in Nigeria and seeking help from appropriate quarters which will help to reduce unnecessary referrals abroad while improving the services rendered to patients locally. Conclusion Plastic surgery in Nigeria has developed significantly both in scope and manpower but it is still faced with a lot of challenges. Knowledge of its scope will help to reduce unnecessary referrals abroad while improving services/skill here in Nigeria.

Micro-structural evolution in plastically deformed crystalline materials

DEFF Research Database (Denmark)

Nellemann, Christopher

predictions for the two models to be obtained. Application of the two models to the pure shear boundary value problem is used to characterize plastic behavior, which also allows for the identification of inherent properties through closed form expressions. Single crystal Monazite containing a void is studied......Two rate-independent strain gradient crystal plasticity models are developed and applied in numerical studies designed to identify the properties inherent to model predictions of plastic deformation. The two models incorporate gradients of slip into the framework of conventional crystal plasticity...... in order to model size-dependent plasticity effects. This gradient dependence is achieved by relating a slip measure which combines both slip and their gradients to a shear hardening curve, as commonly done in conventional plasticity theories. Finite element codes are implemented which allow for numerical...

Indentation of elastically soft and plastically compressible solids

DEFF Research Database (Denmark)

Needleman, A.; Tvergaard, Viggo; Van der Giessen, E.

2015-01-01

rapidly for small deviations from plastic incompressibility and then decreases rather slowly for values of the plastic Poisson's ratio less than 0.25. For both soft elasticity and plastic compressibility, the main reason for the lower values of indentation hardness is related to the reduction......The effect of soft elasticity, i.e., a relatively small value of the ratio of Young's modulus to yield strength and plastic compressibility on the indentation of isotropically hardening elastic-viscoplastic solids is investigated. Calculations are carried out for indentation of a perfectly sticking...... rigid sharp indenter into a cylinder modeling indentation of a half space. The material is characterized by a finite strain elastic-viscoplastic constitutive relation that allows for plastic as well as elastic compressibility. Both soft elasticity and plastic compressibility significantly reduce...

Venous thromboembolism prophylaxis in plastic surgery

DEFF Research Database (Denmark)

Nielsen, Lea Juul; Matzen, Steen H

2017-01-01

BACKGROUND: Venous thromboembolism is a well-documented complication of surgery, including plastic surgery. However, few consensus guidelines on thromboembolism prophylaxis exist in plastic surgery and, thus, the different approaches in the public as well as the private clinics in Denmark were...... investigated using a web-based survey. METHODS: Forty-two clinics were contacted and 45% responded. RESULTS: The collected data reveals a lack of consensus in plastic surgery in Denmark, not only regarding the use of mechanical and chemical prophylaxis, but also which type of prophylaxis to apply, the duration...... of prophylaxis, and how to risk stratify the patients. CONCLUSION: The development of a guideline, based on plastic surgical data, using a validated risk assessment model, which combines the surgical risk with the patient related risk and recommends guidelines for mechanical as well as chemoprophylaxis...

Plastic ingestion by Flesh-footed Shearwaters (Puffinus carneipes): Implications for fledgling body condition and the accumulation of plastic-derived chemicals.

Science.gov (United States)

Lavers, Jennifer L; Bond, Alexander L; Hutton, Ian

2014-04-01

To provide much needed quantitative data on the lethal and sublethal effects of plastic pollution on marine wildlife, we sampled breast feathers and stomach contents from Flesh-footed Shearwater (Puffinus carneipes) fledglings in eastern Australia. Birds with high levels of ingested plastic exhibited reduced body condition and increased contaminant load (p plastic ingestion by seabirds, with 16% of fledglings failing these targets after a single feeding (range: 0.13-3.21 g of plastic/feeding). As top predators, seabirds are considered sentinels of the marine environment. The amount of plastic ingested and corresponding damage to Flesh-footed Shearwater fledglings is the highest reported for any marine vertebrate, suggesting the condition of the Australian marine environment is poor. These findings help explain the ongoing decline of this species and are worrying in light of increasing levels of plastic pollution in our oceans. Copyright © 2013 Elsevier Ltd. All rights reserved.

Deformation-driven diffusion and plastic flow in amorphous granular pillars.

Science.gov (United States)

Li, Wenbin; Rieser, Jennifer M; Liu, Andrea J; Durian, Douglas J; Li, Ju

2015-06-01

We report a combined experimental and simulation study of deformation-induced diffusion in compacted quasi-two-dimensional amorphous granular pillars, in which thermal fluctuations play a negligible role. The pillars, consisting of bidisperse cylindrical acetal plastic particles standing upright on a substrate, are deformed uniaxially and quasistatically by a rigid bar moving at a constant speed. The plastic flow and particle rearrangements in the pillars are characterized by computing the best-fit affine transformation strain and nonaffine displacement associated with each particle between two stages of deformation. The nonaffine displacement exhibits exponential crossover from ballistic to diffusive behavior with respect to the cumulative deviatoric strain, indicating that in athermal granular packings, the cumulative deviatoric strain plays the role of time in thermal systems and drives effective particle diffusion. We further study the size-dependent deformation of the granular pillars by simulation, and find that different-sized pillars follow self-similar shape evolution during deformation. In addition, the yield stress of the pillars increases linearly with pillar size. Formation of transient shear lines in the pillars during deformation becomes more evident as pillar size increases. The width of these elementary shear bands is about twice the diameter of a particle, and does not vary with pillar size.

