WorldWideScience

Sample records for plastic ocean thermal

  1. 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.

  2. Plastic debris in the open ocean

    OpenAIRE

    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. Howeve...

  3. 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.

  4. 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.

  5. 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

  6. Ocean Thermal Extractable Energy Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Ascari, Matthew [Lockheed Martin Corporation, Bethesda, MD (United States)

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world’s ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today’s state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.

  7. Plastic debris in the open ocean

    KAUST Repository

    Cozar, Andres; Echevarrí a, Fidel; Gonzaĺez-Gordillo, Juan Igná cio; Irigoien, Xabier; Ú beda, Bá rbara; Hernandez-Leon, Santiago; Palma, Á lvaro T.; Navarro, Sandra; Garcí a-de-Lomas, Juan; Ruiz, Andrea; Ferná ndez De Puelles, Ma Luz; Duarte, Carlos M.

    2014-01-01

    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

  8. Ocean acidification challenges copepod phenotypic plasticity

    Directory of Open Access Journals (Sweden)

    A. Vehmaa

    2016-11-01

    Full Text Available Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC as a function of acidification (fCO2  ∼  365–1231 µatm and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm or quality (C : N weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

  9. Ocean acidification challenges copepod reproductive plasticity

    Science.gov (United States)

    Vehmaa, A.; Almén, A.-K.; Brutemark, A.; Paul, A.; Riebesell, U.; Furuhagen, S.; Engström-Öst, J.

    2015-11-01

    Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia bifilosa in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ~ 365-1231 μatm), and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal if transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female copepod size and egg hatching success. In addition, we found a threshold of fCO2 concentration (~ 1000 μatm), above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon ~ 55 μm) or quality (C : N) weakens the transgenerational effects. However, females with high ORAC produced eggs with high hatching success. Overall, these results indicate that A. bifilosa could be affected by projected near future CO2 levels.

  10. Ocean acidification challenges copepod phenotypic plasticity

    Science.gov (United States)

    Vehmaa, Anu; Almén, Anna-Karin; Brutemark, Andreas; Paul, Allanah; Riebesell, Ulf; Furuhagen, Sara; Engström-Öst, Jonna

    2016-11-01

    Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ˜ 365-1231 µatm) and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm) or quality (C : N) weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

  11. Marine pollution. Plastic waste inputs from land into the ocean.

    Science.gov (United States)

    Jambeck, Jenna R; Geyer, Roland; Wilcox, Chris; Siegler, Theodore R; Perryman, Miriam; Andrady, Anthony; Narayan, Ramani; Law, Kara Lavender

    2015-02-13

    Plastic debris in the marine environment is widely documented, but the quantity of plastic entering the ocean from waste generated on land is unknown. By linking worldwide data on solid waste, population density, and economic status, we estimated the mass of land-based plastic waste entering the ocean. We calculate that 275 million metric tons (MT) of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million MT entering the ocean. Population size and the quality of waste management systems largely determine which countries contribute the greatest mass of uncaptured waste available to become plastic marine debris. Without waste management infrastructure improvements, the cumulative quantity of plastic waste available to enter the ocean from land is predicted to increase by an order of magnitude by 2025. Copyright © 2015, American Association for the Advancement of Science.

  12. Molecular Plasticity under Ocean Warming: Proteomics and Fitness Data Provides Clues for a Better Understanding of the Thermal Tolerance in Fish.

    Science.gov (United States)

    Madeira, Diana; Araújo, José E; Vitorino, Rui; Costa, Pedro M; Capelo, José L; Vinagre, Catarina; Diniz, Mário S

    2017-01-01

    Ocean warming is known to alter the performance and fitness of marine organisms albeit the proteome underpinnings of species thermal tolerance are still largely unknown. In this 1-month experiment we assessed the vulnerability of the gilt-head sea bream Sparus aurata , taken here as a biological model for some key fisheries species, to ocean warming (control 18°C, nursery ground temperature 24°C and heat wave 30°C). Survival was impaired after 28 days, mainly at 30°C although fishes' condition was unaltered. Muscle proteome modulation was assessed at 14 and 21 days, showing that protein expression profiles were similar between fish exposed to 18 and 24°C, differing from fish exposed to 30°C. Fish subjected to 24°C showed an enhanced glycolytic potential and decreased glycogenolysis mainly at 14 days of exposure. Fish subjected to 30°C also showed enhanced glycolytic potential and up-regulated proteins related to gene expression, cellular stress response (CSR), and homeostasis (mostly cytoskeletal dynamics, acid-base balance, chaperoning). However, inflammatory processes were elicited at 21 days along with a down-regulation of the tricarboxylic acid cycle. Thus, juvenile fish seem able to acclimate to 24°C but possibly not to 30°C, which is the predicted temperature for estuaries during heat waves by the year 2100. This may be related with increasing constraints on organism physiology associated with metabolic scope available for performance and fitness at higher temperatures. Consequently, recruitment of commercial sea breams may be in jeopardy, highlighting the need for improved management plans for fish stocks.

  13. Molecular Plasticity under Ocean Warming: Proteomics and Fitness Data Provides Clues for a Better Understanding of the Thermal Tolerance in Fish

    Directory of Open Access Journals (Sweden)

    Diana Madeira

    2017-10-01

    Full Text Available Ocean warming is known to alter the performance and fitness of marine organisms albeit the proteome underpinnings of species thermal tolerance are still largely unknown. In this 1-month experiment we assessed the vulnerability of the gilt-head sea bream Sparus aurata, taken here as a biological model for some key fisheries species, to ocean warming (control 18°C, nursery ground temperature 24°C and heat wave 30°C. Survival was impaired after 28 days, mainly at 30°C although fishes' condition was unaltered. Muscle proteome modulation was assessed at 14 and 21 days, showing that protein expression profiles were similar between fish exposed to 18 and 24°C, differing from fish exposed to 30°C. Fish subjected to 24°C showed an enhanced glycolytic potential and decreased glycogenolysis mainly at 14 days of exposure. Fish subjected to 30°C also showed enhanced glycolytic potential and up-regulated proteins related to gene expression, cellular stress response (CSR, and homeostasis (mostly cytoskeletal dynamics, acid-base balance, chaperoning. However, inflammatory processes were elicited at 21 days along with a down-regulation of the tricarboxylic acid cycle. Thus, juvenile fish seem able to acclimate to 24°C but possibly not to 30°C, which is the predicted temperature for estuaries during heat waves by the year 2100. This may be related with increasing constraints on organism physiology associated with metabolic scope available for performance and fitness at higher temperatures. Consequently, recruitment of commercial sea breams may be in jeopardy, highlighting the need for improved management plans for fish stocks.

  14. Plastic pollution of the world's seas and oceans as a contemporary challenge in ocean governance.

    Science.gov (United States)

    Haward, Marcus

    2018-02-14

    The pervasive nature of marine plastic pollution was highlighted at the recent United Nations Environment Assembly. This meeting saw strong commitments for action, but at the same time reinforced the challenges for contemporary ocean governance in addressing marine plastic pollution.

  15. Ocean thermal-energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Ford, G; Niblett, C; Walker, L

    1983-03-01

    Ocean thermal-energy conversion (OTEC) is a novel 'alternative' energy technology that has created much interest in a number of countries; namely, the USA, Japan, France, Sweden, Holland, India and most recently, the UK. In particular, the first three of these have had programmes to develop the required technology. However, most interest has been centred in the USA, where the current hiatus in Federal funding provides a timely opportunity to assess progress. This paper offers a survey of the prevailing position there; outlining the outstanding technical and associated problems, and likely future developments. Non-USA programmes are only mentioned to contrast them with the American position. At present, it does not appear that OTEC plants will be commercially viable on a widespread basis even in the tropics. This is particularly true of the larger plants (400 MWe, MWe = megawatts of electrical energy, the final output of a power station) towards which the American programme is ultimately geared. There does seem to be a strong possibility that small OTEC plants, around 40 MWe or less, can be commercial in certain circumstances. This would be possible when one or, preferably, more of the following conditions are met: (i) where a land-based rather than 'at sea' plant is possible, (ii) where alternative energy supplies are at a premium, i.e. islands or regions without indigenous energy supplies, and (iii) where conditions are such that an OTEC plant could operate in conjunction with either or both an aquaculture or desalination plant.

  16. Plastic pollution in islands of the Atlantic Ocean.

    Science.gov (United States)

    Monteiro, Raqueline C P; Ivar do Sul, Juliana A; Costa, Monica F

    2018-07-01

    Marine plastic pollution is present in all oceans, including remote oceanic islands. Despite the increasing number of articles on plastic pollution in the last years, there is still a lack of studies in islands, that are biodiversity hotspots when compared to the surrounding ocean, and even other recognized highly biodiverse marine environments. Articles published in the peer reviewed literature (N = 20) were analysed according to the presence of macro (>5 mm) and microplastics (plastics associated with variables such as position of the beach in relation to wind and currents. Very few studies have analysed plastics colonization by organisms or the identification of persistent organic pollutants (POPs). Islands of the North/South Atlantic and Caribbean Sea were influenced by different sources of macroplastics, being marine-based sources (i.e., fishing activities) predominant in the Atlantic Ocean basin. On the other hand, in the Caribbean Sea, land-based sources were more common. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Thermal and catalytic pyrolysis of plastic waste

    Directory of Open Access Journals (Sweden)

    Débora Almeida

    2016-02-01

    Full Text Available Abstract The amount of plastic waste is growing every year and with that comes an environmental concern regarding this problem. Pyrolysis as a tertiary recycling process is presented as a solution. Pyrolysis can be thermal or catalytical and can be performed under different experimental conditions. These conditions affect the type and amount of product obtained. With the pyrolysis process, products can be obtained with high added value, such as fuel oils and feedstock for new products. Zeolites can be used as catalysts in catalytic pyrolysis and influence the final products obtained.

  18. 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.

  19. Thermal Reduction of NOx with Recycled Plastics.

    Science.gov (United States)

    Oluwoye, Ibukun; Dlugogorski, Bogdan Z; Gore, Jeff; Vyazovkin, Sergey; Boyron, Olivier; Altarawneh, Mohammednoor

    2017-07-05

    This study develops technology for mitigation of NO x formed in thermal processes using recycled plastics such as polyethylene (PE). Experiments involve sample characterization, and thermogravimetric decomposition of PE under controlled atmospheres, with NO x concentration relevant to industrial applications. TGA-Fourier transform infrared (FTIR) spectroscopy and NO x chemiluminescence serve to obtain the removal efficiency of NO x by fragments of pyrolyzing PE. Typical NO x removal efficiency amounts to 80%. We apply the isoconversional method to derive the kinetic parameters, and observe an increasing dependency of activation energy on the reaction progress. The activation energies of the process span 135 kJ/mol to 226 kJ/mol, and 188 kJ/mol to 268 kJ/mol, for neat and recycled PE, respectively, and the so-called compensation effect accounts for the natural logarithmic pre-exponential ln (A/min -1 ) factors of ca. 19-35 and 28-41, in the same order, depending on the PE conversion in the experimental interval of between 5 and 95%. The observed delay in thermal events of recycled PE reflects different types of PE in the plastic, as measurements of intrinsic viscosity indicate that, the recycled PE comprises longer linear chains. The present evaluation of isoconversional activation energies affords accurate kinetic modeling of both isothermal and nonisothermal decomposition of PE in NO x -doped atmosphere. Subsequent investigations will focus on the effect of mass transfer and the presence of oxygen, as reburning of NO x in large-scale combustors take place at higher temperatures than those included in the current study.

  20. Plastic pollution of the world’s seas and oceans as a contemporary challenge in ocean governance

    OpenAIRE

    Haward, Marcus

    2018-01-01

    The pervasive nature of marine plastic pollution was highlighted at the recent United Nations Environment Assembly. This meeting saw strong commitments for action, but at the same time reinforced the challenges for contemporary ocean governance in addressing marine plastic pollution.

  1. Revisit ocean thermal energy conversion system

    International Nuclear Information System (INIS)

    Huang, J.C.; Krock, H.J.; Oney, S.K.

    2003-01-01

    The earth, covered more than 70.8% by the ocean, receives most of its energy from the sun. Solar energy is transmitted through the atmosphere and efficiently collected and stored in the surface layer of the ocean, largely in the tropical zone. Some of the energy is re-emitted to the atmosphere to drive the hydrologic cycle and wind. The wind field returns some of the energy to the ocean in the form of waves and currents. The majority of the absorbed solar energy is stored in vertical thermal gradients near the surface layer of the ocean, most of which is in the tropical region. This thermal energy replenished each day by the sun in the tropical ocean represents a tremendous pollution-free energy resource for human civilization. Ocean Thermal Energy Conversion (OTEC) technology refers to a mechanical system that utilizes the natural temperature gradient that exists in the tropical ocean between the warm surface water and the deep cold water, to generate electricity and produce other economically valuable by-products. The science and engineering behind OTEC have been studied in the US since the mid-seventies, supported early by the U.S. Government and later by State and private industries. There are two general types of OTEC designs: closed-cycle plants utilize the evaporation of a working fluid, such as ammonia or propylene, to drive the turbine-generator, and open-cycle plants use steam from evaporated sea water to run the turbine. Another commonly known design, hybrid plants, is a combination of the two. OTEC requires relatively low operation and maintenance costs and no fossil fuel consumption. OTEC system possesses a formidable potential capacity for renewable energy and offers a significant elimination of greenhouse gases in producing power. In addition to electricity and drinking water, an OTEC system can produce many valuable by-products and side-utilizations, such as: hydrogen, air-conditioning, ice, aquaculture, and agriculture, etc. The potential of these

  2. Strength and thermal stability of fiber reinforced plastic composites ...

    African Journals Online (AJOL)

    Therefore, the strength properties and thermal stability of plastic composites reinforced with rattan fibers were investigated in this work. Particles of rattan species (Eremospatha macrocarpa (EM) and Laccosperma secundiflorum (LS)) were blended with High-Density Polyethylene (HDPE) to produce fiber reinforced plastic ...

  3. Plastic pollution in the marine environment. (Latest citations from Oceanic Abstracts). Published Search

    International Nuclear Information System (INIS)

    1993-02-01

    The bibliography contains citations concerning the adverse effects of synthetic polymers on oceans and beaches. The citations examine the impact of discarded plastics upon fish, seabirds, and other aquatic animals. The sources of plastic litter and the efforts of coastal communities to manage plastics pollution are referenced. International agreements designed to protect the marine environment by banning ocean dumping of plastics are discussed. (Contains a minimum of 145 citations and includes a subject term index and title list.)

  4. Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

    International Nuclear Information System (INIS)

    Soto, Rodrigo; Vergara, Julio

    2014-01-01

    In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

  5. 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 ).

  6. Elastic-plastic fracture mechanics study of thermal shock cracking

    International Nuclear Information System (INIS)

    Hirano, K.; Kobayashi, H.; Nakazawa, H.

    1980-01-01

    This paper describes thermal shock experiments conducted on a nuclear pressure vessel steel (A533 Grade B Class 1), an AISI304 steel and a tool steel (JIS SKD62) using both a new thermal shock test facility and method. Analysis of their quasi-static thermal stress intensity factors is performed on the basis of linear-elastic fracture mechanics; and a thermal shock fracture toughness value, Ksub(tsc) is evaluated. Then elastic-plastic fracture toughness tests are carried out in the same high temperature range of the thermal shock experiment, and a relation between the stretched zone width, SZW, formed as a result of the fatigue precrack tip plastic blunting and the J-integral is clarified. An elastic-plastic thermal shock fracture toughness value, Jsub(tsc), is evaluated from a critical value of the stretched zone width, SZWsub(tsc), at the initiation of the thermal shock cracking by using the relation between SZW and J. The Jsub(tsc) value is compared with an elastic-plastic fracture toughness value, Jsub(Ic), and the difference between these Jsub(tsc) and Jsub(Ic) values is discussed on the basis of fractography. (author)

  7. Numerical Approaches to Thermally Coupled Perfect Plasticity

    Czech Academy of Sciences Publication Activity Database

    Bartels, S.; Roubíček, Tomáš

    2013-01-01

    Roč. 29, č. 6 (2013), s. 1837-1863 ISSN 0749-159X R&D Projects: GA ČR GAP201/10/0357 Institutional support: RVO:61388998 Keywords : thermodynamics * Prandtl-Reuss plasticity * Kelvin-Voigt rheology Subject RIV: BA - General Mathematics Impact factor: 1.057, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/num.21779/full

  8. Ocean thermal energy conversion: Perspective and status

    Science.gov (United States)

    Thomas, Anthony; Hillis, David L.

    The use of the thermal gradient between the warm surface waters and the deep cold waters of tropical oceans was first proposed by J. A. d'Arsonval in 1881 and tried unsuccessfully by George Claude in 1930. Interest in Ocean Thermal Energy Conversion (OTEC) and other renewable energy sources revived in the 1970s as a result of oil embargoes. At that time, the emphasis was on large floating plants miles from shore producing 250 to 400 MW for maintained grids. When the problems of such plants became better understood and the price of oil reversed its upward trend, the emphasis shifted to smaller (10 MW) shore based plants on tropical islands. Such plants would be especially attractive if they produce fresh water as a by-product. During the past 15 years, major progress has been made in converting OTEC unknowns into knowns. Mini-OTEC proved the closed cycle concept. Cost effective heat exchanger concepts were identified. An effective biofouling control technique was discovered. Aluminum was determined to be promising for OTEC heat exchangers. Heat transfer augmentation techniques were identified, which promised a reduction on heat exchanger size and cost. Fresh water was produced by an OTEC open cycle flash evaporator, using the heat energy in the seawater itself. The current R and D emphasis is on the design and construction of a test facility to demonstrate the technical feasibility of the open cycle process. The 10 MW shore-based, closed cycle plant can be built with today's technology; with the incorporation of a flash evaporator, it will produce fresh water as well as electrical power; both valuable commodities on many tropical islands. The open cycle process has unknowns that require solution before the technical feasibility can be demonstrated. The economic viability of either cycle depends on reducing the capital costs of OTEC plants and on future trends in the costs of conventional energy sources.

  9. 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.

  10. Plastics in the Ocean: More Than a Litter Problem.

    Science.gov (United States)

    Center for Environmental Education, Washington, DC.

    Environmental impacts arise from entanglement of marine animals in plastic debris and from ingestion of plastics by marine organisms. Plastic debris can cause potential threats to humans when divers become entangled or vessels become fouled in debris. The depletion of fishery resources, vessel damage, and aesthetic degradation resulting in lost…

  11. Effect of plastic deformation on the niobium thermal expansion

    International Nuclear Information System (INIS)

    Savitskij, E.M.; Bychkova, M.I.; Kanikovskij, V.B.

    1978-01-01

    Using dilatometric method the effect of plastic deformation on change of thermal expansion coefficient (TEC) of niobium of different purity was studied. It was shown that deformation affected the TEC in different ways. At first the deformation degree rising causes linear decrease of the TEC and then linear increase. Carbon intensifies the TEC decrease of deformed niobium. The linear correlation was established between the TEC and the value of macroscopic stresses in plastic deformed niobium. The expression indicating the metal TEC change under loading was defined for case of strain hardening

  12. Thermal homogeneity of plastication processes in single-screw extruders

    Science.gov (United States)

    Bu, L. X.; Agbessi, Y.; Béreaux, Y.; Charmeau, J.-Y.

    2018-05-01

    Single-screw plastication, used in extrusion and in injection moulding, is a major way of processing commodity thermoplastics. During the plastication phase, the polymeric material is melted by the combined effects of shear-induced self-heating (viscous dissipation) and heat conduction coming from the barrel. In injection moulding, a high level of reliability is usually achieved that makes this process ideally suited to mass market production. Nonetheless, process fluctuations still appear that make moulded part quality control an everyday issue. In this work, we used a combined modelling of plastication, throughput calculation and laminar dispersion, to investigate if, and how, thermal fluctuations could propagate along the screw length and affect the melt homogeneity at the end of the metering section. To do this, we used plastication models to relate changes in processing parameters to changes in the plastication length. Moreover, a simple model of throughput calculation is used to relate the screw geometry, the polymer rheology and the processing parameters to get a good estimate of the mass flow rate. Hence, we found that the typical residence time in a single screw is around one tenth of the thermal diffusion time scale. This residence time is too short for the dispersion coefficient to reach a steady state, but too long to be able to neglect radial thermal diffusion and resort to a purely convective solution. Therefore, a full diffusion/convection problem has to be solved with a base flow described by the classic pressure and drag velocity field. Preliminary results already show the major importance of the processing parameters in the breakthrough curve of an arbitrary temperature fluctuation at the end of the metering section of injection moulding screw. When the flow back-pressure is high, the temperature fluctuation is spread more evenly with time, whereas a pressure drop in the flow will results in a breakthrough curve which presents a larger peak of

  13. Relating plastic in the ocean to ecological harm, a review of recent progress in risk analysis

    Science.gov (United States)

    Schuyler, Q. A.; Hardesty, B. D.; Wilcox, C.; van Sebille, E.; Mallos, N. J.; Leonard, G. H.

    2016-02-01

    Plastic pollution in the ocean is emerging as a global environmental concern. Estimates suggest that we dump on the order of 8.4 million tons of plastic in the ocean each year. This plastic reaches substantial concentrations, with at sea sampling measuring densities over 580,000 items per square kilometer. However, it is difficult to relate this exposure to resulting ecological impacts. Animals dying due to plastic ingestion or entanglement may not was ahsore, and sampling at sea is expensive and infrequent. Thus demonstrating a direct relationship between plastic in the envioronment and harm to marine wildlife is challenging. Here we review current progress on risk assessment for impacts to marine wildlife from plastic pollution. The analyses we review range from expert elicitation to integrated statistical and physical models. They range widely in scope, from estimates at the individual level to who taxa analysis. Some of the analyses reach only to exposure to the pressure, whie others carry through to estimate demographic impacts and even mortality due to ingestion of or entanglement in plastic debris in the ocean. We summarize the results of these studies, and provide a roadmap for future contributions toward estimating the actual ecological impact of plastic pollution.

  14. The Arctic Ocean as a dead end for floating plastics in the North Atlantic branch of the Thermohaline Circulation

    KAUST Repository

    Có zar, André s; Martí , Elisa; Duarte, Carlos M.; Garcí a-de-Lomas, Juan; van Sebille, Erik; Ballatore, Thomas J.; Eguí luz, V. M.; Gonzá lez-Gordillo, J. Ignacio; Pedrotti, Maria L.; Echevarrí a, Fidel; Troublè , Romain; Irigoien, Xabier

    2017-01-01

    The subtropical ocean gyres are recognized as great marine accummulation zones of floating plastic debris; however, the possibility of plastic accumulation at polar latitudes has been overlooked because of the lack of nearby pollution sources

  15. Exploring the Disappearing Ocean Micro Plastic Mystery: New Insights from Dissolved Organic Carbon photo production

    Science.gov (United States)

    Zhu, L.; Zhao, S.; Li, D.; Stubbins, A.

    2017-12-01

    Emerging as a novel planetary threat, plastic waste, dominated by millimeter-sized plastic (microplastic), is omnipresent in the oceans, posing broad environmental threats. However, only 1% of the microplastic waste exported from the land is found in the ocean. Most of the lost fraction is in the form of microplastics. The fate of these buoyant plastic fragments is a fundamental gap in our understanding of the fate and impact of plastics in marine ecosystems. To date, an effective sink for the lost microplastics has not been found. In this study, dissolved organic carbon (DOC) photo-production from the three dominant forms of ocean microplastics was assessed. These plastics were: 1) Polyethylene (PE) both for postconsumer samples and pure standard samples; 2) polypropylene (PP); and, expanded polystyrene (EPS). In addition, a Neustonic microplastic samples from the North Pacific Gyre were irradiated. These real-world samples were dominated by PE ( 80%). All samples were placed in seawater, in quartz flasks, and irradiated in a solar simulator for 2 months. During irradiation, DOC photo-production from PP, EPS, and the PE standard was exponential, while DOC photo-production from postconsumer PE and the Neustonic samples was linear. Scanning electron microscopy indicated surface ablation and micro-fragmentation during the irradiation of the three plastics that showed exponential DOC production (PP, EPS and standard PE), suggesting the increase in photo-reactivity of these plastics was a result of an increase in their surface to volume ratios and therefore their per-unit mass light exposure. Based on DOC production, the half-life of the microplastics ranged from 0.26 years for EPS to 86 years for PE, suggesting sunlight is a major removal term for buoyant oceanic microplastics. With respect to the broader carbon cycle, we conservatively estimate that plastic photodegradation releases 6 to 17 thousand metric tons of radiocarbon dead DOC to the surface ocean each year.

  16. Phenotypic plasticity of southern ocean diatoms: key to success in the sea ice habitat?

    Directory of Open Access Journals (Sweden)

    Olivia Sackett

    Full Text Available Diatoms are the primary source of nutrition and energy for the Southern Ocean ecosystem. Microalgae, including diatoms, synthesise biological macromolecules such as lipids, proteins and carbohydrates for growth, reproduction and acclimation to prevailing environmental conditions. Here we show that three key species of Southern Ocean diatom (Fragilariopsis cylindrus, Chaetoceros simplex and Pseudo-nitzschia subcurvata exhibited phenotypic plasticity in response to salinity and temperature regimes experienced during the seasonal formation and decay of sea ice. The degree of phenotypic plasticity, in terms of changes in macromolecular composition, was highly species-specific and consistent with each species' known distribution and abundance throughout sea ice, meltwater and pelagic habitats, suggesting that phenotypic plasticity may have been selected for by the extreme variability of the polar marine environment. We argue that changes in diatom macromolecular composition and shifts in species dominance in response to a changing climate have the potential to alter nutrient and energy fluxes throughout the Southern Ocean ecosystem.

  17. Detecting Plastic PFM-1 Butterfly Mines Using Thermal Infrared Sensing

    Science.gov (United States)

    Baur, J.; de Smet, T.; Nikulin, A.

    2017-12-01

    Remnant plastic-composite landmines, such as the mass-produced PFM-1, represent an ongoing humanitarian threat aggravated by high costs associated with traditional demining efforts. These particular unexploded ordnance (UXO) devices pose a challenge to conventional geophysical detection methods, due their plastic-body design and small size. Additionally, the PFM-1s represent a particularly heinous UXO, due to their low mass ( 25 lb) trigger limit and "butterfly" wing design, earning them the reputation of a "toy mine" - disproportionally impacting children across post-conflict areas. We developed a detection algorithm based on data acquired by a thermal infrared camera mounted to a commercial UAV to detect time-variable temperature difference between the PFM-1 and the surrounding environment. We present results of a field study focused on thermal detection and identification of the PFM-1 anti-personnel landmines from a remotely operated unmanned aerial vehicle (UAV). We conducted a series of field detection experiments meant to simulate the mountainous terrains where PFM-1 mines were historically deployed and remain in place. In our tests, 18 inert PFM-1 mines along with the aluminum KSF-1 casing were randomly dispersed to mimic an ellipsoidal minefield of 8-10 x 18-20 m dimensions in a de-vegetated rubble yard at Chenango Valley State Park (New York State). We collected multiple thermal infrared imagery datasets focused on these model minefields with the FLIR Vue Pro R attached to the 3DR Solo UAV flying at approximately at 2 m. We identified different environmental variables to constrain the optimal time of day and daily temperature variations to reveal presence of these plastic UXOs. We show that in the early-morning hours when thermal inertia is greatest, the PFM-1 mines can be detected based on their differential thermal inertia. Because the mines have statistically different temperatures than background and a characteristic shape, we were able to train a

  18. A thermal engine for underwater glider driven by ocean thermal energy

    International Nuclear Information System (INIS)

    Yang, Yanan; Wang, Yanhui; Ma, Zhesong; Wang, Shuxin

    2016-01-01

    Highlights: • Thermal engine with a double-tube structure is developed for underwater glider. • Isostatic pressing technology is effective to increase volumetric change rate. • Actual volumetric change rate reaches 89.2% of the theoretical value. • Long term sailing of 677 km and 27 days is achieved by thermal underwater glider. - Graphical Abstract: - Abstract: Underwater glider is one of the most popular platforms for long term ocean observation. Underwater glider driven by ocean thermal energy extends the duration and range of underwater glider powered by battery. Thermal engine is the core device of underwater glider to harvest ocean thermal energy. In this paper, (1) model of thermal engine was raised by thermodynamics method and the performance of thermal engine was investigated, (2) thermal engine with a double-tube structure was developed and isostatic pressing technology was applied to improve the performance for buoyancy driven, referencing powder pressing theory, (3) wall thickness of thermal engine was optimized to reduce the overall weight of thermal engine, (4) material selection and dimension determination were discussed for a faster heat transfer design, by thermal resistance analysis, (5) laboratory test and long term sea trail were carried out to test the performance of thermal engine. The study shows that volumetric change rate is the most important indicator to evaluating buoyancy-driven performance of a thermal engine, isostatic pressing technology is effective to improve volumetric change rate, actual volumetric change rate can reach 89.2% of the theoretical value and the average power is about 124 W in a typical diving profile. Thermal engine developed by Tianjin University is a superior thermal energy conversion device for underwater glider. Additionally, application of thermal engine provides a new solution for miniaturization of ocean thermal energy conversion.

  19. Understanding thermally activated plastic deformation behavior of Zircaloy-4

    Science.gov (United States)

    Kumar, N.; Alomari, A.; Murty, K. L.

    2018-06-01

    Understanding micromechanics of plastic deformation of existing materials is essential for improving their properties further and/or developing advanced materials for much more severe load bearing applications. The objective of the present work was to understand micromechanics of plastic deformation of Zircaloy-4, a zirconium-based alloy used as fuel cladding and channel (in BWRs) material in nuclear reactors. The Zircaloy-4 in recrystallized (at 973 K for 4 h) condition was subjected to uniaxial tensile testing at a constant cross-head velocity at temperatures in the range 293 K-1073 K and repeated stress relaxation tests at 293 K, 573 K, and 773 K. The minimum in the total elongation was indicative of dynamic strain aging phenomenon in this alloy in the intermediate temperature regime. The yield stress of the alloy was separated into effective and athermal components and the transition from thermally activated dislocation glide to athermal regime took place at around 673 K with the athermal stress estimated to be 115 MPa. The activation volume was found to be in the range of 40 b3 to 160 b3. The activation volume values and the data analyses using the solid-solution models in literature indicated dislocation-solute interaction to be a potential deformation mechanism in thermally activated regime. The activation energy calculated at 573 K was very close to that found for diffusivity of oxygen in α-Zr that was suggestive of dislocations-oxygen interaction during plastic deformation. This type of information may be helpful in alloy design in selecting different elements to control the deformation behavior of the material and impart desired mechanical properties in those materials for specific applications.

  20. Thermal Tolerance in Widespread and Tropical Drosophila Species: Does Phenotypic Plasticity Increase with Latitude?

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Kristensen, Torsten Nygård; Mitchell, Katherin A

    2011-01-01

    The distribution of insects can often be related to variation in their response to thermal extremes, which in turn may reflect differences in plastic responses or innate variation in resistance. Species with widespread distributions are expected to have evolved higher levels of plasticity than....... The results do not support the hypothesis that widely distributed species have larger phenotypic plasticity for thermal tolerance limits, and Drosophila species distributions are therefore more closely linked to differences in innate thermal tolerance limits....

  1. The Arctic Ocean as a dead end for floating plastics in the North Atlantic branch of the Thermohaline Circulation

    NARCIS (Netherlands)

    Cózar, Andrés; Martí, Elisa; Duarte, Carlos M; García-de-Lomas, Juan; van Sebille, Erik|info:eu-repo/dai/nl/304831921; Ballatore, Thomas J; Eguíluz, Victor M; González-Gordillo, J Ignacio; Pedrotti, Maria L; Echevarría, Fidel; Troublè, Romain; Irigoien, Xabier

    The subtropical ocean gyres are recognized as great marine accummulation zones of floating plastic debris; however, the possibility of plastic accumulation at polar latitudes has been overlooked because of the lack of nearby pollution sources. In the present study, the Arctic Ocean was extensively

  2. Solar Program Assessment: Environmental Factors - Ocean Thermal Energy Conversion.

    Science.gov (United States)

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This report presents the environmental problems which may arise with the further development of Ocean Thermal Energy Conversion, one of the eight Federally-funded solar technologies. To provide a background for this environmental analysis, the history and basic concepts of the technology are reviewed, as are its economic and resource requirements.…

  3. Strategies for reducing ocean plastic debris should be diverse and guided by science

    Science.gov (United States)

    Rochman, Chelsea M.

    2016-04-01

    Studies suggest that trillions of microplastic particles are floating on the surface of the global oceans and that the total amount of plastic waste entering the ocean will increase by an order of magnitude by 2025. As such, this ever-increasing problem demands immediate mitigation and reduction. Diverse solutions have been proposed, ranging from source reduction to ocean-based cleanup. These solutions are most effective when guided by scientific evidence. A study published in Environmental Research Letters (Sherman and van Sebille 2016 Environ. Res. Lett. 11 014006) took a closer look at the potential effectiveness of ocean-based cleanup. They conclude that it will be most cost-effective and ecologically beneficial if clean-up efforts focus on the flux of microplastics from the coasts rather than in the center of the oceans where plastic accumulates in so called ‘garbage patches’. If followed, this example may become one of a series of examples where science has informed a solution to the complex problem of plastic pollution.

  4. Thermal comfort study of plastics manufacturing industry in converting process

    Directory of Open Access Journals (Sweden)

    Sugiono Sugiono

    2017-09-01

    Full Text Available Thermal comfort is one of ergonomics factors that can create a significant impact to workers performance. For a better thermal comfort, several environment factors (air temperature, wind speed and relative humidity should be considered in this research. The object of the study is a building for converting process of plastics manufacturing industry located in Malang, Indonesia. The maximum air temperature inside the building can reach as high as 36°C. The result of this study shows that heat stress is dominantly caused by heat source from machine and wall building. The computational fluid dynamics (CFD simulation is used to show the air characteristic through inside the building. By using the CFD simulation, some scenarios of solution are successfully presented. Employees thermal comfort was investigated based on predicted mean vote model (PMV and predicted percentage of dissatisfied model (PPD. Existing condition gives PMV in range from 1.83 to 2.82 and PPD in range from 68.9 to 98%. Meanwhile, modification of ventilation and replacing ceiling material from clear glass into reflective clear glass gave significant impact to reduce PMV into range from 1.63 to 2.18 and PPD into range from 58.2 to 84.2%. In sort, new design converting building process has more comfortable for workers.

  5. Observations of Near-Surface Current Shear Help Describe Oceanic Oil and Plastic Transport

    Science.gov (United States)

    Laxague, Nathan J. M.; Ö-zgökmen, Tamay M.; Haus, Brian K.; Novelli, Guillaume; Shcherbina, Andrey; Sutherland, Peter; Guigand, Cédric M.; Lund, Björn; Mehta, Sanchit; Alday, Matias; Molemaker, Jeroen

    2018-01-01

    Plastics and spilled oil pose a critical threat to marine life and human health. As a result of wind forcing and wave motions, theoretical and laboratory studies predict very strong velocity variation with depth over the upper few centimeters of the water column, an observational blind spot in the real ocean. Here we present the first-ever ocean measurements of the current vector profile defined to within 1 cm of the free surface. In our illustrative example, the current magnitude averaged over the upper 1 cm of the ocean is shown to be nearly four times the average over the upper 10 m, even for mild forcing. Our findings indicate that this shear will rapidly separate pieces of marine debris which vary in size or buoyancy, making consideration of these dynamics essential to an improved understanding of the pathways along which marine plastics and oil are transported.

  6. Plastic pellets as oviposition site and means of dispersal for the ocean-skater insect Halobates.

    Science.gov (United States)

    Majer, A P; Vedolin, M C; Turra, A

    2012-06-01

    Microplastics are omnipresent in the oceans and generally have negative impacts on the biota. However, flotsam may increase the availability of hard substrates, which are considered a limiting resource for some oceanic species, e.g. as oviposition sites for the ocean insect Halobates. This study describes the use of plastic pellets as an oviposition site for Halobates micans and discusses possible effects on its abundance and dispersion. Inspection of egg masses on stranded particles on beaches revealed that a mean of 24% (from 0% to 62%) of the pellets bore eggs (mean of 5 and max. of 48 eggs per pellet). Most eggs (63%) contained embryos, while 37% were empty egg shells. This shows that even small plastic particles are used as oviposition site by H. micans, and that marine litter may have a positive effect over the abundance and dispersion of this species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. 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.

  8. 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.

  9. Ocean Literacy from kindergarten to secondary school: a vertically articulated curriculum on marine micro-plastics

    Science.gov (United States)

    Realdon, Giulia; Candussio, Giuliana; Manià, Marinella; Palamin, Serenella

    2017-04-01

    Marine micro-plastics are a relatively recent issue in research (Thompson et al. 2004), in the media and in education and, due to novelty and relevance, they are a suitable topic for addressing Ocean Literacy within science teaching to different age groups. In fact marine micro-plastics can be used to introduce Ocean Literacy and environmental science, but also traditional science subjects like biology, chemistry and Earth science, with a system approach focused on "understanding the Ocean's influence on humans and human influence on the Ocean". Inspired by the growing public interest for marine micro-plastics and by the lack of specific teaching activities in our country (Italy), we developed a vertically articulated curriculum on micro-plastics for students aged 5-15 years. Our proposal is based on a number of practical activities realized with different language and communication styles to be suitable for different age groups. For younger students (age 5-7) we use drama to address micro-plastics bioaccumulation in marine food chains: children act as fish of different trophic levels who pretend to "eat" micro-plastics models (built from plastic bottles) until the biggest fish is captured and ends up as a "meal" shared by other pupils. Teachers guide the performance and stimulate observations and remarks about the origin of micro-plastics and the correct management of plastic objects. The performance has been documented in a video and presented in a national teacher workshop (3 Giorni per la Scuola, Napoli 2015). For students aged 8-13 we propose observation and manipulation of common household plastic objects, followed by physical/chemical testing of different polymers to understand plastics characteristics that make these materials valuable but troublesome at the same time. Students then observe sand samples, taken from a local beach, containing natural components and man-made fragments (including micro-plastics), so they can directly experience the fate of

  10. Clay behaviour under thermal gradients elastic and plastic strains

    International Nuclear Information System (INIS)

    Pintado, Xavier; Autio, Jorma; Punkkinen, Olli

    2010-01-01

    Document available in extended abstract form only. The nuclear waste repositories will generate strong temperature gradients at the clay barrier. The heat and water transport generate volume change in the clay. An experimental work is proposed here. The clay reference is the MX-80. The test device imposes a fixed heat flow in one side of the sample and maintains constant the temperature on the other side. Two samples are tested for symmetry. The samples are unconfined and the total mass of water remains constant. This situation creates a strong thermal gradient in the samples. The final radial strains in some places of the sample, the total vertical strain and the water content distribution will be measured just at the end of the test and some weeks later in order to distinguish the elastic strains from the plastic strains. The test period mustn't be longer than two weeks because a large quantity of water loses through the rubber membrane and the heads of the sample. The maximum temperature reached in the cooper is 90 degrees because with higher temperature, the rubber membrane is damaged. This test is already simulated by a numerical code. Thermal, thermo-hydraulic and thermo-hydro-mechanical analyses are being done. These analyses allow studying the different fluxes inside the sample and its quantification. Water content distribution is compared with the water content calculated from the reference parameters in the clay. The water distribution and the change of diameter after the test will also be studied. This experimental work will allow to know what is the percentage of the strains elastic or plastic and check the mechanical model. The experimental diameter change is compared with the diameter change calculated from the reference parameters of the clay. (authors)

  11. The highest global concentrations and increased abundance of oceanic plastic debris in the North Pacific: Evidence from seabirds

    Science.gov (United States)

    Robards, Martin D.; Gould, Patrick J.; Coe, James M.; Rogers, Donald B.

    1997-01-01

    Plastic pollution has risen dramatically with an increase in production of plastic resin during the past few decades. Plastic production in the United States increased from 2.9 million tons in I960 to 47.9 million tons in 1985 (Society of the Plastics Industry 1986). This has been paralleled by a significant increase in the concentration of plastic particles in oceanic surface waters of the North Pacific from the 1970s to the late 1980s (Day and Shaw 1987; Day et al. 1990a). Research during the past few decades has indicated two major interactions between marine life and oceanic plastic: entanglement and ingestion (Laist 1987). Studies in the last decade have documented the prevalence of plastic in the diets of many seabird species in the North Pacific and the need for further monitoring of those species and groups that ingest the most plastic (Day et al. 1985).

  12. Ocean thermal energy: concept and resources, history and perspectives

    International Nuclear Information System (INIS)

    Nihous, Gerard

    2015-10-01

    Two articles address the possibility of exploiting a higher than 20 degrees temperature difference between ocean surfaces and 1 km deep waters to produce electricity. The first article describes the operation principle in closed cycle and briefly presents the open cycle approach. The global energetic assessment is discussed. The author analyses available thermal resources in relationship with the main ocean streams. He outlines that the design of an ocean thermal energy project requires the acquisition and knowledge of a lot of data, modelling and simulations. In the second article, the author notices that past experiments highlighted the difficulties of implementation of the concept. He notably evokes works performed by Georges Claude during the 1920's, projects elaborated at the end of the 20. century, the realisation of a mini OTEC (Ocean Thermal Energy Conversion) station in Hawaii, the OTEC-1 project, a Japanese project in Nauru, the test of a suspended cold water duct, the net power producing experiment in the USA. Perspectives and costs are finally briefly discussed, and recent and promising projects briefly evoked (notably that by DCNS and Akuo Energy in Martinique)

  13. Thermal Coupling Between the Ocean and Mantle of Europa: Implications for Ocean Convection

    Science.gov (United States)

    Soderlund, Krista M.; Schmidt, Britney E.; Wicht, Johannes; Blankenship, Donald D.

    2015-11-01

    Magnetic induction signatures at Europa indicate the presence of a subsurface ocean beneath the cold icy crust. The underlying mantle is heated by radioactive decay and tidal dissipation, leading to a thermal contrast sufficient to drive convection and active dynamics within the ocean. Radiogenic heat sources may be distributed uniformly in the interior, while tidal heating varies spatially with a pattern that depends on whether eccentricity or obliquity tides are dominant. The distribution of mantle heat flow along the seafloor may therefore be heterogeneous and impact the regional vigor of ocean convection. Here, we use numerical simulations of thermal convection in a global, Europa-like ocean to test the sensitivity of ocean dynamics to variations in mantle heat flow patterns. Towards this end, three end-member cases are considered: an isothermal seafloor associated with dominant radiogenic heating, enhanced seafloor temperatures at high latitudes associated with eccentricity tides, and enhanced equatorial seafloor temperatures associated with obliquity tides. Our analyses will focus on convective heat transfer since the heat flux pattern along the ice-ocean interface can directly impact the ice shell and the potential for geologic activity within it.

  14. Thermal and mechanical properties of bio-based plasticizers mixtures on poly (vinyl chloride

    Directory of Open Access Journals (Sweden)

    Boussaha Bouchoul

    2017-09-01

    Full Text Available Abstract The use of mixtures of nontoxic and biodegradable plasticizers coming from natural resources is a good way to replace conventional phthalates plasticizers. In this study, two secondary plasticizers of epoxidized sunflower oil (ESO and epoxidized sunflower oil methyl ester (ESOME were synthesized and have been used with two commercially available biobased plasticizers; isosorbide diesters (ISB and acetyl tributyl citrate (ATBC in order to produce flexible PVC. Different mixtures of these plasticizers have been introduced in PVC formulations. Thermal, mechanical and morphological properties have been studied by using discoloration, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC, dynamic mechanical thermal analysis (DMTA, tensile - strain and scanning electron microscopy (SEM. Studies have shown that PVC plasticization and stabilization were improved by addition of plasticizers blends containing ISB, ATBC, ESO and ESOME. An increase in the content of ESO or ESOME improved thermal and mechanical properties, whereas ESOME/ATBC formulations exhibited the best properties.