Modulation of synaptic plasticity by stress hormone associates with plastic alteration of synaptic NMDA receptor in the adult hippocampus.

Directory of Open Access Journals (Sweden)

Yiu Chung Tse

Full Text Available Stress exerts a profound impact on learning and memory, in part, through the actions of adrenal corticosterone (CORT on synaptic plasticity, a cellular model of learning and memory. Increasing findings suggest that CORT exerts its impact on synaptic plasticity by altering the functional properties of glutamate receptors, which include changes in the motility and function of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid subtype of glutamate receptor (AMPAR that are responsible for the expression of synaptic plasticity. Here we provide evidence that CORT could also regulate synaptic plasticity by modulating the function of synaptic N-methyl-D-aspartate receptors (NMDARs, which mediate the induction of synaptic plasticity. We found that stress level CORT applied to adult rat hippocampal slices potentiated evoked NMDAR-mediated synaptic responses within 30 min. Surprisingly, following this fast-onset change, we observed a slow-onset (>1 hour after termination of CORT exposure increase in synaptic expression of GluN2A-containing NMDARs. To investigate the consequences of the distinct fast- and slow-onset modulation of NMDARs for synaptic plasticity, we examined the formation of long-term potentiation (LTP and long-term depression (LTD within relevant time windows. Paralleling the increased NMDAR function, both LTP and LTD were facilitated during CORT treatment. However, 1-2 hours after CORT treatment when synaptic expression of GluN2A-containing NMDARs is increased, bidirectional plasticity was no longer facilitated. Our findings reveal the remarkable plasticity of NMDARs in the adult hippocampus in response to CORT. CORT-mediated slow-onset increase in GluN2A in hippocampal synapses could be a homeostatic mechanism to normalize synaptic plasticity following fast-onset stress-induced facilitation.

How quickly do albatrosses and petrels digest plastic particles?

Science.gov (United States)

Ryan, Peter G

2015-12-01

Understanding how rapidly seabirds excrete or regurgitate ingested plastic items is important for their use as monitors of marine debris. van Franeker and Law (2015) inferred that fulmarine petrels excrete ∼75% of plastic particles within a month of ingestion based on decreases in the amounts of plastic in the stomachs of adult petrels moving to relatively clean environments to breed. However, similar decreases occur among resident species due to adults passing plastic loads to their chicks. The few direct measures of wear rates and retention times of persistent stomach contents suggest longer plastic residence times in most albatrosses and petrels. Residence time presumably varies with item size, type of plastic, the amount and composition of other persistent stomach contents, and the size at which items are excreted, which may vary among taxa. Accurate measures of ingested plastic retention times are needed to better understand temporal and spatial patterns in ingested plastic loads within marine organisms, especially if they are to be used as indicators of plastic pollution trends. Copyright © 2015 Elsevier Ltd. All rights reserved.

Are consumers concerned about plastic water bottles environmental impact?

OpenAIRE

Caroline Orset; Nicolas Barret; Aurélien Lemaire

2015-01-01

Although plastic induces environmental damages, almost all water bottles are made from plastic. However, these damages are more or less significant according to the plastic used. This study evaluates the consumers' willingness to pay (WTP) for different plastics used for water packaging. Successive messages emphasizing the characteristics of plastic are delivered to participants allowing explaining information influence on the consumers' WTP. We find that information has a significant effect ...

The future of A-150 TE plastic

International Nuclear Information System (INIS)

Goodman, L.J.

1985-01-01

For the past 26 years a large number of laboratories have constructed or purchased ionization chambers, proportional counters, and phantoms made of A-150 tissue-equivalent plastic, and they have amassed a considerable amount of data and experience in its properties and uses. The United States National Bureau of Standards is now considering the desirability of supplying A-150 plastic as a research material with a certified homogeneity. We are, however, faced with a problem since the nylon used in A-150 has been discontinued by the manufacturer and the current stock of A-150 has been estimated to be adequate to supply the demand for only the next 2 or 3 years. Thus, it will be necessary to reformulate the plastic mixture we will be using in the future. This situation offers us the opportunity to change the composition of tissue-equivalent plastic to better conform to present-day requirements. To elucidate just what these requirements are, we have conducted a postal survey of the opinions of neutron dosimetrists and the results are presented and discussed. It is concluded that the present A-150 plastic and a future tissue-equivalent plastic formulation should be made research materials, and that a future tissue-equivalent plastic should be made to conform as closely as possible to the soft tissue composition given in ICRU Report 33

Pervasive plastic

Science.gov (United States)

2018-05-01

Human manipulation of hydrocarbons — as fuel and raw materials for modern society — has changed our world and the indelible imprint we will leave in the rock record. Plastics alone have permeated our lives and every corner of our planet.

Plasticity: A New Materialist Approach to Policy and Methodology

Science.gov (United States)

Ulmer, Jasmine B.

2015-01-01

This article examines Catherine Malabou's philosophical concept of plasticity as a new materialist methodology. Given that plasticity simultaneously maintains the ability to receive, give, and annihilate form, plasticity and plastic readings offer material-discursive possibilities for educational research. This article begins by discussing the…

Three dimensional grain boundary modeling in polycrystalline plasticity

Science.gov (United States)

Yalçinkaya, Tuncay; Özdemir, Izzet; Fırat, Ali Osman

2018-05-01

At grain scale, polycrystalline materials develop heterogeneous plastic deformation fields, localizations and stress concentrations due to variation of grain orientations, geometries and defects. Development of inter-granular stresses due to misorientation are crucial for a range of grain boundary (GB) related failure mechanisms, such as stress corrosion cracking (SCC) and fatigue cracking. Local crystal plasticity finite element modelling of polycrystalline metals at micron scale results in stress jumps at the grain boundaries. Moreover, the concepts such as the transmission of dislocations between grains and strength of the grain boundaries are not included in the modelling. The higher order strain gradient crystal plasticity modelling approaches offer the possibility of defining grain boundary conditions. However, these conditions are mostly not dependent on misorientation of grains and can define only extreme cases. For a proper definition of grain boundary behavior in plasticity, a model for grain boundary behavior should be incorporated into the plasticity framework. In this context, a particular grain boundary model ([l]) is incorporated into a strain gradient crystal plasticity framework ([2]). In a 3-D setting, both bulk and grain boundary models are implemented as user-defined elements in Abaqus. The strain gradient crystal plasticity model works in the bulk elements and considers displacements and plastic slips as degree of freedoms. Interface elements model the plastic slip behavior, yet they do not possess any kind of mechanical cohesive behavior. The physical aspects of grain boundaries and the performance of the model are addressed through numerical examples.

A Sustainable Performance Assessment Framework for Plastic Film Supply Chain Management from a Chinese Perspective

Directory of Open Access Journals (Sweden)

Jiuping Xu

2016-10-01

Full Text Available Academics’ and practitioners’ interest in sustainable supply chain management has received great concern in recent years. The application of biaxially-oriented polypropylene (BOPP plastic film has had a significant influence on the economic, environmental and social performance of supply chain management. However, research on the integration of these three sustainable dimensions is still rare in this field. In this paper, we identify sustainability criteria based on a triple bottom line approach (economic benefit, environmental protection and social responsibility from the supply chain perspective, develop a hybrid multi-criteria decision making framework to evaluate the criteria and select alternatives and apply the proposed approach to a real case study at a focal BOPP plastic film company in China. In the framework, a fuzzy analytical hierarchy process (FAHP is used to determine the performance criteria weights and a fuzzy technique for order performance by similarity to ideal solution (FTOPSIS is applied to rank the alternatives. The case study finds that the economic dimension was the most important aspect with environmental second and social third. The results also verify the effectiveness of the proposed framework. This paper develops an effective and systematic approach for decision makers to conduct evaluations and select optimal alternatives for focal plastic film companies.

The plastic rotation effect in an isotropic gradient plasticity model for applications at the meso scale

NARCIS (Netherlands)

Poh, Leong Hien; Peerlings, R.H.J.

2016-01-01

Although formulated to represent a large system of polycrystals at the macroscopic level, isotropic gradient plasticity models have routinely been adopted at the meso scale. For such purposes, it is crucial to incorporate the plastic rotation effect in order to obtain a reasonable approximation of

Non-uniform plastic deformation of micron scale objects

DEFF Research Database (Denmark)

Niordson, Christian Frithiof; Hutchinson, J. W.

2003-01-01

Significant increases in apparent flow strength are observed when non-uniform plastic deformation of metals occurs at the scale ranging from roughly one to ten microns. Several basic plane strain problems are analyzed numerically in this paper based on a new formulation of strain gradient...... plasticity. The problems are the tangential and normal loading of a finite rectangular block of material bonded to rigid platens and having traction-free ends, and the normal loading of a half-space by a flat, rigid punch. The solutions illustrate fundamental features of plasticity at the micron scale...... that are not captured by conventional plasticity theory. These include the role of material length parameters in establishing the size dependence of strength and the elevation of resistance to plastic flow resulting from constraint on plastic flow at boundaries. Details of the finite element method employed...

Changing trends in plastic surgery training

Directory of Open Access Journals (Sweden)

Ramesh Kumar Sharma

2014-01-01

Full Text Available Background: The currently available training models are being put to scrutiny in India today, both by the residents and the teachers. Plastic surgery specialty was created primarily for reconstructive purposes but the society always perceived it from a cosmetic angle, particularly in the post second world war era. As a result, there is a need to redefine the goals of plastic surgery training in the present times so that the plastic surgeon is "future ready" to meet the needs of society and the market forces. Materials and Methods: The author has reviewed the currently available literature on plastic surgery training from India and the western countries. An attempt has been made to study opinions from the teachers and the trainees. The modules currently available in India and abroad have been analyzed and a suggestion has been made for drafting training programs that would meet the demands of the society as well as prepare the resident both for the aesthetic and reconstructive practice. Conclusions: The plastic surgery training needs to be more vibrant and in tune with the changing times. While maintaining its core nature, the current predominantly reconstructive modules need to incorporate the aesthetic content. The evaluation should be both knowledge and competence based. The teachers need to be educated in the various teaching methods that are more applicable to grown up residents. There is a need to find ways to attract talented people in the academic plastic surgery.