  15. Thermal transgenerational plasticity in natural populations of Daphnia.

    Science.gov (United States)

    Walsh, Matthew R; Whittington, Deirdre; Funkhouser, Collin

    2014-11-01

    Rising temperatures associated with global climatic change threaten the persistence of species. Determining how species adapt to environmental change is paramount. Much work has shown that environmental stressors have the potential to induce phenotypic changes that span multiple generations. Such transgenerational plasticity (TGP) represents a mechanism that may allow for rapid responses to global climatic change. Yet, our understanding of thermal TGP beyond the relationship between parent and offspring is limited. We evaluated thermal TGP in development across three generations (i.e., F0, F1, and F2) in zooplankton (Daphnia ambigua) from lakes in Connecticut. We found that the temperatures at which parents and grandparents were reared significantly influenced age at maturation in the grand-offspring. Comparisons between the F0 and F1 generation show that the offspring of parents reared at low temperatures matured significantly faster than the offspring of parents reared at a higher temperature. However, age at maturation in the grand-offspring was influenced by the interactive effects of parents and grandparents. Such an effect yielded trends that were not readily predicted from the previous generations and whose adaptive significance is unclear. Our results thus call for additional theoretical and empirical work to better understand the transgenerational effects of temperature. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  16. Plastic in the Ocean: A Report on What It Is and a Short Survey on Miyazaki’s Seashore

    OpenAIRE

    Passos, Anderson; Martini, Erika; Mitsuo, Hiroshi; Hirai, Yu

    2014-01-01

    Plastic in the ocean is an environmental issue that has been gaining attention in recent years. It not only affects marine habitats, but ingestion or entanglement can also kill marine life. The final destination of plastic waste is not yet known, but some researchers believe that such debris may be entering our food chain as plastic molecules are broken down and absorbed by marine life. In this study, we are going to discuss some of the effects that plastic in the ocean may have on marine env...

  17. Ocean Thermal Energy Conversion (OTEC) program. FY 1977 program summary

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    An overview is given of the ongoing research, development, and demonstration efforts. Each of the DOE's Ocean Thermal Energy Conversion projects funded during fiscal year 1977 (October 1, 1976 through September 30, 1977) is described and each project's status as of December 31, 1977 is reflected. These projects are grouped as follows: program support, definition planning, engineering development, engineering test and evaluation, and advanced research and technology. (MHR)

  18. Plasticity in thermal tolerance has limited potential to buffer ectotherms from global warming

    Science.gov (United States)

    Gunderson, Alex R.; Stillman, Jonathon H.

    2015-01-01

    Global warming is increasing the overheating risk for many organisms, though the potential for plasticity in thermal tolerance to mitigate this risk is largely unknown. In part, this shortcoming stems from a lack of knowledge about global and taxonomic patterns of variation in tolerance plasticity. To address this critical issue, we test leading hypotheses for broad-scale variation in ectotherm tolerance plasticity using a dataset that includes vertebrate and invertebrate taxa from terrestrial, freshwater and marine habitats. Contrary to expectation, plasticity in heat tolerance was unrelated to latitude or thermal seasonality. However, plasticity in cold tolerance is associated with thermal seasonality in some habitat types. In addition, aquatic taxa have approximately twice the plasticity of terrestrial taxa. Based on the observed patterns of variation in tolerance plasticity, we propose that limited potential for behavioural plasticity (i.e. behavioural thermoregulation) favours the evolution of greater plasticity in physiological traits, consistent with the ‘Bogert effect’. Finally, we find that all ectotherms have relatively low acclimation in thermal tolerance and demonstrate that overheating risk will be minimally reduced by acclimation in even the most plastic groups. Our analysis indicates that behavioural and evolutionary mechanisms will be critical in allowing ectotherms to buffer themselves from extreme temperatures. PMID:25994676

  19. Mineralogical Plasticity Acts as a Compensatory Mechanism to the Impacts of Ocean Acidification.

    Science.gov (United States)

    Leung, Jonathan Y S; Russell, Bayden D; Connell, Sean D

    2017-03-07

    Calcifying organisms are considered particularly susceptible to the future impacts of ocean acidification (OA), but recent evidence suggests that they may be able to maintain calcification and overall fitness. The underlying mechanism remains unclear but may be attributed to mineralogical plasticity, which modifies the energetic cost of calcification. To test the hypothesis that mineralogical plasticity enables the maintenance of shell growth and functionality under OA conditions, we assessed the biological performance of a gastropod (respiration rate, feeding rate, somatic growth, and shell growth of Austrocochlea constricta) and analyzed its shell mechanical and geochemical properties (shell hardness, elastic modulus, amorphous calcium carbonate, calcite to aragonite ratio, and magnesium to calcium ratio). Despite minor metabolic depression and no increase in feeding rate, shell growth was faster under OA conditions, probably due to increased precipitation of calcite and trade-offs against inner shell density. In addition, the resulting shell was functionally suitable for increasingly "corrosive" oceans, i.e., harder and less soluble shells. We conclude that mineralogical plasticity may act as a compensatory mechanism to maintain overall performance of calcifying organisms under OA conditions and could be a cornerstone of calcifying organisms to acclimate to and maintain their ecological functions in acidifying oceans.

  20. Organophosphate Ester Flame Retardants and Plasticizers in Ocean Sediments from the North Pacific to the Arctic Ocean.

    Science.gov (United States)

    Ma, Yuxin; Xie, Zhiyong; Lohmann, Rainer; Mi, Wenying; Gao, Guoping

    2017-04-04

    The presence of organophosphate ester (OPE) flame retardants and plasticizers in surface sediment from the North Pacific to Arctic Ocean was observed for the first time during the fourth National Arctic Research Expedition of China in the summer of 2010. The samples were analyzed for three halogenated OPEs [tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(dichloroisopropyl) phosphate], three alkylated OPEs [triisobutyl phosphate (TiBP), tri-n-butyl phosphate, and tripentyl phosphate], and triphenyl phosphate. Σ 7 OPEs (total concentration of the observed OPEs) was in the range of 159-4658 pg/g of dry weight. Halogenated OPEs were generally more abundant than the nonhalogenated OPEs; TCEP and TiBP dominated the overall concentrations. Except for that of the Bering Sea, Σ 7 OPEs values increased with increasing latitudes from Bering Strait to the Central Arctic Ocean, while the contributions of halogenated OPEs (typically TCEP and TCPP) to the total OPE profile also increased from the Bering Strait to the Central Arctic Ocean, indicating they are more likely to be transported to the remote Arctic. The median budget of 52 (range of 17-292) tons for Σ 7 OPEs in sediment from the Central Arctic Ocean represents only a very small amount of their total production volume, yet the amount of OPEs in Arctic Ocean sediment was significantly larger than the sum of polybrominated diphenyl ethers (PBDEs) in the sediment, indicating they are equally prone to long-range transport away from source regions. Given the increasing level of production and usage of OPEs as substitutes of PBDEs, OPEs will continue to accumulate in the remote Arctic.

  1. Irreversible ocean thermal expansion under carbon dioxide removal

    Science.gov (United States)

    Ehlert, Dana; Zickfeld, Kirsten

    2018-03-01

    In the Paris Agreement in 2015 countries agreed on holding global mean surface air warming to well below 2 °C above pre-industrial levels, but the emission reduction pledges under that agreement are not ambitious enough to meet this target. Therefore, the question arises of whether restoring global warming to this target after exceeding it by artificially removing CO2 from the atmosphere is possible. One important aspect is the reversibility of ocean heat uptake and associated sea level rise, which have very long (centennial to millennial) response timescales. In this study the response of sea level rise due to thermal expansion to a 1 % yearly increase of atmospheric CO2 up to a quadrupling of the pre-industrial concentration followed by a 1 % yearly decline back to the pre-industrial CO2 concentration is examined using the University of Victoria Earth System Climate Model (UVic ESCM). We find that global mean thermosteric sea level (GMTSL) continues to rise for several decades after atmospheric CO2 starts to decline and does not return to pre-industrial levels for over 1000 years after atmospheric CO2 is restored to the pre-industrial concentration. This finding is independent of the strength of vertical sub-grid-scale ocean mixing implemented in the model. Furthermore, GMTSL rises faster than it declines in response to a symmetric rise and decline in atmospheric CO2 concentration partly because the deep ocean continues to warm for centuries after atmospheric CO2 returns to the pre-industrial concentration. Both GMTSL rise and decline rates increase with increasing vertical ocean mixing. Exceptions from this behaviour arise if the overturning circulations in the North Atlantic and Southern Ocean intensify beyond pre-industrial levels in model versions with lower vertical mixing, which leads to rapid cooling of the deep ocean.

  2. Detection of thermal aging degradation and plastic strain damage for duplex stainless steel using SQUID sensor

    International Nuclear Information System (INIS)

    Otaka, M.; Evanson, S.; Hesegawa, K.; Takaku, K.

    1991-01-01

    An apparatus using a SQUID sensor is developed for nondestructive inspection. The measurements are obtained with the SQUID sensor located approximately 150 mm from the specimen. The degradation of thermal aging and plastic strain for duplex stainless steel is successfully detected independently from the magnetic characterization measurements. The magnetic flux density under high polarizing field is found to be independent of thermal aging. Coercive force increases with thermal aging time. On the other hand, the magnetic flux density under high field increases with the plastic strain. Coercive force is found to be independent of the plastic strain. (author)

  3. Beyond electricity: The potential of ocean thermal energy and ocean technology ecoparks in small tropical islands

    International Nuclear Information System (INIS)

    Osorio, Andrés F.; Arias-Gaviria, Jessica; Devis-Morales, Andrea; Acevedo, Diego; Velasquez, Héctor Iván; Arango-Aramburo, Santiago

    2016-01-01

    Small islands face difficult challenges to guarantee energy, freshwater and food supply, and sustainable development. The urge to meet their needs, together with the mitigation and adaptation plans to address climate change, have led them to develop renewable energy systems, with a special interest in Ocean Thermal Energy Conversion (OTEC) in tropical islands. Deep Ocean Water (DOW) is a resource that can provide electricity (through OTEC in combination with warm surface water), low temperatures for refrigeration, and nutrients for food production. In this paper we propose an Ocean Technology Ecopark (OTEP) as an integral solution for small islands that consists of an OTEC plant, other alternative uses of DOW, and a Research and Development (R&D) center. We present an application of OTEP to San Andres, a Colombian island that meets all the necessary conditions for the implementation of OTEC technology, water desalinization, and a business model for DOW. We present the main entrance barriers and a four-stage roadmap for the consolidation and sustainability of the OTEP. - Highlights: • Small islands face problems such as development, energy, freshwater and food supply. • Tropical islands with access to deep ocean water can use OTEC all year round. • An Ocean Ecopark is proposed as an integral solution for San Andrés Island, Colombia. • The Ecopark consists of OTEC, desalinization, SWAC, greenhouses, and R&D activities. • This article discusses entrance barriers and presents a four-stage roadmap

  4. Scales of spatial heterogeneity of plastic marine debris in the northeast pacific ocean.

    Directory of Open Access Journals (Sweden)

    Miriam C Goldstein

    Full Text Available Plastic debris has been documented in many marine ecosystems, including remote coastlines, the water column, the deep sea, and subtropical gyres. The North Pacific Subtropical Gyre (NPSG, colloquially called the "Great Pacific Garbage Patch," has been an area of particular scientific and public concern. However, quantitative assessments of the extent and variability of plastic in the NPSG have been limited. Here, we quantify the distribution, abundance, and size of plastic in a subset of the eastern Pacific (approximately 20-40°N, 120-155°W over multiple spatial scales. Samples were collected in Summer 2009 using surface and subsurface plankton net tows and quantitative visual observations, and Fall 2010 using surface net tows only. We documented widespread, though spatially variable, plastic pollution in this portion of the NPSG and adjacent waters. The overall median microplastic numerical concentration in Summer 2009 was 0.448 particles m(-2 and in Fall 2010 was 0.021 particles m(-2, but plastic concentrations were highly variable over the submesoscale (10 s of km. Size-frequency spectra were skewed towards small particles, with the most abundant particles having a cross-sectional area of approximately 0.01 cm(2. Most microplastic was found on the sea surface, with the highest densities detected in low-wind conditions. The numerical majority of objects were small particles collected with nets, but the majority of debris surface area was found in large objects assessed visually. Our ability to detect high-plastic areas varied with methodology, as stations with substantial microplastic did not necessarily also contain large visually observable objects. A power analysis of our data suggests that high variability of surface microplastic will make future changes in abundance difficult to detect without substantial sampling effort. Our findings suggest that assessment and monitoring of oceanic plastic debris must account for high spatial

  5. The Arctic Ocean as a dead end for floating plastics in the North Atlantic branch of the Thermohaline Circulation

    KAUST Repository

    Cózar, Andrés

    2017-04-20

    The subtropical ocean gyres are recognized as great marine accummulation zones of floating plastic debris; however, the possibility of plastic accumulation at polar latitudes has been overlooked because of the lack of nearby pollution sources. In the present study, the Arctic Ocean was extensively sampled for floating plastic debris from the Tara Oceans circumpolar expedition. Although plastic debris was scarce or absent in most of the Arctic waters, it reached high concentrations (hundreds of thousands of pieces per square kilometer) in the northernmost and easternmost areas of the Greenland and Barents seas. The fragmentation and typology of the plastic suggested an abundant presence of aged debris that originated from distant sources. This hypothesis was corroborated by the relatively high ratios of marine surface plastic to local pollution sources. Surface circulation models and field data showed that the poleward branch of the Thermohaline Circulation transfers floating debris from the North Atlantic to the Greenland and Barents seas, which would be a dead end for this plastic conveyor belt. Given the limited surface transport of the plastic that accumulated here and the mechanisms acting for the downward transport, the seafloor beneath this Arctic sector is hypothesized as an important sink of plastic debris.

  6. Effect of boron compounds on the thermal and combustion properties of wood-plastic composites

    OpenAIRE

    Altuntaş, Ertuğrul; Karaoğul, Eyyup; Alma, Mehmet Hakkı

    2017-01-01

    In this study, the thermal properties and fire resistancesof the wood plastic composites produced with waste lignocellulosic materialswere investigated. For this purpose, lignocellulosic waste, high densitypolyethylene, (HDPE) sodium borate (borax) and boric acid was used to producethe wood-plastic composites. A twin-screw extruder was used during theproduction of the wood plastic composites. The produced composite granule waspressed at 175 °C hot press. The effects of boric acid and borax ad...

  7. Genetic architecture and phenotypic plasticity of thermally-regulated traits in an eruptive species, Dendroctonus ponderosae

    Science.gov (United States)

    Barbara J. Bentz; Ryan B. Bracewell; Karen E. Mock; Michael E. Pfrender

    2011-01-01

    Phenotypic plasticity in thermally-regulated traits enables close tracking of changing environmental conditions, and can thereby enhance the potential for rapid population increase, a hallmark of outbreak insect species. In a changing climate, exposure to conditions that exceed the capacity of existing phenotypic plasticity may occur. Combining information on genetic...

  8. Study of Selected Composites Copper Concentrate-Plastic Waste Using Thermal Analysis

    Science.gov (United States)

    Szyszka, Danuta

    2017-12-01

    The paper presents thermal analysis of selected composites (copper concentrate, plastic waste) in two stages. The first stage consisted in thermogravimetric analysis and differential thermal analysis on the applied plastic waste and copper concentrate, and subsequently, a comparative study has been carried out on products obtained, constituting composites of those materials. As a result of analyses, it was found that up to ca. 400 °C composites show high thermal stability, whereas above that temperature, a thermal decomposition of the composite occurs, resulting in emissions of organic compounds, i.e. hydrocarbon compounds and organic oxygenate derivatives.

  9. Ocean Thermal Energy Conversion Using Double-Stage Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Yasuyuki Ikegami

    2018-03-01

    Full Text Available Ocean Thermal Energy Conversion (OTEC using non-azeotropic mixtures such as ammonia/water as working fluid and the multistage cycle has been investigated in order to improve the thermal efficiency of the cycle because of small ocean temperature differences. The performance and effectiveness of the multistage cycle are barely understood. In addition, previous evaluation methods of heat exchange process cannot clearly indicate the influence of the thermophysical characteristics of the working fluid on the power output. Consequently, this study investigated the influence of reduction of the irreversible losses in the heat exchange process on the system performance in double-stage Rankine cycle using pure working fluid. Single Rankine, double-stage Rankine and Kalina cycles were analyzed to ascertain the system characteristics. The simple evaluation method of the temperature difference between the working fluid and the seawater is applied to this analysis. From the results of the parametric performance analysis it can be considered that double-stage Rankine cycle using pure working fluid can reduce the irreversible losses in the heat exchange process as with the Kalina cycle using an ammonia/water mixture. Considering the maximum power efficiency obtained in the study, double-stage Rankine and Kalina cycles can improve the power output by reducing the irreversible losses in the cycle.

  10. A Watched Ocean World Never Boils: Inspecting the Geochemical Impact on Ocean Worlds from Their Thermal Evolution

    Science.gov (United States)

    Spiers, E. M.; Schmidt, B. E.

    2018-05-01

    I aim to acquire better understanding of coupled thermal evolution and geochemical fluxes of an ocean world through a box model. A box model divides the system into plainer elements with realistically-solvable, dynamic equations.

  11. Thermal and kinetic behaviors of biomass and plastic wastes in co-pyrolysis

    International Nuclear Information System (INIS)

    Çepelioğullar, Özge; Pütün, Ayşe E.

    2013-01-01

    Graphical abstract: - Highlights: • Co-pyrolysis of biomass together with the plastic wastes in thermogravimetric analyzer. • Investigations into thermal and kinetic behaviors at high temperature regions. • Determination of the kinetic parameters. - Abstract: In this study, co-pyrolysis characteristics and kinetics of biomass-plastic blends were investigated. Cotton stalk, hazelnut shell, sunflower residue, and arid land plant Euphorbia rigida, were blended in definite ratio (1:1, w/w) with polyvinyl chloride (PVC) and polyethylene terephthalate (PET). Experiments were conducted with a heating rate of 10 °C min −1 from room temperature to 800 °C in the presence of N 2 atmosphere with a flow rate of 100 cm 3 min −1 . After thermal decomposition in TGA, a kinetic analysis was performed to fit thermogravimetric data and a detailed discussion of co-pyrolysis mechanism was achieved. Experimental results demonstrated that the structural differences between biomass and plastics directly affect their thermal decomposition behaviors. Biomass pyrolysis generally based on three main steps while plastic material’s pyrolysis mechanism resulted in two steps for PET and three steps for PVC. Also, the required activation energies needed to achieve the thermal degradation for plastic were found higher than the biomass materials. In addition, it can be concluded that the evaluation of plastic materials together with biomass created significant changes not only for the thermal behaviors but also for the kinetic behaviors

  12. Thermally induced processes in mixtures of aluminum with organic acids after plastic deformations under high pressure

    Science.gov (United States)

    Zhorin, V. A.; Kiselev, M. R.; Roldugin, V. I.

    2017-11-01

    DSC is used to measure the thermal effects of processes in mixtures of solid organic dibasic acids with powdered aluminum, subjected to plastic deformation under pressures in the range of 0.5-4.0 GPa using an anvil-type high-pressure setup. Analysis of thermograms obtained for the samples after plastic deformation suggests a correlation between the exothermal peaks observed around the temperatures of degradation of the acids and the thermally induced chemical reactions between products of acid degradation and freshly formed surfaces of aluminum particles. The release of heat in the mixtures begins at 30-40°C. The thermal effects in the mixtures of different acids change according to the order of acid reactivity in solutions. The extreme baric dependences of enthalpies of thermal effects are associated with the rearrangement of the electron subsystem of aluminum upon plastic deformation at high pressures.

  13. The effect of particle properties on the depth profile of buoyant plastics in the ocean

    Science.gov (United States)

    Kooi, Merel; Reisser, Julia; Slat, Boyan; Ferrari, Francesco F.; Schmid, Moritz S.; Cunsolo, Serena; Brambini, Roberto; Noble, Kimberly; Sirks, Lys-Anne; Linders, Theo E. W.; Schoeneich-Argent, Rosanna I.; Koelmans, Albert A.

    2016-10-01

    Most studies on buoyant microplastics in the marine environment rely on sea surface sampling. Consequently, microplastic amounts can be underestimated, as turbulence leads to vertical mixing. Models that correct for vertical mixing are based on limited data. In this study we report measurements of the depth profile of buoyant microplastics in the North Atlantic subtropical gyre, from 0 to 5 m depth. Microplastics were separated into size classes (0.5-1.5 and 1.5-5.0 mm) and types (‘fragments’ and ‘lines’), and associated with a sea state. Microplastic concentrations decreased exponentially with depth, with both sea state and particle properties affecting the steepness of the decrease. Concentrations approached zero within 5 m depth, indicating that most buoyant microplastics are present on or near the surface. Plastic rise velocities were also measured, and were found to differ significantly for different sizes and shapes. Our results suggest that (1) surface samplers such as manta trawls underestimate total buoyant microplastic amounts by a factor of 1.04-30.0 and (2) estimations of depth-integrated buoyant plastic concentrations should be done across different particle sizes and types. Our findings can assist with improving buoyant ocean plastic vertical mixing models, mass balance exercises, impact assessments and mitigation strategies.

  14. Compendium of information on identification and testing of materials for plastic solar thermal collectors

    Energy Technology Data Exchange (ETDEWEB)

    McGinniss, V.D.; Sliemers, F.A.; Landstrom, D.K.; Talbert, S.G.

    1980-07-31

    This report is intended to organize and summarize prior and current literature concerning the weathering, aging, durability, degradation, and testing methodologies as applied to materials for plastic solar thermal collectors. Topics covered include (1) rate of aging of polymeric materials; (2) environmental factors affecting performance; (3) evaluation and prediction of service life; (4) measurement of physical and chemical properties; (5) discussion of evaluation techniques and specific instrumentation; (6) degradation reactions and mechanisms; (7) weathering of specific polymeric materials; and (8) exposure testing methodology. Major emphasis has been placed on defining the current state of the art in plastics degradation and on identifying information that can be utilized in applying appropriate and effective aging tests for use in projecting service life of plastic solar thermal collectors. This information will also be of value where polymeric components are utilized in the construction of conventional solar collectors or any application where plastic degradation and weathering are prime factors in material selection.

  15. Plastic Pollution in the World's Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea.

    Directory of Open Access Journals (Sweden)

    Marcus Eriksen

    Full Text Available Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world's oceans from 24 expeditions (2007-2013 across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N = 680 and visual survey transects of large plastic debris (N = 891. Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic 4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove <4.75 mm plastic particles from the ocean surface.

  16. Plastic Pollution in the World's Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea

    Science.gov (United States)

    Eriksen, Marcus; Lebreton, Laurent C. M.; Carson, Henry S.; Thiel, Martin; Moore, Charles J.; Borerro, Jose C.; Galgani, Francois; Ryan, Peter G.; Reisser, Julia

    2014-01-01

    Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world's oceans from 24 expeditions (2007–2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N = 680) and visual survey transects of large plastic debris (N = 891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic 4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove plastic particles from the ocean surface. PMID:25494041

  17. Plastic Pollution in the World's Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea.

    Science.gov (United States)

    Eriksen, Marcus; Lebreton, Laurent C M; Carson, Henry S; Thiel, Martin; Moore, Charles J; Borerro, Jose C; Galgani, Francois; Ryan, Peter G; Reisser, Julia

    2014-01-01

    Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world's oceans from 24 expeditions (2007-2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N = 680) and visual survey transects of large plastic debris (N = 891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic 4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove plastic particles from the ocean surface.

  18. Lab-scale thermal analysis of electronic waste plastics

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wu-Jun; Tian, Ke; Jiang, Hong, E-mail: jhong@ustc.edu.cn; Yu, Han-Qing

    2016-06-05

    Highlights: • We provided the experimental evidence that WEEE can be recovered by pyrolysis method. • We explored the thermochemical behaviors of WEEE using online TG–FTIR–MS technology. • The intramolecular oxygen atoms play a pivotal role in the formation of PBDD/Fs. - Abstract: In this work, we experimentally revealed the thermochemical decomposition pathway of Decabromodiphenyl ethane (DBDPE) and tetrabromobisphenol A (TBBPA) containing electronic waste plastics using an online thermogravimetric–fourier transform infrared–mass spectroscopy (TG–FTIR–MS) system, a high resolution gas chromatography/high resolution mass (HRGC–MS) spectroscopy, and a fixed-bed reactor. We found the distribution and species of produced bromides can be easily controlled by adjusting pyrolytic temperature, which is particularly crucial to their recycle. From the analysis of the liquid and solid phase obtained from the fixed-bed reactor, we proposed that the ·Br radicals formed during the pyrolysis process may be captured by organic species derived from the depolymerization of plastics to form brominated compounds or by the inorganic species in the plastics, and that these species remained in the char residue after pyrolysis. Our work for the first time demonstrates intramolecular oxygen atoms play a pivotal role in the formation of PBDD/Fs that pyrolysis of oxygen-free BFRs is PBDD/Fs-free, whereas pyrolysis of oxygen-containing BFRs is PBDD/Fs-reduced.

  19. Physical and chemical effects of ingested plastic debris on short-tailed shearwaters, Puffinus tenuirostris, in the North Pacific Ocean

    OpenAIRE

    Yamashita, Rei; Takada, Hideshige; Fukuwaka, Masa-aki; Watanuki, Yutaka

    2011-01-01

    We investigated the plastics ingested by short-tailed shearwaters, Puffinus tenuirostris, that were accidentally caught during experimental fishing in the North Pacific Ocean in 2003 and 2005. The mean mass of plastics found in the stomach was 0.23 g per bird (n = 99). Plastic mass did not correlate with body weight. Total PCB (sum of 24 congeners) concentrations in the abdominal adipose tissue of 12 birds ranged from 45 to 529 ng/g-lipid. Although total PCBs or higher-chlorinated congeners, ...

  20. A review on thermal and catalytic pyrolysis of plastic solid waste (PSW).

    Science.gov (United States)

    Al-Salem, S M; Antelava, A; Constantinou, A; Manos, G; Dutta, A

    2017-07-15

    Plastic plays an important role in our daily lives due to its versatility, light weight and low production cost. Plastics became essential in many sectors such as construction, medical, engineering applications, automotive, aerospace, etc. In addition, economic growth and development also increased our demand and dependency on plastics which leads to its accumulation in landfills imposing risk on human health, animals and cause environmental pollution problems such as ground water contamination, sanitary related issues, etc. Hence, a sustainable and an efficient plastic waste treatment is essential to avoid such issues. Pyrolysis is a thermo-chemical plastic waste treatment technique which can solve such pollution problems, as well as, recover valuable energy and products such as oil and gas. Pyrolysis of plastic solid waste (PSW) has gained importance due to having better advantages towards environmental pollution and reduction of carbon footprint of plastic products by minimizing the emissions of carbon monoxide and carbon dioxide compared to combustion and gasification. This paper presents the existing techniques of pyrolysis, the parameters which affect the products yield and selectivity and identify major research gaps in this technology. The influence of different catalysts on the process as well as review and comparative assessment of pyrolysis with other thermal and catalytic plastic treatment methods, is also presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. What Happens to Bio-degradables in the Ocean? Due to the increasing amount of plastic that ends up in the ocean there is much alarm about it killing sea life from ingestion and changing chemical properties of the ocean. But what really happens t these products in the ocean, and how do they affect the ocean.

    Science.gov (United States)

    Lavoie, A.

    2016-12-01

    What Happens to Bio-degradables in the Ocean? Due to the increasing amount of plastic that ends up in the ocean there is much alarm about it killing sea life from entanglement and ingestion and changing chemical properties of the ocean. Our society is trying to take action by purchasing and using materials that claim to be biodegradable. But how long do these materials take to degrade in ocean water and do they actually change the water composition? Answering these questions will determine if one should invest in these materials as an alternative to plastic.

  2. Influence of colorant and film thickness on thermal aging characteristics of oxo-biodegradable plastic bags

    Science.gov (United States)

    Leuterio, Giselle Lou D.; Pajarito, Bryan B.; Domingo, Carla Marie C.; Lim, Anna Patricia G.

    2016-05-01

    Functional, lightweight, strong and cheap plastic bags incorporated with pro-oxidants undergo accelerated degradation under exposure to heat and oxygen. This work investigated the effect of colorant and film thickness on thermal aging characteristics of commercial oxo-biodegradable plastic bag films at 70 °C. Degradation is monitored through changes in infrared absorption, weight, and tensile properties of thermally aged films. The presence of carbonyl band in infrared spectrum after 672 h of thermal aging supports the degradation behavior of exposed films. Results show that incorporation of colorant and increasing thickness exhibit low maximum weight uptake. Titanium dioxide as white colorant in films lowers the susceptibility of films to oxygen uptake but enhances physical degradation. Higher amount of pro-oxidant loading also contributes to faster degradation. Opaque films are characterized by low tensile strength and high elastic modulus. Decreasing the thickness contributes to lower tensile strength of films. Thermally aged films with colorant and low thickness promote enhanced degradation.

  3. Plastic response of thin films due to thermal cycling

    NARCIS (Netherlands)

    Nicola, L.; van der Giessen, E.; Needleman, A.; Ahzi, S; Cherkaoui, M; Khaleel, MA; Zbib, HM; Zikry, MA; Lamatina, B

    2004-01-01

    Discrete dislocation simulations of thin films on semi-infinite substrates under cyclic thermal loading are presented. The thin film is modelled as a two-dimensional single crystal under plane strain conditions. Dislocations of edge character can be generated from initially present sources and glide

  4. Thermal Characteristics of Plastic Film Tension in Roll-to-Roll Gravure Printed Electronics

    Directory of Open Access Journals (Sweden)

    Kui He

    2018-02-01

    Full Text Available In the printing section of a roll-to-roll gravure printed electronics machine, the plastic film tension is directly associated with the product quality. The temperature distribution of the plastic film in the printing section is non-uniform, because of the higher drying temperature and the lower room temperature. Furthermore, the drying temperature and the room temperature are not constants in industrial production. As the plastic film is sensitive to temperature, the temperature of the plastic film will affects the web tension in the printing section. In this paper, the thermal characteristics of the plastic film tension in roll-to-roll gravure printed electronics are studied in order to help to improve the product quality. First, the tension model including the factor of temperature is derived based on the law of mass conservation. Then, some simulations and experiments are carried out in order to in-depth research the effects of the drying temperature and room temperature based on the relations between system inputs and outputs. The results show that the drying temperature and room temperature have significant influences on the web tension. The research on the thermal characteristics of plastic film tension would benefit the tension control accuracy for further study.

  5. Ocean Thermal Energy Conversion (OTEC) Programmatic Environmental Analysis--Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1980-01-01

    The programmatic environmental analysis is an initial assessment of Ocean Thermal Energy Conversion (OTEC) technology considering development, demonstration and commercialization. It is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties. This volume contains these appendices: Appendix A -- Deployment Scenario; Appendix B -- OTEC Regional Characterization; and Appendix C -- Impact and Related Calculations.

  6. Draft environmental assessment: Ocean Thermal Energy Conversion (OTEC) Pilot Plants

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, S.M.; Sands, M.D.; Donat, J.R.; Jepsen, P.; Smookler, M.; Villa, J.F.

    1981-02-01

    This Environmental Assessment (EA) has been prepared, in accordance with the National Environmental Policy Act of 1969, for the deployment and operation of a commercial 40-Megawatt (MW) Ocean Thermal Energy Conversion (OTEC) Pilot Plant (hereafter called the Pilot Plant). A description of the proposed action is presented, and a generic environment typical of the candidate Pilot Plant siting regions is described. An assessment of the potential environmental impacts associated with the proposed action is given, and the risk of credible accidents and mitigating measures to reduce these risks are considered. The Federal and State plans and policies the proposed action will encompass are described. Alternatives to the proposed action are presented. Appendix A presents the navigation and environmental information contained in the US Coast Pilot for each of the candidate sites; Appendix B provides a brief description of the methods and calculations used in the EA. It is concluded that environmental disturbances associated with Pilot Plant activities could potentially cause significant environmental impacts; however, the magnitude of these potential impacts cannot presently be assessed, due to insufficient engineering and environmental information. A site- and design-specific OTEC Pilot Plant Environmental Impact Statement (EIS) is required to resolve the potentially significant environmental effects associated with Pilot Plant deployment and operation. (WHK)

  7. Theoretical basis for a transient thermal elastic-plastic stress analysis of nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hsu, T.R.; Bertels, A.W.M.; Banerjee, S.; Harrison, W.C.

    1976-07-01

    This report presents the theoretical basis for a transient thermal elastic-plastic stress analysis of a nuclear reactor fuel element subject to severe transient thermo-mechanical loading. A finite element formulation is used for both the non-linear stress analysis and thermal analysis. These two major components are linked together to form an integrated program capable of predicting fuel element transient behaviour in two dimensions. Specific case studies are presented to illustrate capabilities of the analysis. (author)

  8. Influence of Cellulose on the Mechanical and Thermal Stability of ABS Plastic Composites

    Directory of Open Access Journals (Sweden)

    K. Crews

    2016-01-01

    Full Text Available Microcrystalline cellulose was explored as possible biodegradable fillers in the fabrication of ABS plastic composites. TGA indicates that upon inclusion of cellulose microcrystals the thermal stability of the ABS plastics was improved significantly when compared to the neat ABS plastic counterparts. Furthermore, inclusion of extracted cellulose from plant biomass showed a higher thermal stability with maximum decomposition temperatures around 131.95°C and 124.19°C for cellulose from cotton and Hibiscus sabdariffa, respectively, when compared to that of the purchased cellulose. In addition, TMA revealed that the average CTE value for the neat ABS and 1 : 1 ratio of cellulose to ABS fabricated in this study was significantly lower than the reported CTE (ca. 73.8 μm/m°C.

  9. New class of thermosetting plastics has improved strength, thermal and chemical stability

    Science.gov (United States)

    Burns, E. A.; Dubrow, B.; Lubowitz, H. R.

    1967-01-01

    New class of thermosetting plastics has high hydrocarbon content, high stiffness, thermal stability, humidity resistance, and workability in the precured state. It is designated cyclized polydiene urethane, and is applicable as matrices to prepare chemically stable ablative materials for rocket nose cones of nozzles.

  10. Comparative environmental analysis of waste brominated plastic thermal treatments

    International Nuclear Information System (INIS)

    Bientinesi, M.; Petarca, L.

    2009-01-01

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of 'fossil fuels' and 'climate change'. Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste

  11. Detection of plastic explosives using thermal neutron radiography

    International Nuclear Information System (INIS)

    Hacidume, Leo Ryoske

    1999-12-01

    The work aims to demonstrate the potentiality of the neutron radiography technique, allied to the computerized tomography by transmission, to both detect and visualize plastic explosive samples in several hidden conditions, using a simple scanner as a digitalisation instrument. Each tomographic essay was obtained in the J-9 channel of the Argonauta Research Reactor of IEN/CNEN, in groups of six neutron radiographic projections, performed with an angular increment of 30 deg C, in a period of time of 30 minutes for each projection. Two groups of tomographic reconstructions were generated, distinguished by the digitalisation process of the interested lines in the reconstruction plane coming from the projection groups, utilization a scanner and a microdensitometer, respectively. The reconstruction of the bi-dimensional image of the transverse section, in relation to this plane, was processed making use of the Image Reconstruction Algorithmic of an Image based on the Maximum Entropy principle (ARIEM). From the qualitative analysis of the images, we conclude that the neutron radiographic system was able to detect the explosive sample in a satisfactory way while the quantitative analysis confirmed the application effectiveness of a scanner to acquire the projection dates whose objective is only a reconnaissance. (author)

  12. Constitutive law for thermally-activated plasticity of recrystallized tungsten

    Science.gov (United States)

    Zinovev, Aleksandr; Terentyev, Dmitry; Dubinko, Andrii; Delannay, Laurent

    2017-12-01

    A physically-based constitutive law relevant for ITER-specification tungsten grade in as-recrystallized state is proposed. The material demonstrates stages III and IV of the plastic deformation, in which hardening rate does not drop to zero with the increase of applied stress. Despite the classical Kocks-Mecking model, valid at stage III, the strain hardening asymptotically decreases resembling a hyperbolic function. The material parameters are fitted by relying on tensile test data and by requiring that the strain and stress at the onset of diffuse necking (uniform elongation and ultimate tensile strength correspondingly) as well as the yield stress be reproduced. The model is then validated in the temperature range 300-600 °C with the help of finite element analysis of tensile tests which confirms the reproducibility of the experimental engineering curves up to the onset of diffuse necking, beyond which the development of ductile damage accelerates the material failure. This temperature range represents the low temperature application window for tungsten as divertor material in fusion reactor ITER.

  13. Gradual plasticity alters population dynamics in variable environments: thermal acclimation in the green alga Chlamydomonas reinhartdii.

    Science.gov (United States)

    Kremer, Colin T; Fey, Samuel B; Arellano, Aldo A; Vasseur, David A

    2018-01-10

    Environmental variability is ubiquitous, but its effects on populations are not fully understood or predictable. Recent attention has focused on how rapid evolution can impact ecological dynamics via adaptive trait change. However, the impact of trait change arising from plastic responses has received less attention, and is often assumed to optimize performance and unfold on a separate, faster timescale than ecological dynamics. Challenging these assumptions, we propose that gradual plasticity is important for ecological dynamics, and present a study of the plastic responses of the freshwater green algae Chlamydomonas reinhardtii as it acclimates to temperature changes. First, we show that C. reinhardtii 's gradual acclimation responses can both enhance and suppress its performance after a perturbation, depending on its prior thermal history. Second, we demonstrate that where conventional approaches fail to predict the population dynamics of C. reinhardtii exposed to temperature fluctuations, a new model of gradual acclimation succeeds. Finally, using high-resolution data, we show that phytoplankton in lake ecosystems can experience thermal variation sufficient to make acclimation relevant. These results challenge prevailing assumptions about plasticity's interactions with ecological dynamics. Amidst the current emphasis on rapid evolution, it is critical that we also develop predictive methods accounting for plasticity. © 2018 The Author(s).

  14. Airborne emissions of carcinogens and respiratory sensitizers during thermal processing of plastics.

    Science.gov (United States)

    Unwin, John; Coldwell, Matthew R; Keen, Chris; McAlinden, John J

    2013-04-01

    Thermoplastics may contain a wide range of additives and free monomers, which themselves may be hazardous substances. Laboratory studies have shown that the thermal decomposition products of common plastics can include a number of carcinogens and respiratory sensitizers, but very little information exists on the airborne contaminants generated during actual industrial processing. The aim of this work was to identify airborne emissions during thermal processing of plastics in real-life, practical applications. Static air sampling was conducted at 10 industrial premises carrying out compounding or a range of processes such as extrusion, blown film manufacture, vacuum thermoforming, injection moulding, blow moulding, and hot wire cutting. Plastics being processed included polyvinyl chloride, polythene, polypropylene, polyethylene terephthalate, and acrylonitrile-butadiene-styrene. At each site, static sampling for a wide range of contaminants was carried out at locations immediately adjacent to the prominent fume-generating processes. The monitoring data indicated the presence of few carcinogens at extremely low concentrations, all less than 1% of their respective WEL (Workplace Exposure Limit). No respiratory sensitizers were detected at any sites. The low levels of process-related fume detected show that the control strategies, which employed mainly forced mechanical general ventilation and good process temperature control, were adequate to control the risks associated with exposure to process-related fume. This substantiates the advice given in the Health and Safety Executive's information sheet No 13, 'Controlling Fume During Plastics Processing', and its broad applicability in plastics processing in general.

  15. Morphology and thermal properties of PLA films plasticized with aliphatic oligoesters

    International Nuclear Information System (INIS)

    Inacio, Erika M.; Dias, Marcos L.; Lima, Maria Celiana P.

    2015-01-01

    The addition of plasticizers to poly(lactic acid) (PLA) is one of the known ways of changing its ductility, making possible the modification of its mechanical and thermal properties. In this work, it was synthesized two biodegradable aliphatic oligoesters: oligo(trimethylene sebacate) (OST) and oligo(trimethylene malonate) (OMT), and these oligomers were used as plasticizer in cast films of commercial film grade PLA at concentrations of 1, 5 and 10 wt% of each plasticizer. X-ray diffraction (XRD) was used to investigate the morphology and differential scanning calorimetry (DSC) was also used aiming the evaluation of the thermal properties of these films. The PLA films containing no plasticizer showed an amorphous behavior, and the addition of PMT on the PLA films acted, simultaneously, decreasing the Tg, and rising the material's crystallinity. In contrast, the increased addition of OST to the PLA films did not change the Tg, and equally, did not have a significant changes in the material's crystallinity. Therefore, it was possible to observe the effect of the concentration of oligomers on the crystallinity of the films as well as the no plasticizer effect of the OST. (author)

  16. Seabirds indicate changes in the composition of plastic litter in the Atlantic and south-western Indian Oceans.

    Science.gov (United States)

    Ryan, Peter G

    2008-08-01

    I compare plastic ingested by five species of seabirds sampled in the 1980s and again in 1999-2006. The numbers of ingested plastic particles have not changed significantly, but the proportion of virgin pellets has decreased 44-79% in all five species: great shearwater Puffinus gravis, white-chinned petrel Procellaria aequinoctialis, broad-billed prion Pachyptila vittata, white-faced storm petrel Pelagodroma marina and white-bellied storm petrel Fregetta grallaria. The populations sampled range widely in the South Atlantic and western Indian Oceans. The most marked reduction occurred in great shearwaters, where the average number of pellets per bird decreased from 10.5 to 1.6. This species migrates between the South and North Atlantic each year. Similar decreases in virgin pellets have been recorded in short-tailed shearwaters Puffinus tenuirostris in the Pacific Ocean and northern fulmars Fulmarus glacialis in the North Sea. More data are needed on the relationship between plastic loads in seabirds and the density of plastic at sea in their foraging areas, but the consistent decrease in pellets in birds suggests there has been a global change in the composition of small plastic debris at sea over the last two decades.

  17. Thermal structure and flow patterns around Seychelles group of Islands (Indian Ocean) during austral autumn

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; RameshBabu, V.; RameshKumar, M.R.

    Properties of thermal structure in the upper 750 m around the Seychelles group of islands in the Indian Ocean, based on Expendable Bathythermograph (XBT) data collected in March 1984, are presented along with the inferred flow patterns...

  18. Thermal structure of the Western Indian Ocean during the southwest monsoon, 1983

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, Y.V.B.; Sarma, M.S.S.; Rao, L.V.G.

    The thermal structure and the variability of heat content of the upper 400 m of the Western Indian Ocean were examined using the expendable bathythermograph (XBT) data collected onboard RV Sagar Kanya during July-August, 1983. Vertical displacement...

  19. Mechanical and thermal properties of physically-blended-plastic films

    International Nuclear Information System (INIS)

    Abu Issa, M. S.

    1983-10-01

    Low density polyethylene (LDPE) and isotactic polypropylene (PP) blend were produced in film form and were characterized by a number of techniques such as wide-angle x-ray diffraction (WAXD), differential thermal analysis (DTA), scanning electron microscopy (SEM), and instron tensile testing. Results of WAXD and DTA showed conclusively that the two components in the blend are incompatible. SEM micrographs indicated that the 60/40 and 40/60 PP/PE blends show approximately fine homogeneous dispersion of the minor component into the matrix of the major component. The mechanical properties of the blend films improved with respect to the PE homo polymer. The improvement was more remarkable with the increase of the PP component in the blend. Results obtained in this work were explained in terms of crystallinity and the crystallite orientation. 28 refs., 29 figs., 5 tabs. (A.M.H.)

  20. Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation

    International Nuclear Information System (INIS)

    Guney, Ali; Poyraz, M. Ibrahim; Kangal, Olgac; Burat, Firat

    2013-01-01

    Highlights: • Both PET and PVC have nearly the same densities. • The best pH value will be 4 for optimizing pH values. • Malic acid gave the best results for selective separation of PET and PVC. - Abstract: Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency

  1. Thermal degradation and kinetic study for different waste/rejected plastic materials

    International Nuclear Information System (INIS)

    Rana, Srujal; Parikh, Jigisha Kamal; Mohanty, Pravakar

    2013-01-01

    A kinetic analysis based on thermal decomposition of rejected polypropylene, plastic film and plastic pellets collected from different industrial outlet has been carried out. Non-isothermal experiments using different heating rates of 5, 10, 20, 30, 40 and 50 .deg. C min"−"1 have been performed from ambient to 700 .deg. C in a thermo-balance with the objective of determining the kinetic parameters. The values of activation energy and frequency factor were found to be in the range of 107-322 kJ/mol, 85-331 kJ/mol, 140-375 kJ/mol and 3.49E+07-4.74E+22 min⌃(-1), 3.52E+06-2.88E+22min⌃(-1), 7.28E+13-1.17E+25 min⌃(-1) for rejected polypropylene, plastic film and plastic pellets, respectively, by Coats-Redfern and Ozawa methods including different models. Kissinger method, a model free analysis is also adopted to find the kinetic parameters. Activation energy and frequency factor were found to be 108 kJ/mol, 98 kJ/mol, 132 kJ/mol and 6.89E+03, 2.12E+02, 8.06E+05 min⌃(-1) for rejected polypropylene, plastic film and plastic pellets, respectively, by using the Kissinger method

  2. Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation.