Changing trends in plastic surgery training.

Science.gov (United States)

Sharma, Ramesh Kumar

2014-05-01

The currently available training models are being put to scrutiny in India today, both by the residents and the teachers. Plastic surgery specialty was created primarily for reconstructive purposes but the society always perceived it from a cosmetic angle, particularly in the post second world war era. As a result, there is a need to redefine the goals of plastic surgery training in the present times so that the plastic surgeon is "future ready" to meet the needs of society and the market forces. The author has reviewed the currently available literature on plastic surgery training from India and the western countries. An attempt has been made to study opinions from the teachers and the trainees. The modules currently available in India and abroad have been analyzed and a suggestion has been made for drafting training programs that would meet the demands of the society as well as prepare the resident both for the aesthetic and reconstructive practice. The plastic surgery training needs to be more vibrant and in tune with the changing times. While maintaining its core nature, the current predominantly reconstructive modules need to incorporate the aesthetic content. The evaluation should be both knowledge and competence based. The teachers need to be educated in the various teaching methods that are more applicable to grown up residents. There is a need to find ways to attract talented people in the academic plastic surgery.

Three-Dimensional Numerical Analysis of Compound Lining in Complex Underground Surge-Shaft Structure

Directory of Open Access Journals (Sweden)

Juntao Chen

2015-01-01

Full Text Available The mechanical behavior of lining structure of deep-embedded cylinder surge shaft with multifork tunnel is analyzed using three-dimensional nonlinear FEM. With the elastic-plastic constitutive relations of rock mass imported and the implicit bolt element and distributed concrete cracking model adopted, a computing method of complex surge shaft is presented for the simulation of underground excavations and concrete lining cracks. In order to reflect the interaction and initial gap between rock mass and concrete lining, a three-dimensional nonlinear interface element is adopted, which can take into account both the normal and tangential characteristics. By an actual engineering computation, the distortion characteristics and stress distribution rules of the dimensional multifork surge-shaft lining structure under different behavior are revealed. The results verify the rationality and feasibility of this computation model and method and provide a new idea and reference for the complex surge-shaft design and construction.

Color change, phenotypic plasticity, and camouflage

Directory of Open Access Journals (Sweden)

Martin eStevens

2016-05-01

Full Text Available The ability to change appearance over a range of timescales is widespread in nature, existing in many invertebrate and vertebrate groups. This can include color change occurring in seconds, minutes, and hours, to longer term changes associated with phenotypic plasticity and development. A major function is for camouflage against predators because color change and plasticity enables animals to match their surroundings and potentially reduce the risk of predation. Recently, we published findings (Stevens et al. 2014a showing how shore crabs can change their appearance and better match the background to predator vision in the short term. This, coupled with a number of past studies, emphasizes the potential that animals have to modify their appearance for camouflage. However, the majority of studies on camouflage and color plasticity have focused on a small number of species capable of unusually rapid changes. There are many broad questions that remain about the nature, mechanisms, evolution, and adaptive value of color change and plasticity for concealment. Here, I discuss past work and outline six questions relating to color change and plasticity, as well as major avenues for future work.

Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste

International Nuclear Information System (INIS)

Adrados, A.; Marco, I. de; Caballero, B.M.; López, A.; Laresgoiti, M.F.; Torres, A.

2012-01-01

Highlights: ► Pyrolysis of plastic waste. ► Comparison of different samples: real waste, simulated and real waste + catalyst. ► Study of the effects of inorganic components in the pyrolysis products. - Abstract: Pyrolysis may be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at complete separation is not technically possible or economically viable, and they are typically sent to landfills or incinerators. For this study, a simulated plastic mixture and a real waste sample from a sorting plant were pyrolyzed using a non-stirred semi-batch reactor. Red mud, a byproduct of the aluminum industry, was used as a catalyst. Despite the fact that the samples had a similar volume of material, there were noteworthy differences in the pyrolysis yields. The real waste sample resulted, after pyrolysis, in higher gas and solid yields and consequently produced less liquid. There were also significant differences noted in the compositions of the compared pyrolysis products.

Introduction to Computational Plasticity

International Nuclear Information System (INIS)

Hartley, P

2006-01-01

The focus of the book on computational plasticity embodies techniques of relevance not only to academic researchers, but also of interest to industrialists engaged in the production of components using bulk or sheet forming processes. Of particular interest is the guidance on how to create modules for use with the commercial system Abaqus for specific types of material behaviour. The book is in two parts, the first of which contains six chapters, starting with microplasticity, but predominantly on continuum plasticity. The first chapter on microplasticty gives a brief description of the grain structure of metals and the existence of slip systems within the grains. This provides an introduction to the concept of incompressibility during plastic deformation, the nature of plastic yield and the importance of the critically resolved shear stress on the slip planes (Schmid's law). Some knowledge of the notation commonly used to describe slip systems is assumed, which will be familiar to students of metallurgy, but anyone with a more general engineering background may need to undertake additional reading to understand the various descriptions. Chapter two introduces one of several yield criteria, that normally attributed to von Mises (though historians of mechanics might argue over who was first to develop the theory of yielding associated with strain energy density), and its two or three-dimensional representation as a yield surface. The expansion of the yield surface during plastic deformation, its translation due to kinematic hardening and the Bauschinger effect in reversed loading are described with a direct link to the material stress-strain curve. The assumption, that the increment of strain is normal to the yield surface, the normality principle, is introduced. Uniaxial loading of an elastic-plastic material is used as an example in which to develop expressions to describe increments in stress and strain. The full presentation of numerous expressions, tensors and

Plasticity: modeling & computation

National Research Council Canada - National Science Library

Borja, Ronaldo Israel

2013-01-01

.... "Plasticity Modeling & Computation" is a textbook written specifically for students who want to learn the theoretical, mathematical, and computational aspects of inelastic deformation in solids...

Semantic modeling of the structural and process entities during plastic deformation of crystals and rocks

Science.gov (United States)

Babaie, Hassan; Davarpanah, Armita

2016-04-01

We are semantically modeling the structural and dynamic process components of the plastic deformation of minerals and rocks in the Plastic Deformation Ontology (PDO). Applying the Ontology of Physics in Biology, the PDO classifies the spatial entities that participate in the diverse processes of plastic deformation into the Physical_Plastic_Deformation_Entity and Nonphysical_Plastic_Deformation_Entity classes. The Material_Physical_Plastic_Deformation_Entity class includes things such as microstructures, lattice defects, atoms, liquid, and grain boundaries, and the Immaterial_Physical_Plastic_Deformation_Entity class includes vacancies in crystals and voids along mineral grain boundaries. The objects under the many subclasses of these classes (e.g., crystal, lattice defect, layering) have spatial parts that are related to each other through taxonomic (e.g., Line_Defect isA Lattice_Defect), structural (mereological, e.g., Twin_Plane partOf Twin), spatial-topological (e.g., Vacancy adjacentTo Atom, Fluid locatedAlong Grain_Boundary), and domain specific (e.g., displaces, Fluid crystallizes Dissolved_Ion, Void existsAlong Grain_Boundary) relationships. The dynamic aspect of the plastic deformation is modeled under the dynamical Process_Entity class that subsumes classes such as Recrystallization and Pressure_Solution that define the flow of energy amongst the physical entities. The values of the dynamical state properties of the physical entities (e.g., Chemical_Potential, Temperature, Particle_Velocity) change while they take part in the deformational processes such as Diffusion and Dislocation_Glide. The process entities have temporal parts (phases) that are related to each other through temporal relations such as precedes, isSubprocessOf, and overlaps. The properties of the physical entities, defined under the Physical_Property class, change as they participate in the plastic deformational processes. The properties are categorized into dynamical, constitutive

33 CFR 183.552 - Plastic encased fuel tanks: Installation.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Plastic encased fuel tanks... § 183.552 Plastic encased fuel tanks: Installation. (a) Each fuel tank encased in cellular plastic foam or in fiber reinforced plastic must have the connections, fittings, and labels accessible for...

Scenarios study on post-consumer plastic packaging waste recycling

NARCIS (Netherlands)

Thoden van Velzen, E.U.; Bos-Brouwers, H.E.J.; Groot, J.J.; Bing Xiaoyun, Xiaoyun; Jansen, M.; Luijsterburg, B.

2013-01-01

We all use plastics on a daily basis. Plastics come in many shapes, sizes and compositions and are used in a wide variety of products. Almost all of the currently used plastic packaging are made from fossil resources, which are finite. The production of plastic packages causes environmental impacts,

From waste plastics to industrial raw materials: A life cycle assessment of mechanical plastic recycling practice based on a real-world case study.

Science.gov (United States)

Gu, Fu; Guo, Jianfeng; Zhang, Wujie; Summers, Peter A; Hall, Philip

2017-12-01

Mechanical recycling of waste plastics is an environmental solution to the problem of waste plastic disposal, and has already become a common practice in industry. However, limited information can be found on either the industralised plastic recycling or the recycled materials, despite the use of recycled plastics has already extended to automobile production. This study investigates the life cycle environmental impacts of mechanical plastic recycling practice of a plastic recycling company in China. Waste plastics from various sources, such as agricultural wastes, plastic product manufacturers, collected solid plastic wastes and parts dismantled from waste electric and electronic equipments, are processed in three routes with products end up in different markets. The results of life cycle assessments show that the extrusion process has the largest environmental impacts, followed by the use of fillers and additives. Compared to production of virgin plastics and composites, the mechanical recycling is proved to be a superior alternative in most environmental aspects. Substituting virgin plastic composites with recycled plastic composites has achieved the highest environmental benefits, as virgin composite production has an impact almost 4 times higher that of the recycled composite production in each ReCiPe endpoint damage factor. Sensitivity analysis shows that the coverage of collecting network contribute affect little to overall environmental impact, and centralisation plays an important role in reducing overall environmental impacts. Among the fillers and additives, impact modifiers account for the most significant contributions to the environmental impacts of recycled composites. This study provides necessary information about the existing industrialised plastic recycling practice, and recommendations are given. Research implications are presented with the purpose to achieve higher substitution rate and lower environmental impact. Copyright © 2017 Elsevier B

Genetic Regulation of Phenotypic Plasticity and Canalisation in Yeast Growth.