    Science.gov (United States)

    Guney, Ali; Poyraz, M Ibrahim; Kangal, Olgac; Burat, Firat

    2013-09-01

    Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation

    Energy Technology Data Exchange (ETDEWEB)

    Guney, Ali; Poyraz, M. Ibrahim; Kangal, Olgac, E-mail: kangal@itu.edu.tr; Burat, Firat

    2013-09-15

    Highlights: • Both PET and PVC have nearly the same densities. • The best pH value will be 4 for optimizing pH values. • Malic acid gave the best results for selective separation of PET and PVC. - Abstract: Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency.

  4. Non-Contact Acousto-Thermal Signatures of Plastic Deformation in TI-6AL-4V

    Science.gov (United States)

    Welter, J. T.; Malott, G.; Schehl, N.; Sathish, S.; Jata, K. V.; Blodgett, M. P.

    2010-02-01

    Plastic deformation introduces changes in a material which include increases in: dislocations, strains, residual stress, and yield stress. However, these changes have a very small impact on the material properties such as elastic modulus, conductivity and ultrasonic wave speed. This is due to the fact that interatomic forces govern these properties, and they are not affected by plastic deformation to any large degree. This is evident from the fact that the changes in electrical resistance and ultrasonic velocity in plastically deformed and virgin samples are very small and can only be determined by highly controlled experiments. Except for X-ray diffraction, there are no direct nondestructive methods for measuring strain and the residual stress. This paper presents an application of the non-contact acousto-thermal signature (NCATS) NDE methodology to detect plastic deformation in flat dog bone Ti-6Al-4V samples. Results of the NCATS measurements on samples subjected to incremental amounts of plastic deformation are presented. The maximum temperature attained by the sample due to acoustic excitation is found to be sensitive to the amount of plastic strain. It is observed that the temperature induced by acoustic excitation increases to a peak followed by a decrease to failure. The maximum temperature peak occurs at plastic strains of 12-14%. It is observed that there is a correlation between the peak in maximum temperature rise and the strain at the experimentally determined ultimate tensile strength. A microstructural based explanation for this will be presented. The results are discussed in reference to utilizing this technique for detection and evaluation of plastic deformation.

  5. No evidence for thermal transgenerational plasticity in metabolism when minimizing the potential for confounding effects.

    Science.gov (United States)

    Kielland, Ø N; Bech, C; Einum, S

    2017-01-11

    Environmental change may cause phenotypic changes that are inherited across generations through transgenerational plasticity (TGP). If TGP is adaptive, offspring fitness increases with an increasing match between parent and offspring environment. Here we test for adaptive TGP in somatic growth and metabolic rate in response to temperature in the clonal zooplankton Daphnia pulex Animals of the first focal generation experienced thermal transgenerational 'mismatch' (parental and offspring temperatures differed), whereas conditions of the next two generations matched the (grand)maternal thermal conditions. Adjustments of metabolic rate occurred during the lifetime of the first generation (i.e. within-generation plasticity). However, no further change was observed during the subsequent two generations, as would be expected under TGP. Furthermore, we observed no tendency for increased juvenile somatic growth (a trait highly correlated with fitness in Daphnia) over the three generations when reared at new temperatures. These results are inconsistent with existing studies of thermal TGP, and we describe how previous experimental designs may have confounded TGP with within-generation plasticity and selective mortality. We suggest that the current evidence for thermal TGP is weak. To increase our understanding of the ecological and evolutionary role of TGP, future studies should more carefully identify possible confounding factors. © 2017 The Author(s).

  6. Is phenotypic plasticity a key mechanism for responding to thermal stress in ants?

    Science.gov (United States)

    Oms, Cristela Sánchez; Cerdá, Xim; Boulay, Raphaël

    2017-06-01

    Unlike natural selection, phenotypic plasticity allows organisms to respond quickly to changing environmental conditions. However, plasticity may not always be adaptive. In insects, body size and other morphological measurements have been shown to decrease as temperature increases. This relationship may lead to a physiological conflict in ants, where larger body size and longer legs often confer better thermal resistance. Here, we tested the effect of developmental temperature (20, 24, 28 or 32 °C) on adult thermal resistance in the thermophilic ant species Aphaenogaster senilis. We found that no larval development occurred at 20 °C. However, at higher temperatures, developmental speed increased as expected and smaller adults were produced. In thermal resistance tests, we found that ants reared at 28 and 32 °C had half-lethal temperatures that were 2 °C higher than those of ants reared at 24 °C. Thus, although ants reared at higher temperatures were smaller in size, they were nonetheless more thermoresistant. These results show that A. senilis can exploit phenotypic plasticity to quickly adjust its thermal resistance to local conditions and that this process is independent of morphological adaptations. This mechanism may be particularly relevant given current rapid climate warming.

  7. Plastic ingestion in oceanic-stage loggerhead sea turtles (Caretta caretta) off the North Atlantic subtropical gyre.

    Science.gov (United States)

    Pham, Christopher K; Rodríguez, Yasmina; Dauphin, Axelle; Carriço, Rita; Frias, João P G L; Vandeperre, Frederic; Otero, Vanessa; Santos, Marco R; Martins, Helen R; Bolten, Alan B; Bjorndal, Karen A

    2017-08-15

    Juvenile oceanic-stage sea turtles are particularly vulnerable to the increasing quantity of plastic coming into the oceans. In this study, we analysed the gastrointestinal tracts of 24 juvenile oceanic-stage loggerheads (Caretta caretta) collected off the North Atlantic subtropical gyre, in the Azores region, a key feeding ground for juvenile loggerheads. Twenty individuals were found to have ingested marine debris (83%), composed exclusively of plastic items (primarily polyethylene and polypropylene) identified by μ-Fourier Transform Infrared Spectroscopy. Large microplastics (1-5mm) represented 25% of the total number of debris and were found in 58% of the individuals sampled. Average number of items was 15.83±6.09 (±SE) per individual, corresponding to a mean dry mass of 1.07±0.41g. The results of this study demonstrate that plastic pollution acts as another stressor for this critical life stage of loggerhead turtles in the North Atlantic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Elastic-plastic Fracture Mechanics Assessment of nozzle corners submitted to thermal shock loading

    International Nuclear Information System (INIS)

    Chapuliot, S.; Marie, S.

    2016-01-01

    This paper focuses on the development of a simplified analytical scheme for the elastic-plastic Fracture Mechanics Assessment of large nozzle corners. Within that frame, following the specific numerical effort performed for the definition of a Stress Intensity Factor compendium, complementary elastic-plastic developments are proposed here for the consideration of the thermal shock loading in the elastic-plastic domain: this type of loading is a major loading for massive structures such as nozzle corners of large components. Thus, an important numerical was performed in order to extend the applicability domain of existing analytical schemes to those complex geometries. The final formulation is a simple one, applicable to a large variety of materials and geometrical configurations as long as the structure is large and the defect remains small in comparison to the internal radius of the nozzle. - Highlights: • Fracture Mechanics Assessment of large nozzle corners. • Elastic-plastic Stress Intensity Factor determination under thermal shock loading. • Semi-analytical schemes for J calculation.

  9. Dissolved organic carbon leaching from plastics stimulates microbial activity in the ocean

    NARCIS (Netherlands)

    Romera-Castillo, C.; Pinto, M.; Langer, T.M.; Alvarez-Salgado, X.A.; Herndl, G.

    2018-01-01

    Approximately 5.25 trillion plastic pieces are floating at the sea surface. The impact of plastic pollution on the lowest trophic levels of the food web, however, remains unknown. Here we show that plastics release dissolved organic carbon (DOC) into the ambient seawater stimulating the activity of

  10. No evidence for thermal transgenerational plasticity in metabolism when minimizing the potential for confounding effects

    OpenAIRE

    Kielland, Øystein Nordeide; Bech, Claus; Einum, Sigurd

    2017-01-01

    Environmental change may cause phenotypic changes that are inherited across generations through transgenerational plasticity (TGP). If TGP is adaptive, offspring fitness increases with an increasing match between parent and offspring environment. Here we test for adaptive TGP in somatic growth and metabolic rate in response to temperature in the clonal zooplankton Daphnia pulex. Animals of the first focal generation experienced thermal transgenerational ‘mismatch’ (parental and offspring temp...

  11. Effect of the plastic cover properties on the thermal efficiency of a greenhouse

    Energy Technology Data Exchange (ETDEWEB)

    Bernaud, P. [Faculte des Sciences et Techniques, Monastir (Tunisia); Champagne, J. Y.; Palec, G. Le; Bournot, P.; Muynck, B. de; Vandevelde, R.

    1984-07-01

    The greenhouse effect is due to the dependency of the transmission factor upon the wavelength of the incident radiation. Experiments have been done that confirm the theoretically admitted results on the thermal behaviour of greenhouses. It is also pointed out that the internal global solar irradiance is characteristic of the plastic cover. A model based on a static description of the system is proposed. A few results are given concerning this model. (author)

  12. Scaling Relations for the Thermal Structure of Segmented Oceanic Transform Faults

    Science.gov (United States)

    Wolfson-Schwehr, M.; Boettcher, M. S.; Behn, M. D.

    2015-12-01

    Mid-ocean ridge-transform faults (RTFs) are a natural laboratory for studying strike-slip earthquake behavior due to their relatively simple geometry, well-constrained slip rates, and quasi-periodic seismic cycles. However, deficiencies in our understanding of the limited size of the largest RTF earthquakes are due, in part, to not considering the effect of short intra-transform spreading centers (ITSCs) on fault thermal structure. We use COMSOL Multiphysics to run a series of 3D finite element simulations of segmented RTFs with visco-plastic rheology. The models test a range of RTF segment lengths (L = 10-150 km), ITSC offset lengths (O = 1-30 km), and spreading rates (V = 2-14 cm/yr). The lithosphere and upper mantle are approximated as steady-state, incompressible flow. Coulomb failure incorporates brittle processes in the lithosphere, and a temperature-dependent flow law for dislocation creep of olivine activates ductile deformation in the mantle. ITSC offsets as small as 2 km affect the thermal structure underlying many segmented RTFs, reducing the area above the 600˚C isotherm, A600, and thus the size of the largest expected earthquakes, Mc. We develop a scaling relation for the critical ITSC offset length, OC, which significantly reduces the thermal affect of adjacent fault segments of length L1 and L2. OC is defined as the ITSC offset that results in an area loss ratio of R = (Aunbroken - Acombined)/Aunbroken - Adecoupled) = 63%, where Aunbroken = C600(L1+L2)1.5V-0.6 is A600 for an RTF of length L1 + L2; Adecoupled = C600(L11.5+L21.5)V-0.6 is the combined A600 of RTFs of lengths L1 and L2, respectively; and Acombined = Aunbroken exp(-O/ OC) + Adecoupled (1-exp(-O/ OC)). C600 is a constant. We use OC and kinematic fault parameters (L1, L2, O, and V) to develop a scaling relation for the approximate seismogenic area, Aseg, for each segment of a RTF system composed of two fault segments. Finally, we estimate the size of Mc on a fault segment based on Aseg. We

  13. Thermal Properties of Wood-Plastic Composites Prepared from Hemicellulose-extracted Wood Flour

    Directory of Open Access Journals (Sweden)

    A.A. Enayati

    2013-01-01

    Full Text Available Hemicellulose of Southern Yellow Pine wood spices was extracted by pressurized hot water at three different temperatures: 140°C, 155°C and 170°C. Compounding with PP (polypropylene was performed by extrusion after preparing wood flour and sieving to determine its mesh size. The ratio of wood to polymer was 50:50 based on oven-dry weight of wood flour. All extraction treatments and control samples were compounded under two sets of conditions, without and with 2% MAPP as coupling agent. Injection molding was used to make tensile test samples (dogbone from the pellets made by extrusion. Thermal properties of wood-plastic composites were studied by TGA and DSC while the thermal stability of pretreated wood flours, PP and MAPP were studied by TGA as well. The greater weight loss of wood materials was an indication that higher treatment temperature increases the extractability of hemicellulose. The removal of hemicellulose by extraction improves thermal stability of wood flour, especially for extraction at 170°C. Wood-plastic composites made from extracted fibers at 170°C showed the highest thermal stability. Coupling agent did not have a significant effect on thermal stability but it improved the degree of crystallinity of the composites.Surface roughness of wood fiber increased after treatment. Extraction of hemicellulose increased the degree of crystallinity but it was not significant except for samples from treated wood flour at 170°C and with MAPP.

  14. A study on the ocean circulation and thermal diffusion near a nuclear power plant

    International Nuclear Information System (INIS)

    Shu, Kyung Suk; Han, Moon Hee; Kim, Eun Han; Hwang, Won Tae

    1994-08-01

    The thermal discharge used with cooling water at nuclear power plant is released to a neighbour sea and it is influenced on marine environment. The thermal discharge released from power plant is mainly transported and diffused by ocean circulation of neighbour sea. So the evaluation for characteristics of ocean circulation around neighbour sea is firstly performed. The purpose of this research is primarily analyzed the thermal diffusion in sea around Yongkwang nuclear power plant. For this viewpoint, fundamental oceanographic data sets are collected and analyzed in Yellow sea, west sea of Korea, sea around Yongkwang. The ocean circulation and the effects of temperature increase by thermal discharge are evaluated using these data. The characteristics of tide is interpreted by the analysis of observed tidal elevation and tidal currents. The characteristics of temperature and salinity is investigated by the long-term observation of Korea Fisheries Research and Development Agency and the short-term observation around Yongkwang. (Author)

  15. Plastics in the Ocean: Engaging Students in Core Competencies Through Issues-Based Activities in the Science Classroom.

    Science.gov (United States)

    Fergusson-Kolmes, L. A.

    2016-02-01

    Plastic pollution in the ocean is a critical issue. The high profile of this issue in the popular media makes it an opportune vehicle for promoting deeper understanding of the topic while also advancing student learning in the core competency areas identified in the NSF's Vision and Change document: integration of the process of science, quantitative reasoning, modeling and simulation, and an understanding of the relationship between science and society. This is a challenging task in an introductory non-majors class where the students may have very limited math skills and no prior science background. In this case activities are described that ask students to use an understanding of density to make predictions and test them as they consider the fate of different kinds of plastics in the marine environment. A comparison of the results from different sampling regimes introduces students to the difficulties of carrying out scientific investigations in the complex marine environment as well as building quantitative literacy skills. Activities that call on students to make connections between global issues of plastic pollution and personal actions include extraction of microplastic from personal care products, inventories of local plastic-recycling options and estimations of contributions to the waste stream on an individual level. This combination of hands-on-activities in an accessible context serves to help students appreciate the immediacy of the threat of plastic pollution and calls them to reflect on possible solutions.

  16. Optimized use of cooling holes to decrease the amount of thermal damage on a plastic gear tooth

    OpenAIRE

    Demagna Koffi; Alencar Bravo; Lotfi Toubal; Fouad Erchiqui

    2016-01-01

    The full potential of plastic gear usage is limited by not only poor mechanical properties but also equally poor temperature limits and poor heat conduction properties. Cooling holes were developed to decrease the amount of thermal damage on the contact surface. These cooling holes promote increased stress and tooth deflection, thus exerting a negative effect. This article compares various cooling holes for plastic gear configurations and proposes novel cooling holes. Thermal and mechanical s...

  17. Ocean acidification increases the sensitivity of and variability in physiological responses of an intertidal limpet to thermal stress

    Science.gov (United States)

    Wang, Jie; Russell, Bayden D.; Ding, Meng-Wen; Dong, Yun-Wei

    2018-05-01

    Understanding physiological responses of organisms to warming and ocean acidification is the first step towards predicting the potential population- and community-level ecological impacts of these stressors. Increasingly, physiological plasticity is being recognized as important for organisms to adapt to the changing microclimates. Here, we evaluate the importance of physiological plasticity for coping with ocean acidification and elevated temperature, and its variability among individuals, of the intertidal limpet Cellana toreuma from the same population in Xiamen. Limpets were collected from shaded mid-intertidal rock surfaces. They were acclimated under combinations of different pCO2 concentrations (400 and 1000 ppm, corresponding to a pH of 8.1 and 7.8) and temperatures (20 and 24 °C) in a short-term period (7 days), with the control conditions (20 °C and 400 ppm) representing the average annual temperature and present-day pCO2 level at the collection site. Heart rates (as a proxy for metabolic performance) and expression of genes encoding inducible and constitutive heat-shock proteins (hsp70 and hsc70) at different heat-shock temperatures (26, 30, 34, and 38 °C) were measured. Hsp70 and Hsc70 play important roles in protecting cells from heat stresses, but have different expression patterns, with Hsp70 significantly increased in expression during stress and Hsc70 constitutively expressed and only mildly induced during stress. Analysis of heart rate showed significantly higher temperature coefficients (Q10 rates) for limpets at 20 °C than at 24 °C and post-acclimation thermal sensitivity of limpets at 400 ppm was lower than at 1000 ppm. Expression of hsp70 linearly increased with the increasing heat-shock temperatures, with the largest slope occurring in limpets acclimated under a future scenario (24 °C and 1000 ppm pCO2). These results suggested that limpets showed increased sensitivity and stress response under future conditions. Furthermore, the

  18. Commentary: Plastic ocean and the cancer connection: 7 questions and answers.

    Science.gov (United States)

    Benno Meyer-Rochow, V; Valérie Gross, J; Steffany, Frank; Zeuss, Dominique; Erren, Thomas C

    2015-10-01

    A plethora of recent scientific reports testifies to challenges the world is facing from an ever-increasing marine plastic pollution. Toxicological concerns have been put forward, but possible links between the now ubiquitous synthetic polymers and human as well as wildlife cancers remain to be investigated. Hence, this commentary which addresses seven questions. Given numerous uncertainties on the factual impacts of plastics, we should embark on empirical studies into the validity of biologically plausible links between plastic residues and cancers and concomitantly consider ways to reduce plastics in the world within and around us. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Effects of hypoxia and ocean acidification on the upper thermal niche boundaries of coral reef fishes.

    Science.gov (United States)

    Ern, Rasmus; Johansen, Jacob L; Rummer, Jodie L; Esbaugh, Andrew J

    2017-07-01

    Rising ocean temperatures are predicted to cause a poleward shift in the distribution of marine fishes occupying the extent of latitudes tolerable within their thermal range boundaries. A prevailing theory suggests that the upper thermal limits of fishes are constrained by hypoxia and ocean acidification. However, some eurythermal fish species do not conform to this theory, and maintain their upper thermal limits in hypoxia. Here we determine if the same is true for stenothermal species. In three coral reef fish species we tested the effect of hypoxia on upper thermal limits, measured as critical thermal maximum (CT max ). In one of these species we also quantified the effect of hypoxia on oxygen supply capacity, measured as aerobic scope (AS). In this species we also tested the effect of elevated CO 2 (simulated ocean acidification) on the hypoxia sensitivity of CT max We found that CT max was unaffected by progressive hypoxia down to approximately 35 mmHg, despite a substantial hypoxia-induced reduction in AS. Below approximately 35 mmHg, CT max declined sharply with water oxygen tension ( P w O 2 ). Furthermore, the hypoxia sensitivity of CT max was unaffected by elevated CO 2 Our findings show that moderate hypoxia and ocean acidification do not constrain the upper thermal limits of these tropical, stenothermal fishes. © 2017 The Author(s).

  20. A method of solution of the elastic-plastic thermal stress problem

    International Nuclear Information System (INIS)

    Rafalski, P.

    1975-01-01

    The purpose of the work is an improvement of the numerical technique for calculating the thermal stress distribution in an elastic-plastic structural element. The work consists of two parts. In the first a new method of solution of the thermal stress problem for the elastic-plastic body is presented. In the second a particular numerical technique, based on the above method, for calculating the stress and strain fields is proposed. A new mathematical approach consists in treating the stress and strain fields as mathematical objects defined in the space-time domain. The methods commonly applied use the stress and strain fields defined in the space domain and establish the relations between them at a given instant t. They reduce the problem to the system of ordinary differential equations with respect to time, which are usually solved with a step-by-step technique. The new method reduces the problem to the system of nonlinear algebraic equations. In the work the Hilbert space of admissible tensor fields is constructed. This space is the orthogonal sum of two subspaces: of statically admissible and kinematically admissible fields. Two alternative orthogonality conditions, which correspond to the equilibrium and compatibility equations with the appropriate boundary conditions, are derived. The results of the work are to be used for construction of the computer program for calculation the stress and strain fields in the elastic-plastic body with a prescribed temperature field in the interior and appropriate displacement and force conditions on the boundary

  1. Investigation of thermodynamic parameters in the thermal decomposition of plastic waste-waste lube oil compounds.

    Science.gov (United States)

    Kim, Yong Sang; Kim, Young Seok; Kim, Sung Hyun

    2010-07-01

    Thermal decomposition properties of plastic waste-waste lube oil compounds were investigated under nonisothermal conditions. Polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) were selected as representative household plastic wastes. A plastic waste mixture (PWM) and waste lube oil (WLO) were mixed with mixing ratios of 33, 50, and 67 (w/w) % on a PWM weight basis, and thermogravimetric (TG) experiments were performed from 25 to 600 degrees C. The Flynn-Wall method and the Ozawa-Flynn-Wall method were used for analyses of thermodynamic parameters. In this study, activation energies of PWM/WLO compounds ranged from 73.4 to 229.6 kJ/mol between 0.2 and 0.8 of normalized mass conversions, and the 50% PWM/WLO compound had lower activation energies and enthalpies among the PWM/WLO samples at each mass conversion. At the point of maximum differential mass conversion, the analyzed activation energies, enthalpies, entropies, and Gibbs free energies indicated that mixing PWM and WLO has advantages in reducing energy to decrease the degree of disorder. However, no difference in overall energy that would require overcoming both thermal decomposition reactions and degree of disorder was observed among PWM/WLO compounds under these experimental conditions.

  2. Thermal recycling of plastic waste using pyrolysis-gasification process for energy production

    Energy Technology Data Exchange (ETDEWEB)

    Forbit, George Teke

    2012-04-04

    The disposal of mixed waste in landfills, dump sites and open burning without material and energy recovery leads to resource loss, causes health problems, pollution and littering. Increasing energy demand for industrial and domestic application with rising costs due to scarcity motivates a constant search for alternative clean energy sources. Recovering energy from waste presents various incentives e.g. creating jobs, alleviating poverty, combating and mitigating climate change, protecting the environment and reducing dependence on traditional fuels sources. Hence, plastics end up in landfills, surface waters and ocean bed with serious negative impact on terrestrial and aquatic biodiversity. Plastic waste with high calorific value (36-46MJ/kg) occupies the greatest portion of landfill space. Hence, using an appropriate technology to transform waste plastic to a hot gaseous mixture which is burned in-situ produces enormous amount of energy without pollution. Based on this hypothesis, the study objectives accomplished were to: 1. Characterise, quantify and classify waste fractions and plastic components common in MSW by manual sorting 2. Evaluate options for sustainable plastic waste management especially for developing countries 3. Design, construct, test and optimize an appropriate technology that applies pyrolysis and gasification processes to convert non-PVC plastic waste to energy 4. Assess the efficiency of the technology based on the functioning, the engineering, mass and energy analysis including socioeconomic and environmental impacts An integrated methodology involving review of current literature, field and laboratory experiments on mixed waste and plastic waste analysis was used. In addition, the pyrolysis-gasification technology (PGT) was conceptualised, designed, constructed, tested and optimised at BTU Cottbus, Germany; Lagos, Nigeria and Dschang, Cameroon. Field studies involving natural observation, interviews, personal discussions and visits to

  3. A Citizen's Guide to Plastics in the Ocean: More than a Litter Problem. Second Edition.

    Science.gov (United States)

    O'Hara, Kathryn J.; And Others

    This publication gives an overview of the problems caused by plastic debris in the marine environment and describes how citizens and public officials are working together to solve these problems. Chapter I introduces the reader to the problems caused by plastic debris in the marine environment. Chapter II examines the types of debris that are…

  4. Plastic ingestion by juvenile polar cod (Boreogadus saida) in the Arctic Ocean

    NARCIS (Netherlands)

    Kühn, Susanne; Schaafsma, Fokje L.; Werven, van Bernike; Flores, Hauke; Bergmann, Melanie; Egelkraut-Holtus, Marion; Tekman, Mine B.; Franeker, van Jan A.

    2018-01-01

    One of the recently recognised stressors in Arctic ecosystems concerns plastic litter. In this study, juvenile polar cod (Boreogadus saida) were investigated for the presence of plastics in their stomachs. Polar cod is considered a key species in the Arctic ecosystem. The fish were collected both

  5. Plastics and microplastics in the oceans: From emerging pollutants to emerged threat.

    Science.gov (United States)

    Avio, Carlo Giacomo; Gorbi, Stefania; Regoli, Francesco

    2017-07-01

    Plastic production has increased dramatically worldwide over the last 60 years and it is nowadays recognized as a serious threat to the marine environment. Plastic pollution is ubiquitous, but quantitative estimates on the global abundance and weight of floating plastics are still limited, particularly for the Southern Hemisphere and the more remote regions. Some large-scale convergence zones of plastic debris have been identified, but there is the urgency to standardize common methodologies to measure and quantify plastics in seawater and sediments. Investigations on temporal trends, geographical distribution and global cycle of plastics have management implications when defining the origin, possible drifting tracks and ecological consequences of such pollution. An elevated number of marine species is known to be affected by plastic contamination, and a more integrated ecological risk assessment of these materials has become a research priority. Beside entanglement and ingestion of macro debris by large vertebrates, microplastics are accumulated by planktonic and invertebrate organisms, being transferred along food chains. Negative consequences include loss of nutritional value of diet, physical damages, exposure to pathogens and transport of alien species. In addition, plastics contain chemical additives and efficiently adsorb several environmental contaminants, thus representing a potential source of exposure to such compounds after ingestion. Complex ecotoxicological effects are increasingly reported, but the fate and impact of microplastics in the marine environment are still far to be fully clarified. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The Effect of Thermal Cycling on Crystal-Liquid Separation During Lunar Magma Ocean Differentiation

    Science.gov (United States)

    Mills, Ryan D.

    2013-01-01

    Differentiation of magma oceans likely involves a mixture of fractional and equilibrium crystallization [1]. The existence of: 1) large volumes of anorthosite in the lunar highlands and 2) the incompatible- rich (KREEP) reservoir suggests that fractional crystallization may have dominated during differentiation of the Moon. For this to have occurred, crystal fractionation must have been remarkably efficient. Several authors [e.g. 2, 3] have hypothesized that equilibrium crystallization would have dominated early in differentiation of magma oceans because of crystal entrainment during turbulent convection. However, recent numerical modeling [4] suggests that crystal settling could have occurred throughout the entire solidification history of the lunar magma ocean if crystals were large and crystal fraction was low. These results indicate that the crystal size distribution could have played an important role in differentiation of the lunar magma ocean. Here, I suggest that thermal cycling from tidal heating during lunar magma ocean crystallization caused crystals to coarsen, leading to efficient crystal-liquid separation.

  7. Bis(pinacolato)diboron as an additive for the detection of thermal neutrons in plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Mahl, Adam [Department of Physics and the Nuclear Science and Engineering Center (NuSEC), Colorado School of Mines, Golden, CO 80401 (United States); Yemam, Henok A.; Stuntz, John [Department of Chemistry and Geochemistry and the Materials Science Program Colorado School of Mines, Golden, CO 80401 (United States); Remedes, Tyler [Department of Physics and the Nuclear Science and Engineering Center (NuSEC), Colorado School of Mines, Golden, CO 80401 (United States); Sellinger, Alan [Department of Chemistry and Geochemistry and the Materials Science Program Colorado School of Mines, Golden, CO 80401 (United States); Greife, Uwe, E-mail: ugreife@mines.edu [Department of Physics and the Nuclear Science and Engineering Center (NuSEC), Colorado School of Mines, Golden, CO 80401 (United States)

    2016-04-21

    A readily available and inexpensive boron compound was tested as an additive for the detection of thermal neutrons in plastic scintillators. Bis(pinacolato)diboron (B{sub 2}Pin{sub 2}) was determined to be a compatible boron source (8.51 wt% boron, 1.70 wt% {sup 10}B) in poly(vinyltoluene) based matrices. Plastic scintillator blends of 1–20 wt% 2,5-diphenyloxazole (PPO), 0.1 wt% 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP) and 1–15 wt% B{sub 2}Pin{sub 2} were prepared that provided optical clarity, good mechanical properties, and the capability of thermal neutron detection. Independent of B{sub 2}Pin{sub 2} concentration, strong {sup 10}B neutron capture signals around 90 keV{sub ee} were observed at essentially constant light output. Increasing PPO concentration allowed for the use of pulse shape discrimination (PSD) in both fast and thermal neutron detection. High PPO concentrations appear to cause additional alpha quenching that affected the {sup 10}B neutron capture signal. Aging effects after storage in air for several months were observed, which led to degradation of performance and in some samples of mechanical stability.

  8. Bis(pinacolato)diboron as an additive for the detection of thermal neutrons in plastic scintillators

    International Nuclear Information System (INIS)

    Mahl, Adam; Yemam, Henok A.; Stuntz, John; Remedes, Tyler; Sellinger, Alan; Greife, Uwe

    2016-01-01

    A readily available and inexpensive boron compound was tested as an additive for the detection of thermal neutrons in plastic scintillators. Bis(pinacolato)diboron (B_2Pin_2) was determined to be a compatible boron source (8.51 wt% boron, 1.70 wt% "1"0B) in poly(vinyltoluene) based matrices. Plastic scintillator blends of 1–20 wt% 2,5-diphenyloxazole (PPO), 0.1 wt% 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP) and 1–15 wt% B_2Pin_2 were prepared that provided optical clarity, good mechanical properties, and the capability of thermal neutron detection. Independent of B_2Pin_2 concentration, strong "1"0B neutron capture signals around 90 keV_e_e were observed at essentially constant light output. Increasing PPO concentration allowed for the use of pulse shape discrimination (PSD) in both fast and thermal neutron detection. High PPO concentrations appear to cause additional alpha quenching that affected the "1"0B neutron capture signal. Aging effects after storage in air for several months were observed, which led to degradation of performance and in some samples of mechanical stability.

  9. Finite element analysis of thermal convection in deep ocean sediments

    International Nuclear Information System (INIS)

    Gartling, D.K.

    1980-01-01

    Of obvious importance to the study and engineering of a seabed disposal is the determination of the temperature and fluid flow fields existing in the sediment layer and the perturbation of these fields due to the implantation of localized heat sources. The fluid mechanical and heat transfer process occurring in oceanic sediments may be characterized as free (or natural) convection in a porous material. In the case of an undisturbed sediment layer, the driving force for the natural circulation of pore water comes from the geothermal heat flux. Current theories for heat flow from the sea floor suggest the possibility of large scale hydrothermal circulation in the oceanic crust (see e.g., Ribando, et al. 1976) which is in turn coupled with a convection process in the overlying sediment layer (Anderson 1980, Anderson, et al. 1979). The introduction of a local heat source, such as a waste canister, into a saturated sediment layer would by itself initiate a convection process due to buoyancy forces. Since the mathematical description of natural convection in a porous medium is of sufficient complexity to preclude the use of most analytic methods of analysis, approximate numerical procedures are often employed. In the following sections, a particular type of numerical method is described that has proved useful in the solution of a variety of porous flow problems. However, rather than concentrate on the details of the numerical algorithm the main emphasis of the presentation will be on the types of problems and results that are encountered in the areas of oceanic heat flow and seabed waste disposal

  10. Sensitivity of the tropical climate to an interhemispheric thermal gradient: the role of tropical ocean dynamics

    Science.gov (United States)

    Talento, Stefanie; Barreiro, Marcelo

    2018-03-01

    This study aims to determine the role of the tropical ocean dynamics in the response of the climate to extratropical thermal forcing. We analyse and compare the outcomes of coupling an atmospheric general circulation model (AGCM) with two ocean models of different complexity. In the first configuration the AGCM is coupled with a slab ocean model while in the second a reduced gravity ocean (RGO) model is additionally coupled in the tropical region. We find that the imposition of extratropical thermal forcing (warming in the Northern Hemisphere and cooling in the Southern Hemisphere with zero global mean) produces, in terms of annual means, a weaker response when the RGO is coupled, thus indicating that the tropical ocean dynamics oppose the incoming remote signal. On the other hand, while the slab ocean coupling does not produce significant changes to the equatorial Pacific sea surface temperature (SST) seasonal cycle, the RGO configuration generates strong warming in the central-eastern basin from April to August balanced by cooling during the rest of the year, strengthening the seasonal cycle in the eastern portion of the basin. We hypothesize that such changes are possible via the dynamical effect that zonal wind stress has on the thermocline depth. We also find that the imposed extratropical pattern affects El Niño-Southern Oscillation, weakening its amplitude and low-frequency behaviour.

  11. Open cycle ocean thermal energy conversion system structure

    Science.gov (United States)

    Wittig, J. Michael

    1980-01-01

    A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially situated in the mushroom's stem portion. Upon expansion through the turbine, the motive steam enters a shell and tube condenser annularly disposed about the rotor axis and axially situated beneath the turbine in the stem portion. Relatively warm ocean water is circulated up through the radially outer skirt-conduit structure entering the evaporator through a radially outer portion thereof, flashing a portion thereof into motive steam, and draining the unflashed portion from the evaporator through a radially inner skirt-conduit structure. Relatively cold cooling water enters the annular condenser through the radially inner edge and travels radially outwardly into a channel situated along the radially outer edge of the condenser. The channel is also included in the radially inner skirt-conduit structure. The cooling water is segregated from the potable, motive steam condensate which can be used for human consumption or other processes requiring high purity water. The expansion energy of the motive steam is partially converted into rotational mechanical energy of the turbine rotor when the steam is expanded through the shaft attached blades. Such mechanical energy drives a generator also included in the enlarged mushroom portion for producing electrical energy. Such power generation equipment arrangement provides a compact power system from which additional benefits may be obtained by fabricating the enclosing equipment, housings and component casings from low density materials, such as prestressed concrete, to permit those casings and housings to also function as a floating

  12. Changes in thermal plasticity of low grade coals during selective extraction of metals

    Directory of Open Access Journals (Sweden)

    В. Ю. Бажин

    2016-08-01

    Full Text Available As the world oil market tends to be highly volatile, the coal becomes a primary source of organic raw materials for chemical and metallurgical industries. Fossil coals can accumulate high amounts of elements and mixtures quite often reaching commercially valuable concentrations. Reserves of scandium and other rare elements in coal deposits in Siberia alone are sufficient to satisfy the expected global demand for several decades. This study is intended to solve complex tasks associated with extraction of metal oxides using the developed enrichment method to ensure the required thermal plasticity determining the quality and properties of metallurgical coke.Laboratory experiments have been conducted for the enrichment of high-ash coals containing the highest concentrations of metals. Thermal plasticity values have been determined with the help of Gieseler plastometer . Using modern technologies and equipment individual deposits can be turned into profitable production of enriched coking coals with concurrent extraction of rare metals. It has been proven that the highest commercial potential lies with the extraction of scandium and some other rare metals in the form of oxides from the coal.

  13. The size, mass, and composition of plastic debris in the western North Atlantic Ocean.

    Science.gov (United States)

    Morét-Ferguson, Skye; Law, Kara Lavender; Proskurowski, Giora; Murphy, Ellen K; Peacock, Emily E; Reddy, Christopher M

    2010-10-01

    This study reports the first inventory of physical properties of individual plastic debris in the North Atlantic. We analyzed 748 samples for size, mass, and material composition collected from surface net tows on 11 expeditions from Cape Cod, Massachusetts to the Caribbean Sea between 1991 and 2007. Particles were mostly fragments less than 10mm in size with nearly all lighter than 0.05 g. Material densities ranged from 0.808 to 1.24 g ml(-1), with about half between 0.97 and 1.04 g ml(-1), a range not typically found in virgin plastics. Elemental analysis suggests that samples in this density range are consistent with polypropylene and polyethylene whose densities have increased, likely due to biofouling. Pelagic densities varied considerably from that of beach plastic debris, suggesting that plastic particles are modified during their residence at sea. These analyses provide clues in understanding particle fate and potential debris sources, and address ecological implications of pelagic plastic debris. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. The Response of the Ocean Thermal Skin Layer to Variations in Incident Infrared Radiation

    Science.gov (United States)

    Wong, Elizabeth W.; Minnett, Peter J.

    2018-04-01

    Ocean warming trends are observed and coincide with the increase in concentrations of greenhouse gases in the atmosphere resulting from human activities. At the ocean surface, most of the incoming infrared (IR) radiation is absorbed within the top micrometers of the ocean's surface where the thermal skin layer (TSL) exists. Thus, the incident IR radiation does not directly heat the upper few meters of the ocean. This paper investigates the physical mechanism between the absorption of IR radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that given the heat lost through the air-sea interface is controlled by the TSL, the TSL adjusts in response to variations in incident IR radiation to maintain the surface heat loss. This modulates the flow of heat from below and hence controls upper ocean heat content. This hypothesis is tested using the increase in incoming longwave radiation from clouds and analyzing vertical temperature profiles in the TSL retrieved from sea-surface emission spectra. The additional energy from the absorption of increasing IR radiation adjusts the curvature of the TSL such that the upward conduction of heat from the bulk of the ocean into the TSL is reduced. The additional energy absorbed within the TSL supports more of the surface heat loss. Thus, more heat beneath the TSL is retained leading to the observed increase in upper ocean heat content.

  15. Optimized use of cooling holes to decrease the amount of thermal damage on a plastic gear tooth

    Directory of Open Access Journals (Sweden)

    Demagna Koffi

    2016-05-01

    Full Text Available The full potential of plastic gear usage is limited by not only poor mechanical properties but also equally poor temperature limits and poor heat conduction properties. Cooling holes were developed to decrease the amount of thermal damage on the contact surface. These cooling holes promote increased stress and tooth deflection, thus exerting a negative effect. This article compares various cooling holes for plastic gear configurations and proposes novel cooling holes. Thermal and mechanical simulations that consider specific aspects of plastic gear meshing were performed. The main objective of this article was to verify the best methods for reducing thermal damage through cooling holes. The results indicate the best compromise between the temperature reduction and the mechanical properties of the new tooth geometry. The results also indicate that the simple variations in the cooling holes proposed can improve tooth performance.

  16. Temperature dependent mechanical properties and thermal activation plasticity of nanocrystalline and coarse grained Ni-18.75 at.% Fe alloy

    International Nuclear Information System (INIS)

    Tabachnikova, E D; Podolskiy, A V; Smirnov, S N; Psaruk, I A; Liao, P K

    2014-01-01

    Mechanical properties of Ni-18.75 at.% Fe in coarse grained (average grain size 15 gm) and nanocrystalline (average grain size 22 nm) states were studied in uniaxial compression in the temperature range 4.2-350 K. Temperature dependences of the flow stress, strain rate sensitivity and activation volume of plastic deformation were measured. The thermal activation analysis of the experimental data has been fulfilled for the the plastic deformation value of 2 %. It was shown that plastic deformation in temperature range from 35 to 350 K in both studied structural states has the thermally activated type. Comparative analysis of low temperature thermal activation plastic deformation was carried out for the alloy in coarse grained and nanocrystalline states. Empirical estimates of parameters of the dislocation interaction with local barriers and internal stress value estimates were obtained for the both studied structural states. Analysis of the results indicates that different mechanisms control the thermal activation plasticity of the Ni-18.75 at.% Fe alloy in coarse grained and nanocrystalline states. Possible mechanisms, which control plactisity of the studied states, are disscussed

  17. Thermal behavior and pyrolytic degradation kinetics of polymeric mixtures from waste packaging plastics

    Directory of Open Access Journals (Sweden)

    R. Tuffi

    2018-01-01

    Full Text Available The thermal behavior and pyrolytic kinetic analysis of main waste polymers (polypropylene (PP, polyethylene film (PE, poly(ethylene terephthalate (PET, polystyrene (PS and three synthetic mixtures representing commingled postconsumer plastics wastes (CPCPWs output from material recovery facilities were studied. Thermogravimetry (TG pyrolysis experiments revealed that the thermal degradation of single polymers and the synthetic mixture enriched in PP occurred in one single step. The other two mixtures underwent a two-consecutive, partially overlapping degradation steps, whose peaks related to the first-order derivative of TG were deconvoluted into two distinct processes. Further TG experiments carried out on binary mixtures (PS/PP, PET/PP, PET/PEfilm and PP/PEfilm showed a thermal degradation reliance on composition, structure and temperatures of single polymer components. A kinetic analysis was made for each step using the Kissinger-Akahira-Sunose (KAS method, thus determining almost constant activation energy (Ea for pyrolysis of PS, PET, PP and PE film in the range 0.25<α<0.85, unlike for pyrolysis of CPCPWs, with particular reference to CPCPW1 and the second step of CPCPW2 and CPCPW3, both ascribable to degradation of PP and PE film. To account for the reliability of these values the integral isoconversional modified method developed by Vyazovkin was also applied.

  18. Thermal adaptation and phenotypic plasticity in a warming world: Insights from common garden experiments on Alaskan sockeye salmon

    Science.gov (United States)

    Sparks, Morgan M.; Westley, Peter A. H.; Falke, Jeffrey A.; Quinn, Thomas P.

    2017-01-01

    An important unresolved question is how populations of coldwater-dependent fishes will respond to rapidly warming water temperatures. For example, the culturally and economically important group, Pacific salmon (Oncorhynchus spp.), experience site-specific thermal regimes during early development that could be disrupted by warming. To test for thermal local adaptation and heritable phenotypic plasticity in Pacific salmon embryos, we measured the developmental rate, survival, and body size at hatching in two populations of sockeye salmon (Oncorhynchus nerka) that overlap in timing of spawning but incubate in contrasting natural thermal regimes. Using a split half-sibling design, we exposed embryos of 10 families from each of two populations to variable and constant thermal regimes. These represented both experienced temperatures by each population, and predicted temperatures under plausible future conditions based on a warming scenario from the downscaled global climate model (MIROC A1B scenario). We did not find evidence of thermal local adaptation during the embryonic stage for developmental rate or survival. Within treatments, populations hatched within 1 day of each other, on average, and amongtreatments, did not differ in survival in response to temperature. We did detect plasticity to temperature; embryos developed 2.5 times longer (189 days) in the coolest regime compared to the warmest regime (74 days). We also detected variation in developmental rates among families within and among temperature regimes, indicating heritable plasticity. Families exhibited a strong positive relationship between thermal variability and phenotypic variability in developmental rate but body length and mass at hatching were largely insensitive to temperature. Overall, our results indicated a lack of thermal local adaptation, but a presence of plasticity in populations experiencing contrasting conditions, as well as family-specific heritable plasticity that could

  19. Thermal recycling of plastic waste using pyrolysis-gasification process for energy production

    Energy Technology Data Exchange (ETDEWEB)

    Forbit, George Teke

    2012-04-04

    The disposal of mixed waste in landfills, dump sites and open burning without material and energy recovery leads to resource loss, causes health problems, pollution and littering. Increasing energy demand for industrial and domestic application with rising costs due to scarcity motivates a constant search for alternative clean energy sources. Recovering energy from waste presents various incentives e.g. creating jobs, alleviating poverty, combating and mitigating climate change, protecting the environment and reducing dependence on traditional fuels sources. Hence, plastics end up in landfills, surface waters and ocean bed with serious negative impact on terrestrial and aquatic biodiversity. Plastic waste with high calorific value (36-46MJ/kg) occupies the greatest portion of landfill space. Hence, using an appropriate technology to transform waste plastic to a hot gaseous mixture which is burned in-situ produces enormous amount of energy without pollution. Based on this hypothesis, the study objectives accomplished were to: 1. Characterise, quantify and classify waste fractions and plastic components common in MSW by manual sorting 2. Evaluate options for sustainable plastic waste management especially for developing countries 3. Design, construct, test and optimize an appropriate technology that applies pyrolysis and gasification processes to convert non-PVC plastic waste to energy 4. Assess the efficiency of the technology based on the functioning, the engineering, mass and energy analysis including socioeconomic and environmental impacts An integrated methodology involving review of current literature, field and laboratory experiments on mixed waste and plastic waste analysis was used. In addition, the pyrolysis-gasification technology (PGT) was conceptualised, designed, constructed, tested and optimised at BTU Cottbus, Germany; Lagos, Nigeria and Dschang, Cameroon. Field studies involving natural observation, interviews, personal discussions and visits to

  20. Design and cost of near-term OTEC (Ocean Thermal Energy Conversion) plants for the production of desalinated water and electric power. [Ocean Thermal Energy Conversion (OTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Rabas, T.; Panchal, C.; Genens, L.