Directory of Open Access Journals (Sweden)

Anupama Yadav

Full Text Available The ability of a genotype to show diverse phenotypes in different environments is called phenotypic plasticity. Phenotypic plasticity helps populations to evade extinctions in novel environments, facilitates adaptation and fuels evolution. However, most studies focus on understanding the genetic basis of phenotypic regulation in specific environments. As a result, while it's evolutionary relevance is well established, genetic mechanisms regulating phenotypic plasticity and their overlap with the environment specific regulators is not well understood. Saccharomyces cerevisiae is highly sensitive to the environment, which acts as not just external stimulus but also as signalling cue for this unicellular, sessile organism. We used a previously published dataset of a biparental yeast population grown in 34 diverse environments and mapped genetic loci regulating variation in phenotypic plasticity, plasticity QTL, and compared them with environment-specific QTL. Plasticity QTL is one whose one allele exhibits high plasticity whereas the other shows a relatively canalised behaviour. We mapped phenotypic plasticity using two parameters-environmental variance, an environmental order-independent parameter and reaction norm (slope, an environmental order-dependent parameter. Our results show a partial overlap between pleiotropic QTL and plasticity QTL such that while some plasticity QTL are also pleiotropic, others have a significant effect on phenotypic plasticity without being significant in any environment independently. Furthermore, while some plasticity QTL are revealed only in specific environmental orders, we identify large effect plasticity QTL, which are order-independent such that whatever the order of the environments, one allele is always plastic and the other is canalised. Finally, we show that the environments can be divided into two categories based on the phenotypic diversity of the population within them and the two categories have

Triboelectrostatic separation for granular plastic waste recycling: a review.

Science.gov (United States)

Wu, Guiqing; Li, Jia; Xu, Zhenming

2013-03-01

The world's plastic consumption has increased incredibly in recent decades, generating more and more plastic waste, which makes it a great public concern. Recycling is the best treatment for plastic waste since it cannot only reduce the waste but also reduce the consumption of oil for producing new virgin plastic. Mechanical recycling is recommended for plastic waste to avoid the loss of its virgin value. As a mechanical separation technology, triboelectrostatic separation utilizes the difference between surface properties of different materials to get them oppositely charged, deflected in the electric field and separately collected. It has advantages such as high efficiency, low cost, no concern of water disposal or secondary pollution and a relatively wide processing range of particle size especially suitable for the granular plastic waste. The process of triboelectrostatic separation for plastic waste is reviewed in this paper. Different devices have been developed and proven to be effective for separation of plastic waste. The influence factors are also discussed. It can be concluded that the triboelectrostatic separation of plastic waste is a promising technology. However, more research is required before it can be widely applied in industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

Contaminants in northern fulmars (Fulmarus glacialis) exposed to plastic

OpenAIRE

Ask, Amalie V.; Anker-Nilssen, Tycho; Herzke, Dorte; Trevail, Alice; Franeker, Jan Andries van; Gabrielsen, Geir Wing

2016-01-01

Northern fulmars are seabirds which feed exclusively at sea, and as such, they are useful indicators of ocean health. Marine plastic pollution is an ever-increasing and global issue that affects the northern fulmar as they are frequently found to have ingested plastic. In this report we investigate whether the amount of ingested plastic affects the concentration of certain plastic-adsorbed toxicants in their tissues. Marine plastic pollution is a field of utmost importance. It is our hope tha...

COMPOSITES FROM RECYCLED WOOD AND PLASTICS

Science.gov (United States)

The ultimate goal of this research was to develop technology to convert recycled wood fiber and plastics into durable products that are recyclable and otherwise environmentally friendly. Two processing technologies were used to prepare wood-plastic composites: air-laying and melt...

49 CFR 192.59 - Plastic pipe.

Science.gov (United States)

2010-10-01

... Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe...

RP-1 Polymer Identification System : Recycler of Plastics

OpenAIRE

ECT Team, Purdue

2007-01-01

It has been noticed that one of the primary obstacles in recycling is the lack of sufficient means to avoid cross contamination during collection. In particular, the new method to quickly and easily identify materials has been demanded in plastic industry due to the dramatic acceleration of plastic consumption in the last forty years. SpectraCode's new technology enables the instant point-and-shoot identification of black plastics, extracting a definitive signature from most black plastics in...