    1990-01-01

    There currently is an increasing need for both potable water and power for many islands in the Pacific and Caribbean. The Ocean Thermal Energy Conversion (OTEC) technology fills these needs and is a viable option because of the unlimited supply of ocean thermal energy for the production of both desalinated water and electricity. The OTEC plant design must be flexible to meet the product-mix demands that can be very different from site to site. This paper describes different OTEC plants that can supply various mixes of desalinated water and vapor -- the extremes being either all water and no power or no water and all power. The economics for these plants are also presented. The same flow rates and pipe sizes for both the warm and cold seawater streams are used for different plant designs. The OTEC plant designs are characterized as near-term because no major technical issues need to be resolved or demonstrated. The plant concepts are based on DOE-sponsored experiments dealing with power systems, advanced heat exchanger designs, corrosion and fouling of heat exchange surfaces, and flash evaporation and moisture removal from the vapor using multiple spouts. In addition, the mature multistage flash evaporator technology is incorporated into the plant designs were appropriate. For the supply and discharge warm and cold uncertainties do exist because the required pipe sizes are larger than the maximum currently deployed -- 40-inch high-density polyethylene pipe at Keahole Point in Hawaii. 30 refs., 6 figs., 8 tabs.

  1. Effect of Plasticizer Type and Concentration on Tensile, Thermal and Barrier Properties of Biodegradable Films Based on Sugar Palm (Arenga pinnata Starch

    Directory of Open Access Journals (Sweden)

    Muhammed L. Sanyang

    2015-06-01

    Full Text Available The use of starch based films as a potential alternative choice to petroleum derived plastics is imperative for environmental waste management. This study presents a new biopolymer (sugar palm starch for the preparation of biodegradable packaging films using a solution casting technique. The effect of different plasticizer types (glycerol (G, sorbitol (S and glycerol-sorbitol (GS combination with varying concentrations (0, 15, 30 and 45, w/w% on the tensile, thermal and barrier properties of sugar palm starch (SPS films was evaluated. Regardless of plasticizer types, the tensile strength of plasticized SPS films decreased, whereas their elongation at break (E% increased as the plasticizer concentrations were raised. However, the E% for G and GS-plasticized films significantly decreased at a higher plasticizer concentration (45% w/w due to the anti-plasticization effect of plasticizers. Change in plasticizer concentration showed an insignificant effect on the thermal properties of S-plasticized films. The glass transition temperature of SPS films slightly decreased as the plasticizer concentration increased from 15% to 45%. The plasticized films exhibited increased water vapor permeability values from 4.855 × 10−10 to 8.70 × 10−10 g·m−1·s−1·Pa−1, irrespective of plasticizer types. Overall, the current study manifested that plasticized sugar palm starch can be regarded as a promising biopolymer for biodegradable films.

  2. Ocean acidification has little effect on developmental thermal windows of echinoderms from Antarctica to the tropics.

    Science.gov (United States)

    Karelitz, Sam E; Uthicke, Sven; Foo, Shawna A; Barker, Mike F; Byrne, Maria; Pecorino, Danilo; Lamare, Miles D

    2017-02-01

    As the ocean warms, thermal tolerance of developmental stages may be a key driver of changes in the geographical distributions and abundance of marine invertebrates. Additional stressors such as ocean acidification may influence developmental thermal windows and are therefore important considerations for predicting distributions of species under climate change scenarios. The effects of reduced seawater pH on the thermal windows of fertilization, embryology and larval morphology were examined using five echinoderm species: two polar (Sterechinus neumayeri and Odontaster validus), two temperate (Fellaster zelandiae and Patiriella regularis) and one tropical (Arachnoides placenta). Responses were examined across 12-13 temperatures ranging from -1.1 °C to 5.7 °C (S. neumayeri), -0.5 °C to 10.7 °C (O. validus), 5.8 °C to 27 °C (F. zelandiae), 6.0 °C to 27.1 °C (P. regularis) and 13.9 °C to 34.8 °C (A. placenta) under present-day and near-future (2100+) ocean acidification conditions (-0.3 pH units) and for three important early developmental stages 1) fertilization, 2) embryo (prehatching) and 3) larval development. Thermal windows for fertilization were broad and were not influenced by a pH decrease. Embryological development was less thermotolerant. For O. validus, P. regularis and A. placenta, low pH reduced normal development, albeit with no effect on thermal windows. Larval development in all five species was affected by both temperature and pH; however, thermal tolerance was not reduced by pH. Results of this study suggest that in terms of fertilization and development, temperature will remain as the most important factor influencing species' latitudinal distributions as the ocean continues to warm and decrease in pH, and that there is little evidence of a synergistic effect of temperature and ocean acidification on the thermal control of species ranges. © 2016 John Wiley & Sons Ltd.

  3. Incidence, mass and variety of plastics ingested by Laysan (Phoebastria immutabilis) and Black-footed Albatrosses (P. nigripes) recovered as by-catch in the North Pacific Ocean.

    Science.gov (United States)

    Gray, Holly; Lattin, Gwendolyn L; Moore, Charles J

    2012-10-01

    Laysan Albatrosses (Phoebastria immutabilis) and Black-footed Albatrosses (P. nigripes) ingest plastic debris, as evidenced by studies showing plastic in the digestive contents of their chicks, but there is little documentation of the frequency and amount of ingested plastics carried in foraging adults. In this study, we quantify plastics among the digestive contents of 18 Laysan Albatrosses and 29 Black-footed Albatrosses collected as by-catch in the North Pacific Ocean. We found ingested plastic in 30 of the 47 birds examined, with Laysan Albatrosses exhibiting a greater frequency of plastic ingestion (83.3% n=18) than Black-footed Albatrosses (51.7% n=29) (X(2)=4.8, df=1, P=0.03). Though the mass of ingested plastic in both species (mean±SD=0.463g±1.447) was lower than previously noted among albatross chicks, the high frequency of ingested plastic we found in this study suggests that long-term effects, e.g. absorption of contaminants from plastics, may be of concern throughout the population. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Climate change in the oceans: evolutionary versus phenotypically plastic responses of marine animals and plants.

    Science.gov (United States)

    Reusch, Thorsten B H

    2014-01-01

    I summarize marine studies on plastic versus adaptive responses to global change. Due to the lack of time series, this review focuses largely on the potential for adaptive evolution in marine animals and plants. The approaches were mainly synchronic comparisons of phenotypically divergent populations, substituting spatial contrasts in temperature or CO2 environments for temporal changes, or in assessments of adaptive genetic diversity within populations for traits important under global change. The available literature is biased towards gastropods, crustaceans, cnidarians and macroalgae. Focal traits were mostly environmental tolerances, which correspond to phenotypic buffering, a plasticity type that maintains a functional phenotype despite external disturbance. Almost all studies address coastal species that are already today exposed to fluctuations in temperature, pH and oxygen levels. Recommendations for future research include (i) initiation and analyses of observational and experimental temporal studies encompassing diverse phenotypic traits (including diapausing cues, dispersal traits, reproductive timing, morphology) (ii) quantification of nongenetic trans-generational effects along with components of additive genetic variance (iii) adaptive changes in microbe-host associations under the holobiont model in response to global change (iv) evolution of plasticity patterns under increasingly fluctuating environments and extreme conditions and (v) joint consideration of demography and evolutionary adaptation in evolutionary rescue approaches.

  5. Heavy metals dispersion during thermal treatment of plastic bags and its recovery.

    Science.gov (United States)

    Alam, Ohidul; Wang, Sijia; Lu, Wentao

    2018-04-15

    One of the main worries for thermal treatment of plastic bag (PB) is the air pollution resulting from heavy metal (HM) evaporation and emission. The quest of the study was to investigate their fate during thermal treatment varying with temperature and atmosphere to explore the appropriate treatment technology. Four commonly consumed polymer bags such as PE, HDPE, LDPE and PVC were selected for the analysis. The elemental compositions, heating values and total metal contents of the samples were measured by an elemental analyzer, a sulphur/halogen analyzer, a bomb calorimeter and an ICP-OES, respectively. Thermal treatments of the samples were conducted in a tube furnace at 350, 550, 650, 750, and 850 °C with 1 L/min air or N 2 gas flow, respectively. 5% HNO 3 /10% H 2 O 2 solution was used for absorbing metals from gas phase, and then HM distributions both in flue gas and bottom ash were determined. Results revealed that the lower heating values of HDPE, LDPE, PVC and PE bags were 33.32, 34.28, 24.82 and 36.7 MJ/kg, respectively indicating energy recovery potential. Thermal treatment showed the maximum mass reduction (>90%) of PB at 850 °C. The higher percentage of metals was distributed in ash at initial temperature that promoted to gas with rise of temperature. The used absorption solution exhibited tremendous quantity of metals recovery. However, there was no significant difference between using air and N 2 gas flow during treatment of PB. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Modeling the response of Northwest Greenland to enhanced ocean thermal forcing and subglacial discharge

    Science.gov (United States)

    Morlighem, M.; Wood, M.; Seroussi, H. L.; Bondzio, J. H.; Rignot, E. J.

    2017-12-01

    Glacier-front dynamics is an important control on Greenland's ice mass balance. Warm and salty Atlantic water, which is typically found at a depth below 200-300 m, has the potential to trigger ice-front retreats of marine-terminating glaciers, and the corresponding loss in resistive stress leads to glacier acceleration and thinning. It remains unclear, however, which glaciers are currently stable but may retreat in the future, and how far inland and how fast they will retreat. Here, we quantify the sensitivity and vulnerability of marine-terminating glaciers along the Northwest coast of Greenland (from 72.5° to 76°N) to ocean forcing using the Ice Sheet System Model (ISSM), and its new ice front migration capability. We rely on the ice melt parameterization from Rignot et al. 2016, and use ocean temperature and salinity from high-resolution ECCO2 simulations on the continental shelf to constrain the thermal forcing. The ice flow model includes a calving law based on a Von Mises criterion. We investigate the sensitivity of Northwest Greenland to enhanced ocean thermal forcing and subglacial discharge. We find that some glaciers, such as Dietrichson Gletscher or Alison Gletscher, are sensitive to small increases in ocean thermal forcing, while others, such as Illullip Sermia or Qeqertarsuup Sermia, are very difficult to destabilize, even with a quadrupling of the melt. Under the most intense melt experiment, we find that Hayes Gletscher retreats by more than 50 km inland into a deep trough and its velocity increases by a factor of 10 over only 15 years. The model confirms that ice-ocean interactions are the triggering mechanism of glacier retreat, but the bed controls its magnitude. This work was performed at the University of California Irvine under a contract with the National Aeronautics and Space Administration, Cryospheric Sciences Program (#NNX15AD55G), and the National Science Foundation's ARCSS program (#1504230).

  7. Review of the nuclear reactor thermal hydraulic research in ocean motions

    International Nuclear Information System (INIS)

    Yan, B.H.

    2017-01-01

    The research and development of small modular reactor in floating platform has been strongly supported by Chinese government and enterprises. Due to the effect of ocean waves, the thermal hydraulic behavior and safety characteristics of floating reactor are different from that of land-based reactor. Many scholars including the author have published their research and results in open literatures. Much of these literatures are valuable but there are also some contradictory conclusions. In this wok, the nuclear reactor thermal hydraulic research in ocean motions was systematically summarized. Valuable results and experimental data were analyzed and classified. Inherent mechanism for controversial issues in different experiments was explained. Necessary work needed in the future was suggested. Through this work, we attempt to find as many valuable results as possible for the designing and subsequent research.

  8. Review of the nuclear reactor thermal hydraulic research in ocean motions

    Energy Technology Data Exchange (ETDEWEB)

    Yan, B.H., E-mail: yanbh3@mail.sysu.edu.cn

    2017-03-15

    The research and development of small modular reactor in floating platform has been strongly supported by Chinese government and enterprises. Due to the effect of ocean waves, the thermal hydraulic behavior and safety characteristics of floating reactor are different from that of land-based reactor. Many scholars including the author have published their research and results in open literatures. Much of these literatures are valuable but there are also some contradictory conclusions. In this wok, the nuclear reactor thermal hydraulic research in ocean motions was systematically summarized. Valuable results and experimental data were analyzed and classified. Inherent mechanism for controversial issues in different experiments was explained. Necessary work needed in the future was suggested. Through this work, we attempt to find as many valuable results as possible for the designing and subsequent research.

  9. Ocean thermal plantships for production of ammonia as the hydrogen carrier.

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, C.B.; Pandolfini, P. P.; Kumm, W. H.; Energy Systems; Johns Hopkins Univ.; Arctic Energies, Ltd.

    2009-12-02

    Conventional petroleum, natural gas, and coal are the primary sources of energy that have underpinned modern civilization. Their continued availability in the projected quantities required and the impacts of emission of greenhouse gases (GHGs) on the environment are issues at the forefront of world concerns. New primary sources of energy are being sought that would significantly reduce the emissions of GHGs. One such primary source that can help supply energy, water, and fertilizer without GHG emissions is available in the heretofore unexploited thermal gradients of the tropical oceans. The world's oceans are the largest natural collector and reservoir of solar energy. The potential of ocean energy is limitless for producing base-load electric power or ammonia as the hydrogen carrier and fresh water from seawater. However, until now, ocean energy has been virtually untapped. The general perception is that ocean thermal energy is limited to tropical countries. Therefore, the full potential of at-sea production of (1) ammonia as a hydrogen carrier and (2) desalinated water has not been adequately evaluated. Using ocean thermal plantships for the at-sea co-production of ammonia as a hydrogen carrier and desalinated water offer potential energy, environmental, and economic benefits that support the development of the technology. The introduction of a new widespread solution to our projected energy supply requires lead times of a decade or more. Although continuation of the ocean thermal program from the 1970s would likely have put us in a mitigating position in the early 2000s, we still have a window of opportunity to dedicate some of our conventional energy sources to the development of this renewable energy by the time new sources would be critically needed. The primary objective of this project is to evaluate the technical and economic viability of ocean thermal plantships for the production of ammonia as the hydrogen carrier. This objective is achieved by

  10. An interplay between plasticity and parental phenotype determines impacts of ocean acidification on a reef fish.

    Science.gov (United States)

    Schunter, Celia; Welch, Megan J; Nilsson, Göran E; Rummer, Jodie L; Munday, Philip L; Ravasi, Timothy

    2018-02-01

    The impacts of ocean acidification will depend on the ability of marine organisms to tolerate, acclimate and eventually adapt to changes in ocean chemistry. Here, we use a unique transgenerational experiment to determine the molecular response of a coral reef fish to short-term, developmental and transgenerational exposure to elevated CO 2 , and to test how these responses are influenced by variations in tolerance to elevated CO 2 exhibited by the parents. Within-generation responses in gene expression to end-of-century predicted CO 2 levels indicate that a self-amplifying cycle in GABAergic neurotransmission is triggered, explaining previously reported neurological and behavioural impairments. Furthermore, epigenetic regulator genes exhibited a within-generation specific response, but with some divergence due to parental phenotype. Importantly, we find that altered gene expression for the majority of within-generation responses returns to baseline levels following parental exposure to elevated CO 2 conditions. Our results show that both parental variation in tolerance and cross-generation exposure to elevated CO 2 are crucial factors in determining the response of reef fish to changing ocean chemistry.

  11. An interplay between plasticity and parental phenotype determines impacts of ocean acidification on a reef fish

    KAUST Repository

    Schunter, Celia Marei

    2017-12-15

    The impacts of ocean acidification will depend on the ability of marine organisms to tolerate, acclimate and eventually adapt to changes in ocean chemistry. Here, we use a unique transgenerational experiment to determine the molecular response of a coral reef fish to short-term, developmental and transgenerational exposure to elevated CO2, and to test how these responses are influenced by variations in tolerance to elevated CO2 exhibited by the parents. Within-generation responses in gene expression to end-of-century predicted CO2 levels indicate that a self-amplifying cycle in GABAergic neurotransmission is triggered, explaining previously reported neurological and behavioural impairments. Furthermore, epigenetic regulator genes exhibited a within-generation specific response, but with some divergence due to parental phenotype. Importantly, we find that altered gene expression for the majority of within-generation responses returns to baseline levels following parental exposure to elevated CO2 conditions. Our results show that both parental variation in tolerance and cross-generation exposure to elevated CO2 are crucial factors in determining the response of reef fish to changing ocean chemistry.

  12. An interplay between plasticity and parental phenotype determines impacts of ocean acidification on a reef fish

    KAUST Repository

    Schunter, Celia Marei; Welch, Megan J.; Nilsson, Gö ran E.; Rummer, Jodie L.; Munday, Philip L.; Ravasi, Timothy

    2017-01-01

    The impacts of ocean acidification will depend on the ability of marine organisms to tolerate, acclimate and eventually adapt to changes in ocean chemistry. Here, we use a unique transgenerational experiment to determine the molecular response of a coral reef fish to short-term, developmental and transgenerational exposure to elevated CO2, and to test how these responses are influenced by variations in tolerance to elevated CO2 exhibited by the parents. Within-generation responses in gene expression to end-of-century predicted CO2 levels indicate that a self-amplifying cycle in GABAergic neurotransmission is triggered, explaining previously reported neurological and behavioural impairments. Furthermore, epigenetic regulator genes exhibited a within-generation specific response, but with some divergence due to parental phenotype. Importantly, we find that altered gene expression for the majority of within-generation responses returns to baseline levels following parental exposure to elevated CO2 conditions. Our results show that both parental variation in tolerance and cross-generation exposure to elevated CO2 are crucial factors in determining the response of reef fish to changing ocean chemistry.

  13. The Response of the Ocean Thermal Skin Layer to Air-Sea Surface Heat Fluxes

    Science.gov (United States)

    Wong, Elizabeth Wing-See

    There is much evidence that the ocean is heating as a result of an increase in concentrations of greenhouse gases (GHGs) in the atmosphere from human activities. GHGs absorb infrared radiation and re-emit infrared radiation back to the ocean's surface which is subsequently absorbed. However, the incoming infrared radiation is absorbed within the top micrometers of the ocean's surface which is where the thermal skin layer exists. Thus the incident infrared radiation does not directly heat the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of infrared radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that since heat lost through the air-sea interface is controlled by the thermal skin layer, which is directly influenced by the absorption and emission of infrared radiation, the heat flow through the thermal skin layer adjusts to maintain the surface heat loss, assuming the surface heat loss does not vary, and thus modulates the upper ocean heat content. This hypothesis is investigated through utilizing clouds to represent an increase in incoming longwave radiation and analyzing retrieved thermal skin layer vertical temperature profiles from a shipboard infrared spectrometer from two research cruises. The data are limited to night-time, no precipitation and low winds of less than 2 m/s to remove effects of solar radiation, wind-driven shear and possibilities of thermal skin layer disruption. The results show independence of the turbulent fluxes and emitted radiation on the incident radiative fluxes which rules out the immediate release of heat from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation and increase infrared emission. Furthermore, independence was confirmed between the incoming and outgoing radiative flux which implies the heat sink for upward flowing heat at the air-sea interface is more

  14. Ocean thermal gradient as a generator of electricity. OTEC power plant

    Science.gov (United States)

    Enrique, Luna-Gomez Victor; Angel, Alatorre-Mendieta Miguel

    2016-04-01

    The OTEC (Ocean Thermal Energy Conversion) is a power plant that uses the thermal gradient of the sea water between the surface and a depth of about 700 meters. It works by supplying the heat to a steam machine, for evaporation, with sea water from the surface and cold, to condense the steam, with deep sea water. The energy generated by the power plant OTEC can be transferred to the electric power grid, another use is to desalinate seawater. During the twentieth century in some countries experimental power plants to produce electricity or obtaining drinking water they were installed. On the Mexico's coast itself this thermal gradient, as it is located in tropical seas it occurs, so it has possibilities of installing OTEC power plant type. In this paper one type OTEC power plant operation is represented in most of its components.

  15. Thermal and catalytic decomposition behavior of PVC mixed plastic waste with petroleum residue

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Mohammad Farhat; Siddiqui, Mohammad Nahid [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2005-08-15

    The pyrolysis and hydropyrolysis of PVC mixed plastic waste alone and with petroleum residue was carried out at 150 and 350{sup o}C under N{sub 2} gas and at 430{sup o}C under 6.5MPa H{sub 2} gas pressure. The behavior of plastic waste during thermal and catalytic decomposition has also been studied in single- and two-stage reaction processes. In the individual pyrolysis process, both the petroleum residue and polystyrene (PS) undergo more than 90% conversion to liquid and gaseous products, whereas low-density polyethylene (LDPE) and high-density polyethylene (HDPE) yielded lower conversions products, and polypropylene (PP) and polyvinyl chloride (PVC) afforded somewhere a moderate to high conversion products. In a single-stage pyrolysis reaction, PVC was processed with petroleum residue at 150 and 430{sup o}C, under N{sub 2} gas for 1h at each temperature in a glass reactor. The model PVC and waste PVC showed slight variations in the products distribution obtained from the glass reactor. In two-stage process, model PVC, vacuum gas oil (VGO) and a number of different catalysts were used in a stainless steel autoclave micro tubular reactor at 350{sup o}C under the stream of N{sub 2} gas for 1h and at 430{sup o}C under 950psi (6.5MPa) H{sub 2} pressure for the duration of 2h. Significantly, different products distributions were obtained. Among the catalysts used, fluid catalytic cracking (FCC) and hydrocracking catalysts (HC-1) were most effective in producing liquid fuel (hexane soluble) materials. The study shows that the catalytic coprocessing of PVC with VGO is a feasible process by which PVC and VGO materials can be converted into transportation fuels.

  16. Composite of wood-plastic and micro-encapsulated phase change material (MEPCM) used for thermal energy storage

    International Nuclear Information System (INIS)

    Jamekhorshid, A.; Sadrameli, S.M.; Barzin, R.; Farid, M.M.

    2017-01-01

    Highlights: • A composite of wood–plastic-MEPCM has been produced. • Compression molding has been used for the composite preparation. • Thermal and properties were investigated using DSC analysis and cycling test. • Leakage test has been performed for the encapsulated PCM. • The composites can be used as a building material for thermal energy management. - Abstract: Application of phase change materials (PCMs) in lightweight building is growing due to the high latent heat of fusion of PCMs and their ability to control temperature by absorbing and releasing heat efficiently. Wood-plastic composites (WPC) are materials used in the interior parts of buildings that have improved properties compared to conventional materials. However, these materials have low energy storage capacity, which can be improved by incorporating PCM in them. Leakage of PCM is a major obstacle to the industrial applications, which can be solved through the use of microencapsulated PCM (MEPCM). This paper presents the performance tests conducted for a composite of wood-plastic-MEPCM for using in buildings for thermal storage. The wood-plastic-MEPCM composites were produced in this project using compression molding and their thermal and mechanical properties were investigated using DSC analysis, cycling test, leakage test, and three point bending analysis. The results showed that there is no leakage of PCM during phase change. The results also indicated that the composite has reasonable thermal properties, but its mechanical properties need to be improved by increasing the pressure during the molding process or by using extrusion method. The produced composites can be used as a building material for thermal energy management of building.

  17. 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.

  18. Data on thermal conductivity, water vapour permeability and water absorption of a cementitious mortar containing end-of-waste plastic aggregates

    OpenAIRE

    Di Maio, Luciano; Coppola, Bartolomeo; Courard, Luc; Michel, Frédéric; Incarnato, Loredana; Scarfato, Paola

    2018-01-01

    The data presented in this article are related to the research article entitled “Hygro-thermal and durability properties of a lightweight mortar made with foamed plastic waste aggregates ” (Coppola et al., 2018). This article focuses the attention on thermal conductivity, water vapour permeability and water absorption of a lightweight cementitious mortar containing foamed end-of-waste plastic aggregates, produced via foam extrusion process. Thermal conductivity, water vapour permeability ...

  19. Variation in plastic responses of a globally distributed picoplankton species to ocean acidification

    Science.gov (United States)

    Schaum, Elisa; Rost, Björn; Millar, Andrew J.; Collins, Sinéad

    2013-03-01

    Phytoplankton are the basis of marine food webs, and affect biogeochemical cycles. As CO2 levels increase, shifts in the frequencies and physiology of ecotypes within phytoplankton groups will affect their nutritional value and biogeochemical function. However, studies so far are based on a few representative genotypes from key species. Here, we measure changes in cellular function and growth rate at atmospheric CO2 concentrations predicted for the year 2100 in 16 ecotypes of the marine picoplankton Ostreococcus. We find that variation in plastic responses among ecotypes is on par with published between-genera variation, so the responses of one or a few ecotypes cannot estimate changes to the physiology or composition of a species under CO2 enrichment. We show that ecotypes best at taking advantage of CO2 enrichment by changing their photosynthesis rates most should increase in relative fitness, and so in frequency in a high-CO2 environment. Finally, information on sampling location, and not phylogenetic relatedness, is a good predictor of ecotypes likely to increase in frequency in this system.

  20. Thermal effect of laser ablation on the surface of carbon fiber reinforced plastic during laser processing

    Science.gov (United States)

    Ohkubo, Tomomasa; Sato, Yuji; Matsunaga, Ei-ichi; Tsukamoto, Masahiro

    2018-02-01

    Although laser processing is widely used for many applications, the cutting quality of carbon fiber reinforced plastic (CFRP) decreases around the heat-affected zone (HAZ) during laser processing. Carbon fibers are exposed around the HAZ, and tensile strength decreases with increasing length of the HAZ. Some theoretical studies of thermal conductions that do not consider fluid dynamics have been performed; however, theoretical considerations that include the dynamics of laser ablation are scarce. Using removed mass and depth observed from experiments, the dynamics of laser ablation of CFRP with high-temperature and high-pressure of compressive gas is simulated herein. In this calculation, the mushroom-like shape of laser ablation is qualitatively simulated compared with experiments using a high-speed camera. Considering the removal temperature of the resin and the temperature distribution at each point on the surface, the simulation results suggest that a wide area of the resin is removed when the processing depth is shallow, and a rounded kerf is generated as the processing depth increases.

  1. Corrosion and biofouling on the non-heat-exchanger surfaces of an ocean thermal energy conversion power plant: a survey

    Energy Technology Data Exchange (ETDEWEB)

    Castelli, V.J. (ed.)

    1979-05-01

    Of the many foreseeable problems confronting economical ocean thermal energy conversion operation, two major items are the deterioration of the structural and functional components, which prevents efficient operation, and the biofouling of the surfaces, which adds excess weight to the floating ocean platform. The techniques required for effective long-term control of deterioration and corrosion have been investigated actively for many years, and successful solutions for most situations have been developed. For the most part, these solutions can be directly transferred to the ocean thermal energy conversion plant. The majority of problems in these areas are expected to be associated with scale-up and will require some advanced development due to the immensity of the ocean thermal energy conversion platform. Current antifouling control systems are not effective for long-term fouling prevention. Commercially available antifouling coatings are limited to a 3-year service life in temperate waters, and even shorter in tropical waters. However, underwater cleaning techniques and some fouling-control systems presently being used by conventional power plants may find utility on an ocean thermal energy conversion plant. In addition, some recent major advances in long-term antifouling coatings sponsored by the Navy may be applicable to ocean thermal energy conversion. 132 references.

  2. Ocean Thermal Energy Conversion Life Cycle Cost Assessment, Final Technical Report, 30 May 2012

    Energy Technology Data Exchange (ETDEWEB)

    Martel, Laura [Lockheed Martin, Manassas, VA (United States); Smith, Paul [John Halkyard and Associates: Glosten Associates, Houston, TX (United States); Rizea, Steven [Makai Ocean Engineering, Waimanalo, HI (United States); Van Ryzin, Joe [Makai Ocean Engineering, Waimanalo, HI (United States); Morgan, Charles [Planning Solutions, Inc., Vancouver, WA (United States); Noland, Gary [G. Noland and Associates, Inc., Pleasanton, CA (United States); Pavlosky, Rick [Lockheed Martin, Manassas, VA (United States); Thomas, Michael [Lockheed Martin, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates: Glosten Associates, Houston, TX (United States)

    2012-05-30

    The Ocean Thermal Energy Conversion (OTEC) Life Cycle Cost Assessment (OLCCA) is a study performed by members of the Lockheed Martin (LM) OTEC Team under funding from the Department of Energy (DOE), Award No. DE-EE0002663, dated 01/01/2010. OLCCA objectives are to estimate procurement, operations and maintenance, and overhaul costs for two types of OTEC plants: -Plants moored to the sea floor where the electricity produced by the OTEC plant is directly connected to the grid ashore via a marine power cable (Grid Connected OTEC plants) -Open-ocean grazing OTEC plant-ships producing an energy carrier that is transported to designated ports (Energy Carrier OTEC plants) Costs are developed using the concept of levelized cost of energy established by DOE for use in comparing electricity costs from various generating systems. One area of system costs that had not been developed in detail prior to this analysis was the operations and sustainment (O&S) cost for both types of OTEC plants. Procurement costs, generally referred to as capital expense and O&S costs (operations and maintenance (O&M) costs plus overhaul and replacement costs), are assessed over the 30 year operational life of the plants and an annual annuity calculated to achieve a levelized cost (constant across entire plant life). Dividing this levelized cost by the average annual energy production results in a levelized cost of electricity, or LCOE, for the OTEC plants. Technical and production efficiency enhancements that could result in a lower value of the OTEC LCOE were also explored. The thermal OTEC resource for Oahu, Hawaii and projected build out plan were developed. The estimate of the OTEC resource and LCOE values for the planned OTEC systems enable this information to be displayed as energy supplied versus levelized cost of the supplied energy; this curve is referred to as an Energy Supply Curve. The Oahu Energy Supply Curve represents initial OTEC deployment starting in 2018 and demonstrates the

  3. Performance study of K{sub e} factors in simplified elastic plastic fatigue analyses with emphasis on thermal cyclic loading

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Hermann, E-mail: hermann.lang@areva.com [AREVA NP GmbH, PEEA-G, Henri-Dunant-Strasse 50, 91058 Erlangen (Germany); Rudolph, Juergen; Ziegler, Rainer [AREVA NP GmbH, PEEA-G, Henri-Dunant-Strasse 50, 91058 Erlangen (Germany)

    2011-08-15

    As code-based fully elastic plastic code conforming fatigue analyses are still time consuming, simplified elastic plastic analysis is often applied. This procedure is known to be overly conservative for some conditions due to the applied plastification (penalty) factor K{sub e}. As a consequence, less conservative fully elastic plastic fatigue analyses based on non-linear finite element analyses (FEA) or simplified elastic plastic analysis based on more realistic K{sub e} factors have to be used for fatigue design. The demand for more realistic K{sub e} factors is covered as a requirement of practical fatigue analysis. Different code-based K{sub e} procedures are reviewed in this paper with special regard to performance under thermal cyclic loading conditions. Other approximation formulae such as those by Neuber, Seeger/Beste or Kuehnapfel are not evaluated in this context because of their applicability to mechanical loading excluding thermal cyclic loading conditions typical for power plant operation. Besides the current code-based K{sub e} corrections, the ASME Code Case N-779 (e.g. Adam's proposal) and its modification in ASME Section VIII is considered. Comparison of elastic plastic results and results from the Rules for Nuclear Facility Components and Rules for Pressure Vessels reveals a considerable overestimation of usage factor in the case of ASME III and KTA 3201.2 for the examined examples. Usage factors according to RCC-M, Adams (ASME Code Case N-779), ASME VIII (alternative) and EN 13445-3 are essentially comparable and less conservative for these examples. The K{sub v} correction as well as the applied yield criterion (Tresca or von Mises) essentially influence the quality of the more advanced plasticity corrections (e.g. ASME Code Case N-779 and RCC-M). Hence, new proposals are based on a refined K{sub v} correction.

  4. Performance study of Ke factors in simplified elastic plastic fatigue analyses with emphasis on thermal cyclic loading

    International Nuclear Information System (INIS)

    Lang, Hermann; Rudolph, Juergen; Ziegler, Rainer

    2011-01-01

    As code-based fully elastic plastic code conforming fatigue analyses are still time consuming, simplified elastic plastic analysis is often applied. This procedure is known to be overly conservative for some conditions due to the applied plastification (penalty) factor K e . As a consequence, less conservative fully elastic plastic fatigue analyses based on non-linear finite element analyses (FEA) or simplified elastic plastic analysis based on more realistic K e factors have to be used for fatigue design. The demand for more realistic K e factors is covered as a requirement of practical fatigue analysis. Different code-based K e procedures are reviewed in this paper with special regard to performance under thermal cyclic loading conditions. Other approximation formulae such as those by Neuber, Seeger/Beste or Kuehnapfel are not evaluated in this context because of their applicability to mechanical loading excluding thermal cyclic loading conditions typical for power plant operation. Besides the current code-based K e corrections, the ASME Code Case N-779 (e.g. Adam's proposal) and its modification in ASME Section VIII is considered. Comparison of elastic plastic results and results from the Rules for Nuclear Facility Components and Rules for Pressure Vessels reveals a considerable overestimation of usage factor in the case of ASME III and KTA 3201.2 for the examined examples. Usage factors according to RCC-M, Adams (ASME Code Case N-779), ASME VIII (alternative) and EN 13445-3 are essentially comparable and less conservative for these examples. The K v correction as well as the applied yield criterion (Tresca or von Mises) essentially influence the quality of the more advanced plasticity corrections (e.g. ASME Code Case N-779 and RCC-M). Hence, new proposals are based on a refined K v correction.

  5. Differential effects of developmental thermal plasticity across three generations of guppies (Poecilia reticulata): canalization and anticipatory matching.

    Science.gov (United States)

    Le Roy, Amélie; Loughland, Isabella; Seebacher, Frank

    2017-06-28

    Developmental plasticity can match offspring phenotypes to environmental conditions experienced by parents. Such epigenetic modifications are advantageous when parental conditions anticipate offspring environments. Here we show firstly, that developmental plasticity manifests differently in males and females. Secondly, that under stable conditions, phenotypic responses (metabolism and locomotion) accumulate across several generations. Metabolic scope in males was greater at warmer test temperatures (26-36 °C) in offspring bred at warm temperatures (29-30 °C) compared to those bred at cooler temperatures (22-23 °C), lending support to the predictive adaptive hypothesis. However, this transgenerational matching was not established until the second (F2) generation. For other responses, e.g. swimming performance in females, phenotypes of offspring bred in different thermal environments were different in the first (F1) generation, but became more similar across three generations, implying canalization. Thirdly, when environments changed across generations, the grandparental environment affected offspring phenotypes. In females, the mode of the swimming thermal performance curve shifted to coincide with the grandparental rather than the parental or offspring developmental environments, and this lag in response may represent a cost of plasticity. These findings show that the effects of developmental plasticity differ between traits, and may be modulated by the different life histories of males and females.

  6. Plasticization-resistant hollow fiber membranes for CO2/CH4 separation based on a thermally crosslinkable polyimide

    KAUST Repository

    Chen, Chien-Chiang

    2011-10-01

    Decarboxylation-induced thermal crosslinking has been demonstrated to be effective for stabilizing membranes against plasticization in dense films. This study extends this promising crosslinking approach from dense films to industrially relevant asymmetric hollow fiber membranes. Crosslinkable asymmetric hollow fiber membranes were spun from a carboxylic acid containing polyimide, 6FDA-DAM:DABA. Dope and spinning conditions were optimized to obtain fibers with a defect-free selective skin layer. It is found that slightly defective fibers suffered severe selectivity loss after thermal crosslinking, suggesting that defect-free property is essential to the performance of the resulting crosslinked hollow fiber membranes. The crosslinked fibers were tested for CO 2/CH 4 separation. The excellent plasticization resistance under high pressure feeds (with highest CO 2 partial pressure of 400psia) suggests that these robust membranes are promising for aggressive natural gas purification. © 2011 Elsevier B.V.

  7. Elastic-Plastic Nonlinear Response of a Space Shuttle External Tank Stringer. Part 2; Thermal and Mechanical Loadings

    Science.gov (United States)

    Knight, Norman F., Jr.; Warren, Jerry E.; Elliott, Kenny B.; Song, Kyongchan; Raju, Ivatury S.

    2012-01-01

    Elastic-plastic, large-deflection nonlinear thermo-mechanical stress analyses are performed for the Space Shuttle external tank s intertank stringers. Detailed threedimensional finite element models are developed and used to investigate the stringer s elastic-plastic response for different thermal and mechanical loading events from assembly through flight. Assembly strains caused by initial installation on an intertank panel are accounted for in the analyses. Thermal loading due to tanking was determined to be the bounding loading event. The cryogenic shrinkage caused by tanking resulted in a rotation of the intertank chord flange towards the center of the intertank, which in turn loaded the intertank stringer feet. The analyses suggest that the strain levels near the first three fasteners remain sufficiently high that a failure may occur. The analyses also confirmed that the installation of radius blocks on the stringer feet ends results in an increase in the stringer capability.

  8. Plasticization-resistant hollow fiber membranes for CO2/CH4 separation based on a thermally crosslinkable polyimide

    KAUST Repository

    Chen, Chien-Chiang; Qiu, Wulin; Miller, Stephen J.; Koros, William J.

    2011-01-01

    Decarboxylation-induced thermal crosslinking has been demonstrated to be effective for stabilizing membranes against plasticization in dense films. This study extends this promising crosslinking approach from dense films to industrially relevant asymmetric hollow fiber membranes. Crosslinkable asymmetric hollow fiber membranes were spun from a carboxylic acid containing polyimide, 6FDA-DAM:DABA. Dope and spinning conditions were optimized to obtain fibers with a defect-free selective skin layer. It is found that slightly defective fibers suffered severe selectivity loss after thermal crosslinking, suggesting that defect-free property is essential to the performance of the resulting crosslinked hollow fiber membranes. The crosslinked fibers were tested for CO 2/CH 4 separation. The excellent plasticization resistance under high pressure feeds (with highest CO 2 partial pressure of 400psia) suggests that these robust membranes are promising for aggressive natural gas purification. © 2011 Elsevier B.V.

  9. Effects of ocean acidification increase embryonic sensitivity to thermal extremes in Atlantic cod, Gadus morhua.

    Science.gov (United States)

    Dahlke, Flemming T; Leo, Elettra; Mark, Felix C; Pörtner, Hans-Otto; Bickmeyer, Ulf; Frickenhaus, Stephan; Storch, Daniela

    2017-04-01

    Thermal tolerance windows serve as a powerful tool for estimating the vulnerability of marine species and their life stages to increasing temperature means and extremes. However, it remains uncertain to which extent additional drivers, such as ocean acidification, modify organismal responses to temperature. This study investigated the effects of CO 2 -driven ocean acidification on embryonic thermal sensitivity and performance in Atlantic cod, Gadus morhua, from the Kattegat. Fertilized eggs were exposed to factorial combinations of two PCO 2 conditions (400 μatm vs. 1100 μatm) and five temperature treatments (0, 3, 6, 9 and 12 °C), which allow identifying both lower and upper thermal tolerance thresholds. We quantified hatching success, oxygen consumption (MO 2 ) and mitochondrial functioning of embryos as well as larval morphometrics at hatch and the abundance of acid-base-relevant ionocytes on the yolk sac epithelium of newly hatched larvae. Hatching success was high under ambient spawning conditions (3-6 °C), but decreased towards both cold and warm temperature extremes. Elevated PCO 2 caused a significant decrease in hatching success, particularly at cold (3 and 0 °C) and warm (12 °C) temperatures. Warming imposed limitations to MO 2 and mitochondrial capacities. Elevated PCO 2 stimulated MO 2 at cold and intermediate temperatures, but exacerbated warming-induced constraints on MO 2 , indicating a synergistic interaction with temperature. Mitochondrial functioning was not affected by PCO 2 . Increased MO 2 in response to elevated PCO 2 was paralleled by reduced larval size at hatch. Finally, ionocyte abundance decreased with increasing temperature, but did not differ between PCO 2 treatments. Our results demonstrate increased thermal sensitivity of cod embryos under future PCO 2 conditions and suggest that acclimation to elevated PCO 2 requires reallocation of limited resources at the expense of embryonic growth. We conclude that ocean acidification

  10. Fatigue life of fibre reinforced plastics at 295 K after thermal cycling between 295 K and 77 K

    Science.gov (United States)

    Belisario, G.; Caproni, F.; Marchetti, E.

    Results of low cycle three-point end fatigue tests at 295 K are reported. These were obtained from fibre reinforced plastics (FRP) flat specimens made of epoxy matrix reinforced with glass rovings only or glass rovings and Kevlar cloth. It is shown that previous thermal cycles between 295 K and 77 K exert an influence on the fatigue life as well on the acoustic emission results.

  11. An Experimental Study on the Thermal Performance of Phase-Change Material and Wood-Plastic Composites for Building Roofs

    Directory of Open Access Journals (Sweden)

    Min Hee Chung

    2017-02-01

    Full Text Available We assessed the usefulness of phase-change material (PCM-based thermal plates fabricated from wood-plastic composites (WPCs in mitigating the urban heat island effect. The thermal performance of plates containing PCMs with two different melting temperatures and with two different albedo levels was evaluated. The results showed that the PCM with a melting temperature of 44 °C maintained lower surface and inner temperatures than the PCM with a melting temperature of 25 °C. Moreover, a higher surface albedo resulted in a lower surface temperature. However, the thermal performance of PCMs with different melting temperatures but the same surface albedo did not differ. Using PCM-based materials in roof finishing materials can reduce surface temperatures and improve thermal comfort.

  12. Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum

    Science.gov (United States)

    Sluijs, A.; Schouten, S.; Pagani, M.; Woltering, M.; Brinkhuis, H.; Damste, J.S.S.; Dickens, G.R.; Huber, M.; Reichart, G.-J.; Stein, R.; Matthiessen, J.; Lourens, L.J.; Pedentchouk, N.; Backman, J.; Moran, K.; Clemens, S.; Cronin, T.; Eynaud, F.; Gattacceca, J.; Jakobsson, M.; Jordan, R.; Kaminski, M.; King, J.; Koc, N.; Martinez, N.C.; McInroy, D.; Moore, T.C.; O'Regan, M.; Onodera, J.; Palike, H.; Rea, B.; Rio, D.; Sakamoto, T.; Smith, D.C.; St John, K.E.K.; Suto, I.; Suzuki, N.; Takahashi, K.; Watanabe, M. E.; Yamamoto, M.

    2006-01-01

    The Palaeocene/Eocene thermal maximum, ???55 million years ago, was a brief period of widespread, extreme climatic warming, that was associated with massive atmospheric greenhouse gas input. Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition. We show that sea surface temperatures near the North Pole increased from ???18??C to over 23??C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. At the same time, sea level rose while anoxic and euxinic conditions developed in the ocean's bottom waters and photic zone, respectively. Increasing temperature and sea level match expectations based on palaeoclimate model simulations, but the absolute polar temperatures that we derive before, during and after the event are more than 10??C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms-perhaps polar stratospheric clouds or hurricane-induced ocean mixing-to amplify early Palaeogene polar temperatures. ?? 2006 Nature Publishing Group.