49 CFR 192.193 - Valve installation in plastic pipe.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Valve installation in plastic pipe. 192.193... Components § 192.193 Valve installation in plastic pipe. Each valve installed in plastic pipe must be designed so as to protect the plastic material against excessive torsional or shearing loads when the valve...

49 CFR 192.191 - Design pressure of plastic fittings.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Design pressure of plastic fittings. 192.191... Components § 192.191 Design pressure of plastic fittings. (a) Thermosetting fittings for plastic pipe must conform to ASTM D 2517, (incorporated by reference, see § 192.7). (b) Thermoplastic fittings for plastic...

21 CFR 878.3925 - Plastic surgery kit and accessories.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Plastic surgery kit and accessories. 878.3925... (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3925 Plastic surgery kit and accessories. (a) Identification. A plastic surgery kit and accessories is a device intended to...

Overview of Facial Plastic Surgery and Current Developments

Science.gov (United States)

Chuang, Jessica; Barnes, Christian; Wong, Brian J. F.

2016-01-01

Facial plastic surgery is a multidisciplinary specialty largely driven by otolaryngology but includes oral maxillary surgery, dermatology, ophthalmology, and plastic surgery. It encompasses both reconstructive and cosmetic components. The scope of practice for facial plastic surgeons in the United States may include rhinoplasty, browlifts, blepharoplasty, facelifts, microvascular reconstruction of the head and neck, craniomaxillofacial trauma reconstruction, and correction of defects in the face after skin cancer resection. Facial plastic surgery also encompasses the use of injectable fillers, neural modulators (e.g., BOTOX Cosmetic, Allergan Pharmaceuticals, Westport, Ireland), lasers, and other devices aimed at rejuvenating skin. Facial plastic surgery is a constantly evolving field with continuing innovative advances in surgical techniques and cosmetic adjunctive technologies. This article aims to give an overview of the various procedures that encompass the field of facial plastic surgery and to highlight the recent advances and trends in procedures and surgical techniques. PMID:28824978

Diacylglycerol kinases in the coordination of synaptic plasticity

Directory of Open Access Journals (Sweden)

Dongwon Lee

2016-08-01

Full Text Available Synaptic plasticity is activity-dependent modification of the efficacy of synaptic transmission. Although detailed mechanisms underlying synaptic plasticity are diverse and vary at different types of synapses, diacylglycerol (DAG-associated signaling has been considered as an important regulator of many forms of synaptic plasticity, including long-term potentiation (LTP and long-term depression (LTD. Recent evidence indicate that DAG kinases (DGKs, which phosphorylate DAG to phosphatidic acid to terminate DAG signaling, are important regulators of LTP and LTD, as supported by the results from mice lacking specific DGK isoforms. This review will summarize these studies and discuss how specific DGK isoforms distinctly regulate different forms of synaptic plasticity at pre- and postsynaptic sites. In addition, we propose a general role of DGKs as coordinators of synaptic plasticity that make local synaptic environments more permissive for synaptic plasticity by regulating DAG concentration and interacting with other synaptic proteins.

The plastic-associated microorganisms of the North Pacific Gyre

International Nuclear Information System (INIS)

Carson, Henry S.; Nerheim, Magnus S.; Carroll, Katherine A.; Eriksen, Marcus

2013-01-01

Highlights: • Microorganisms mediate processes affecting the fate and impacts of marine plastic. • North Pacific Gyre (NPG) plastics were examined with scanning-electron microscopy. • Bacillus bacteria and pennate diatoms dominated the NPG plastic fouling community. • Bacterial abundance was patchily distributed but increased on foamed polystyrene. • Diatom abundance increased on rough surfaces and at sites with high plastic density. -- Abstract: Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm −2 ) and pennate diatoms (1097 ± 154 mm −2 ) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution

Joining by plastic deformation

DEFF Research Database (Denmark)

Mori, Ken-ichiro; Bay, Niels; Fratini, Livan

2013-01-01

As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating opportuni......As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating...

Dynamic plastic buckling of cylindrical and spherical shells

International Nuclear Information System (INIS)

Jones, N.; Okawa, D.M.

1975-01-01

A theoretical analysis is developed to predict the dynamic plastic buckling of a long, impulsively loaded cylindrical shell in order to examine various features of plastic buckling and to assess the importance of several approximations with previous authors have introduced in dynamic plastic buckling studies. The influence of a time-dependent circumferential membrane force, the sharpness of the peaks in the displacement and velocity amplification functions, the restrictions which are implicit when employing the Prandtl-Reuss equations in this class of problems, and the limitations due to elastic unloading are examined in some detail. A summary of all previously published theoretical investigations known to the authors is undertaken for the dynamic plastic behavior of cylindrical shells and rings which are made from rigid-plastic, rigid-visco-plastic, elastic-plastic and elastic-visco-plastic materials and subjected to initial axisymmetric impulsive velocity fields. The theoretical predictions of the dominant motions, critical mode numbers, and threshold impulses are compared and critically reviewed. An experimental investigation was also undertaken into the dynamic plastic buckling of circular rings subjected to uniformly distributed external impulsive velocities. It appears that no experiments have been reported previously on mild steel cylindrical shells with an axial length (L) less than four times the shell radius (R). The experimental values of the average final radial deflections, critical mode numbers and dimensions of the permanent wrinkles in the mild steel and some aliminium 6,061 T6 specimens are compared with all the previously published theoretical predictions and experimental results on cylindrical shells with various axial lengths. (orig./HP) [de