  13. Thermally activated plastic flow in the presence of multiple obstacle types

    International Nuclear Information System (INIS)

    Dong, Y; Curtin, W A

    2012-01-01

    The rate- and temperature-dependent plastic flow in a material containing two types of thermally activatable obstacles to dislocation motion is studied both numerically and theoretically in a regime of relative obstacle densities for which the zero-temperature stress is additive. The numerical methods consider the low-density ‘forest’ obstacles first as point obstacles and then as extended obstacles having a finite interaction length with the dislocation, while the high-density ‘solute’ obstacles are treated as point obstacles. Results show that the finite-temperature flow stresses due to different obstacle strengthening mechanisms are additive, as proposed by Kocks et al, only when all strengthening obstacles can be approximated as point-like obstacles. When the activation distance of the low-density extended obstacles exceeds the spacing between the high-density obstacles, the finite-temperature flow stress is non-additive and the effective activation energy differs from that of the Kocks et al model. An analytical model for the activation energy versus flow stress is proposed, based on analysis of the simulation results, to account for the effect of the finite interaction length. In this model, for high forest activation energies, the point-pinning solute obstacles provide a temperature-dependent backstress σ b on dislocation and the overall activation energy is otherwise controlled by the forest activation energy. The model predictions agree well with numerical results for a wide range of obstacle properties, clearly showing the effect due to the finite interaction between dislocation and the obstacles. The implications of our results on the activation volume are discussed with respect to experimental results on solute-strengthened fcc alloys. (paper)

  14. Thermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Ocean

    KAUST Repository

    Coello-Camba, Alexandra

    2017-06-02

    Polar areas are experiencing the steepest warming rates on Earth, a trend expected to continue in the future. In these habitats, phytoplankton communities constitute the basis of the food web and their thermal tolerance may dictate how warming affects these delicate environments. Here, we compiled available data on thermal responses of phytoplankton growth in polar waters. We assembled 53 growth-vs.-temperature curves (25 from the Arctic, 28 from the Southern oceans), indicating the limited information available for these ecosystems. Half of the data from Arctic phytoplankton came from natural communities where low ambient concentrations could limit growth rates. Phytoplankton from polar waters grew faster under small temperature increases until reaching an optimum (TOPT), and slowed when temperatures increased beyond this value. This left-skewed curves were characterized by higher activation energies (Ea) for phytoplankton growth above than below the TOPT. Combining these thermal responses we obtained a community TOPT of 6.5°C (±0.2) and 5.2°C (±0.1) for Arctic and Southern Ocean phytoplankton communities, respectively. These threshold temperatures were already exceeded at 70°N during the first half of August 2013, evidenced by sea surface temperatures (SSTs, satellite data, http://www.ncdc.noaa.gov). We forecasted SSTs for the end of the twenty-first century by assuming an overall 3°C increase, equivalent to a low emission scenario. Our forecasts show that SSTs at 70°N are expected to exceed TOPT during summer by 2100, and during the first half of August at 75°N. While recent Arctic spring temperatures average 0.5°C and −0.7°C at 70°N and 75°N, respectively, they could increase to 2.8°C at 70°N and 2.2°C at 75°N as we approach 2100. Such temperature increases could lead to intense phytoplankton blooms, shortened by fast nutrient consumption. As SSTs increase, thermal thresholds for phytoplankton growth would be eventually exceeded during bloom

  15. Thermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Ocean

    Directory of Open Access Journals (Sweden)

    Alexandra Coello-Camba

    2017-06-01

    Full Text Available Polar areas are experiencing the steepest warming rates on Earth, a trend expected to continue in the future. In these habitats, phytoplankton communities constitute the basis of the food web and their thermal tolerance may dictate how warming affects these delicate environments. Here, we compiled available data on thermal responses of phytoplankton growth in polar waters. We assembled 53 growth-vs.-temperature curves (25 from the Arctic, 28 from the Southern oceans, indicating the limited information available for these ecosystems. Half of the data from Arctic phytoplankton came from natural communities where low ambient concentrations could limit growth rates. Phytoplankton from polar waters grew faster under small temperature increases until reaching an optimum (TOPT, and slowed when temperatures increased beyond this value. This left-skewed curves were characterized by higher activation energies (Ea for phytoplankton growth above than below the TOPT. Combining these thermal responses we obtained a community TOPT of 6.5°C (±0.2 and 5.2°C (±0.1 for Arctic and Southern Ocean phytoplankton communities, respectively. These threshold temperatures were already exceeded at 70°N during the first half of August 2013, evidenced by sea surface temperatures (SSTs, satellite data, http://www.ncdc.noaa.gov. We forecasted SSTs for the end of the twenty-first century by assuming an overall 3°C increase, equivalent to a low emission scenario. Our forecasts show that SSTs at 70°N are expected to exceed TOPT during summer by 2100, and during the first half of August at 75°N. While recent Arctic spring temperatures average 0.5°C and −0.7°C at 70°N and 75°N, respectively, they could increase to 2.8°C at 70°N and 2.2°C at 75°N as we approach 2100. Such temperature increases could lead to intense phytoplankton blooms, shortened by fast nutrient consumption. As SSTs increase, thermal thresholds for phytoplankton growth would be eventually exceeded

  16. Thermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Ocean

    KAUST Repository

    Coello-Camba, Alexandra; Agusti, Susana

    2017-01-01

    Polar areas are experiencing the steepest warming rates on Earth, a trend expected to continue in the future. In these habitats, phytoplankton communities constitute the basis of the food web and their thermal tolerance may dictate how warming affects these delicate environments. Here, we compiled available data on thermal responses of phytoplankton growth in polar waters. We assembled 53 growth-vs.-temperature curves (25 from the Arctic, 28 from the Southern oceans), indicating the limited information available for these ecosystems. Half of the data from Arctic phytoplankton came from natural communities where low ambient concentrations could limit growth rates. Phytoplankton from polar waters grew faster under small temperature increases until reaching an optimum (TOPT), and slowed when temperatures increased beyond this value. This left-skewed curves were characterized by higher activation energies (Ea) for phytoplankton growth above than below the TOPT. Combining these thermal responses we obtained a community TOPT of 6.5°C (±0.2) and 5.2°C (±0.1) for Arctic and Southern Ocean phytoplankton communities, respectively. These threshold temperatures were already exceeded at 70°N during the first half of August 2013, evidenced by sea surface temperatures (SSTs, satellite data, http://www.ncdc.noaa.gov). We forecasted SSTs for the end of the twenty-first century by assuming an overall 3°C increase, equivalent to a low emission scenario. Our forecasts show that SSTs at 70°N are expected to exceed TOPT during summer by 2100, and during the first half of August at 75°N. While recent Arctic spring temperatures average 0.5°C and −0.7°C at 70°N and 75°N, respectively, they could increase to 2.8°C at 70°N and 2.2°C at 75°N as we approach 2100. Such temperature increases could lead to intense phytoplankton blooms, shortened by fast nutrient consumption. As SSTs increase, thermal thresholds for phytoplankton growth would be eventually exceeded during bloom

  17. Thermal image analysis of plastic deformation and fracture behavior by a thermo-video measurement system

    International Nuclear Information System (INIS)

    Ohbuchi, Yoshifumi; Sakamoto, Hidetoshi; Nagatomo, Nobuaki

    2016-01-01

    The visualization of the plastic region and the measurement of its size are necessary and indispensable to evaluate the deformation and fracture behavior of a material. In order to evaluate the plastic deformation and fracture behavior in a structural member with some flaws, the authors paid attention to the surface temperature which is generated by plastic strain energy. The visualization of the plastic deformation was developed by analyzing the relationship between the extension of the plastic deformation range and the surface temperature distribution, which was obtained by an infrared thermo-video system. Furthermore, FEM elasto-plastic analysis was carried out with the experiment, and the effectiveness of this non-contact measurement system of the plastic deformation and fracture process by a thermography system was discussed. The evaluation method using an infrared imaging device proposed in this research has a feature which does not exist in the current evaluation method, i.e. the heat distribution on the surface of the material has been measured widely by noncontact at 2D at high speed. The new measuring technique proposed here can measure the macroscopic plastic deformation distribution on the material surface widely and precisely as a 2D image, and at high speed, by calculation from the heat generation and the heat propagation distribution. (paper)

  18. Epoxidized Vegetable Oils Plasticized Poly(lactic acid Biocomposites: Mechanical, Thermal and Morphology Properties

    Directory of Open Access Journals (Sweden)

    Buong Woei Chieng

    2014-10-01

    Full Text Available Plasticized poly(lactic acid PLA with epoxidized vegetable oils (EVO were prepared using a melt blending method to improve the ductility of PLA. The plasticization of the PLA with EVO lowers the Tg as well as cold-crystallization temperature. The tensile properties demonstrated that the addition of EVO to PLA led to an increase of elongation at break, but a decrease of tensile modulus. Plasticized PLA showed improvement in the elongation at break by 2058% and 4060% with the addition of 5 wt % epoxidized palm oil (EPO and mixture of epoxidized palm oil and soybean oil (EPSO, respectively. An increase in the tensile strength was also observed in the plasticized PLA with 1 wt % EPO and EPSO. The use of EVO increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The SEM micrograph of the plasticized PLA showed good compatible morphologies without voids resulting from good interfacial adhesion between PLA and EVO. Based on the results of this study, EVO may be used as an environmentally friendly plasticizer that can improve the overall properties of PLA.

  19. A database for the monitoring of thermal anomalies over the Amazon forest and adjacent intertropical oceans.

    Science.gov (United States)

    Jiménez-Muñoz, Juan C; Mattar, Cristian; Sobrino, José A; Malhi, Yadvinder

    2015-01-01

    Advances in information technologies and accessibility to climate and satellite data in recent years have favored the development of web-based tools with user-friendly interfaces in order to facilitate the dissemination of geo/biophysical products. These products are useful for the analysis of the impact of global warming over different biomes. In particular, the study of the Amazon forest responses to drought have recently received attention by the scientific community due to the occurrence of two extreme droughts and sustained warming over the last decade. Thermal Amazoni@ is a web-based platform for the visualization and download of surface thermal anomalies products over the Amazon forest and adjacent intertropical oceans using Google Earth as a baseline graphical interface (http://ipl.uv.es/thamazon/web). This platform is currently operational at the servers of the University of Valencia (Spain), and it includes both satellite (MODIS) and climatic (ERA-Interim) datasets. Thermal Amazoni@ is composed of the viewer system and the web and ftp sites with ancillary information and access to product download.

  20. Measurement of Three-Dimensional Anisotropic Thermal Diffusivities for Carbon Fiber-Reinforced Plastics Using Lock-In Thermography

    Science.gov (United States)

    Ishizaki, Takuya; Nagano, Hosei

    2015-11-01

    A new measurement technique to measure the in-plane thermal diffusivity, the distribution of in-plane anisotropy, and the out-of-plane thermal diffusivity has been developed to evaluate the thermal conductivity of anisotropic materials such as carbon fiber-reinforced plastics (CFRPs). The measurements were conducted by using a laser-spot-periodic-heating method. The temperature of the sample is detected by using lock-in thermography. Thermography can analyze the phase difference between the periodic heat input and the temperature response of the sample. Two kinds of samples, unidirectional (UD) and cross-ply (CP) pitch-based CFRPs, were fabricated and tested in an atmospheric condition. All carbon fibers of the UD sample run in one direction [90°]. The carbon fibers of the CP sample run in two directions [0°/90°]. It is found that, by using lock-in thermography, it is able to visualize the thermal anisotropy and calculate the angular dependence of the in-plane thermal diffusivity of the CFRPs. The out-of-plane thermal diffusivity of CFRPs was also measured by analyzing the frequency dependence of the phase difference.

  1. Preparation and performance of lipophilic α-zirconium phosphate with high thermal stability and its application in thermal-plastic polymers

    Directory of Open Access Journals (Sweden)

    Ya Du

    2015-10-01

    Full Text Available To prepare lipophilic α-zirconium phosphate with high grafting ratio and thermal stability (OZrP-HT and explore its potential application in thermal-plastic polymers, a novel method was developed by surface lipophilicity enhancement strategy. The commercial α-zirconium phosphate (α-ZrP was pre-intercalated by n-propylamine (PA and grafted by silane coupling agents. Then the pre-intercalated PA was removed by heat-treatment, and the obtained OZrP-HT was utilized to fabricate the phosphorous-containing polyester (P-co-PET/OZrP-HT nanocomposites by melt-blending method. The prepared OZrP-HT and P-co-PET/OZrP-HT nanocomposites were characterized by Wide Angle X-ray Diffraction (WAXD, Fourier Transform Infrared Spectroscopy (FTIR, Thermogravimetric Analysis (TGA, Transmission Electron Microscope (TEM, etc. The results show that OZrP-HT with high grafting ratio (13.78 wt% and thermal stability (Tonset=368 °C was successfully prepared via this novel method and was uniformly intercalated by P-co-PET molecular chains. OZrP-HT had no significant effect on the fiber processability of P-co-PET polymer, and flame retardant properties of (P-co-PET/OZrP-HT nanocomposites were improved. This method may be suitable for organic modification of general inorganic layered compounds and could extend the potential applications in thermo-plastic polymers.

  2. Selected legal and institutional issues related to Ocean Thermal Energy Conversion (OTEC) development

    Energy Technology Data Exchange (ETDEWEB)

    Nanda, V. P.

    1979-06-01

    Ocean Thermal Energy Conversion (OTEC), an attractive alternative to traditional energy sources, is still in the early stages of development. To facilitate OTEC commercialization, it is essential that a legal and institutional framework be designed now so as to resolve uncertainties related to OTEC development, primarily involving jurisdictional, regulatory, and environmental issues. The jurisdictional issues raised by OTEC use are dependent upon the site of an OTEC facility and its configuration; i.e., whether the plant is a semipermanent fixture located offshore or a migrating plant ship that provides a source of energy for industry at sea. These issues primarily involve the division of authority between the Federal Government and the individual coastal states. The regulatory issues raised are largely speculative: they involve the adaptation of existing mechanisms to OTEC operation. Finally, the environmental issues raised center around compliance with the National Environmental Policy Act (NEPA) as well as international agreements. 288 references.

  3. Impact of anthropogenic ocean acidification on thermal tolerance of the spider crab Hyas araneus

    Directory of Open Access Journals (Sweden)

    H. O. Pörtner

    2009-10-01

    Full Text Available Future scenarios for the oceans project combined developments of CO2 accumulation and global warming and their impact on marine ecosystems. The synergistic impact of both factors was addressed by studying the effect of elevated CO2 concentrations on thermal tolerance of the cold-eurythermal spider crab Hyas araneus from the population around Helgoland. Here ambient temperatures characterize the southernmost distribution limit of this species. Animals were exposed to present day normocapnia (380 ppm CO2, CO2 levels expected towards 2100 (710 ppm and beyond (3000 ppm. Heart rate and haemolymph PO2 (PeO2 were measured during progressive short term cooling from 10 to 0°C and during warming from 10 to 25°C. An increase of PeO2 occurred during cooling, the highest values being reached at 0°C under all three CO2 levels. Heart rate increased during warming until a critical temperature (Tc was reached. The putative Tc under normocapnia was presumably >25°C, from where it fell to 23.5°C under 710 ppm and then 21.1°C under 3000 ppm. At the same time, thermal sensitivity, as seen in the Q10 values of heart rate, rose with increasing CO2 concentration in the warmth. Our results suggest a narrowing of the thermal window of Hyas araneus under moderate increases in CO2 levels by exacerbation of the heat or cold induced oxygen and capacity limitation of thermal tolerance.

  4. Physiological response of the cold-water coral Desmophyllum dianthus to thermal stress and ocean acidification.

    Science.gov (United States)

    Gori, Andrea; Ferrier-Pagès, Christine; Hennige, Sebastian J; Murray, Fiona; Rottier, Cécile; Wicks, Laura C; Roberts, J Murray

    2016-01-01

    Rising temperatures and ocean acidification driven by anthropogenic carbon emissions threaten both tropical and temperate corals. However, the synergistic effect of these stressors on coral physiology is still poorly understood, in particular for cold-water corals. This study assessed changes in key physiological parameters (calcification, respiration and ammonium excretion) of the widespread cold-water coral Desmophyllum dianthus maintained for ∼8 months at two temperatures (ambient 12 °C and elevated 15 °C) and two pCO2 conditions (ambient 390 ppm and elevated 750 ppm). At ambient temperatures no change in instantaneous calcification, respiration or ammonium excretion rates was observed at either pCO2 levels. Conversely, elevated temperature (15 °C) significantly reduced calcification rates, and combined elevated temperature and pCO2 significantly reduced respiration rates. Changes in the ratio of respired oxygen to excreted nitrogen (O:N), which provides information on the main sources of energy being metabolized, indicated a shift from mixed use of protein and carbohydrate/lipid as metabolic substrates under control conditions, to less efficient protein-dominated catabolism under both stressors. Overall, this study shows that the physiology of D. dianthus is more sensitive to thermal than pCO2 stress, and that the predicted combination of rising temperatures and ocean acidification in the coming decades may severely impact this cold-water coral species.

  5. Elasto/visco-plastic deformation of moderately thick shells of revolution under thermal loading due to fluid

    International Nuclear Information System (INIS)

    Takezono, S.; Tao, K.; Aoki, T.; Inamura, E.

    1993-01-01

    This paper is concerned with an analytical formulation and a numerical solution of the thermo-elasto/visco-plastic deformation of general, moderately thick shells of revolution subjected to thermal loads due to fluid. At first the temperature distribution through the thickness is supposed to be curves of second order, and the temperature field in the shell under the appropriate initial and boundary conditions is determined by using the equations of heat conduction and heat transfer. Secondly the stresses and deformations are derived from the thermal stress equations. The equations of equilibrium and the relations between the strains and displacements are developed by extending the Reissner-Naghdi theory for elastic shells. For the constitutive relations, the Perzyna elasto/visco-plastic equations including the temperature effect are employed. The fundamental equations derived are numerically solved by the finite difference method. As a numerical example, the simply supported cylindrical shell made of mild steel under thermal loading due to fluid is analyzed, and the results are compared with those from classical theory which neglects the effect of shear deformations. (author)

  6. Role of fluttering dislocations in the thermal interface resistance between a silicon crystal and plastic solid 4He

    Science.gov (United States)

    Amrit, Jay; Ramiere, Aymeric; Volz, Sebastian

    2018-01-01

    A quantum solid (solid 4He) in contact with a classical solid defines a new class of interfaces. In addition to its quantum nature, solid 4He is indeed a very plastic medium. We examine the thermal interface resistance upon solidification of superfluid 4He in contact with a silicon crystal surface (111) and show that dislocations play a crucial role in the thermal interface transport. The growth of solid 4He and the measurements are conducted at the minimum of the melting curve of helium (0.778 K and ˜25 bar ). The results display a first-order transition in the Kapitza resistance from a value of RK ,L=(80 ±8 ) c m2K /W at a pressure of 24.5 bar to a value of RK ,S=(41.7 ±8 ) c m2K /W after the formation of solid helium at ˜25.2 bar . The drop in RK ,S is only of a factor of ˜2 , although transverse phonon modes in solid 4He now participate in heat transmission at the interface. We provide an explanation for the measured RK ,S by considering the interaction of thermal phonons with vibrating dislocations in solid 4He. We demonstrate that this mechanism, also called fluttering, induces a thermal resistance RF l∝NdT-6 , where T is the temperature and Nd is the density of dislocations. We estimate that for dislocation densities on the order of ˜107c m-2 , RF l predominates over the boundary resistance RK ,S. These fundamental findings shed light on the role of dislocations and provide a quantitative explanation for previous experiments which showed no measurable change in the Kapitza resistance between Cu and superfluid 4He upon solidification of the latter. This demonstrates the possibility of using dislocations as an additional means to tailor thermal resistances at interfaces, formed especially with a plastic material.

  7. How do Greenhouse Gases Warm the Ocean? Investigation of the Response of the Ocean Thermal Skin Layer to Air-Sea Surface Heat Fluxes.

    Science.gov (United States)

    Wong, E.; Minnett, P. J.

    2016-12-01

    There is much evidence that the ocean is heating due to an increase in concentrations of greenhouse gases (GHG) in the atmosphere from human activities. GHGs absorbs infrared (IR) radiation and re-emits the radiation back to the ocean's surface which is subsequently absorbed resulting in a rise in the ocean heat content. However, the incoming longwave radiation, LWin, is absorbed within the top micrometers of the ocean's surface, where the thermal skin layer (TSL) exists and does not directly heat the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of IR radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that since heat lost through the air-sea interface is controlled by the TSL, which is directly influenced by the absorption and emission of IR radiation, the heat flow through the TSL adjusts to maintain the surface heat loss, and thus modulates the upper ocean heat content. This hypothesis is investigated through utilizing clouds to represent an increase in LWin and analyzing retrieved TSL vertical profiles from a shipboard IR spectrometer from two research cruises. The data is limited to night-time, no precipitation and low winds of heat from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation. Instead, we observe the surplus energy, from absorbing increasing levels of LWin, adjusts the curvature of the TSL such that there is a lower gradient at the interface between the TSL and the mixed layer. The release of heat stored within the mixed layer is therefore hindered while the additional energy within the TSL is cycled back into the atmosphere. This results in heat beneath the TSL, which is a product of the absorption of solar radiation during the day, to be retained and cause an increase in upper ocean heat content.

  8. Thermal Microstructural Stability of AZ31 Magnesium after Severe Plastic Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Young, John P.; Askari, Hesam A.; Hovanski, Yuri; Heiden, Michael J.; Field, David P.

    2015-03-01

    Both equal channel angular pressing and friction stir processing have the ability to refine the grain size of twin roll cast AZ31 magnesium and potentially improve its superplastic properties. This work used isochronal and isothermal heat treatments to investigate the microstructural stability of twin roll cast, equal channel angular pressed and friction stir processed AZ31 magnesium. For both heat treatment conditions, it was found that the twin roll casted and equal channel angular pressed materials were more stable than the friction stir processed material. Calculations of the grain growth kinetics showed that severe plastic deformation processing decreased the activation energy for grain boundary motion with the equal channel angular pressed material having the greatest Q value of the severely plastically deformed materials and that increasing the tool travel speed of the friction stir processed material improved microstructural stability. The Hollomon-Jaffe parameter was found to be an accurate means of identifying the annealing conditions that will result in substantial grain growth and loss of potential superplastic properties in the severely plastically deformed materials. In addition, Humphreys’s model of cellular microstructural stability accurately predicted the relative microstructural stability of the severely plastically deformed materials and with some modification, closely predicted the maximum grain size ratio achieved by the severely plastically deformed materials.

  9. Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers

    Science.gov (United States)

    Evans, R.J.; Chum, H.L.

    1994-06-14

    A process is described using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents. 68 figs.

  10. Controlled catalystic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers

    Science.gov (United States)

    Evans, Robert J.; Chum, Helena L.

    1994-01-01

    A process of using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents.

  11. Ocean acidification narrows the acute thermal and salinity tolerance of the Sydney rock oyster Saccostrea glomerata.

    Science.gov (United States)

    Parker, Laura M; Scanes, Elliot; O'Connor, Wayne A; Coleman, Ross A; Byrne, Maria; Pörtner, Hans-O; Ross, Pauline M

    2017-09-15

    Coastal and estuarine environments are characterised by acute changes in temperature and salinity. Organisms living within these environments are adapted to withstand such changes, yet near-future ocean acidification (OA) may challenge their physiological capacity to respond. We tested the impact of CO 2 -induced OA on the acute thermal and salinity tolerance, energy metabolism and acid-base regulation capacity of the oyster Saccostrea glomerata. Adult S. glomerata were acclimated to three CO 2 levels (ambient 380μatm, moderate 856μatm, high 1500μatm) for 5weeks (24°C, salinity 34.6) before being exposed to a series of acute temperature (15-33°C) and salinity (34.2-20) treatments. Oysters acclimated to elevated CO 2 showed a significant metabolic depression and extracellular acidosis with acute exposure to elevated temperature and reduced salinity, especially at the highest CO 2 of 1500μatm. Our results suggest that the acute thermal and salinity tolerance of S. glomerata and thus its distribution will reduce as OA continues to worsen. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. An atlast of XBT thermal structures and TOPEX/POSEIDON sea surface heights in the north Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalakrishna, V.V.; Ali, M.M.; Araligidad, N.; Shenoi, S.S.C.; Shum, C.K.; Yi, Y.

    the Indian XBT Program were used to plot the sub-surface thermal structures of the Indian Ocean for 1993 to 2003. Since these in situ measurements are just along the ship tracks, sea surface height observations from the TOPEX altimeter were also plotted over...

  13. Seawater Circulation and Thermal Sink at OCEAN Ridges - FIELD Evidence in Oman Ophiolite

    Science.gov (United States)

    Nicolas, A. A.; Boudier, F. I.; Cathles, L. M.; Buck, W. R.; Celerier, B. P.

    2014-12-01

    Exceptionally, the lowermost gabbros in the Oman ophiolite are black and totally fresh, except for minute traces of impregnation by seawater fluids at very high temperature (~1000°C). These black gabbros sharply contrast with normal, whitish gabbros altered down to Low-T~500-350°C. These hydrous alterations are ascribed to an unconventional model of seawater circulation and cooling of the permanent magma chambers of fast spreading ocean ridges. In this model, gabbros issued from the magma chamber cross a ~100 m thick thermal boundary layer (TBL) before reaching a narrow, Low-T high permeability channel where the heated return seawater is flowing towards black smokers and the local gabbros are altered. Uprising mantle diapirs in Oman diverge at ~5 km on each side of the palaeo-ridge axis and feed an overlying magma chamber that closes at this distance from axis. Preservation of black gabbros along the Moho implies that the loop of seawater alteration locally does not reach Moho beyond this ~5km distance (otherwise black gabbros would be altered in whitish gabbros). This defines an internal "thermal sink" within ~5 km to the ridge axis. There, the sink is efficiently cooled by the active hydrothermal convection that is ridge transverse. This has been documented near the Galapagos ridge by marine geophysical data, within the same distance. Beyond this critical distance, the cooling system becomes dominantly conductive and ridge-parallel. The TBL and attached return flow channels must be rising into the overcooled, accreted crust. Beyond the thermal sink, the 500°C isotherm rebounds into the crust. It is only after ~ 1My of crustal drift that this isotherm penetrates into the uppermost mantle in a sustained fashion, developing serpentinites at the expense of peridotites.

  14. Parameters identification in strain-rate and thermal sensitive visco-plastic material model for an alumina dispersion strengthened copper

    CERN Document Server

    Scapin, M; Peroni, M

    2011-01-01

    The main objective of this paper is getting strain-hardening, thermal and strain-rate parameters for a material model in order to correctly reproduce the deformation process that occurs in high strain-rate scenario, in which the material reaches also high levels of plastic deformation and temperature. In particular, in this work the numerical inverse method is applied to extract material strength parameters from experimental data obtained via mechanical tests at different strain-rates (from quasi-static loading to high strain-rate) and temperatures (between 20 C and 1000 C) for an alumina dispersion strengthened copper material, which commercial name is GLIDCOP. Thanks to its properties GLIDCOP finds several applications in particle accelerator technologies, where problems of thermal management, combined with structural requirements, play a key role. Currently, it is used for the construction of structural and functional parts of the particle beam collimation system. Since the extreme condition in which the m...

  15. Determination of structural and mechanical properties, diffractometry, and thermal analysis of chitosan and hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol

    Directory of Open Access Journals (Sweden)

    Jefferson Rotta

    2011-06-01

    Full Text Available In this work, the structural, mechanical, diffractometric, and thermal parameters of chitosan-hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol were studied. Solutions of HPMC (2% w/v in water and chitosan (2% w/v in 2% acetic acid solution were prepared. The concentration of sorbitol used was 10% (w/w to both polymers. This solutions were mixed at different proportions (100/0; 70/30; 50/50; 30/70, and 0/100 of chitosan and HPMC, respectively, and 20 mL was cast in Petri dishes for further analysis of dried films. The miscibility of polymers was assessed by X-ray diffraction, scanning electronic microscopy (SEM, differential scanning calorimetry (DSC, and thermal gravimetric analysis (TGA. The results obtained indicate that the films are not fully miscible at a dry state despite the weak hydrogen bonding between the polymer functional groups.

  16. Preparation of multishell ICF target plastic-foam cushion materials by thermally induced phase-inversion processes

    International Nuclear Information System (INIS)

    Young, A.T.; Moreno, D.K.; Marsters, R.G.

    1981-01-01

    Homogenous, low-density plastic foams for ICF targets have been prepared by thermally induced phase inversion processes. Uniform, open cell foams have been obtained by the rapid freezing of water solutions of modified cellulose polymers with densities in the range of 5 mg/cm 3 to 0.7 mg/cm 3 and respective average cell sizes of 2 to 40 micrometers. In addition, low-density, microcellular foams have been prepared from the hydrocarbon polymer poly(4-methyl-l-pentene) via a similar phase inversion process using homogenous solutions in organic solvents. These foams have densities from 2 to 5 mg/cm 3 and average cell sizes of 20 micrometers. The physical-chemical aspects of the thermally induced phase inversion process is presented

  17. A pyrolysis study for the thermal and kinetic characteristics of an agricultural waste with two different plastic wastes.

    Science.gov (United States)

    Çepelioğullar, Özge; Pütün, Ayşe E

    2014-10-01

    In this study, thermochemical conversion of plastic wastes (PET and PVC) together with an agricultural waste (hazelnut shell) was investigated. In order to determine the thermal and kinetic behaviours, pyrolysis experiments were carried out from room temperature to 800 °C, with a heating rate of 10 °C min(-1) in the presence of a N2 atmosphere in a thermogravimetric analyzer. With the obtained thermogravimetric data, an appropriate temperature was specified for the pyrolysis of biomass-plastic wastes in a fixed-bed reactor. At the second step, pyrolysis experiments were carried out at the same conditions with the thermogravimetric analyzer, except the final temperature which was up to 500 °C in this case. After pyrolysis experiments, pyrolysis yields were calculated and characterization studies for bio-oil were investigated. Experimental results showed that co-pyrolysis has an important role in the determination of the pyrolysis mechanism and the process conditions while designing/implementing a thermochemical conversion method where biomass-plastic materials were preferred as raw materials. © The Author(s) 2014.

  18. Thermal stabilization and plasticization of poly(vinyl chloride) by ester thiols: Update and current status

    International Nuclear Information System (INIS)

    Starnes, William H.; Du, Bin; Kim, Soungkyoo; Zaikov, Vadim G.; Ge, Xianlong; Culyba, Elizabeth K.

    2006-01-01

    Poly(vinyl chloride) (PVC) is one of the most important medical plastics. Recently, however, the safety of flexible PVC containing the common plasticizer, di(2-ethylhexyl) phthalate, has been called into question. Widely used heat stabilizers for PVC that incorporate toxic heavy metals also have fallen into disfavor. In order to address these problems, we have synthesized and tested, as potential replacements, several organic thiols that contain one or more carboxylate ester functions and thus are highly compatible with the polymer. When introduced into PVC at high loading levels (e.g., 30-35 parts by weight), the ester thiols are extremely effective as heat stabilizers and also useful as primary plasticizers. When used at a low loading level (e.g., 3 parts by weight), they still are excellent heat stabilizers for both plasticized and rigid PVC. Importantly, their high potency is achieved in the absence of any costabilizers that incorporate heavy metals. Their syntheses are simple and straightforward, and their odors are not offensive, because their volatilities are low. Described here are some typical results obtained with this new additive technology, which was licensed for commercialization in 2005

  19. Processing and characterization of biodegradable soy plastics: Effects of crosslinking with glyoxal and thermal treatment

    NARCIS (Netherlands)

    Vaz, C.M.; Doeveren, van P.F.N.M.; Yilmaz, G.; Graaf, de L.A.; Reis, R.L.; Cunha, A.M.

    2005-01-01

    Processing and modification routes to produce and to improve properties of biodegradable plastics from soy isolate were studied. Soy isolate, acid-treated and crosslinked soy were subsequently compounded, extruded, and injection molded. Acetic acid and glyoxal were examined concerning their

  20. Thermal, mechanical and morphological characterization of plasticized PLA-PHB blends

    Science.gov (United States)

    A blend of poly(lactic acid) (PLA) (75% by weight) and poly(3-hydroxybutyrate) (PHB) (25% by weight) with a polyester plasticizer (Lapol 108) at two different concentrations (5 and 7% by weight per 100 parts of the blends) were investigated by TGA, DSC, XRD, SEM, mechanical testing and biodegradatio...

  1. With respect to coefficient of linear thermal expansion, bacterial vegetative cells and spores resemble plastics and metals, respectively.

    Science.gov (United States)

    Nakanishi, Koichi; Kogure, Akinori; Fujii, Takenao; Kokawa, Ryohei; Deuchi, Keiji; Kuwana, Ritsuko; Takamatsu, Hiromu

    2013-10-09

    If a fixed stress is applied to the three-dimensional z-axis of a solid material, followed by heating, the amount of thermal expansion increases according to a fixed coefficient of thermal expansion. When expansion is plotted against temperature, the transition temperature at which the physical properties of the material change is at the apex of the curve. The composition of a microbial cell depends on the species and condition of the cell; consequently, the rate of thermal expansion and the transition temperature also depend on the species and condition of the cell. We have developed a method for measuring the coefficient of thermal expansion and the transition temperature of cells using a nano thermal analysis system in order to study the physical nature of the cells. The tendency was seen that among vegetative cells, the Gram-negative Escherichia coli and Pseudomonas aeruginosa have higher coefficients of linear expansion and lower transition temperatures than the Gram-positive Staphylococcus aureus and Bacillus subtilis. On the other hand, spores, which have low water content, overall showed lower coefficients of linear expansion and higher transition temperatures than vegetative cells. Comparing these trends to non-microbial materials, vegetative cells showed phenomenon similar to plastics and spores showed behaviour similar to metals with regards to the coefficient of liner thermal expansion. We show that vegetative cells occur phenomenon of similar to plastics and spores to metals with regard to the coefficient of liner thermal expansion. Cells may be characterized by the coefficient of linear expansion as a physical index; the coefficient of linear expansion may also characterize cells structurally since it relates to volumetric changes, surface area changes, the degree of expansion of water contained within the cell, and the intensity of the internal stress on the cellular membrane. The coefficient of linear expansion holds promise as a new index for

  2. Effect of Palm Oil Bio-Based Plasticizer on the Morphological, Thermal and Mechanical Properties of Poly(Vinyl Chloride

    Directory of Open Access Journals (Sweden)

    Kar Min Lim

    2015-10-01

    Full Text Available Flexible poly(vinyl chloride (PVC was fabricated using a palm oil-based alkyd as a co-plasticizer to di-octyl phthalate (DOP and di-isononyl phthalate (DiNP. The effects of the incorporation of the palm oil-based alkyd on morphological, thermal and mechanical properties of PVC compounds were studied. Results showed the incorporation of the alkyd enhanced the mechanical and thermal properties of the PVC compounds. Fourier transform infrared spectroscopy (FTIR results showed that the polar –OH and –C=O groups of alkyd have good interaction with the –C–Cl group in PVC via polar interaction. The morphological results showed good incorporation of the plasticizers with PVC. Improved tensile strength, elastic modulus, and elongation at break were observed with increasing amount of the alkyd, presumably due to chain entanglement of the alkyd with the PVC molecules. Thermogravimetric analysis results confirmed that the alkyd has improved the thermostability of the PVC compounds.

  3. Southern ocean warming, sea level and hydrological change during the Paleocene-Eocene thermal maximum

    Directory of Open Access Journals (Sweden)

    A. Sluijs

    2011-01-01

    Full Text Available A brief (~150 kyr period of widespread global average surface warming marks the transition between the Paleocene and Eocene epochs, ~56 million years ago. This so-called "Paleocene-Eocene thermal maximum" (PETM is associated with the massive injection of 13C-depleted carbon, reflected in a negative carbon isotope excursion (CIE. Biotic responses include a global abundance peak (acme of the subtropical dinoflagellate Apectodinium. Here we identify the PETM in a marine sedimentary sequence deposited on the East Tasman Plateau at Ocean Drilling Program (ODP Site 1172 and show, based on the organic paleothermometer TEX86, that southwest Pacific sea surface temperatures increased from ~26 °C to ~33°C during the PETM. Such temperatures before, during and after the PETM are >10 °C warmer than predicted by paleoclimate model simulations for this latitude. In part, this discrepancy may be explained by potential seasonal biases in the TEX86 proxy in polar oceans. Additionally, the data suggest that not only Arctic, but also Antarctic temperatures may be underestimated in simulations of ancient greenhouse climates by current generation fully coupled climate models. An early influx of abundant Apectodinium confirms that environmental change preceded the CIE on a global scale. Organic dinoflagellate cyst assemblages suggest a local decrease in the amount of river run off reaching the core site during the PETM, possibly in concert with eustatic rise. Moreover, the assemblages suggest changes in seasonality of the regional hydrological system and storm activity. Finally, significant variation in dinoflagellate cyst assemblages during the PETM indicates that southwest Pacific climates varied significantly over time scales of 103 – 104 years during this event, a finding comparable to similar studies of PETM successions from the New Jersey Shelf.

  4. Structure of the marine atmospheric boundary layer over an oceanic thermal front: SEMAPHORE experiment

    Science.gov (United States)

    Kwon, B. H.; BéNech, B.; Lambert, D.; Durand, P.; Druilhet, A.; Giordani, H.; Planton, S.

    1998-10-01

    The Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, the third phase of which took place between October 4 and November 17, 1993, was conducted over the oceanic Azores Current located in the Azores basin and mainly marked at the surface by a thermal front due to the gradient of the sea surface temperature (SST) of about 1° to 2°C per 100 km. The evolution of the marine atmospheric boundary layer (MABL) over the SST front was studied with two aircraft and a ship in different meteorological conditions. For each case, the influence of the incoming air direction with respect to the orientation of the oceanic front was taken into account. During the campaign, advanced very high resolution radiometer pictures did not show any relation between the SST field and the cloud cover. The MABL was systematically thicker on the warm side than on the cold side. The mean MABL structure described from aircraft data collected in a vertical plane crossing the oceanic front was characterized by (1) an atmospheric horizontal gradient of 1° to 2°C per 100 km in the whole depth of the mixed layer and (2) an increase of the wind intensity from the cold to the warm side when the synoptic wind blew from the cold side. The surface sensible heat (latent heat) flux always increased from the cold to the warm sector owing to the increase of the wind and of the temperature (specific humidity) difference between the surface and the air. Turbulence increased from the cold to the warm side in conjunction with the MABL thickening, but the normalized profiles presented the same structure, regardless of the position over the SST front. In agreement with the Action de Recherche Programme te Petite Echelle and Grande Echelle model, the mean temperature and momentum budgets were highly influenced by the horizontal temperature gradient. In particular, the strong ageostrophic influence in the MABL above the SST front seems

  5. Ocean Thermal Extractable Energy Visualization- Final Technical Report on Award DE-EE0002664. October 28, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Ascari, Matthew B.; Hanson, Howard P.; Rauchenstein, Lynn; Van Zwieten, James; Bharathan, Desikan; Heimiller, Donna; Langle, Nicholas; Scott, George N.; Potemra, James; Nagurny, N. John; Jansen, Eugene

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world's ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today's state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources. The OTEEV project leverages existing NREL renewable energy GIS technologies and integrates extractable energy estimated from quality-controlled data and projected optimal achievable energy conversion rates. Input data are synthesized from a broad range of existing in-situ measurements and ground-truthed numerical models with temporal and spatial resolutions sufficient to reflect the local resource. Energy production rates are calculated for regions based on conversion rates estimated for current technology, local energy density of the resource, and sustainable resource extraction. Plant spacing and maximum production rates are then estimated based on a default plant size and transmission mechanisms. The resulting data are organized, displayed, and accessed using a multi-layered GIS mapping tool, http://maps.nrel.gov/mhk_atlas with a user-friendly graphical user interface.

  6. Thermal and catalytic pyrolysis of a mixture of plastics from small waste electrical and electronic equipment (WEEE).

    Science.gov (United States)

    Santella, Chiara; Cafiero, Lorenzo; De Angelis, Doina; La Marca, Floriana; Tuffi, Riccardo; Vecchio Ciprioti, Stefano

    2016-08-01

    Pyrolysis seems a promising route for recycling of heterogeneous, contaminated and additives containing plastics from waste electrical and electronic equipment (WEEE). This study deals with the thermal and catalytic pyrolysis of a synthetic mixture containing real waste plastics, representative of polymers contained in small WEEE. Two zeolite-based catalysts were used at 400°C: HUSY and HZSM-5 with a high silica content, while three different temperatures were adopted for the thermal cracking: 400, 600 and 800°C. The mass balance showed that the oil produced by pyrolysis is always the main product regardless the process conditions selected, with yields ranging from 83% to 93%. A higher yield was obtained when pyrolysis was carried out with HZSM-5 at 400°C and without catalysts, but at 600 and 800°C. Formation of a significant amount of solid residue (about 13%) is observed using HUSY. The oily liquid product of pyrolysis, analysed by GC-MS and GC-FID, as well as by elemental analysis and for energy content, appeared lighter, less viscous and with a higher concentration of monoaromatics under catalytic condition, if compared to the liquid product derived from thermal degradation at the same temperature. HZSM-5 led to the production of a high yield of styrene (17.5%), while HUSY favoured the formation of ethylbenzene (15%). Energy released by combustion of the oil was around 39MJ/kg, thus suggesting the possibility to exploit it as a fuel, if the recovery of chemical compounds could not be realised. Elemental and proximate analysis of char and GC-TCD analysis of the gas were also performed. Finally, it was estimated to what extent these two products, showing a relevant ability to release energy, could fulfil the energy demand requested in pyrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Ocean thermal energy conversion (OTEC) power system development. Preliminary design report, Appendices, Part 1 (Final)

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the developed computer models, water system dynamic studies, miscellaneous performance analysis, materials and processes, detailed equipment lists, turbine design studies, tube cleaner design, ammonia leak detection, and heat exchanger design supporting data. (WHK)

  8. Thermal Study of Polyols for the Technological Application as Plasticizers in Food Industry

    Directory of Open Access Journals (Sweden)

    Alberto Toxqui-Terán

    2018-04-01

    Full Text Available In this work is presented the complete thermal analysis of polyols by direct methods such as simultaneous thermogravimetric and differential thermal analyzer (TGA-DTA, differential scanning calorimetry (DSC, modulated DSC (MDSC, and supercooling MDSC. The different thermal events in the temperature range of 113–553 K were identified for glycerol (GL, ethylene glycol (EG, and propylene glycol (PG. Boiling temperature (TB decreased as GL > EG > PG, but increased with the heating rate. GL showed a complex thermal event at 191–199 K, identified as the glass transition temperature (Tg and devitrification temperature (Tdv, and a liquid–liquid transition (TL-L at 215–221 K was identified as the supercooling temperature. EG showed several thermal events such as Tg and Tdv at 154 K, crystallization temperature (Tc at 175 K, and melting temperature (Tm at 255 K. PG also showed a complex thermal event (Tg and Tdv at 167 K, a second devitrification at 193 K, and TL-L at 245 K. For PG, crystallization was not observed, indicating that, during the cooling, the liquid remained as an amorphous solid.

  9. Antimicrobial, Rheological, and Thermal Properties of Plasticized Polylactide Films Incorporated with Essential Oils to Inhibit Staphylococcus aureus and Campylobacter jejuni.

    Science.gov (United States)

    Ahmed, Jasim; Hiremath, Nikhil; Jacob, Harsha

    2016-02-01

    Polylactide (PLA) is the most mature biobased and biodegradable polymer. Due to its inherent brittleness, the polymer cannot be used as a packaging material without plasticizer. An attempt was made to develop antimicrobial plasticized PLA film by incorporating polyethylene glycol (PEG) and 3 essential oils (EO), namely cinnamon, garlic, and clove by solvent casting method. Physical, thermal, and rheological properties of those films were evaluated for practical applications whereas the antimicrobial properties were tested against Staphylococcus aureus and Campylobacter jejuni-pathogens related to poultry industry. Both PEG and EOs led to the formation of flexible PLA/PEG/EO films with significant drop in the glass transition temperature (Tg ), and mechanical property. Time-temperature superposition (TTS) principle was employed to melt rheology of EO-based films at selected temperature, and rheological moduli superimposed well in an extended frequency range. Among EOs, cinnamon and clove oil-based films (PLA/PEG/CIN and PLA/PEG/CLO) exhibited a complete zone of inhibition against C. jejuni at the maximum concentration (1.6 mL per 2 g PLA/PEG blend) whereas the garlic oil-based film (PLA/PEG/GAR) had the lowest activity. © 2016 Institute of Food Technologists®

  10. Analysis of thermal-plastic response of shells of revolution by numerical integration

    International Nuclear Information System (INIS)

    Leonard, J.W.

    1975-01-01

    An economic technique for the numerical analysis of the elasto-plastic behaviour of shells of revolution would be of considerable value in the nuclear reactor industry. A numerical method based on the numerical integration of the governing shell equations has been shown, for elastic cases, to be more efficient than the finite element method when applied to shells of revolution. In the numerical integration method, the governing differential equations of motion are converted into a set of initial-value problems. Each initial-value problem is integrated numerically between meridional boundary points and recombined so as to satisfy boundary conditions. For large-deflection elasto-plastic behaviour, the equations are nonlinear and, hence, are recombined in an iterative manner using the Newton-Raphson procedure. Suppression techniques are incorporated in order to eliminate extraneous solutions within the numerical integration procedure. The Reissner-Meissner shell theory for shells of revolution is adopted to account for large deflection and higher-order rotation effects. The computer modelling of the equations is quite general in that specific shell segment geometries, e.g. cylindrical, spherical, toroidal, conical segments, and any combinations thereof can be handled easily. (Auth.)

  11. Analysis of thermal-plastic response of shells of revolution by numerical integration

    International Nuclear Information System (INIS)

    Leonard, J.W.