Recent advancements and prospects of plastic surgery

Directory of Open Access Journals (Sweden)

Xin XING

2011-09-01

Full Text Available Objective To summarize the recent advancements and developmental prospects of plastic surgery worldwide,and to describe the future directions,aims,and highlights of Chinese military plastic surgery.Methods Relevant articles published in the last five years were retrieved through a search in PubMed,Medline,and CMCC.A statistical survey was conducted to summarize the achievements obtained by the Chinese military plastic surgery unit in the last five years.Results Considerable progress has been achieved in both clinical treatment and basic research of plastic surgery in the past five years.Its important role in the early treatment of combat injury and trauma has been recognized and emphasized.Chinese military plastic surgery has achieved considerable accomplishments in the last five years,especially in chronic wound repair;mechanism,prevention,and treatment of explosive soft tissue injuries and seawater immersion wounds;and new remedies of maxillofacial traumatic deformity,composite facial tissue allograft,and so on.Conclusions The repair and reconstruction of tissue defect and deformity caused by war injury and trauma will be the future major research direction of military plastic surgery.Research work should focus on tissue engineering,composite tissue allograft,stem cell therapy,mechanism of abnormal scar formation,among others,to solve the clinical problems of destructive facial injuries,extensive thora-abdominal wall defects,chronic ulcer,abnormal scars,and so on.Furthermore,plastic surgeons should fully utilize their special skills and take active part in the early treatment of war injury and trauma.

Seasonal Change in Nearshore and Channel Morphology at Packery Channel, A New Inlet Serving Corpus Christi, Texas

Science.gov (United States)

2011-01-01

position defined by limiting features such as the dune toe or seawall. Individual transects are spaced at 1 to 30 m apart. These surveys usually require...associated nominal depths (MSL) are: 1) a wading survey conducted from the landward limiting feature, such as dune or seawall, to offshore depth of...Hall Pier. The surge forced water up to the dune line adjacent to the channel. The water was funneled toward and into the inlet, introducing sand from

49 CFR 178.519 - Standards for plastic film bags.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for plastic film bags. 178.519 Section... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.519 Standards for plastic film bags. (a) The identification code for a plastic film bag is 5H4. (b) Construction requirements for plastic film...

Plastics Distribution and Degradation on Lake Huron Beaches

Science.gov (United States)

Zbyszewski, M.; Corcoran, P.

2009-05-01

The resistivity of plastic debris to chemical and mechanical weathering processes poses a serious threat to the environment. Numerous marine beaches are littered with plastic fragments that entangle and become ingested by organisms including birds, turtles and plankton. Although many studies have been conducted to determine the amount and effects of plastics pollution on marine organisms, relatively little is known about the distribution and quantity of polymer types along lacustrine beaches. Plastic particles sampled from selected beaches on Lake Huron were analyzed using Fourier Transform Infrared Spectroscopy (FTIR) to determine polymer composition. The majority of the plastic fragments are industrial pellets composed of polypropylene and polyethylene. Varying degrees of oxidation are indicated by multiple irregular peaks in the lower wavenumber region on the FTIR spectra. The oxidized pellets also represent the plastic particles with the most pronounced surface textures, as identified using Scanning Electron Microscopy (SEM). Crazes and flakey, fibrous, or granular textures are consistent with chemical weathering processes, whereas gauges and pits occur through abrasion during mechanical weathering. Further textural and compositional analysis will indicate which polymer types are more resistant to weathering processes. Additional investigation of the distribution of plastic debris along the beaches of Lake Huron will indicate the amount and primary transport directions of resistant plastic debris polluting one of Ontario's Great Lakes.

Migration of DEHP from plastic to food simulants under microwave heating

Science.gov (United States)

Zhu, X.; Li, F.; Qiu, Z. Z.; Huang, J. W.

2017-05-01

The migration of plasticizer DEHP from the plastic products (4 kinds of commonly used plastic food containers under microwave heating: plastic wrap, food bags, ordinary plastic boxes, microwave special plastic boxes) through food contact materials to food simulants (isooctane, 10% ethanol-water solution (v/v), 3% acetic acid-water solution (w/w) and distilled water) was studied under microwave heating (power levels of 400 W). The results shows that the DEHP mobility increases with the increase of microwave heating time, DEHP mobility in isooctane and 3% acetic acid-water solution (w/w) is significantly greater than in 10% ethanol-water solution (v/v) and distilled water; the order of DEHP mobility in isooctane is plastic wrap>food bag>common plastic box>microwave-safe plastic box, while in 3% acetic acid (w/w), the order is food bag>common plastic box>microwave-safe plastic box>plastic wrap.

Life cycle assessment of post-consumer plastics production from waste electrical and electronic equipment (WEEE) treatment residues in a Central European plastics recycling plant