    1975-01-01

    A numerical method based instead on the numerical integration of the governing shell equations has been shown, for elastic cases, to be more efficient than the finite element method when applied to shells of revolution. In the numerical integration method, the governing differential equations of motions are converted into a set of initial-value problems. Each initial-value problem is integrated numerically between meridional boundary points and recombined so as to satisfy boundary conditions. For large-deflection elasto-plastic behavior, the equations are nonlinear and, hence, are recombined in an iterative manner using the Newton-Raphson procedure. Suppression techniques are incorporated in order to eliminate extraneous solutions within the numerical integration procedure. The Reissner-Meissner shell theory for shells of revolution is adopted to account for large deflection and higher-order rotation effects. The computer modelling of the equations is quite general in that specific shell segment geometries, e.g. cylindrical, spherical, toroidal, conical segments, and any combinations thereof can be handled easily. The elasto-plastic constitutive relations adopted are in accordance with currently recommended constitutive equations for inelastic design analysis of FFTF Components. The Von Mises yield criteria and associated flow rule is used and the kinematic hardening law is followed. Examples are considered in which stainless steels common to LMFBR application are used

  12. Recent advances in thermal analysis and stability evaluation of insensitive plastic bonded explosives (PBXs)

    International Nuclear Information System (INIS)

    Yan, Qi-Long; Zeman, Svatopluk; Elbeih, Ahmed

    2012-01-01

    Highlights: ► We summarize currently used insensitive polymer based explosives and their ingredients. ► We examine the calculation methods that are suitable for kinetic evaluation of polymer based explosives. ► The calculation method for thermal stability parameters of polymer based explosives are summarized, which mainly include shelf life, explosion delay, critical temperature, thermostability threshold, 500 day cookoff temperature and approximate time to explosion. ► The polymer bases could greatly affect the thermal properties of PBXs, including their thermal stability, kinetic parameters and thermodynamic properties. ► PBXs, containing some innovative energetic fillers such as CL-20, NTO, Fox-12 and BCHMX, are only at design stage, which need more research work in the future. - Abstract: In this paper, several fundamental investigations published over the past decades with regard to the thermal analysis of polymer-based explosives (PBXs) have been briefly reviewed. A number of explosive fillers and polymer bases that were used as their main ingredients of PBXs are summarized herein. In addition, the calculation methods for their decomposition kinetics and thermal stability parameters are also introduced in detail. It was concluded that only PBXs based on HMX, RDX and TATB have been widely investigated, and that some other PBXs containing innovative fillers, such as CL-20, TNAZ, NTO and BCHMX are at the design stage. The isoconversional methods and model fitting procedures are usually used to analyze the discrete thermolysis processes of PBXs. In addition, their thermal stability parameters such as shelf life, explosion delay, critical temperature, thermostability threshold, 500-day cookoff temperature and approximate time to explosion could be calculated easily from the kinetic data.

  13. Plasticity of trophic interactions among sharks from the oceanic south-western Indian Ocean revealed by stable isotope and mercury analyses

    Science.gov (United States)

    Kiszka, Jeremy J.; Aubail, Aurore; Hussey, Nigel E.; Heithaus, Michael R.; Caurant, Florence; Bustamante, Paco

    2015-02-01

    Sharks are a major component of the top predator guild in oceanic ecosystems, but the trophic relationships of many populations remain poorly understood. We examined chemical tracers of diet and habitat (δ15N and δ13C, respectively) and total mercury (Hg) concentrations in muscle tissue of seven pelagic sharks: blue shark (Prionace glauca), short-fin mako shark (Isurus oxyrinchus), oceanic whitetip shark (Carcharhinus longimanus), scalloped hammerhead shark (Sphyrna lewini), pelagic thresher shark (Alopias pelagicus), crocodile shark (Pseudocarcharias kamoharai) and silky shark (Carcharhinus falciformis), from the data poor south-western tropical Indian Ocean. Minimal interspecific variation in mean δ15N values and a large degree of isotopic niche overlap - driven by high intraspecific variation in δ15N values - was observed among pelagic sharks. Similarly, δ13C values of sharks overlapped considerably for all species with the exception of P. glauca, which had more 13C-depleted values indicating possibly longer residence times in purely pelagic waters. Geographic variation in δ13C, δ15N and Hg were observed for P. glauca and I. oxyrinchus. Mean Hg levels were similar among species with the exception of P. kamoharai which had significantly higher Hg concentrations likely related to mesopelagic feeding. Hg concentrations increased with body size in I. oxyrinchus, P. glauca and C. longimanus. Values of δ15N and δ13C varied with size only in P. glauca, suggesting ontogenetic shifts in diets or habitats. Together, isotopic data indicate that - with few exceptions - variance within species in trophic interactions or foraging habitats is greater than differentiation among pelagic sharks in the south-western Indian Ocean. Therefore, it is possible that this group exhibits some level of trophic redundancy, but further studies of diets and fine-scale habitat use are needed to fully test this hypothesis.

  14. Study of elastic and thermal parameters of a composite material fluoro-plastic - thermo-exfoliated graphite by photothermoacoustic method

    International Nuclear Information System (INIS)

    Kozachenko, V.V.; Kucherov, I.Ya.; Revo, S.L.

    2004-01-01

    Full text: The composite materials (CM) with success are widely used in a science and in an industry. From the practical point of view important for CM the mechanical and thermal properties are. Therefore, study of these properties for them is the important problem. At change of a temperature state of materials of their property in many cases are featured by combinations of elastic and thermal parameters E/1-σ=E n and χ/ρc=D T , where E, -σ, ρ and c are the Young's modulus, Poisson's ratio, thermal conductivity coefficient, density and specific heat of materials, respectively. Now for examination of substances in various aggregate states has received development a photothermoacoustic (PTA) method. As shown in this work, use a PTA method with piezoelectric detection of a PTA signal from a layered plate, under certain conditions, allows immediately determining the reduced Young's modulus E n and thermal diffusivity D T . Therefore, the purpose of this work was study the PTA effect with piezoelectric detection of an informative signal from CM. Were explored steel-copper CM such as 'sandwich' and fluoro plastic-thermo exfoliated graphite FP-TEG CM. Explored triplex structure as a plate made of a CM sample and a two-layer piezoelectric transducer. The surface of a CM is uniformly irradiated with a modulated light flux. The sample is heated and the thermal waves are generated. In the sample, the temperature field of thermal waves generates, due to the thermoelastic effect, acoustic vibration and waves that are registered by a piezoelectric. The rather low frequencies of modulation are considered, at which length of ultrasonic waves is much more than the reference sizes of structure (quasi-static approach). The amplitudes ratio and phase difference of voltages oscillations taken from separate layer of piezoelectric transducer, as functions of physical and geometrical parameters of structure and a frequency of a light flux modulation is found. Experimentally the

  15. Plastic deformation tests on fragile materials using a thermal expansion machine

    International Nuclear Information System (INIS)

    Orozco, E.; Morales, A.; Mendoza, A.

    1991-01-01

    Applying an electrical current on an iron bar, a thermal expansion can be induced. We have taken advantage of this to deform fragile materials, in order to study their mechanical properties. In this paper we show some gels and high T c oxide superconductors (Author)

  16. Photosynthetic plasticity of populations of Heliotropium curassavicum L. originating from differing thermal regimes.

    Science.gov (United States)

    Mooney, H A

    1980-01-01

    Plants of the widely distributed species Heliotropium curassavicum L. have a large photosynthetic acclimation potential to temperature. There are, however, some differences among the acclimation potentials of populations occupying dissimilar thermal regimes. Plants of populations originating from a cool maritime climate have a greater acclimation potential than plants of populations originating from a desert habitat, which is characterized by large seasonal changes in temperature.

  17. 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...

  18. Comparative Study of Chemical, Mechanical, Thermal, and Barrier Properties of Poly(Lactic Acid Plasticized with Epoxidized Soybean Oil and Epoxidized Palm Oil

    Directory of Open Access Journals (Sweden)

    Yee Bond Tee

    2015-12-01

    Full Text Available To investigate epoxidized palm oil’s (EPO potential as plasticizer for poly(lactic acid (PLA, its plasticizing effect was compared with commercialized epoxidized soybean oil (ESO. The plasticizers were respectively melt-compounded into PLA at 3, 5, 10, and 15 wt.%. As it was aimed for the blends to be characterized towards packaging appropriate for food products, they were hot-pressed into ~0.3-mm sheets, which is the approximate thickness of clamshell packaging. Fourier transform infrared spectroscopy (FTIR confirmed the plasticizers’ compatibility with PLA. At similar loadings, EPO was superior in reinforcing elongation at break (EAB, thermal, and barrier properties of PLA. The ductility of PLA was notably improved to 50.0% with addition of 3 wt.% of EPO. From thermogravimetric analysis (TGA, PLA/EPO5 improved PLA’s thermal stability, while all PLA/ESO blends reported reduced thermal stability. From differential scanning calorimetry (DSC, the increase in crystallinity and the shifts in enthalpy of fusions in all plasticized blends denoted facilitation of PLA to form thermally stable α-form crystals. The addition of EPO enabled PLA to become highly impermeable to oxygen, which can extend its potential in packaging extensive range of oxygen sensitive food.

  19. System and plastic scintillator for discrimination of thermal neutron, fast neutron, and gamma radiation

    Science.gov (United States)

    Zaitseva, Natalia P.; Carman, M. Leslie; Faust, Michelle A.; Glenn, Andrew M.; Martinez, H. Paul; Pawelczak, Iwona A.; Payne, Stephen A.

    2017-05-16

    A scintillator material according to one embodiment includes a polymer matrix; a primary dye in the polymer matrix, the primary dye being a fluorescent dye, the primary dye being present in an amount of 3 wt % or more; and at least one component in the polymer matrix, the component being selected from a group consisting of B, Li, Gd, a B-containing compound, a Li-containing compound and a Gd-containing compound, wherein the scintillator material exhibits an optical response signature for thermal neutrons that is different than an optical response signature for fast neutrons and gamma rays. A system according to one embodiment includes a scintillator material as disclosed herein and a photodetector for detecting the response of the material to fast neutron, thermal neutron and gamma ray irradiation.

  20. Phenotypic variance, plasticity and heritability estimates of critical thermal limits depend on methodological context

    DEFF Research Database (Denmark)

    Chown, Steven L.; Jumbam, Keafon R.; Sørensen, Jesper Givskov

    2009-01-01

    used during assessments of critical thermal limits to activity. To date, the focus of work has almost exclusively been on the effects of rate variation on mean values of the critical limits. 2.  If the rate of temperature change used in an experimental trial affects not only the trait mean but also its...... this is the case for critical thermal limits using a population of the model species Drosophila melanogaster and the invasive ant species Linepithema humile. 4.  We found that effects of the different rates of temperature change are variable among traits and species. However, in general, different rates...... of temperature change resulted in different phenotypic variances and different estimates of heritability, presuming that genetic variance remains constant. We also found that different rates resulted in different conclusions regarding the responses of the species to acclimation, especially in the case of L...

  1. Biodegradable blends of urea plasticized thermoplastic starch (UTPS) and poly(ε-caprolactone) (PCL): Morphological, rheological, thermal and mechanical properties.

    Science.gov (United States)

    Correa, Ana Carolina; Carmona, Vitor Brait; Simão, José Alexandre; Capparelli Mattoso, Luiz Henrique; Marconcini, José Manoel

    2017-07-01

    Biodegradable blends of urea plasticized thermoplastic starch (UTPS) and poly(ε-caprolactone) (PCL) were prepared in a co-rotating twin screw extruder. The UTPS and PCL content varied in a range of 25wt%. The materials were characterized by capillary rheometry, scanning electron microscopy (SEM), termogravimetry (TGA), differential scanning calorimetry (DSC) and tensile tests. Capillary rheometry showed better interaction between UTPS and PCL at 110°C than at 130°C. SEM showed immiscibility of all blends and good dispersion of UTPS in PCL matrix up to 50wt%. However, a co-continuous morphology was found for UTPS/PCL 75/25. Thermal analysis showed that introducing PCL in UTPS, increased T onset due to higher thermal stability of PCL, and blends presented an intermediate behavior of neat polymers. The presence of PCL in blends improved significantly the mechanical properties of neat UTPS. Because they are totally biodegradable, these blends can be vehicles for controlled or slow release of nutrients to the soil while degraded. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Usage of waste products from thermal recycling of plastics waste in enhanced oil recovery or in-situ coal conversion

    Energy Technology Data Exchange (ETDEWEB)

    Fink, M; Fink, J K [Montanuniversitaet Leoben (Austria)

    1998-09-01

    In this contribution a thermal method for crude oil mobilization and in-situ liquefaction of coal is discussed, which will finally yield more organic material, as which has been put in from plastics waste originally into the process. The conversion product from thermal treatment is pumped down into exhausted crude oil reservoirs, where the hydrogen can degrade the residual high viscous oil to cause it to become more prone to flow so that it can be recovered. Such a process will envision two goals: 1. more organic raw material (as crude oil) will be recovered than is initially put in as waste product. 2. atmospheric pollutants from the conversion plant will be trapped in the reservoir, which simplifies the construction of the plant. An analogous process may be performed with coal seams. Coal seams with their high porosity and large specific surface are believed to be in particular useful to filter atmospheric pollutants. Depending on the type of coal the mobilization of organic material by this process may be in the background. (orig./SR)

  3. Integrating metabolic performance, thermal tolerance, and plasticity enables for more accurate predictions on species vulnerability to acute and chronic effects of global warming.

    Science.gov (United States)

    Magozzi, Sarah; Calosi, Piero

    2015-01-01

    Predicting species vulnerability to global warming requires a comprehensive, mechanistic understanding of sublethal and lethal thermal tolerances. To date, however, most studies investigating species physiological responses to increasing temperature have focused on the underlying physiological traits of either acute or chronic tolerance in isolation. Here we propose an integrative, synthetic approach including the investigation of multiple physiological traits (metabolic performance and thermal tolerance), and their plasticity, to provide more accurate and balanced predictions on species and assemblage vulnerability to both acute and chronic effects of global warming. We applied this approach to more accurately elucidate relative species vulnerability to warming within an assemblage of six caridean prawns occurring in the same geographic, hence macroclimatic, region, but living in different thermal habitats. Prawns were exposed to four incubation temperatures (10, 15, 20 and 25 °C) for 7 days, their metabolic rates and upper thermal limits were measured, and plasticity was calculated according to the concept of Reaction Norms, as well as Q10 for metabolism. Compared to species occupying narrower/more stable thermal niches, species inhabiting broader/more variable thermal environments (including the invasive Palaemon macrodactylus) are likely to be less vulnerable to extreme acute thermal events as a result of their higher upper thermal limits. Nevertheless, they may be at greater risk from chronic exposure to warming due to the greater metabolic costs they incur. Indeed, a trade-off between acute and chronic tolerance was apparent in the assemblage investigated. However, the invasive species P. macrodactylus represents an exception to this pattern, showing elevated thermal limits and plasticity of these limits, as well as a high metabolic control. In general, integrating multiple proxies for species physiological acute and chronic responses to increasing

  4. Electrical, thermal and structural properties of plasticized waste cooking oil-based polyurethane solid polymer electrolyte

    Science.gov (United States)

    Huzaizi, Rahmatina Mohd; Tahir, Syuhada Mohd; Mahbor, Kamisah Mohamad

    2017-12-01

    Waste cooking oil-based polyol was synthesized using epoxidation and hydroxylation methods. The polyol was combined with 4,4-diphenylmethane diisocyanate to produce polyurethane (PU) to be used as polymer host in solid polymer electrolyte. 30 wt% LiClO4 was added as doping salt and two types of plasticizers were used; ethylene carbonate (PU-EC) and polyethylene glycol (PU-PEG). The SPE films were characterized using Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The highest conductivity achieved was 8.4 x 10-8 S cm-1 upon addition of 10 wt% EC. The XRD results showed a decrease of crystalline peaks in PU-EC and the increase in PU-PEG. DSC results revealed that the films; PU, PU-EC and PU-PEG had glass transition temperatures of 159.7, 106.0 and 179.7 °C, respectively. The results showed that the addition of EC increased the amorphous region and the free volume in the SPE structure, thus resulted in higher ionic conductivity.

  5. Application to cleaning of waste plastic surfaces using atmospheric non-thermal plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Araya, Masayuki [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Yuji, Toshifumi [Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan)]. E-mail: t-yuji@hiroshima-cmt.ac.jp; Watanabe, Takayuki [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Kashihara, Junzou [SHARP corporation, 1-9-2 Nakase, Mihama-Ku, Chiba 261-8520 (Japan); Sumida, Yoshitake [SHARP corporation, 2613-1 Ichinomoto-cho, Tenri 632-8567 (Japan)

    2007-03-12

    The removal of paint on the surface of waste plastics is difficult by the conventional process; in this research, a new cleaning mechanism using atmospheric plasmas was examined through optical emission spectroscopy, electron spectroscopy for chemical analysis, and scanning electron microscopy. Results indicate that an increase of pulse frequency enables for a short processing time for the removal of the paint film, signifying that the production of radicals in plasma, especially oxygen radicals, can be controlled by pulse frequency. Plasma jets were generated under the experimental conditions of an input power of 250 W to 400 W, a pulse frequency of 2 kHz to 12 kHz, and a plasma gas flow rate of 30 L/min. Examination of the intensity ratio of the reactive species, as measured by emission spectroscopy, showed that the O/N value increased with an increase in pulse frequency. Results of analysis with electron spectroscopy for chemical analysis show that nitrogen atoms and molybdenum in only the paint film decreased through plasma processing.

  6. Application to cleaning of waste plastic surfaces using atmospheric non-thermal plasma jets

    International Nuclear Information System (INIS)

    Araya, Masayuki; Yuji, Toshifumi; Watanabe, Takayuki; Kashihara, Junzou; Sumida, Yoshitake

    2007-01-01

    The removal of paint on the surface of waste plastics is difficult by the conventional process; in this research, a new cleaning mechanism using atmospheric plasmas was examined through optical emission spectroscopy, electron spectroscopy for chemical analysis, and scanning electron microscopy. Results indicate that an increase of pulse frequency enables for a short processing time for the removal of the paint film, signifying that the production of radicals in plasma, especially oxygen radicals, can be controlled by pulse frequency. Plasma jets were generated under the experimental conditions of an input power of 250 W to 400 W, a pulse frequency of 2 kHz to 12 kHz, and a plasma gas flow rate of 30 L/min. Examination of the intensity ratio of the reactive species, as measured by emission spectroscopy, showed that the O/N value increased with an increase in pulse frequency. Results of analysis with electron spectroscopy for chemical analysis show that nitrogen atoms and molybdenum in only the paint film decreased through plasma processing

  7. A Preliminary Investigation of the Effect of Ocean Thermal Energy Conversion (OTEC Effluent Discharge Options on Global OTEC Resources

    Directory of Open Access Journals (Sweden)

    Gérard Nihous

    2018-03-01

    Full Text Available A simple algorithm previously used to evaluate steady-state global Ocean Thermal Energy Conversion (OTEC resources is extended to probe the effect of various effluent discharge methodologies. It is found that separate evaporator and condenser discharges potentially increase OTEC net power limits by about 60% over a comparable mixed discharge scenario. This stems from a relatively less severe degradation of the thermal resource at given OTEC seawater flow rates, which corresponds to a smaller heat input into the ocean. Next, the most practical case of a mixed discharge into the mixed layer is found to correspond to only 80% of the so-called baseline case (mixed discharge at a water depth of initial neutral buoyancy. In general, locating effluent discharges at initial neutral-buoyancy depths appears to be nearly optimal in terms of OTEC net power production limits. The depth selected for the OTEC condenser effluent discharge, however, has by far the greatest impact. Clearly, these results are preliminary and should be investigated in more complex ocean general circulation models.

  8. Thermally robust and biomolecule-friendly room-temperature bonding for the fabrication of elastomer-plastic hybrid microdevices.

    Science.gov (United States)

    Nguyen, T P O; Tran, B M; Lee, N Y

    2016-08-16

    Here, we introduce a simple and fast method for bonding a poly(dimethylsiloxane) (PDMS) silicone elastomer to different plastics. In this technique, surface modification and subsequent bonding processes are performed at room temperature. Furthermore, only one chemical is needed, and no surface oxidation step is necessary prior to bonding. This bonding method is particularly suitable for encapsulating biomolecules that are sensitive to external stimuli, such as heat or plasma treatment, and for embedding fracturable materials prior to the bonding step. Microchannel-fabricated PDMS was first oxidized by plasma treatment and reacted with aminosilane by forming strong siloxane bonds (Si-O-Si) at room temperature. Without the surface oxidation of the amine-terminated PDMS and plastic, the two heterogeneous substrates were brought into intimate physical contact and left at room temperature. Subsequently, aminolysis occurred, leading to the generation of a permanent seal via the formation of robust urethane bonds after only 5 min of assembling. Using this method, large-area (10 × 10 cm) bonding was successfully realized. The surface was characterized by contact angle measurements and X-ray photoelectron spectroscopy (XPS) analyses, and the bonding strength was analyzed by performing peel, delamination, leak, and burst tests. The bond strength of the PDMS-polycarbonate (PC) assembly was approximately 409 ± 6.6 kPa, and the assembly withstood the injection of a tremendous amount of liquid with the per-minute injection volume exceeding 2000 times its total internal volume. The thermal stability of the bonded microdevice was confirmed by performing a chamber-type multiplex polymerase chain reaction (PCR) of two major foodborne pathogens - Escherichia coli O157:H7 and Salmonella typhimurium - and assessing the possibility for on-site direct detection of PCR amplicons. This bonding method demonstrated high potential for the stable construction of closed microfluidic systems

  9. Morphology and thermal properties of PLA films plasticized with aliphatic oligoesters; Morfologia e propriedades termicas de filmes de PLA plastificados com oligoesteres alifaticos

    Energy Technology Data Exchange (ETDEWEB)

    Inacio, Erika M.; Dias, Marcos L., E-mail: erika.minacio@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Lima, Maria Celiana P. [Instituto Federal do Rio de Janeiro (IFRJ), Duque de Caxias, RJ (Brazil)

    2015-07-01

    The addition of plasticizers to poly(lactic acid) (PLA) is one of the known ways of changing its ductility, making possible the modification of its mechanical and thermal properties. In this work, it was synthesized two biodegradable aliphatic oligoesters: oligo(trimethylene sebacate) (OST) and oligo(trimethylene malonate) (OMT), and these oligomers were used as plasticizer in cast films of commercial film grade PLA at concentrations of 1, 5 and 10 wt% of each plasticizer. X-ray diffraction (XRD) was used to investigate the morphology and differential scanning calorimetry (DSC) was also used aiming the evaluation of the thermal properties of these films. The PLA films containing no plasticizer showed an amorphous behavior, and the addition of PMT on the PLA films acted, simultaneously, decreasing the Tg, and rising the material's crystallinity. In contrast, the increased addition of OST to the PLA films did not change the Tg, and equally, did not have a significant changes in the material's crystallinity. Therefore, it was possible to observe the effect of the concentration of oligomers on the crystallinity of the films as well as the no plasticizer effect of the OST. (author)

  10. People and Oceans.

    Science.gov (United States)

    NatureScope, 1988

    1988-01-01

    Discusses people's relationship with oceans, focusing on ocean pollution, use, and protective measures of the sea and its wildlife. Activities included are "Mythical Monsters"; "Globetrotters"; "Plastic in the Sea"; and "Sea of Many Uses." (RT)

  11. The potential of oceanic transport and onshore leaching of additive-derived lead by marine macro-plastic debris.

    Science.gov (United States)

    Nakashima, Etsuko; Isobe, Atsuhiko; Kako, Shin'ichiro; Itai, Takaaki; Takahashi, Shin; Guo, Xinyu

    2016-06-15

    The long-distance transport potential of toxic lead (Pb) by plastic marine debris was examined by pure water leaching experiments using plastic fishery floats containing high level of additive-Pb such as 5100±74.3mgkg(-1). The leaching of Pb ended after sequential 480-h leaching experiments, and the total leaching amount is equivalent to approximately 0.1% of total Pb in a float. But it recovered when the float was scratched using sandpaper. We propose that a "low-Pb layer," in which Pb concentration is negligibly small, be generated on the float surface by the initial leaching process. Thickness of the layer is estimated at 2.5±1.2μm, much shallower than flaws on floats scratched by sandpaper and floats littering beaches. The result suggests that the low-Pb layer is broken by physical abrasion when floats are washed ashore, and that Pb inside the floats can thereafter leach into beaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A new plastic correction for the stress intensity factor of an under-clad defect in a PWR vessel subjected to a pressurised thermal shock

    International Nuclear Information System (INIS)

    Marie, S.; Nedelec, M.

    2007-01-01

    For the assessment of an under-clad defect in a vessel subjected to a cold pressurised thermal shock, plasticity is considered through the amplification β of the elastic stress intensity factor K I in the ferritic part of the vessel. An important effort has been made recently by CEA to improve the analytical tools in the frame of R and D activities funded by IRSN. The current solution in the French RSE-M code has been developed from fitted F.E. calculation results. A more physical solution is proposed in this paper. This takes into account two phenomena: the amplification of the elastic K I due to plasticity in the cladding and a plastic zone size correction in the ferritic part. The first correction has been established by representing the cladding plasticity by an imposed displacement on the crack faces at the interface between the cladding and the ferritic vessel. The corresponding elastic stress intensity factor is determined from the elastic plane strain asymptotic solution for the opening displacement. Plasticity in the ferritic steel is considered through a classical plastic zone size correction. The application of the solution to axisymmetric defects is first checked. The case of semi-elliptical defects is also investigated. For the correction determined at the interface between the cladding and the ferritic vessel, an amplification of the correction proposed for the deepest point is determined from a fitting of the 3D F.E. calculation results. It is also shown that the proposition of RSE-M, which consists in applying the same β correction at the deepest point and the interface point is not suitable. The applicability to a thermal shock, eventually combined with an internal pressure has been verified. For the deepest point, the proposed correction leads to similar results to the RSE-M method, but presents an extended domain of validity (no limits on the crack length are imposed)

  13. Characterization of plastic nuclear track detectors on solid state, CR-39 and LR-115 and its possibilities application on thermal and fast neutron dosimetry

    International Nuclear Information System (INIS)

    Vallejo Delgado, L.R.

    1989-01-01

    This work is an study about the use feasibility of plastic nuclear track detectors, LR 115, II-B (of Eastmann Kodak Co) and CR-39 (of American Acrylics and Plastics), for thermal and fast neutron dosimetry, respectively. The LR-115 with converter (n, alpha) was exposed to thermal neutrons with energy of 0,046 e V, proceeding from nuclear reactor RECH-1 of Nuclear Energy Chilean Commission. The irradiated films were submited to a chemical etching with NaOH, plus a washing and brushing. The CR-39 with polyethylene irradiator, was exposed to fast neutrons proceeding of calibrated sources of Am-Se. The irradiated plates were submited to a chemical pre-etching with KOH and a electrochemical post-etching. (author)

  14. Losing a winner: thermal stress and local pressures outweigh the positive effects of ocean acidification for tropical seagrasses.

    Science.gov (United States)

    Collier, Catherine J; Langlois, Lucas; Ow, Yan; Johansson, Charlotte; Giammusso, Manuela; Adams, Matthew P; O'Brien, Katherine R; Uthicke, Sven

    2018-06-01

    Seagrasses are globally important coastal habitat-forming species, yet it is unknown how seagrasses respond to the combined pressures of ocean acidification and warming of sea surface temperature. We exposed three tropical species of seagrass (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri) to increasing temperature (21, 25, 30, and 35°C) and pCO 2 (401, 1014, and 1949 μatm) for 7 wk in mesocosms using a controlled factorial design. Shoot density and leaf extension rates were recorded, and plant productivity and respiration were measured at increasing light levels (photosynthesis-irradiance curves) using oxygen optodes. Shoot density, growth, photosynthetic rates, and plant-scale net productivity occurred at 25°C or 30°C under saturating light levels. High pCO 2 enhanced maximum net productivity for Z. muelleri, but not in other species. Z. muelleri was the most thermally tolerant as it maintained positive net production to 35°C, yet for the other species there was a sharp decline in productivity, growth, and shoot density at 35°C, which was exacerbated by pCO 2 . These results suggest that thermal stress will not be offset by ocean acidification during future extreme heat events and challenges the current hypothesis that tropical seagrass will be a 'winner' under future climate change conditions. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  15. Fracture mechanics analysis of reactor pressure vessel under pressurized thermal shock - The effect of elastic-plastic behavior and stainless steel cladding -

    International Nuclear Information System (INIS)

    Joo, Jae Hwang; Kang, Ki Ju; Jhung, Myung Jo

    2002-01-01

    Performed here is an assessment study for deterministic fracture mechanics analysis of a pressurized thermal shock (PTS). The PTS event means an event or transient in pressurized water reactors (PWRs) causing severe overcooling (thermal shock) concurrent with or followed by significant pressure in the reactor vessel. The problems consisting of two transients and 10 cracks are solved and maximum stress intensity factors and maximum allowable nil-ductility reference temperatures are calculated. Their results are compared each other to address the general characteristics between transients, crack types and analysis methods. The effects of elastic-plastic material behavior and clad coating on the inner surface are explored

  16. Contribution to the numerical study of concrete behaviour and of reinforced concrete structures submitted to coupled thermal and mechanical solicitations: a damageable thermo-elasto-plastic approach

    International Nuclear Information System (INIS)

    Nechnech, W.

    2000-12-01

    The aim of this research is the development of an Finite Element model for the analysis of reinforced concrete structures under thermal, mechanical loadings or any combination of them. An available synthesis of results on the concrete behavior under thermal solicitation is exposed. The different behavior of concrete that can be founded notably in thermo-mechanical analysis (Damage, unilateral phenomenon, thermo-mechanical interaction,...) are underlined. The various families of modeling are analyzed thereafter while underlining the important aspects of the behavior that each one can re-transcribe. A new thermo-plastic damage model for plain concrete subjected to combined thermal and cyclic loading is developed using the concept of plastic-work-hardening and stiffness degradation in continuum damage mechanics. Two damage variables are used: the first one for mechanical action and the second one for thermal action. Further, thermo-mechanical interaction strains have been introduced to describe the influence of mechanical loading on the physical process of thermal expansion of concrete. The constitutive relations for elastoplastic responses are decoupled from the degradation damage responses by using the effective stress concept. This method provides advantages in the numerical implementation. A simple and thermodynamically consistent scalar degradation model is introduced to simulate the effect of damage on elastic stiffness and its recovery during crack opening and closing. Efficient computational algorithms for the proposed model are subsequently explored and performance of this model is demonstrated with numerical examples. (author)

  17. Effects of ocean acidification on the marine calcium isotope record at the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Griffith, Elizabeth M.; Fantle, Matthew S.; Eisenhauer, Anton; Paytan, Adina; Bullen, Thomas D.

    2015-06-01

    Carbonates are used extensively to reconstruct paleoclimate and paleoceanographic conditions over geologic time scales. However, these archives are susceptible to diagenetic alteration via dissolution, recrystallization and secondary precipitation, particularly during ocean acidification events when intense dissolution can occur. Despite the possible effects of diagenesis on proxy fidelity, the impacts of diagenesis on the calcium isotopic composition (δ44Ca) of carbonates are unclear. To shed light on this issue, bulk carbonate δ44Ca was measured at high resolution in two Pacific deep sea sediment cores (ODP Sites 1212 and 1221) with considerably different dissolution histories over the Paleocene-Eocene Thermal Maximum (PETM, ∼ 55 Ma). The δ44Ca of marine barite was also measured at the deeper Site 1221, which experienced severe carbonate dissolution during the PETM. Large variations (∼ 0.8 ‰) in bulk carbonate δ44Ca occur in the deeper of the two sites at depths corresponding to the peak carbon isotope excursion, which correlate with a large drop in carbonate weight percent. Such an effect is not observed in either the 1221 barite record or the bulk carbonate record at the shallower Site 1212, which is also less affected by dissolution. We contend that ocean chemical changes associated with abrupt and massive carbon release into the ocean-atmosphere system and subsequent ocean acidification at the PETM affected the bulk carbonate δ44Ca record via diagenesis in the sedimentary column. Such effects are considerable, and need to be taken into account when interpreting Ca isotope data and, potentially, other geochemical proxies over extreme climatic events that drive sediment dissolution.

  18. Evaluation of Haney-Type Surface Thermal Boundary Conditions Using a Coupled Atmosphere and Ocean Model

    National Research Council Canada - National Science Library

    Chu, Peter C; Chen, Yuchun; Lu, Shihua

    2001-01-01

    ... (Russell et al,, 1995) was used to verify the validity of Haney-type surface thermal boundary condition, which linearly connects net downward surface heat flux Q to air / sea temperature difference DeltaT by a relaxation coefficient K...

  19. A numerical investigation of the atmosphere-ocean thermal contrast over the coastal upwelling region of Cabo Frio, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Dourado, M. [Departamento de Meteorologia, Universidade Federal de Pelotas, Pelotas RS (Brazil)]. E-mail: marcelo_dourado@ufpel.edu.br; Pereira de Oliveira, A. [Departamento de Ciencias Atmosfericas, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, (Brazil)

    2008-01-15

    An one-dimensional atmospheric second order closure model, coupled to an oceanic mixed layer model, is used to investigate the short term variation of the atmospheric and oceanic boundary layers in the coastal upwelling area of Cabo Frio, Brazil (23 degrees Celsius S, 42 degrees Celsius 08' W). The numerical simulations were carried out to evaluate the impact caused by the thermal contrast between atmosphere and ocean on the vertical extent and other properties of both atmospheric and oceanic boundary layers. The numerical simulations were designed taking as reference the observations carried out during the passage of a cold front that disrupted the upwelling regime in Cabo Frio in July of 1992. The simulations indicated that in 10 hours the mechanical mixing, sustained by a constant background flow of 10 m s-1, increases the atmospheric boundary layer in 214 m when the atmosphere is initially 2 K warmer than the ocean (positive thermal contrast observed during upwelling regime). For an atmosphere initially -2 K colder than the ocean (negative thermal contrast observed during passage of the cold front), the incipient thermal convection intensifies the mechanical mixing increasing the vertical extent of the atmospheric boundary layer in 360 m. The vertical evolution of the atmospheric boundary layer is consistent with the observations carried out in Cabo Frio during upwelling condition. When the upwelling is disrupted, the discrepancy between the simulated and observed atmospheric boundary layer heights in Cabo Frio during July of 1992 increases considerably. During the period of 10 hours, the simulated oceanic mixed layer deepens 2 m and 5.4 m for positive and negative thermal contrasts of 2 K and -2 K, respectively. In the latter case, the larger vertical extent of the oceanic mixed layer is due to the presence of thermal convection in the atmospheric boundary layer, which in turn is associated to the absence of upwelling caused by the passage of cold fronts

  20. Investigating Ocean Pollution.

    Science.gov (United States)

    LeBeau, Sue

    1998-01-01

    Describes a fifth-grade class project to investigate two major forms of ocean pollution: plastics and oil. Students work in groups and read, discuss, speculate, offer opinions, and participate in activities such as keeping a plastics journal, testing the biodegradability of plastics, and simulating oil spills. Activities culminate in…

  1. Influence of solar radiation absorbed by phytoplankton on the thermal structure and circulation of the tropical Atlantic Ocean

    Science.gov (United States)

    Frouin, Robert; Ueyoshi, Kyozo; Kampel, Milton

    2007-09-01

    Numerical experiments conducted with an ocean general ocean circulation model reveal the potential influence of solar radiation absorbed by phytoplankton on the thermal structure and currents of the Tropical Atlantic Ocean. In the model, solar radiation penetration is parameterized explicitly as a function of chlorophyll-a concentration, the major variable affecting water turbidity in the open ocean. Two types of runs are performed, a clear water (control) run with a constant minimum chlorophyll-a concentration of 0.02 mgm -3, and a turbid water (chlorophyll) run with space- and time-varying chlorophyll-a concentration from satellite data. The difference between results from the two runs yields the biological effects. In the chlorophyll run, nutrients and biology production are implicitly taken into account, even though biogeochemical processes are not explicitly included, since phytoplankton distribution, prescribed from observations, is the result of those processes. Due to phytoplankton-radiation forcing, the surface temperature is higher by 1-2 K on average annually in the region of the North Equatorial current, the Northern part of the South Equatorial current, and the Caribbean system, and by 3-4 K in the region of the Guinea current. In this region, upwelling is reduced, and heat trapped in the surface layers by phytoplankton is not easily removed. The surface temperature is lower by 1 K in the Northern region of the Benguela current, due to increased upwelling. At depth, the equatorial Atlantic is generally cooler, as well as the eastern part of the tropical basin (excluding the region of the sub-tropical gyres). The North and South equatorial currents, as well as the Equatorial undercurrent, are enhanced by as much as 3-4 cms -1, and the circulation of the subtropical gyres is increased. Pole-ward heat transport is slightly reduced North of 35°N, suggesting that phytoplankton, by increasing the horizontal return flow in the subtropical region, may exert a

  2. 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.

  3. An Adaptive Neuro-Fuzzy Inference System for Sea Level Prediction Considering Tide-Generating Forces and Oceanic Thermal Expansion

    Directory of Open Access Journals (Sweden)

    Li-Ching Lin Hsien-Kuo Chang

    2008-01-01

    Full Text Available The paper presents an adaptive neuro fuzzy inference system for predicting sea level considering tide-generating forces and oceanic thermal expansion assuming a model of sea level dependence on sea surface temperature. The proposed model named TGFT-FN (Tide-Generating Forces considering sea surface Temperature and Fuzzy Neuro-network system is applied to predict tides at five tide gauge sites located in Taiwan and has the root mean square of error of about 7.3 - 15.0 cm. The capability of TGFT-FN model is superior in sea level prediction than the previous TGF-NN model developed by Chang and Lin (2006 that considers the tide-generating forces only. The TGFT-FN model is employed to train and predict the sea level of Hua-Lien station, and is also appropriate for the same prediction at the tide gauge sites next to Hua-Lien station.

  4. Ocean thermal energy conversion power system development-I. Phase I. Preliminary design report. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-18

    The results of a conceptual and preliminary design study of Ocean Thermal Energy Conversion (OTEC) closed loop ammonia power system modules performed by Lockheed Missiles and Space Company, Inc. (LMSC) are presented. This design study is the second of 3 tasks in Phase I of the Power System Development-I Project. The Task 2 objectives were to develop: 1) conceptual designs for a 40 to 50-MW(e) closed cycle ammonia commercial plant size power module whose heat exchangers are immersed in seawater and whose ancillary equipments are in a shirt sleeve environment; preliminary designs for a modular application power system sized at 10-MW(e) whose design, construction and material selection is analogous to the 50 MW(e) module, except that titanium tubes are to be used in the heat exchangers; and 3) preliminary designs for heat exchanger test articles (evaporator and condenser) representative of the 50-MW(e) heat exchangers using aluminum alloy, suitable for seawater service, for testing on OTEC-1. The reference ocean platform was specified by DOE as a surface vessel with the heat exchanger immersed in seawater to a design depth of 0 to 20 ft measured from the top of the heat exchanger. For the 50-MW(e) module, the OTEC 400-MW(e) Plant Ship, defined in the Platform Configuration and Integration study, was used as the reference platform. System design, performance, and cost are presented. (WHK)

  5. Diversity in thermal affinity among key piscivores buffers impacts of ocean warming on predator-prey interactions.

    Science.gov (United States)

    Selden, Rebecca L; Batt, Ryan D; Saba, Vincent S; Pinsky, Malin L

    2018-01-01

    Asymmetries in responses to climate change have the potential to alter important predator-prey interactions, in part by altering the location and size of spatial refugia for prey. We evaluated the effect of ocean warming on interactions between four important piscivores and four of their prey in the U.S. Northeast Shelf by examining species overlap under historical conditions (1968-2014) and with a doubling in CO 2 . Because both predator and prey shift their distributions in response to changing ocean conditions, the net impact of warming or cooling on predator-prey interactions was not determined a priori from the range extent of either predator or prey alone. For Atlantic cod, an historically dominant piscivore in the region, we found that both historical and future warming led to a decline in the proportion of prey species' range it occupied and caused a potential reduction in its ability to exert top-down control on these prey. In contrast, the potential for overlap of spiny dogfish with prey species was enhanced by warming, expanding their importance as predators in this system. In sum, the decline in the ecological role for cod that began with overfishing in this ecosystem will likely be exacerbated by warming, but this loss may be counteracted by the rise in dominance of other piscivores with contrasting thermal preferences. Functional diversity in thermal affinity within the piscivore guild may therefore buffer against the impact of warming on marine ecosystems, suggesting a novel mechanism by which diversity confers resilience. © 2017 John Wiley & Sons Ltd.

  6. Poultry rearing on perforated plastic floors and the effect on air quality, growth performance, and carcass injuries-Experiment 1: Thermal Comfort.

    Science.gov (United States)

    de Almeida, Eduardo Alves; Arantes de Souza, Lilian Francisco; Sant'Anna, Aline Cristina; Bahiense, Raphael Nogueira; Macari, Marcos; Furlan, Renato Luis

    2017-09-01

    The present study investigated the use of perforated plastic floors in the rearing of male and female poultry under thermal comfort conditions. The study was conducted in 2 climate chambers, in one was conventional poultry litter (wood shavings) and in the other was a perforated plastic floor. The experimental design was a completely randomized design with the factors wood shavings and plastic floor. In each chamber, the animals were divided into 16 experimental pens (8 with males and 8 with females) with a density of 12 birds/m2. The poultry rearing effect was evaluated in terms of air quality (% concentration of ammonia [NH3] and carbon dioxide [CO2]); broiler performance, e.g., weight gain (kg), feed intake (kg), feed conversion, carcass yield and parts (%), meat production (kg/m2), and viability (% of live birds at d 42); scores of hygiene and mobility; and injuries in the chest, hocks, and footpads. Treatments affected air quality, with higher concentrations of NH3 on d 42 (25 ppm vs. 2 ppm) and CO2 (1,400 ppm vs. 1,000 ppm) for wood shavings than for perforated plastic floor, respectively. Males showed a better performance (weight gain, feed intake and feed conversion) than females on d 42 in both floor types (wood shavings and plastic floor). Males reared on wood shavings showed a higher meet production (35.992 kg/m2) than females (32.257 kg/m2). On the plastic floor, males showed a better viability (100%) than females (94.05%), as well better meet production for males (38.55 kg·m-2) than females (31.64 kg/m2). There was no incidence of breast lesions in any of the studied systems. The birds reared on the plastic floor had better hygiene scores and lower hock injury rates than birds reared in the wood shavings chambers. The results of the present study show that the use of perforated plastic floors in chicken farming is an efficient method, which promotes a better-quality environment, superior production rates, and reduced incidence of injuries.

  7. Experimental study and simulation of transformation induced plasticity, and multiphase behaviour of the 16MND5 vessel steel under aniso-thermal multiaxial loading

    International Nuclear Information System (INIS)

    Coret, M.

    2001-01-01

    This work deals with the aniso-thermal multiphase behaviour of the French vessel steel and more specially about the transformation plasticity in the cases of multiaxial non-proportional loadings paths. The first part of this report is devoted to the presentation of a high temperature tension-torsion experimental device enable of obtaining a large range of cooling rate. This experimental set-up is used to explore the transformation plasticity under proportional or non-proportional loading paths, during austenitic, bainitic and martensitic transformations. The results of the tests are compared to the Leblond's model. In the last part, we propose a two-scale behaviour model in which the type of each phase behaviour can be different. This meso-model is finally used to simulate two real tests on structures. (author) [fr

  8. Ocean thermal energy conversion power system development. Final design report: PSD-I, Phase II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-06-30

    The PSD-I program provides a heat exchanger sytem consisting of an evaporator, condenser and various ancillaries with ammonia used as a working fluid in a closed simulated Rankine cycle. It is to be installed on the Chepachet Research Vessel for test and evaluation of a number of OTEC concepts in a true ocean environment. It is one of several test articles to be tested. Primary design concerns include control of biofouling, corrosion and erosion of aluminum tubes, selection of materials, and the development of a basis for scale-up to large heat exchangers so as to ultimately demonstrate economic feasibility on a commercial scale. The PSD-I test article is devised to verify thermodynamic, environmental, and mechanical performance of basic design concepts. The detailed design, development, fabrication, checklist, delivery, installation support, and operation support for the Test Article Heat Exchangers are described. (WHK)

  9. Thermal Niche Tracking and Future Distribution of Atlantic Mackerel Spawning in response to Ocean Warming

    Directory of Open Access Journals (Sweden)

    Antoine eBruge

    2016-06-01

    Full Text Available North-east Atlantic mackerel spawning distribution has shifted northward in the last three decades probably in response to global sea warming. Yet, uncertainties subsist regarding on the shift rate, causalities, and how this species will respond to future conditions. Using egg surveys, we explored the influence of temperature change on mackerel’s spawning distribution (western and southern spawning components of the stock between 1992 and 2013, and projected how it may change under future climate change scenarios. We developed three generalized additive models: (i a spatiotemporal model to reconstruct the spawning distribution for the north-east Atlantic stock over the period 1992-2013, to estimate the rate of shift; (ii a thermal habitat model to assess if spawning mackerel have tracked their thermal spawning-niche; and (iii a niche-based model to project future spawning distribution under two predicted climate change scenarios. Our findings showed that mackerel spawning activity has shifted northward at a rate of 15.9 ± 0.9 km/decade between 1992 and 2013. Similarly, using the thermal habitat model, we detected a northward shift of the thermal spawning-niche. This indicates that mackerel has spawned at higher latitudes to partially tracking their thermal spawning-niche, at a rate of 28.0 ± 9.0 km/°C of sea warming. Under future scenarios (mid and end of the century, the extrapolation of the niche-based model to coupled hydroclimatic and biogeochemical models indicates that centre of gravity of mackerel spawning distribution is expected to shift westward (32 to 117 km and northward (0.5 to 328 km, but with high variability according to scenarios and time frames. The future of the overall egg production in the area is uncertain (change from -9.3% to 12%. With the aim to allow the fishing industry to anticipate the future distribution of mackerel shoals during the spawning period, future research should focus on reducing uncertainty in

  10. The timescale and extent of thermal expansion of the global ocean due to climate change

    Directory of Open Access Journals (Sweden)

    S. Marčelja

    2010-02-01

    Full Text Available With recently improved instrumental accuracy, the change in the heat content of the oceans and the corresponding contribution to the change of the sea level can be determined from in situ measurements of temperature variation with depth. Nevertheless, it would be favourable if the same changes could be evaluated from just the sea surface temperatures because the past record could then be reconstructed and future scenarios explored. Using a single column model we show that the average change in the heat content of the oceans and the corresponding contribution to a global change in the sea level can be evaluated from the past sea surface temperatures. The calculation is based on the time-dependent diffusion equation with the known fixed average upwelling velocity and eddy diffusivity, as determined from the steady-state limit. In this limit, the model reduces to the 1966 Munk profile of the potential temperature variation as a function of depth.

    There are no adjustable parameters in the calculation and the results are in good agreement with the estimates obtained from the in situ data. The method allows us to obtain relevant timescales and average temperature profiles. The evaluation of the thermosteric sea level change is extended back to the beginning of accurate sea surface temperature records. The changes in sea surface temperature from 1880 until the present time are estimated to have produced a thermosteric sea level rise of 35 mm. Application to future IPCC scenarios gives results similar to the average prediction of more complex climate models.

  11. Coupling Between The North Indian Ocean And The Monsoons: A Model Based Study Of The Thermal Structure Cycling In The Central Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, R.K.

    To examine the role of various intervening processes in controlling the upper ocean thermal structure in the central Arabian Sea, a 1-D mixed-layer model based on turbulent closure scheme is forced by atmospheric fluxes and advective heat fluxes...

  12. A novel Carnot-based cycle for ocean thermal energy conversion

    International Nuclear Information System (INIS)

    Semmari, Hamza; Stitou, Driss; Mauran, Sylvain

    2012-01-01

    A thermodynamic engine cycle can be implemented by exploiting the temperature difference existing between the warm surface seawater and cold deep seawater. It employs a working fluid that evaporates by warm seawater, produces work in an expander device, such as a gas turbine and finally condenses by cold deep seawater. A new Carnot-based cycle for OTEC applications, called CAPILI cycle is presented. In this new engine cycle, work is produced by the movement of an inert liquid through a hydraulic turbine. This inert liquid characterized by a very low saturation pressure and immiscibility with the working fluid, acts as a liquid piston that moves alternately between two insulated cylinders. The insulated cylinders are connected alternately to an evaporator and a condenser, each of them operates at different pressure and temperature levels. A performance study which consists in a steady state energy balance is realised first to select the most suitable working fluid for this specific application. It was found that the best fluid is the HFC refrigerant R134a. A dynamic modelling based on the concept of equivalent Gibbs system is carried out to appreciate the dynamic behaviour and the performances of this new thermal conversion process. -- Highlights: ► A novel Carnot-based cycle operating with a liquid piston is investigated for OTEC application. ► The most suitable working fluid giving the best performances is found to be the HFC R134a. ► The performances of this new thermal process are evaluated using a dynamic modelling. ► A thermal efficiency of 1.9% can be obtained by exploiting seawater temperature difference of 20 °C. ► A net cycle efficiency of 1.2% is achieved considering a net to gross power production ratio of 61%.

  13. Drift in ocean currents impacts intergenerational microbial exposure to temperature.

    Science.gov (United States)

    Doblin, Martina A; van Sebille, Erik

    2016-05-17

    Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034-1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming.

  14. High density polyethylene (HDPE-2) and polystyrene (PS-6) waste plastic mixture turns into valuable fuel energy

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin; Rashid, Mohammad Mamunor; Rahman, Md. Sadikur; Molla, Mohammed [Department of Research and Development, Natural State Research Inc, Stamford, (United States)

    2011-07-01

    Disposal of waste plastic is a serious concern in USA. Waste plastic generated from different cities and towns is a part of municipal solid waste. It is a matter of concern that disposal of waste plastic is causing many problems such as leaching impact on land and ground water, choking of drains, making land infertile, indiscriminate burning causes environmental hazards etc. Waste plastics being nonbiodegradable it can remain as a long period of landfill. Over 48 million tons of synthetic polymer material is produced in the United States every year. Plastic are made from limited resources such as petroleum. When waste plastic come in contact with light and starts photo degrading, it starts releasing harmful such as carbon, chlorine and sulfur causing the soil around them to decay, contributing many complications for cultivation. Waste plastics also end up in the ocean, where it becomes small particles due to the reaction caused by the sun ray and salt from the ocean. Million of ocean habitants die from consuming these small plastic particles when they mistake them for food. To solve this problem countries are resorting to dumping the waste plastics, which requires a lot of effort and money yet they are only able to recycle a fraction of waste plastics. This developed a new technology which will remove these waste plastics form landfill and ocean and convert them into useful liquid fuels. The fuels show high potential for commercialization due to the fact, its influence to the environment. Keywords: waste plastics, fuel, energy, polystyrene, high density polyethylene, thermal, environmental.

  15. Simultaneous Screening of Major Flame Retardants and Plasticizers in Polymer Materials Using Pyrolyzer/Thermal Desorption Gas Chromatography Mass Spectrometry (Py/TD–GC–MS

    Directory of Open Access Journals (Sweden)

    Hiroyuki Yanagisawa

    2018-03-01

    Full Text Available This study was conducted with the aim of achieving the simultaneous screening of various additives in polymer materials by utilizing a solvent-free pyrolyzer/thermal desorption gas chromatography mass spectrometry (Py/TD-GC–MS method. As a first step to achieve this goal, simultaneous screening has been examined by selecting major substances representing plasticizers and flame retardants, such as short chain chlorinated paraffins (SCCPs, decabromodiphenyl ether (DecaBDE, hexabromocyclododecane (HBCDD, and di(2-ethylhexyl phthalate (DEHP. A quantitative MS analysis was performed to check for the peak areas and sensitivities. Since Py/TD-GC–MS is fraught with the risk of thermal degradation of the sample, temperatures during the analytical process were finely tuned for securing reliable results. The instrumental sensitivity was confirmed by the S/N ratio on each component. The detection limits of all components were less than 50 mg/kg, which are sufficiently lower than the regulatory criteria. With regard to reproducibility, a relative standard deviation (RSD of about 5% was confirmed by employing a spike recovery test on a polystyrene polymer solution containing mixed standard solution (ca. 1000 mg/kg. In conclusion, the results obtained in this study indicate that Py/TD-GC–MS is applicable for the screening of major flame retardants and plasticizers in real samples with sufficient reproducibility at regulatory levels.

  16. Synergistic effect on thermal behavior and char morphology analysis during co-pyrolysis of paulownia wood blended with different plastics waste

    International Nuclear Information System (INIS)

    Chen, Lin; Wang, Shuzhong; Meng, Haiyu; Wu, Zhiqiang; Zhao, Jun

    2017-01-01

    Highlights: • Positive synergistic effect on volatiles yield during co-pyrolysis of PAW and PP. • Higher char yields than predicated value during PAW/PVC and PAW/PET blends pyrolysis. • Co-pyrolysis of PAW and plastics reduced the mean activation energy of the blends. • The plastics affected the surface morphology of co-pyrolysis chars significantly. - Abstract: Thermal behavior of Paulownia wood (PAW), model plastics (polypropylene, polyvinyl chloride and polyethylene terephthalate, abbreviated as PP, PVC and PET) and their mixtures during pyrolysis process were studied through thermogravimetric analyzer. Scanning electron microscopy technology (SEM) and fractal theory were applied to evaluate the surface morphology of pyrolysis chars. This study found that PP showed synergistic effect on PAW pyrolysis with more volatiles release than predicated value, and the maximum volatiles yield exhibited with 25% PAW blending ratio. However, higher char yields were observed compared with the predicted values during co-pyrolysis process of PAW blends with PVC or PET, and the maximum char yields were obtained under the PAW blending ratio of 75% and 25% respectively. An evident decline in mean activation energy was found during co-pyrolysis of the PAW blending with plastics. The minimum values of mean activation energy for the PAW/PP, PAW/PVC and PAW/PET were gained when the PAW blending ratio were 75%, 50% and 75% respectively. Quantitative information about surface topography of pyrolysis chars were obtained by fractal analysis of the SEM microphotograph. The fractal dimension of residual chars from PAW/PP blends increased from 1.75 to 1.84 as increasing the ratio of PP from 25% to 75%, indicating that PP addition promoted the nonuniformity of the co-pyrolysis chars. The surface morphology of residual chars from PAW/PET and PAW/PVC blends showed a contrary tendency, and the minimum values of fractal dimension were respectively 1.62 and 1.61 under 25% PAW blending

  17. Results of scoping tests for open-cycle OTEC (ocean thermal energy conversion) components operating with seawater

    Energy Technology Data Exchange (ETDEWEB)

    Zangrando, F; Bharathan, D; Green, H J; Link, H F; Parsons, B K; Parsons, J M; Pesaran, A A [Solar Energy Research Inst., Golden, CO (USA); Panchal, C B [Argonne National Lab., IL (USA)

    1990-09-01

    This report presents comprehensive documentation of the experimental research conducted on open-cycle ocean thermal energy conversion (OC-OTEC) components operating with seawater as a working fluid. The results of this research are presented in the context of previous analysis and fresh-water testing; they provide a basis for understanding and predicting with confidence the performance of all components of an OC-OTEC system except the turbine. Seawater tests have confirmed the results that were obtained in fresh-water tests and predicted by the analytical models of the components. A sound technical basis has been established for the design of larger systems in which net power will be produced for the first time from OC-OTEC technology. Design and operation of a complete OC-OTEC system that produces power will provide sufficient confidence to warrant complete transfer of OC-OTEC technology to the private sector. Each components performance is described in a separate chapter written by the principal investigator responsible for technical aspects of the specific tests. Chapters have been indexed separately for inclusion on the data base.

  18. Marine pastures: a by-product of large (100 megawatt or larger) floating ocean-thermal power plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, S.; Roels, O.A.

    1976-08-31

    The potential biological productivity of an open-sea mariculture system utilizing the deep-sea water discharged from an ocean-thermal energy conversion (OTEC) plant was investigated. In a series of land-based studies, surface water was used to inoculate deep water and the primary production of the resultant blooms was investigated. Each cubic meter of deep water can produce approximately 2.34 g of phytoplankton protein, and that an OTEC plant discharging deep water at a rate of 4.5 x 10/sup 4/ m/sup 3/ min/sup -1/ could produce 5.3 x 10/sup 7/ kg of phytoplankton protein per 350-day year. A series of land-based shellfish studies indicated that, when fed at a constant rate of 1.83 x 10/sup -3/ g of protein per second per 70-140 g of whole wet weight, the clam, Tapes japonica, could convert the phytoplankton protein-nitrogen into shellfish meat protein-nitrogen with an efficiency of about 33 per cent. Total potential wet meat weight production from an OTEC plant pumping 4.5 x 10/sup 4/ m/sup 3/ min/sup -1/ is approximately 4.14 x 10/sup 8/ kg for a 350-day year. Various factors affecting the feasibility of open-sea mariculture are discussed. It is recommended that future work concentrate on a technical and economic analysis. (WDM)

  19. Effect of Hybrid Talc-Basalt Fillers in the Shell Layer on Thermal and Mechanical Performance of Co-Extruded Wood Plastic Composites.

    Science.gov (United States)

    Huang, Runzhou; Mei, Changtong; Xu, Xinwu; Kärki, Timo; Lee, Sunyoung; Wu, Qinglin

    2015-12-08

    Hybrid basalt fiber (BF) and Talc filled high density polyethylene (HDPE) and co-extruded wood-plastic composites (WPCs) with different BF/Talc/HDPE composition levels in the shell were prepared and their mechanical, morphological and thermal properties were characterized. Incorporating BFs into the HDPE-Talc composite substantially enhanced the thermal expansion property, flexural, tensile and dynamic modulus without causing a significant decrease in the tensile and impact strength of the composites. Strain energy estimation suggested positive and better interfacial interactions of HDPE with BFs than that with talc. The co-extruded structure design improved the mechanical properties of WPC due to the protective shell layer. The composite flexural and impact strength properties increased, and the thermal expansion decreased as BF content increased in the hybrid BF/Talc filled shells. The cone calorimetry data demonstrated that flame resistance of co-extruded WPCs was improved with the use of combined fillers in the shell layer, especially with increased loading of BFs. The combined shell filler system with BFs and Talc could offer a balance between cost and performance for co-extruded WPCs.

  20. PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix

    Directory of Open Access Journals (Sweden)

    Wieczorek Anna

    2015-12-01

    Full Text Available The polystyrene doped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenylbenzoxazole as a wavelength shifter prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260, 283, and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.

  1. 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 " ...

  2. Calcium Isotope (δ44/40Ca) Composition of Morozovella Velascoensis During the Paleocene Eocene Thermal Maximum Ocean Acidification Event

    Science.gov (United States)

    Kitch, G. D.; Jacobson, A. D.; Hurtgen, M.; Sageman, B. B.; Harper, D. T.; Zachos, J. C.

    2017-12-01

    Ocean acidification (OA) events are transient disruptions to the carbonate chemistry of seawater that involve decreases in pH, [CO32-] and carbonate mineral saturation states (Ω). Numerical modeling studies predict that the Ca isotope (δ44/40Ca) composition of primary marine carbonate should be sensitive to OA1, and recent evidence from the rock record may support this hypothesis2. Boron isotope (δ11B) data for the planktonic foraminifera Morozovella velascoensis indicate that the Paleocene-Eocene Thermal Maximum (PETM; 55 Mya) was an interval of pronounced OA3, although the Ca isotope composition of the bulk carbonate record appears to show post-burial diagenetic effects4. To further evaluate the Ca isotope proxy, we used a high-precision (2σSD=±0.04‰), double-spike (43Ca-42Ca) TIMS method5 to measure δ44/40Ca values of well-preserved M. velascoensis tests spanning the PETM. M. velascoensis tests (250-355 µm) were picked from samples recovered during ODP Leg 198, Site 1209 on Shatsky Rise in the equatorial Pacific. Five M. velascoensis tests were combined per sample, dissolved, spiked, and analyzed using a Triton TIMS. Repeat dissolutions of ten samples gave δ44/40Ca values within ±0.04‰ of the original measurements. Method and procedural blanks were negligible. δ44/40Ca values are elevated, even before the negative carbon isotope excursion (CIE) that marks the PETM. When δ11/10B values decrease during the CIE, δ44/40Ca values remain elevated, but then decrease by 0.10‰ as δ11B values return to pre-CIE levels. The apparent inverse correlation between δ44/40Ca and δ11B values suggests that Ca isotope fractionation by M. velascoensis was sensitive to OA. A decrease in pH indicated by lower δ11B values is consistent with higher δ44/40Ca values (decreased fractionation) due to elevated [Ca2+]/[CO32-] ratios and reduced W. The Ca isotope composition of pristine foraminiferal calcite may have potential for reconstructing [CO32-]. The current

  3. Characterization of Wood-Plastic Composites Made with Different Lignocellulosic Materials that Vary in Their Morphology, Chemical Composition and Thermal Stability

    Directory of Open Access Journals (Sweden)

    Ke-Chang Hung

    2017-12-01

    Full Text Available In this study, four kinds of lignocellulosic fibers (LFs, namely, those from Chinese fir (Cunninghamia lanceolata, Taiwan red pine (Pinus taiwanensis, India-charcoal trema (Trema orientalis and makino bamboo (Phyllostachys makinoi, were selected as reinforcements and incorporated into high-density polyethylene (HDPE to manufacture wood-plastic composites (WPCs by a flat platen pressing process. In addition to comparing the differences in the physico-mechanical properties of these composites, their chemical compositions were evaluated and their thermal decomposition kinetics were analyzed to investigate the effects of the lignocellulosic species on the properties of the WPCs. The results showed that the WPC made with Chinese fir displayed a typical M-shaped vertical density profile due to the high aspect ratio of its LFs, while a flat vertical density profile was observed for the WPCs made with other LFs. Thus, the WPC made with Chinese fir exhibited higher flexural properties and lower internal bond strength (IB than other WPCs. In addition, the Taiwan red pine contained the lowest holocellulose content and the highest extractives and α-cellulose contents, which gave the resulting WPC lower water absorption and flexural properties. On the other hand, consistent with the flexural properties, the results of thermal decomposition kinetic analysis showed that the activation energy of the LFs at 10% of the conversion rate increased in the order of Taiwan red pine (146–161 kJ/mol, makino bamboo (158–175 kJ/mol, India-charcoal trema (185–194 kJ/mol and Chinese fir (194–202 kJ/mol. These results indicate that the morphology, chemical composition and thermal stability of the LFs can have a substantial impact on the physico-mechanical properties of the resulting WPCs.

  4. 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

  5. Development of composite ceramic materials with improved thermal conductivity and plasticity based on garnet-type oxides

    Science.gov (United States)

    Golovkina, L. S.; Orlova, A. I.; Boldin, M. S.; Sakharov, N. V.; Chuvil'deev, V. N.; Nokhrin, A. V.; Konings, R.; Staicu, D.

    2017-06-01

    Powders based on the complex garnet-type oxide Y2.5Nd0.5Al5O12 - x wt. % Ni (x = 0, 10, 20) were prepared using wet chemistry methods. Ceramics based on these compounds were obtained by Spark Plasma Sintering (SPS) with a relative densities: 99%. 4% (TD = 4.77 g/cm3 (0%)), 97.6% (TD = 4.88 g/cm3 (10%)), 94.4% (TD = 5.06 g/cm3 (20%)). The influence of nickel concentration on the mechanical (fracture toughness, microhardness) and thermophysical (thermal conductivity) properties of the composites was studied.

  6. Development of composite ceramic materials with improved thermal conductivity and plasticity based on garnet-type oxides

    Energy Technology Data Exchange (ETDEWEB)

    Golovkina, L.S., E-mail: golovkina_lyudmila@mail.ru [Lobachevsky State University of Nizhni Novgorod, 603950 Nizhni Novgorod (Russian Federation); Orlova, A.I.; Boldin, M.S.; Sakharov, N.V.; Chuvil' deev, V.N.; Nokhrin, A.V. [Lobachevsky State University of Nizhni Novgorod, 603950 Nizhni Novgorod (Russian Federation); Konings, R.; Staicu, D. [European Commission, Joint Research Centre, Directorate G – Nuclear Safety and Security, 76125 Karlsruhe (Germany)

    2017-06-15

    Powders based on the complex garnet-type oxide Y{sub 2.5}Nd{sub 0.5}Al{sub 5}O{sub 12} - x wt. % Ni (x = 0, 10, 20) were prepared using wet chemistry methods. Ceramics based on these compounds were obtained by Spark Plasma Sintering (SPS) with a relative densities: 99%. 4% (TD = 4.77 g/cm{sup 3} (0%)), 97.6% (TD = 4.88 g/cm{sup 3} (10%)), 94.4% (TD = 5.06 g/cm{sup 3} (20%)). The influence of nickel concentration on the mechanical (fracture toughness, microhardness) and thermophysical (thermal conductivity) properties of the composites was studied. - Highlights: •Powders were prepared using wet chemistry methods. •Ceramics were sintering by SPS method (ρ{sub rel} ∼ 99%); t{sub shrinkage} < 10 min. •By increasing Ni concentration in composites, their fracture toughness was enhanced. •Thermal conductivity increases with elevated concentration of Ni.

  7. 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

  8. Ocean energy

    International Nuclear Information System (INIS)

    2009-01-01

    There are 5 different ways of harnessing ocean energy: tides, swells, currents, osmotic pressure and deep water thermal gradients. The tidal power sector is the most mature. A single French site - The Rance tidal power station (240 MW) which was commissioned in 1966 produces 90% of the world's ocean energy. Smaller scale power stations operate around the world, 10 are operating in the European Union and 5 are being tested. Underwater generators and wave energy converters are expanding. In France a 1 km 2 sea test platform is planned for 2010. (A.C.)

  9. Thermal Evolution of Juvenile Subduction Zones ' New Constraints from Lu-Hf Geochronology on HP oceanic rocks (Halilbaǧi, Central Anatolia)

    Science.gov (United States)

    Pourteau, Amaury; Scherer, Erik; Schmidt, Alexander; Bast, Rebecca

    2015-04-01

    The thermal structure of subduction zones plays a key role on mechanical and chemical processes taking place along the slab-mantle interface. Until now, changes through time of this thermal structure have been explored mostly by the means of numerical simulations. However, both "warm" (i.e., epidote-bearing), and "cold" (i.e., lawsonite-bearing) HP oceanic rocks have been reported in some fossil subduction complexes exposed at the Earth's surface (e.g., Franciscan Complex, California; Rio San Juan Complex, Hispañola; Halilbağı Unit, Central Anatolia). These a-priori "incompatible" rocks witness different thermal stages of ancient subduction zones and their study might provide complementary constraints to numerical models. To decipher the meaning of these contrasting metamorphic rocks in the Halilbağı Unit, we are carrying out Lu-Hf geochronology on garnet (grt) and lws from a variety of HP oceanic rocks, as well as the metamorphic sole of the overlying ophiolite. We selected five samples that are representative of the variety of metamorphic evolutions (i.e. peak conditions and P-T paths) encountered in this area. Preliminary analyses yielded 110 Ma (grt-hbl isochron) for a sub-ophiolitic grt amphibolite; 92 Ma (grt-omp) for an eclogite with prograde and retrograde ep; 90 Ma (grt-omp) for an eclogitic metabasite with prograde ep and retrograde ep+lws; 87 Ma (grt-gln) for a lws eclogite with prograde ep; and 86 Ma (grt-gln) for a blueschist with prograde and retrograde lws. These ages are mainly two-point isochrons. Further-refined data will be presented at the EGU General Assembly 2015, in Vienna. The consistent younging trend from "warm" to "cold" metamorphic rocks revealed by these first-order results points to metamorphic-sole formation during the initiation of intra-oceanic subduction at ~110 Ma, and subsequent cooling of the slab-mantle interface between 92 and 86 Ma. Therefore, the contrasting metamorphic evolutions encountered in the Halilbağı Unit

  10. Effects of the plastic deformation and thermal cycles on the mechanical properties of fully recrystallized Zircaloy-4

    International Nuclear Information System (INIS)

    Litvack, Nicolas

    2005-01-01

    The development of crystallographic texture in a product depends, for a given material, of its fabrication history. In our case, the evolution of that texture results from a combination of cold working and thermal cycles applied together or separately. In the present work, cold working levels ranging from 50 % to approximately 90 % and different heat treatment cycles has been applied to Zircaloy-4 sheets and tubes. Using X-ray diffraction techniques and the direct pole figure method, the evolution of crystallographic texture has been analyzed for each fabrication route. We observed that cold working levels up to 90 % without intermediate annealing heat treatment do not change significantly the classic angle between basal pole and the normal/radial direction of the product (φ ≅ ± 25 degrees). Furthermore, the application of intermediate cold working levels (50 % - 60 %) and more than two intermediate annealing heat treatments exhibits a marked modification of the basal pole orientation. The basal poles appear now parallel to the normal direction (φ ≅ 0 degrees) of the product. Additionally, the crystallographic texture change observed with X-ray procedures was evaluated by the measure of anisotropic parameters R and P. The results here obtained will be use in the future as a basis for the design of a fabrication route capable to obtain in a HPTR process, seamless calandria tubes strengthened by crystallographic texture. (author) [es

  11. 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 ...

  12. 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.

  13. All is not lost: Deriving a top-down mass budget of plastic at sea.

    NARCIS (Netherlands)

    Koelmans, Bart; Kooi, Merel; Law, Kara Lavender; Sebille, van Erik

    2017-01-01

    Understanding the global mass inventory is one of the main challenges in present research on plastic marine debris. Especially the fragmentation and vertical transport processes of oceanic plastic are poorly understood. However, whereas fragmentation rates are unknown, information on plastic

  14. A new hybrid ocean thermal energy conversion–Offshore solar pond (OTEC–OSP) design: a cost optimization approach

    NARCIS (Netherlands)

    Straatman, P.J.T.; van Sark, W.G.J.H.M.

    2008-01-01

    Solar thermal electricity (STE) generation offers an excellent opportunity to supply electricity with a non-CO2 emitting technology. However, present costs hamper widespread deployment and therefore research and development efforts are concentrated on accelerated cost reductions and efficiency

  15. 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

  16. Postrelease survival, vertical and horizontal movements, and thermal habitats of five species of pelagic sharks in the central Pacific Ocean

    DEFF Research Database (Denmark)

    Musyl, Michael K.; Brill, Richard W.; Curran, Daniel S.

    2011-01-01

    ]) in the central Pacific Ocean to determine speciesspecific movement patterns and survival rates after release from longline fishing gear. Only a single postrelease mortality could be unequivocally documented: a male blue shark which succumbed seven days after release. Meta-analysis of published reports......From 2001 to 2006, 71 pop-up satellite archival tags (PSATs) were deployed on five species of pelagic shark (blue shark [Prionace glauca]; shortfin mako [Isurus oxyrinchus]; silky shark [Carcharhinus falciformis]; oceanic whitetip shark [C. longimanus]; and bigeye thresher [Alopias superciliosus...... and the current study (n=78 reporting PSATs) indicated that the summary effect of postrelease mortality for blue sharks was 15% (95% CI, 8.5-25.1%) and suggested that catch-and-release in longline fisheries can be a viable management tool to protect parental biomass in shark populations. Pelagic sharks displayed...

  17. 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.

  18. Modeling the Physical and Biochemical Influence of Ocean Thermal Energy Conversion Plant Discharges into their Adjacent Waters

    Energy Technology Data Exchange (ETDEWEB)

    PAT GRANDELLI, P.E.; GREG ROCHELEAU; JOHN HAMRICK, Ph.D.; MATT CHURCH, Ph.D.; BRIAN POWELL, Ph.D.

    2012-09-29

    This paper describes the modeling work by Makai Ocean Engineering, Inc. to simulate the biochemical effects of of the nutrient-enhanced seawater plumes that are discharged by one or several 100 megawatt OTEC plants. The modeling is needed to properly design OTEC plants that can operate sustainably with acceptably low biological impact. In order to quantify the effect of discharge configuration and phytoplankton response, Makai Ocean Engineering implemented a biological and physical model for the waters surrounding O`ahu, Hawai`i, using the EPA-approved Environmental Fluid Dynamics Code (EFDC). Each EFDC grid cell was approximately 1 square kilometer by 20 meters deep, and used a time step of three hours. The biological model was set up to simulate the biochemical response for three classes of organisms: Picoplankton (< 2 um) such as prochlorococccus, nanoplankton (2-20 um), and microplankton (> 20 um) e.g., diatoms. The dynamic biological phytoplankton model was calibrated using chemical and biological data collected for the Hawaii Ocean Time Series (HOTS) project. Peer review of the biological modeling was performed. The physical oceanography model uses boundary conditions from a surrounding Hawai'i Regional Ocean Model, (ROM) operated by the University of Hawai`i and the National Atmospheric and Oceanic Administration. The ROM provided tides, basin scale circulation, mesoscale variability, and atmospheric forcing into the edges of the EFDC computational domain. This model is the most accurate and sophisticated Hawai'ian Regional Ocean Model presently available, assimilating real-time oceanographic observations, as well as model calibration based upon temperature, current and salinity data collected during 2010 near the simulated OTEC site. The ROM program manager peer-reviewed Makai's implementation of the ROM output into our EFDC model. The supporting oceanographic data was collected for a Naval Facilities Engineering Command / Makai project

  19. Geomechanical, Hydraulic and Thermal Characteristics of Deep Oceanic Sandy Sediments Recovered during the Second Ulleung Basin Gas Hydrate Expedition

    Directory of Open Access Journals (Sweden)

    Yohan Cha

    2016-09-01

    Full Text Available This study investigates the geomechanical, hydraulic and thermal characteristics of natural sandy sediments collected during the Ulleung Basin gas hydrate expedition 2, East Sea, offshore Korea. The studied sediment formation is considered as a potential target reservoir for natural gas production. The sediments contained silt, clay and sand fractions of 21%, 1.3% and 77.7%, respectively, as well as diatomaceous minerals with internal pores. The peak friction angle and critical state (or residual state friction angle under drained conditions were ~26° and ~22°, respectively. There was minimal or no apparent cohesion intercept. Stress- and strain-dependent elastic moduli, such as tangential modulus and secant modulus, were identified. The sediment stiffness increased with increasing confining stress, but degraded with increasing strain regime. Variations in water permeability with water saturation were obtained by fitting experimental matric suction-water saturation data to the Maulem-van Genuchen model. A significant reduction in thermal conductivity (from ~1.4–1.6 to ~0.5–0.7 W·m−1·K−1 was observed when water saturation decreased from 100% to ~10%–20%. In addition, the electrical resistance increased quasi-linearly with decreasing water saturation. The geomechanical, hydraulic and thermal properties of the hydrate-free sediments reported herein can be used as the baseline when predicting properties and behavior of the sediments containing hydrates, and when the hydrates dissociate during gas production. The variations in thermal and hydraulic properties with changing water and gas saturation can be used to assess gas production rates from hydrate-bearing deposits. In addition, while depressurization of hydrate-bearing sediments inevitably causes deformation of sediments under drained conditions, the obtained strength and stiffness properties and stress-strain responses of the sedimentary formation under drained loading conditions

  20. 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...

  1. 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

  2. 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.

  3. Ocean energies

    International Nuclear Information System (INIS)

    Charlier, R.H.; Justus, J.R.

    1993-01-01

    This timely volume provides a comprehensive review of current technology for all ocean energies. It opens with an analysis of ocean thermal energy conversion (OTEC), with and without the use of an intermediate fluid. The historical and economic background is reviewed, and the geographical areas in which this energy could be utilized are pinpointed. The production of hydrogen as a side product, and environmental consequences of OTEC plants are considered. The competitiveness of OTEC with conventional sources of energy is analysed. Optimisation, current research and development potential are also examined. Separate chapters provide a detailed examination of other ocean energy sources. The possible harnessing of solar ponds, ocean currents, and power derived from salinity differences is considered. There is a fascinating study of marine winds, and the question of using the ocean tides as a source of energy is examined, focussing on a number of tidal power plant projects, including data gathered from China, Australia, Great Britain, Korea and the USSR. Wave energy extraction has excited recent interest and activity, with a number of experimental pilot plants being built in northern Europe. This topic is discussed at length in view of its greater chance of implementation. Finally, geothermal and biomass energy are considered, and an assessment of their future is given. The authors also distinguished between energy schemes which might be valuable in less-industrialized regions of the world, but uneconomical in the developed countries. A large number of illustrations support the text. This book will be of particular interest to energy economists, engineers, geologists and oceanographers, and to environmentalists and environmental engineers

  4. Plastic collapse load of corroded steel plates

    Indian Academy of Sciences (India)

    Keywords. Corroded steel plate; plastic collapse; FEM; rough surface. ... The main aim of present work is to study plastic collapse load of corroded steel plates with irregular surfaces under tension. Non-linear finite element method ... Department of Ocean Engineering, AmirKabir University of Technology, 15914 Tehran, Iran ...

  5. Energy from rivers and oceans

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role energy from rivers and oceans may have in the energy future of the US. The topics discussed in the chapter include historical aspects of using energy from rivers and oceans, hydropower assessment including resources, technology and costs, and environmental and regulatory issues, ocean thermal energy conversion including technology and costs and environmental issues, tidal power, and wave power

  6. Ocean thermal energy conversion (OTEC) power system development (PSD) II. Preliminary design report. Appendix II: supporting data

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-10

    The trade studies, calculations, and reports which provide the rationale for design conclusions for the 10 MWe OTEC power system are presented in this volume. These appendices include: (1) system design and optimization model; (2) system off-design performance computer model; (3) seawater system dynamics; (4) system mechanical design studies; (5) electrical design studies; (6) structural design studies; (7) tube cleaner design report and proposed brush test program; (8) heat exchangers: mechanical design; (9) heat exchangers: thermal hydraulic computer model; (10) heat exchangers: manufacturing flow plan; (11) heat exchangers: installation and removal procedures; (12) heat exchangers: stainless steel conceptual design; (13) heat exchangers: cost studies; (14)heat exchangers: materials selection and corrosion; and (15) heat exchangers: quality assurance. (WHK)

  7. 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.)

  8. Constraints on the Lost City Hydrothermal System from borehole thermal data; 3-D models of heat flow and hydrothermal circulation in an oceanic core complex.

    Science.gov (United States)

    Titarenko, S.; McCaig, A. M.

    2014-12-01

    A perennial problem in near-ridge hydrothermal circulation is that the only directly measurable data to test models is often vent fluid temperature. Surface heat flow measurements may be available but without the underlying thermal structure it is not known if they are transient and affected by local hydrothermal flow, or conductive. The Atlantis Massif oceanic core complex at 30 °N on the mid-Atlantic Ridge, offers a unique opportunity to better constrain hydrothermal circulation models. The temperature profile in gabbroic rocks of IODP Hole 1309D was measured in IODPExpedition 340T, and found to be near-conductive, but with a slight inflexion at ~750 mbsf indicating downward advection of fluid above that level. The lack of deep convection is especially remarkable given that the long-lived Lost City Hydrothermal Field (LCHF) is located only 5km to the south. We have modelled hydrothermal circulation in the Massif using Comsol Multiphysics, comparing 2-D and 3-D topographic models and using temperature-dependent conductivity to give the best estimate of heatflow into the Massif. We can constrain maximum permeability in gabbro below 750 mbsf to 5e-17 m2. The thermal gradient in the upper part of the borehole can be matched with a permeability of 3e-14 m2 in a 750 m thick layer parallel to the surface of the massif, with upflow occurring in areas of high topography and downflow at the location of the borehole. However in 3-D the precise flow pattern is quite model dependent, and the thermal structure can be matched either by downflow centred on the borehole at lower permeability or centred a few hundred metres from the borehole at higher permeability. The borehole gradient is compatible with the longevity (>120 kyr) and outflow temperature (40-90 °C) of the LCHF either with a deep more permeable (1e-14 m2 to 1e-15 m2) domain beneath the vent site in 2-D or a permeable fault slot 500 to 1000m wide and parallel to the transform fault in 3-D. In both cases topography

  9. 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

  10. Molding apparatus. [for thermosetting plastic compositions

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    Apparatus for compression molding of thermosetting plastics compositions including interfitting hollow male and female components is reported. The components are adapted to be compressed to form a rocket nozzle in a cavity. A thermal jacket is provided exteriorly adjacent to the female component for circulating a thermal transfer fluid to effect curing of a thermosetting plastics material being molded. Each of the male and female components is provided with suitable inlets and outlets for circulating a thermal transfer fluid.

  11. Thermal springs list for the United States; National Oceanic and Atmospheric Administration Key to Geophysical Records Documentation No. 12

    Energy Technology Data Exchange (ETDEWEB)

    Berry, G.W.; Grim, P.J.; Ikelman, J.A. (comps.)

    1980-06-01

    The compilation has 1702 thermal spring locations in 23 of the 50 States, arranged alphabetically by State (Postal Service abbreviation) and degrees of latitude and longitude within the State. It shows spring name, surface temperature in degrees Fahrenheit and degrees Celsius; USGS Professional Paper 492 number, USGS Circular 790 number, NOAA number, north to south on each degree of latitude and longitude of the listed. USGS 1:250,000-scale (AMS) map; and the USGS topographic map coverage, 1:63360- or 1:62500-scale (15-minute) or 1:24000-scale (7.5-minute) quadrangle also included is an alphabetized list showing only the spring name and the State in which it is located. Unnamed springs are omitted. The list includes natural surface hydrothermal features: springs, pools, mud pots, mud volcanoes, geysers, fumaroles, and steam vents at temperature of 20{sup 0}C (68[sup 0}F) or greater. It does not include wells or mines, except at sites where they supplement or replace natural vents presently or recently active, or, in some places, where orifices are not distinguishable as natural or artificial. The listed springs are located on the USGS 1:250,000 (AMS) topographic maps. (MHR)

  12. 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.

  13. 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...

  14. 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

  15. Dynamic mechanical and molecular weight measurements on polymer bonded explosives from thermally accelerated aging tests. III. Kraton block copolymer binder and plasticizers

    International Nuclear Information System (INIS)

    Caley, L.E.; Hoffman, D.M.

    1981-01-01

    The dynamic mechanical properties and molecular weight distribution of two experimental polymer bonded explosives, X-0287 and X-0298, maintained at 23, 60, and 74 0 C for 3 years were examined. X-0287 is 97% 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane explosive, 1.8% Kraton G-1650, and 1.2% B 2 was 170. X-0298 is 97.4% explosive, 1.4% Kraton G-1650, and 1.2% Cenco Hi-vac oil. The relaxation associated with the Kraton rubber block glass transition is observed in both X-0287 and X-0298. In the unaged X-0298 it occurs at -59 0 C and in the aged explosive at 50 0 C. This is caused by migration of the oil plasticizer out of the explosive. In X-0287 the Kraton rubber block T/sub g/ is weak and broad due to the presence of the wax plasticizer. X-0287 has a second broad relaxation associated with the melting of the wax from 10 to 65 0 C. The molecular weight of the Kraton binder decreased with increasing accelerated aging temperature. The oil plasticizer had no stabilizing effect, but below its melting point the wax reduced Kraton chain scission considerably. The simple random chain scission model predicted a 20.5 year use-life for X-0298, but X-0287 was stabilized against degradation below the wax melting point

  16. 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.

  17. 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.

  18. Thermo-plastic finite element analysis for metal honeycomb structure

    Directory of Open Access Journals (Sweden)

    Ji Zhanling

    2013-01-01

    Full Text Available This paper deals with thermal-plastic analysis for the metal honeycomb structure. The heat transfer equation and thermal elastoplastic constitutive equation of a multilayer panel are established and studied numerically using ANSYS software. The paper elucidates that only the outer skin produces easily plastic deformation, and the outer skin still exists some residual stress and residual deformation after cooling. The dynamic evolution of plastic deformation and material performance degradation under high energy thermal load are revealed.

  19. 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.

  20. 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.

  1. 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.

  2. Plastic deformation

    NARCIS (Netherlands)

    Sitter, de L.U.

    1937-01-01

    § 1. Plastic deformation of solid matter under high confining pressures has been insufficiently studied. Jeffreys 1) devotes a few paragraphs to deformation of solid matter as a preface to his chapter on the isostasy problem. He distinguishes two properties of solid matter with regard to its

  3. 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.

  4. 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) ...

  5. All is not lost: Deriving a top-down mass budget of plastic at sea.

    OpenAIRE

    Koelmans, Bart; Kooi, Merel; Law, Kara Lavender; Sebille, van, Erik

    2017-01-01

    Understanding the global mass inventory is one of the main challenges in present research on plastic marine debris. Especially the fragmentation and vertical transport processes of oceanic plastic are poorly understood. However, whereas fragmentation rates are unknown, information on plastic emissions, concentrations of plastics in the ocean surface layer (OSL) and fragmentation mechanisms is available. Here, we apply a systems engineering analytical approach and propose a tentative 'whole oc...

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Global Models of Ridge-Push Force, Geoid, and Lithospheric Strength of Oceanic plates

    Science.gov (United States)

    Mahatsente, Rezene

    2017-12-01

    An understanding of the transmission of ridge-push related stresses in the interior of oceanic plates is important because ridge-push force is one of the principal forces driving plate motion. Here, I assess the transmission of ridge-push related stresses in oceanic plates by comparing the magnitude of the ridge-push force to the integrated strength of oceanic plates. The strength is determined based on plate cooling and rheological models. The strength analysis includes low-temperature plasticity (LTP) in the upper mantle and assumes a range of possible tectonic conditions and rheology in the plates. The ridge-push force has been derived from the thermal state of oceanic lithosphere, seafloor depth and crustal age data. The results of modeling show that the transmission of ridge-push related stresses in oceanic plates mainly depends on rheology and predominant tectonic conditions. If a lithosphere has dry rheology, the estimated strength is higher than the ridge-push force at all ages for compressional tectonics and at old ages (>75 Ma) for extension. Therefore, under such conditions, oceanic plates may not respond to ridge-push force by intraplate deformation. Instead, the plates may transmit the ridge-push related stress in their interior. For a wet rheology, however, the strength of young lithosphere (stress may dissipate in the interior of oceanic plates and diffuses by intraplate deformation. The state of stress within a plate depends on the balance of far-field and intraplate forces.

  13. Trans-generational plasticity in physiological thermal tolerance is modulated by maternal pre-reproductive environment in the polychaete Ophryotrocha labronica.

    Science.gov (United States)

    Massamba-N'Siala, Gloria; Prevedelli, Daniela; Simonini, Roberto

    2014-06-01

    Maternal temperature is known to affect many aspects of offspring phenotype, but its effect on offspring physiological thermal tolerance has received less attention, despite the importance of physiological traits in defining organismal ability to cope with temperature changes. To fill this gap, we used the marine polychaete Ophryotrocha labronica to investigate the influence of maternal temperature on offspring upper and lower thermal tolerance limits, and assess whether maternal influence changed according to the stage of offspring pre-zygotic development at which a thermal cue was provided. Measurements were taken on adult offspring acclimated to 18 or 30°C, produced by mothers previously reared at 24°C and then exposed to 18 or 30°C at an early and late stage of oogenesis. When the shift from 24°C was provided early during oogenesis, mothers produced offspring with greater cold and heat tolerance whenever mother-offspring temperatures did not match, with respect to when they matched, suggesting the presence of an anticipatory maternal effect triggered by the thermal variation. Conversely, when the cue was provided later during oogenesis, more tolerant offspring were observed when temperatures persisted across generations. In this case, maternal exposure to 18 or 30°C may have benefited offspring performance, while limitations in the transmission of the thermal cue may account for the lack of correlation between maternal experiences and offspring performance when mother-offspring environments did not match. Our results provided evidence for a trans-generational effect of temperature on physiological performance characterised by a high context dependency, and are discussed in the light of maternal pre-reproductive experiences. © 2014. Published by The Company of Biologists Ltd.

  14. Ocean Acidification | Smithsonian Ocean Portal

    Science.gov (United States)

    Natural History Blog For Educators At The Museum Media Archive Ocean Life & Ecosystems Mammals Sharks Mangroves Poles Census of Marine Life Planet Ocean Tides & Currents Waves & Storms The Seafloor ocean is affected. Such a relatively quick change in ocean chemistry doesn't give marine life, which

  15. Observed intra-seasonal to interannual variability of the upper ocean thermal structure in the southeastern Arabian Sea during 2002-2008

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalakrishna, V.V.; Durand, F.; Nisha, K.; Lengaigne, M.; Boyer, T.P; Costa, J.; Rao, R.R.; Ravichandran, M.; Amrithash, S.; John, L.; Girish, K.; Ravichandran, C.; Suneel, V.

    in the Arabian Sea. Deep Sea Res. II, 49, 12, 2231–2264. Gill, A. E., 1982. Atmosphere-Ocean Dynamics, Volume 30, Academic Press, 662 pp. Graham, N. E., Barnet, T.P., 1987. Sea surface temperature, surface wind divergence and convection over tropical oceans...003631 Locarnini, R. A., Mishonov, A. V., Antonov, J. I., Boyer, T. P., Garcia, H. E., 2006. World Ocean Atlas 2005, Volume 1: Temperature, S. Levitus, Ed. NOAA Atlas NESDIS 61, U.S. Government Printing Office, Washington, D.C., 182. Masson, S., Luo...

  16. Recycling of plastic packaging material from separate collection from the dual system Germany. Current LCA results compared to disposal in thermal waste incineration plants; Werkstoffliche Verwertung von Verpackungskunststoffen aus der Getrenntsammlung Dualer Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Heyde, Michael; Gerke, Gilian; Muehle, Sarah [Deutsche Gesellschaft fuer Kreislaufwirtschaft und Rohstoffe (DKR) mbH, Koeln (Germany)

    2010-01-15

    Due to the implementation of the European waste framework directive into German law it is discussed which contribution waste incineration makes to resource protection and the reduction of greenhouse gas emissions. A number of players question if it is still contemporary to adhere to recycling as a priority. The following article compares today's recycling of separately collection of plastics waste from the German packaging recovery system and the disposal in thermal waste treatment plants under ecological aspects. The separate collected of packaging waste materials is a prerequisite of high quality recycling. If this were to be abandoned and - hypothetically - this waste stream would be disposed in thermal waste treatment plants in Germany, significant drawbacks in the reduction of greenhouse gas emissions and primary energy demand would arise. This is shown in a study conducted by the Institute fuer Energie- und Umweltforschung (ifeu) in Heidelberg. Further it could be proved that there is still optimization potential in the recycling market that has been developed over the last two decades in Germany. However, to max this potential significantly depends on stable political framework requirements. The following article underlines that recycling and high quality energy recovery cause remarkable savings of CO{sub 2}-emissions and energy. (orig.)

  17. Ocean tides

    Science.gov (United States)

    Hendershott, M. C.

    1975-01-01

    A review of recent developments in the study of ocean tides and related phenomena is presented. Topics briefly discussed include: the mechanism by which tidal dissipation occurs; continental shelf, marginal sea, and baroclinic tides; estimation of the amount of energy stored in the tide; the distribution of energy over the ocean; the resonant frequencies and Q factors of oceanic normal modes; the relationship of earth tides and ocean tides; and numerical global tidal models.

  18. Microbes on a bottle: substrate, season and geography influence community composition of microbes colonizing marine plastic debris

    OpenAIRE

    Carter, Dee A.; Oberbeckmann, Sonja; Osborn, A. Mark; Duhaime, Melissa B.

    2016-01-01

    Plastic debris pervades in our oceans and freshwater systems and the potential ecosystem-level impacts of this anthropogenic litter require urgent evaluation. Microbes readily colonize aquatic plastic debris and members of these biofilm communities are speculated to include pathogenic, toxic, invasive or plastic degrading-species. The influence of plastic-colonizing microorganisms on the fate of plastic debris is largely unknown, as is the role of plastic in selecting for unique microbial com...

  19. Plastic scintillator

    International Nuclear Information System (INIS)

    Andreeshchev, E.A.; Kilin, S.F.; Kavyrzina, K.A.

    1978-01-01

    A plastic scintillator for ionizing radiation detectors with high time resolution is suggested. To decrease the scintillation pulse width and to maintain a high light yield, the 4 1 , 4 5 -dibromo-2 1 , 2 5 , 5 1 , 5 5 -tetramethyl-n-quinquiphenyl (Br 2 Me 4 Ph) in combination with n-terphenyl (Ph 3 ) or 2, 5-diphenyloxadiazol-1, 3, 4 (PPD) is used as a luminescent addition. Taking into consideration the results of a special study, it is shown, that the following ratio of ingradients is the optimum one: 3-4 mass% Ph 3 or 4-7 mas% PPD + 2-5 mass% Br 2 Me 4 Ph + + polymeric base. The suggested scintillator on the basis of polystyrene has the light yield of 0.23-0.26 arbitrary units and the scintillation pulse duration at half-height is 0.74-0.84 ns

  20. Warm Water Entrainment Impacts and Environmental Life Cycle Assessment of a Proposed Ocean Thermal Energy Conversion Pilot Plant Offshore Oahu, Hawaii

    Science.gov (United States)

    Hauer, Whitney Blanchard

    Ocean thermal energy conversion (OTEC) is a marine renewable energy technology that uses the temperature difference of large volumes of cold deep and warm surface seawater in tropical regions to generate electricity. One anticipated environmental impact of OTEC operations is the entrainment and subsequent mortality of ichthyoplankton (fish eggs and larvae) from the withdrawal of cold and warm seawater. The potential ichthyoplankton loss from the warm water intake was estimated for a proposed 10 MW OTEC pilot plant offshore Oahu, HI based on ambient vertical distribution data. The estimated losses due to entrainment from the warm water intake were 8.418E+02 larvae/1000 m3, 3.26E+06 larvae/day, and 1.19E+09 larvae/year. The potential entrained larvae/year is 1.86 X greater than at the Kahe Generating Station (Kapolei, HI), a 582 MW oil-fired power plant. Extrapolating to age-1 equivalence (9.2E+02 and 2.9E+02 yellowfin and skipjack tuna, respectively), the estimated yearly losses from warm water entrainment of yellowfin and skipjack tuna fish eggs and larvae represent 0.25-0.26 % and 0.09-0.11 % of Hawaii's commercial yellowfin and skipjack tuna industry in 2011 and 2012. An environmental life cycle assessment (LCA) was developed for the proposed OTEC plant operating for 20 and 40 years with availability factors of 0.85, 0.95, and 1.0 to determine the global warming potential (GWP) and cumulative energy demand (CED) impacts. For a 20 year operational OTEC plant, the GWP, CED, energy return on investment (EROI), and energy payback time (EPBT) ranged from 0.047 to 0.055 kg CO2eq/kWh, 0.678 to 0.798 MJ/kWh, 4.51 to 5.31 (unitless), and 3.77 to 4.43 years, respectively. For a 40 year operational OTEC plant, the GWP, CED, EROI, and EBPT ranged from 0.036 to 0.043 kg CO2eq/kWh, 0.527 to 0.620 MJ/kWh, 5.81 to 6.83 (unitless), and 5.85 to 6.89 years, respectively. The GWP impacts are within the range of renewable energy technologies and less than conventional electricity

  1. Contaminants in northern fulmars (Fulmarus glacialis) exposed to plastic

    NARCIS (Netherlands)

    Ask, A.; Anker-Nilssen, T.; Herzke, D.; Trevail, Alice; Franeker, van J.A.; Gabrielsen, G.W.

    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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Oceanic archipelagos

    DEFF Research Database (Denmark)

    Triantis, Kostas A.; Whittaker, Robert James; Fernández-Palacios, José María

    2016-01-01

    Since the contributions of Charles Darwin and Alfred Russel Wallace, oceanic archipelagos have played a central role in the development of biogeography. However, despite the critical influence of oceanic islands on ecological and evolutionary theory, our focus has remained limited to either the i...... of the archipelagic geological dynamics that can affect diversity at both the island and the archipelagic level. We also reaffirm that oceanic archipelagos are appropriate spatiotemporal units to frame analyses in order to understand large scale patterns of biodiversity....

  7. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  8. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... This analysis starts with a review of ocean transportation demand and supply including projections of ship capacity demand and world shipbuilding capacity under various economic and political assumptions...

  9. 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...

  10. Thermophysical characteristics of plastic bottles as an element of water heat accumulators in solar greenhouses

    International Nuclear Information System (INIS)

    Khalimov, A. G.; Khairiddinov, B. Eh.; Kim, V. D.; Khalimov, G. G.

    2012-01-01

    This article considers the thermophysical and granulometric characteristics of polyethylene terephthalate (PET) plastic bottles filled with water. The given figures allow one to conduct calculations of thermal plastic bottles as heat storage elements for solar greenhouses. (author)

  11. Ocean technology

    Digital Repository Service at National Institute of Oceanography (India)

    Peshwe, V.B.

    stream_size 2 stream_content_type text/plain stream_name Voices_Oceans_1996_113.pdf.txt stream_source_info Voices_Oceans_1996_113.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  12. Ocean acidification

    National Research Council Canada - National Science Library

    Gattuso, J.P; Hansson, L

    2011-01-01

    The fate of much of the CO 2 we produce will be to enter the ocean. In a sense, we are fortunate that ocean water is endowed with the capacity to absorb far more CO 2 per litre than were it salt free...

  13. Incidence of plastic debris in Sooty Tern nests: A preliminary study on Trindade Island, a remote area of Brazil.

    Science.gov (United States)

    de Souza Petersen, Elisa; Krüger, Lucas; Dezevieski, Alexandre; Petry, MariaVirginia; Montone, Rosalinda Carmela

    2016-04-15

    Plastic is abundant in the oceans, reaching pelagic zones away from continents. Here we present the first recordings of plastic used as nest material in Sooty Tern nests, on a remote oceanic island. We describe our findings in terms of quantity, size and color of plastic debris. A total of 78 plastics were noted in 54 nests. Four color categories were found: Blue, White, Green and Red. Blue fragments were the most frequent color, present three times as much as white debris. This pattern was present despite blue fragments being smaller and lighter. The plastic debris of lowest frequency were the larger and heavier pieces (red). To our knowledge this is the first record of plastic in Sooty Tern nests. Trindade Island is on an oceanic zone expected to accumulate garbage due to the dynamic ocean currents. Such findings call for a closer inspection of pollution in the Atlantic Ocean. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. External insulation with cellular plastic materials

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2014-01-01

    External thermal insulation composite systems (ETICS) can be used as extra insulation of existing buildings. The system can be made of cellular plastic materials or mineral wool. There is a European Technical guideline, ETAG 004, that describe the tests that shall be conducted on such systems....... This paper gives a comparison of systems with mineral wool and cellular plastic, based on experience from practice and literature. It is important to look at the details in the system and at long time stability of the properties such as thermal insulation, moisture and fire. Investigation of fire properties...

  15. Marine renewable energies. When researchers consider the ocean as an energy source. Offshore wind power. The thermal energy of seas, a solar resource to be no longer neglected. Lipid biofuels production by micro-algae

    International Nuclear Information System (INIS)

    Ruer, J.; Gauthier, M.; Zaharia, R.; Cadoret, J.P.

    2008-01-01

    In the present day context of search for renewable energy sources, it is surprising that the oceans energy, potentially enormous, is poorly taken into consideration with respect to the other renewable energy sources, while France has been a pioneer in this domain with the construction of the Rance tidal power plant in the 1960's, and still in operation today. However, the scientific community, and in particular the IFREMER institute in France, is developing R and D programs on marine energy technologies. On the other hand, the development of wind power is growing up rapidly with a worldwide installed capacity exceeding today 94000 MW and supplying 3% of the electricity consumed in Europe. The development of offshore wind farms represents today 1122 MW and should grow up very fast in the coming years. The ocean is also a huge reservoir of thermal energy which can be exploited to generate electricity and desalinated water. Finally, the cultivation of micro-algae for the enhanced production of lipids may be a more ecological alternative to the terrestrial production of biofuels, strongly criticized today for its long term environmental impacts. (J.S.)

  16. Caracterização fenológica e requerimento térmico da cultivar moscato giallo sob cobertura plástica Phenological characterization and thermal requirement of moscato giallo cultivar under plastic cover

    Directory of Open Access Journals (Sweden)

    Geraldo Chavarria

    2009-03-01

    Full Text Available Os efeitos da cobertura plástica (CP sobre a fenologia e o requerimento térmico da Vitis vinifera L. 'Moscato Giallo' foram estudados em dois ciclos (2005/2006 e 2006/2007. Determinou-se a duração média dos principais períodos fenológicos por meio de avaliações semanais, desde a poda até a queda das folhas. O somatório térmico em graus-dia acumulados (GD foi calculado considerando-se a temperatura-base de 10ºC, e medidas da temperatura do ar máxima e mínima ao longo de todo o ciclo, nas áreas coberta e descoberta (testemunha. A cobertura plástica aumentou o somatório térmico e antecipou o início da brotação, reduzindo a duração das etapas fenológicas da poda até a mudança de cor das bagas. Entretanto, a redução da radiação fotossinteticamente ativa (RFA proporcionada pela cobertura plástica atrasou, em média, 18 dias o processo de maturação das uvas da cultivar Moscato Giallo. A soma térmica acumulada (poda até colheita das áreas coberta e descoberta foi, respectivamente, 2.079 e 1.847 GD no primeiro ciclo, e 1.864 e 1.640 GD no segundo ciclo. A cobertura plástica exige uma alteração nas práticas culturais, como a necessidade de poda verde para reduzir os efeitos da restrição de RFA e o atraso na data de colheita, em relação ao cultivo convencional, em função da menor taxa de evolução da maturação sob a cobertura.The plastic overhead cover (POC effects on phenology and thermal requirement of grapevine Vitis vinifera L. 'Moscato Giallo' were evaluated in two seasons (2005/2006 and 2006/2007. The phenology was weekly determined since the winter pruning until the falling of the leaves. The thermal requirement as degree-days (GDºC was calculated in the same period using 10ºC as base temperature and measured of maximal and minimal air temperature throughout both cycles in covered and uncovered areas. POC increased the thermal sum and it anticipated the budburst and decreased the duration of

  17. Ocean energy

    International Nuclear Information System (INIS)

    2006-01-01

    This annual evaluation is a synthesis of works published in 2006. Comparisons are presented between the wind power performances and European Commission White Paper and Biomass action plan objectives. The sector covers the energy exploitation of all energy flows specifically supplied by the seas and oceans. At present, most efforts in both research and development and in experimental implementation are concentrated on tidal currents and wave power. 90% of today worldwide ocean energy production is represented by a single site: the Rance Tidal Power Plant. Ocean energies must face up two challenges: progress has to be made in finalizing and perfecting technologies and costs must be brought under control. (A.L.B.)

  18. Challenges to Plastic Up-Cycling in Small Island Communities: A Palauan Tale

    OpenAIRE

    Starkey, Lark

    2017-01-01

    Plastics in the marine environment are a growing environmental threat with mounting research on impacts, sources and management strategies. Small island communities are subject to greater threats because of dual inputs of marine plastics via ocean currents and locally used plastics, with a heavy reliance on imported packaged goods. The resulting plastic buildup on islands is often combined with a lack of infrastructure and remoteness, leaving few options for management. However, a number of e...

  19. Chemical Pollutants Released to the Marine Environment by Degradation of Plastic Debris

    OpenAIRE

    Gewert, Berit

    2018-01-01

    Since the beginning of the mass production in the 1940s, plastic has been manufactured in quickly increasing amounts. Plastic debris accumulates in the environment and lately much attention has been drawn to the pollution in the world’s oceans. Despite the rapid development and ubiquitous presence of plastic, degradation in the marine environment and potential risks associated with plastic are not fully understood. Thus, these knowledge gaps were addressed in this thesis, which adds informati...

  20. Reducing Uncertainty and Confronting Ignorance about the Possible Impacts of Weathering Plastic in the Marine Environment

    OpenAIRE

    Jahnke, Annika; Arp, Hans Petter Heinrich; Escher, Beate I.; Gewert, Berit; Gorokhova, Elena; Kühnel, Dana; Ogonowski, Martin; Potthof, Annegret; Rummel, Christophe Daniel; Schmitt-Jansen, Mechtild; Toorman, Erik; MacLeod, Matthew

    2017-01-01

    Plastic in the global oceans fulfills two of the three conditions for pollution to pose a planetary boundary threat because it is causing planetary-scale exposure that is not readily reversible. Plastic is a planetary boundary threat if it is having a currently unrecognized disruptive effect on a vital Earth system process. Discovering possible unknown effects is likely to be aided by achieving a fuller understanding of the environmental fate of plastic. Weathering of plastic generates microp...

  1. Ocean Acidification

    Science.gov (United States)

    Ocean and coastal acidification is an emerging issue caused by increasing amounts of carbon dioxide being absorbed by seawater. Changing seawater chemistry impacts marine life, ecosystem services, and humans. Learn what EPA is doing and what you can do.

  2. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... The discussion of technology considers the ocean transportation system as a whole, and the composite subsystems such as hull, outfit, propulsion, cargo handling, automation, and control and interface technology...

  3. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... In ocean transportation economics we present investment and operating costs as well as the results of a study of financing of shipping. Similarly, a discussion of government aid to shipping is presented.

  4. Ocean Color

    Data.gov (United States)

    National Aeronautics and Space Administration — Satellite-derived Ocean Color Data sets from historical and currently operational NASA and International Satellite missions including the NASA Coastal Zone Color...

  5. Ocean Quality

    OpenAIRE

    Brevik, Roy Schjølberg; Jordheim, Nikolai; Martinsen, John Christian; Labori, Aleksander; Torjul, Aleksander Lelis

    2017-01-01

    Bacheloroppgave i Internasjonal Markedsføring fra ESADE i Spania, 2017 In this thesis we were going to answer the problem definition “which segments in the Spanish market should Ocean Quality target”. By doing so we started to collect data from secondary sources in order to find information about the industry Ocean Quality are operating in. After conducting the secondary research, we still lacked essential information about the existing competition in the aquaculture industry o...

  6. Stochastic Inversion of Geomagnetic Observatory Data Including Rigorous Treatment of the Ocean Induction Effect With Implications for Transition Zone Water Content and Thermal Structure

    Science.gov (United States)

    Munch, F. D.; Grayver, A. V.; Kuvshinov, A.; Khan, A.

    2018-01-01

    In this paper we estimate and invert local electromagnetic (EM) sounding data for 1-D conductivity profiles in the presence of nonuniform oceans and continents to most rigorously account for the ocean induction effect that is known to strongly influence coastal observatories. We consider a new set of high-quality time series of geomagnetic observatory data, including hitherto unused data from island observatories installed over the last decade. The EM sounding data are inverted in the period range 3-85 days using stochastic optimization and model exploration techniques to provide estimates of model range and uncertainty. The inverted conductivity profiles are best constrained in the depth range 400-1,400 km and reveal significant lateral variations between 400 km and 1,000 km depth. To interpret the inverted conductivity anomalies in terms of water content and temperature, we combine laboratory-measured electrical conductivity of mantle minerals with phase equilibrium computations. Based on this procedure, relatively low temperatures (1200-1350°C) are observed in the transition zone (TZ) underneath stations located in Southern Australia, Southern Europe, Northern Africa, and North America. In contrast, higher temperatures (1400-1500°C) are inferred beneath observatories on islands, Northeast Asia, and central Australia. TZ water content beneath European and African stations is ˜0.05-0.1 wt %, whereas higher water contents (˜0.5-1 wt %) are inferred underneath North America, Asia, and Southern Australia. Comparison of the inverted water contents with laboratory-constrained water storage capacities suggests the presence of melt in or around the TZ underneath four geomagnetic observatories in North America and Northeast Asia.

  7. 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)

  8. 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 ...

  9. Extracting DNA from ocean microplastics: a method comparison study

    NARCIS (Netherlands)

    Debeljak, P.; Proietti, M.; Reisser, J.; Ferrari, F.F.; Abbas, B.; van Loosdrecht, M.C.M.; Slat, B.; Herndl, G.J.

    2017-01-01

    AbstractThe ubiquity of plastics in oceans worldwide raises concerns about their ecological implications. Suspended microplastics (<5 mm) can be ingested by a wide range of marine organisms and may accumulate up the food web along with associated chemicals. Additionally, plastics provide a stable

  10. Extracting DNA from ocean microplastics : A method comparison study

    NARCIS (Netherlands)

    Debeljak, Pavla; Pinto, M.J.; Proietti, Maira; Reisser, Julia; Ferrari, Francesco F.; Abbas, B.A.; van Loosdrecht, Mark C.M.; Slat, Boyan; Herndl, Gerhard J.

    2017-01-01

    The ubiquity of plastics in oceans worldwide raises concerns about their ecological implications. Suspended microplastics (<5 mm) can be ingested by a wide range of marine organisms and may accumulate up the food web along with associated chemicals. Additionally, plastics provide a stable

  11. 4 π physics with the plastic ball

    International Nuclear Information System (INIS)

    Gutbrod, H.H.; Loehner, H.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Warwick, A.; Weik, F.; Wieman, H.

    1982-10-01

    4 π data taken with the Plastic Ball show that cluster production in relativistic nuclear collisions depends on both the size of the participant volume and the finite size of the cluster. The measurement of the degree of thermalization and the search for collective flow will permit the study of the applicability of macroscopic concepts such as temperature and density

  12. Microbial biotechnology addressing the plastic waste disaster

    OpenAIRE

    Narancic, Tanja; O'Connor, Kevin E.

    2017-01-01

    Oceans are a major source of biodiversity, they provide livelihood, and regulate the global ecosystem by absorbing heat and CO 2. However, they are highly polluted with plastic waste. We are discussing here microbial biotechnology advances with the view to improve the start and the end of life of biodegradable polymers, which could contribute to the sustainable use of marine and coastal ecosystems (UN Sustainability development goal 14).

  13. Colored plastic mulch microclimates affect strawberry fruit yield and quality.

    Science.gov (United States)

    Shiukhy, Saeid; Raeini-Sarjaz, Mahmoud; Chalavi, Vida

    2015-08-01

    Significant reduction of strawberry (Fragaria × ananassa, Duch.) fruit yield and quality, as a consequence of conventional cultivation method, is common in the Caspian Sea region, Iran. Recently, growers started using plastic mulches to overcome these shortcomings. Plastic mulches have different thermal and radiation properties and could affect strawberry fruit yield and quality. In the present study, the effect of different colored plastic mulches (black, red, and white) along with conventional practice was tested on yield and quality of strawberry Camarosa cultivar, in a completely randomized block design. Colored plastic mulches had highly significant effect on fruit weight, size, and phytochemical contents. In the most harvest times, mean fruit weight was significantly higher in red plastic relative to white and control treatments. Total fruit weight of plastic mulches was not significantly different, while all were statistically higher than that of control. Fruit size significantly increased over red plastic mulch. Total fruit numbers over plastic mulches were significantly higher than that of control treatment. The content of phenolic compounds was similar between treatments, while anthocyanin content, IC(50) value, and flavonoid content significantly were affected by colored plastics. In conclusion, colored plastic mulches could affect strawberry fruit weight and quality through altering strawberry thermal and radiation environment.

  14. 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.

  15. 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....

  16. 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.

  17. 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.

  18. 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.)

  19. 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...

  20. Oceans Past

    DEFF Research Database (Denmark)

    Based on research for the History of Marine Animal Populations project, Oceans Past examines the complex relationship our forebears had with the sea and the animals that inhabit it. It presents eleven studies ranging from fisheries and invasive species to offshore technology and the study of marine...... environmental history, bringing together the perspectives of historians and marine scientists to enhance understanding of ocean management of the past, present and future. In doing so, it also highlights the influence that changes in marine ecosystems have upon the politics, welfare and culture of human...

  1. The Ocean Food and Energy Farm Project

    Science.gov (United States)

    Wilcox, Howard A.

    1976-01-01

    This three-phase, 15-year project is designed to explore and develop the ability to raise the grant California kelp and other marine organisms for food, fuels, fertilizers and plastics in the temperate and tropical oceans. The needed technology is established, but the economic feasibility is yet to be determined. (BT)

  2. Ocean Acidification

    Science.gov (United States)

    Ludwig, Claudia; Orellana, Mónica V.; DeVault, Megan; Simon, Zac; Baliga, Nitin

    2015-01-01

    The curriculum module described in this article addresses the global issue of ocean acidification (OA) (Feely 2009; Figure 1). OA is a harmful consequence of excess carbon dioxide (CO[subscript 2]) in the atmosphere and poses a threat to marine life, both algae and animal. This module seeks to teach and help students master the cross-disciplinary…

  3. Life in the "plastisphere": microbial communities on plastic marine debris.

    Science.gov (United States)

    Zettler, Erik R; Mincer, Tracy J; Amaral-Zettler, Linda A

    2013-07-02

    Plastics are the most abundant form of marine debris, with global production rising and documented impacts in some marine environments, but the influence of plastic on open ocean ecosystems is poorly understood, particularly for microbial communities. Plastic marine debris (PMD) collected at multiple locations in the North Atlantic was analyzed with scanning electron microscopy (SEM) and next-generation sequencing to characterize the attached microbial communities. We unveiled a diverse microbial community of heterotrophs, autotrophs, predators, and symbionts, a community we refer to as the "Plastisphere". Pits visualized in the PMD surface conformed to bacterial shapes suggesting active hydrolysis of the hydrocarbon polymer. Small-subunit rRNA gene surveys identified several hydrocarbon-degrading bacteria, supporting the possibility that microbes play a role in degrading PMD. Some Plastisphere members may be opportunistic pathogens (the authors, unpublished data) such as specific members of the genus Vibrio that dominated one of our plastic samples. Plastisphere communities are distinct from surrounding surface water, implying that plastic serves as a novel ecological habitat in the open ocean. Plastic has a longer half-life than most natural floating marine substrates, and a hydrophobic surface that promotes microbial colonization and biofilm formation, differing from autochthonous substrates in the upper layers of the ocean.

  4. Inter-annual variability in the thermal structure of an oceanic time series station off Ecuador (1990-2003) associated with El Niño events

    Science.gov (United States)

    Garcés-Vargas, José; Schneider, Wolfgang; Abarca del Río, Rodrigo; Martínez, Rodney; Zambrano, Eduardo

    2005-10-01

    Previously unpublished data (1990-2003) from a marine station located 20 km off the coast of Ecuador (Station La Libertad, 02°12'S, 080°55'W) are employed to investigate oceanic inter-annual variability in the far eastern equatorial Pacific, and its relation to the central-eastern equatorial Pacific. La Libertad is the only time series station between the Galapagos Islands and the South American coast, the region most affected by El Niño events (El Niño 2 region, 0-5°S, 90°W-80°W). Although configured and serviced differently, station La Libertad can be looked at as an eastern extension of the TAO/TRITON monitoring system, whose easternmost mooring is located at 95°W, 1550 km offshore. This study of El Niño's impact on the thermocline and its relationship to sea surface temperature revealed anomalies in the thermocline at station La Libertad some 2-4 months before their appearance at the sea surface. Inter-annual variability, namely quasi-biennial and quasi-quadrennial oscillations, accounts for roughly 80% of the total variance in temperature anomalies observed in the water column at station La Libertad. The coincidence in both phase and amplitude of these inter-annual oscillations explains the strength of El Niño events in the water column off La Libertad. We further show that anomalies in heat content appear 8-9 weeks earlier at 140°W in the equatorial Pacific (6550 km away from the coast) than at the coast itself. The arrival of El Niño, which has important regional social consequences as well as those for local fisheries, could therefore be predicted in the sub-surface waters off Ecuador by using these anomalies as a complementary index. In addition, the speed of the eastward propagation of these El Niño-associated anomalies' suggests the possible participation of higher-order baroclinic mode Kelvin waves and associated interaction processes in the eastern Pacific, which should be further investigated.

  5. Temperature profile data collected using XBTs from the HARUNA MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-01-23 to 1977-02-03 (NODC Accession 8100367)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from HARUNA MARU in the Pacific Ocean from January 23, 1977 to February 3, 1977. Data...

  6. Temperature profile data collected using XBTs from the QUEENS WAY BRIDGE from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-07-02 to 1977-07-09 (NODC Accession 8100225)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from QUEENS WAY BRIDGE in the Pacific Ocean from July 2, 1977 to July 9, 1977. Data...

  7. Temperature profile data collected using XBTs from the KASHU MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1976-10-18 to 1977-06-09 (NODC Accession 8100137)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from KASHU MARU in the Pacific Ocean from October 18, 1976 to July 9, 1977. Data were...

  8. Temperature profile data collected using XBTs from the AUSTRAL RAINBOW from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1976-10-20 to 1976-10-23 (NODC Accession 8100228)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from AUSTRAL RAINBOW in the Pacific Ocean from October 20, 1976 to October 23, 1976....

  9. Temperature profile data collected using XBTs from the JAPAN ACE from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1976-11-24 to 1976-12-04 (NODC Accession 8100260)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from JAPAN ACE in the Pacific Ocean from November 24, 1976 to December 4, 1976. Data...

  10. Temperature profile data collected using XBTs from the HIEI MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-07-16 to 1977-07-23 (NODC Accession 8100176)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from HIEI MARU in the Pacific Ocean from July 16, 1977 to July 23, 1977. Data were...

  11. Temperature profile data collected using XBTs from the PRESIDENT MCKINLEY from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-05-19 to 1977-05-29 (NODC Accession 8100323)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from PRESIDENT MCKINLEY in the Pacific Ocean from May 19, 1977 to May 29, 1977. Data...

  12. Temperature, salinity, and water chemistry data from quarterly surface transects of the Comprehensive Environmental Monitoring Program at the Ocean Thermal Energy Conversion plant in Keahole, Island of Hawaii 1993-2016 (NCEI Accession 0156452)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NATURAL ENERGY LABORATORY OF HAWAII AUTHORITY (NELHA) is a state agency that operates a unique and innovative ocean science and Technology park in Kailua-Kona on...

  13. Temperature, salinity, and water chemistry data from quarterly bottom transects of the Comprehensive Environmental Monitoring Program at the Ocean Thermal Energy Conversion plant in Keahole, Island of Hawaii 1993-2007 (NCEI Accession 0156980)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NATURAL ENERGY LABORATORY OF HAWAII AUTHORITY (NELHA) is a state agency that operates a unique and innovative ocean science and technology park in Kailua-Kona on...

  14. Temperature, salinity, and water chemistry data from the Comprehensive Environmental Monitoring Program of the Ocean Thermal Energy Conversion plant at Keahole, Island of Hawaii, from shallow and deep intake pipes during 1982-2016 (NODC Accession 0001623)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NATURAL ENERGY LABORATORY OF HAWAII AUTHORITY (NELHA) is a state agency that operates a unique and innovative ocean science and technology park in Kailua-Kona on...

  15. Temperature profile data collected using XBTs from the ASIA MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-01-08 to 1977-01-17 (NODC Accession 8100280)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from ASIA MARU in the Pacific Ocean from January 8, 1977 to January 17, 1977. Data were...

  16. Temperature profile data collected using XBTs from the ASIA MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1976-12-18 to 1976-12-27 (NODC Accession 8100251)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from QUEENS WAY BRIDGE in the Pacific Ocean from December 18, 1976 to December 27,...

  17. Temperature profile data collected using XBTs from the KASHU MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-06-01 to 1977-06-08 (NODC Accession 8100135)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature project data were collected using bathythermograph (BT/XBT) casts from KASHU MARU in the Pacific Ocean from June 1, 1977 to June 8, 1977. Data were...

  18. Temperature profile data collected using XBTs from the RUHR EXPRESS and other platforms from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1984-11-16 to 1985-01-28 (NODC Accession 8500030)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from RUHR EXPRESS and other platforms in the Pacific Ocean from November 16, 1984 to...

  19. Temperature profile data collected using XBTs from the AMERICA MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-07-06 to 1977-07-14 (NODC Accession 8100352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from AMERICA MARU in the Pacific Ocean from July 6, 1977 to July 14, 1977. Data were...

  20. Temperature profile data collected using XBTs from the HIEI MARU from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1977-04-15 to 1977-04-23 (NODC Accession 8100190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from HIEI MARU in the Pacific Ocean from April 15, 1977 to April 23, 1977. Data were...

  1. Temperature profile data collected using XBTs from the ELBE EXPRESS and other platforms from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1985-01-21 to 1985-04-23 (NODC Accession 8500165)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from ELBE EXPRESS and other platforms in the Pacific Ocean from January 21, 1985 to...

  2. Temperature profile data collected using XBTs from the ELBE EXPRESS and other platforms from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1983-12-03 to 1986-01-29 (NODC Accession 8600103)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from ELBE EXPRESS and other platforms in the Pacific Ocean from December 3, 1983 to...

  3. Temperature profile data collected using XBTs from the ELBE EXPRESS and other platforms from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1985-02-19 to 1985-08-20 (NODC Accession 8500185)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from ELBE EXPRESS and other platforms in the Pacific Ocean from February 19, 1985 to...

  4. Temperature profile data collected using XBTs from the ELBE EXPRESS and other platforms from the Pacific Ocean during the Thermal Structure Monitoring Program in the Pacific (TRANSPAC) project, 1985-01-02 to 1985-03-19 (NODC Accession 8500081)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using bathythermograph (BT/XBT) casts from ELBE EXPRESS and other platforms in the Pacific Ocean from January 2, 1985 to...

  5. 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...

  6. 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.

  7. 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

  8. Optical absorption in recycled waste plastic polyethylene

    Science.gov (United States)

    Aji, M. P.; Rahmawati, I.; Priyanto, A.; Karunawan, J.; Wati, A. L.; Aryani, N. P.; Susanto; Wibowo, E.; Sulhadi

    2018-03-01

    We investigated the optical properties of UV spectrum absorption in recycled waste plastic from polyethylene polymer type. Waste plastic polyethylene showed an optical spectrum absorption after it’s recycling process. Spectrum absorption is determined using spectrophotometer UV-Nir Ocean Optics type USB 4000. Recycling method has been processed using heating treatment around the melting point temperature of the polyethylene polymer that are 200°C, 220°C, 240°C, 260°C, and 280°C. In addition, the recycling process was carried out with time variations as well, which are 1h, 1.5h, 2h, and 2.5h. The result of this experiment shows that recycled waste plastic polyethylene has a spectrum absorption in the ∼ 340-550 nm wavelength range. The absorbance spectrum obtained from UV light which is absorbed in the orbital n → π* and the orbital π → π*. This process indicates the existence of electron transition phenomena. This mechanism is affected by the temperature and the heating time where the intensity of absorption increases and widens with the increase of temperature and heating time. Furthermore this study resulted that the higher temperature affected the enhancement of the band gap energy of waste plastic polyethylene. These results show that recycled waste plastic polyethylene has a huge potential to be absorber materials for solar cell.

  9. Plastic waste in the marine environment: A review of sources, occurrence and effects.

    Science.gov (United States)

    Li, W C; Tse, H F; Fok, L

    2016-10-01

    This review article summarises the sources, occurrence, fate and effects of plastic waste in the marine environment. Due to its resistance to degradation, most plastic debris will persist in the environment for centuries and may be transported far from its source, including great distances out to sea. Land- and ocean-based sources are the major sources of plastic entering the environment, with domestic, industrial and fishing activities being the most important contributors. Ocean gyres are particular hotspots of plastic waste accumulation. Both macroplastics and microplastics pose a risk to organisms in the natural environment, for example, through ingestion or entanglement in the plastic. Many studies have investigated the potential uptake of hydrophobic contaminants, which can then bioaccumulate in the food chain, from plastic waste by organisms. To address the issue of plastic pollution in the marine environment, governments should first play an active role in addressing the issue of plastic waste by introducing legislation to control the sources of plastic debris and the use of plastic additives. In addition, plastics industries should take responsibility for the end-of-life of their products by introducing plastic recycling or upgrading programmes. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The effect of wind mixing on the vertical distribution of buoyant plastic debris

    Science.gov (United States)

    Kukulka, T.; Proskurowski, G.; Morét-Ferguson, S.; Meyer, D. W.; Law, K. L.

    2012-04-01

    Micro-plastic marine debris is widely distributed in vast regions of the subtropical gyres and has emerged as a major open ocean pollutant. The fate and transport of plastic marine debris is governed by poorly understood geophysical processes, such as ocean mixing within the surface boundary layer. Based on profile observations and a one-dimensional column model, we demonstrate that plastic debris is vertically distributed within the upper water column due to wind-driven mixing. These results suggest that total oceanic plastics concentrations are significantly underestimated by traditional surface measurements, requiring a reinterpretation of existing plastic marine debris data sets. A geophysical approach must be taken in order to properly quantify and manage this form of marine pollution.

  11. 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.

  12. 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.

  13. 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...

  14. Thermodynamic theory of dislocation-enabled plasticity

    International Nuclear Information System (INIS)

    Langer, J. S.

    2017-01-01

    The thermodynamic theory of dislocation-enabled plasticity is based on two unconventional hypotheses. The first of these is that a system of dislocations, driven by external forces and irreversibly exchanging heat with its environment, must be characterized by a thermodynamically defined effective temperature that is not the same as the ordinary temperature. The second hypothesis is that the overwhelmingly dominant mechanism controlling plastic deformation is thermally activated depinning of entangled pairs of dislocations. This paper consists of a systematic reformulation of this theory followed by examples of its use in analyses of experimentally observed phenomena including strain hardening, grain-size (Hall-Petch) effects, yielding transitions, and adiabatic shear banding.

  15. Proceedings of oceans '91

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This volume contains the proceedings of the Oceans '91 Conference. Topics addressed include: ocean energy conversion, marine communications and navigation, ocean wave energy conversion, environmental modeling, global climate change, ocean minerals technology, oil spill technology, and submersible vehicles

  16. 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...

  17. 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.

  18. 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.

  19. Ocean acidification

    International Nuclear Information System (INIS)

    Soubelet, Helene; Veyre, Philippe; Monnoyer-Smith, Laurence

    2017-09-01

    This brief publication first recalls and outlines that ocean acidification is expected to increase, and will result in severe ecological impacts (more fragile coral reefs, migration of species, and so on), and therefore social and economic impacts. This issue is particularly important for France who possesses the second exclusive maritime area in the world. The various impacts of ocean acidification on living species is described, notably for phytoplankton, coral reefs, algae, molluscs, and fishes. Social and economic impacts are also briefly presented: tourism, protection against risks (notably by coral reefs), shellfish aquaculture and fishing. Issues to be addressed by scientific research are evoked: interaction between elements of an ecosystem and between different ecosystems, multi-stress effects all along organism lifetime, vulnerability and adaptability of human societies

  20. The Ecological Impacts of Marine Plastic Debris in the South Pacific Region

    OpenAIRE

    Chowra, Isabella

    2013-01-01

    The population in the Pacific Islands region is vastly dependant on their oceanic resources, for food, protection and economic income. Today the Pacific Ocean faces many threats that could risk the living hood of its population. This study aims to map the extent of plastic pollution in the South Pacific and possible measurements against it. The study will also be focused on plastic shopping bags and try to assess the most environmentally friendly option. This will be achieved by literature re...

  1. Anisotropic plastic deformation by viscous flow in ion tracks

    NARCIS (Netherlands)

    van Dillen, T; Polman, A; Onck, PR; van der Giessen, E

    2005-01-01

    A model describing the origin of ion beam-induced anisotropic plastic deformation is derived and discussed. It is based on a viscoelastic thermal spike model for viscous flow in single ion tracks derived by Trinkaus and Ryazanov. Deviatoric (shear) stresses, brought about by the rapid thermal

  2. Determining the amount of waste plastics in the feed of Austrian waste-to-energy facilities

    OpenAIRE

    Schwarzb?ck, Therese; Van Eygen, Emile; Rechberger, Helmut; Fellner, Johann

    2016-01-01

    Although thermal recovery of waste plastics is widely practiced in many European countries, reliable information on the amount of waste plastics in the feed of waste-to-energy plants is rare. In most cases the amount of plastics present in commingled waste, such as municipal solid waste, commercial, or industrial waste, is estimated based on a few waste sorting campaigns, which are of limited significance with regard to the characterisation of plastic flows. In the present study, an alternati...

  3. 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 .

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

    OpenAIRE

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

    2017-01-01

    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 alo...

  5. Concept for a hyperspectral remote sensing algorithm for floating marine macro plastics

    NARCIS (Netherlands)

    Goddijn-Murphy, Lonneke; Peters, Steef; van Sebille, Erik; James, Neil A.; Gibb, Stuart

    2018-01-01

    There is growing global concern over the chemical, biological and ecological impact of plastics in the ocean. Remote sensing has the potential to provide long-term, global monitoring but for marine plastics it is still in its early stages. Some progress has been made in hyperspectral remote sensing

  6. U.S. Navy Shipboard-Generated Plastic Waste Pilot Recycling Program

    Science.gov (United States)

    1991-03-01

    ship’s stores or vending machines often makes it way into "plastics only" containers located in work and berthing spaces. During the Escambia MRFsort...from Ships, or MARPOL). This legislation, which bans the disposal of plastics into the ocean, resulted from international and national pressures to halt...plastic by weight from a mixed, municipal waste stream produces a good product using the Er-1 extrusion technology. The Er-1 machine is a batch

  7. Threat of plastic pollution to seabirds is global, pervasive, and increasing

    OpenAIRE

    Wilcox, C; Van Sebille, E; Hardesty, BD

    2015-01-01

    Plastic pollution in the ocean is a rapidly emerging global environmental concern, with high concentrations (up to 580,000 pieces per km2) and a global distribution, driven by exponentially increasing production. Seabirds are particularly vulnerable to this type of pollution and are widely observed to ingest floating plastic. We used a mixture of literature surveys, oceanographic modeling, and ecological models to predict the risk of plastic ingestion to 186 seabird species globally. Impacts ...

  8. Marine plastic pollution in waters around Australia: characteristics, concentrations, and pathways

    OpenAIRE

    Reisser, Julia Wiener; Shaw, Jeremy; Wilcox, Chris; Hardesty, Britta Denise; Proietti, Maíra Carneiro; Thums, Michele; Pattiaratchi, Charitha

    2013-01-01

    Plastics represent the vast majority of human-made debris present in the oceans. However, their characteristics, accumulation zones, and transport pathways remain poorly assessed. We characterised and estimated the concentration of marine plastics in waters around Australia using surface net tows, and inferred their potential pathways using particle-tracking models and real drifter trajectories. The 839 marine plastics recorded were predominantly small fragments ("microplastics", median lengt...

  9. A global inventory of small floating plastic debris

    NARCIS (Netherlands)

    Sebille, van Erik; Wilcox, Chris; Lebreton, Laurent; Maximenko, Nikolai; Hardesty, Britta Denise; Franeker, van J.A.; Eriksen, Marcus; Siegel, David; Galgani, F.; Law, Kara Lavender

    2015-01-01

    Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on

  10. A global inventory of small floating plastic debris

    NARCIS (Netherlands)

    Van Sebille, Erik; Wilcox, Chris; Lebreton, Laurent; Maximenko, Nikolai; Hardesty, Britta Denise; Van Franeker, Jan A.; Eriksen, Marcus; Siegel, David; Galgani, Francois; Law, Kara Lavender

    2015-01-01

    Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on the North

  11. Do plastic particles affect microalgal photosynthesis and growth?

    NARCIS (Netherlands)

    Sjollema, S.B.; Redondo-Hasselerharm, P.; Leslie, H.A.; Kraak, M.H.S.; Vethaak, A.D.

    2016-01-01

    The unbridled increase in plastic pollution of the world’s oceans raises concerns about potential effects these materials may have on microalgae, which are primary producers at the basis of the food chain and a major global source of oxygen. Our current understanding about the potential modes and

  12. Do plastic particles affect microalgal photosynthesis and growth?

    NARCIS (Netherlands)

    Sjollema, S.B.; Redondo-Hasselerharm, P.; Leslie, H.A.; Kraak, M.H.S.; Vethaak, A.D.

    2016-01-01

    The unbridled increase in plastic pollution of the world's oceans raises concerns about potential effects these materials may have on microalgae, which are primary producers at the basis of the food chain and a major global source of oxygen. Our current understanding about the potential modes and

  13. 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

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

    NARCIS (Netherlands)

    O'Connor, I.A.; Golsteijn, L.; Hendriks, A.J.

    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

  15. Plastic debris ingestion by marine catfish: an unexpected fisheries impact.

    Science.gov (United States)

    Possatto, Fernanda E; Barletta, Mário; Costa, Monica F; do Sul, Juliana A Ivar; Dantas, David V

    2011-05-01

    Plastic marine debris is a pervasive type of pollution. River basins and estuaries are a source of plastics pollution for coastal waters and oceans. Estuarine fauna is therefore exposed to chronic plastic pollution. Three important catfish species [Cathorops spixii (N=60), Cathorops agassizii (N=60) and Sciades herzbergii (N=62)] from South Western Atlantic estuaries were investigated in a tropical estuary of the Brazilian Northeast in relation to their accidental ingestion of plastic marine debris. Individuals from all three species had ingested plastics. In C. spixii and C. agassizii, 18% and 33% of individuals had plastic debris in their stomachs, respectively. S. herzbergii showed 18% of individuals were contaminated. All ontogenetic phases (juveniles, sub-adults and adults) were contaminated. Nylon fragments from cables used in fishery activities (subsistence, artisanal and commercial) played a major role in this contamination. These catfish spend their entire life cycles within the estuary and are an important feeding resource for larger, economically important, species. It is not yet possible to quantify the scale and depth of the consequences of this type of pollution. However, plastics are well known threat to living resources in this and other estuaries. Conservation actions will need to from now onto take plastics pollution into consideration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. 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.

  17. Method for compression molding of thermosetting plastics utilizing a temperature gradient across the plastic to cure the article

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    A method is described for compression molding of thermosetting plastics composition. Heat is applied to the compressed load in a mold cavity and adjusted to hold molding temperature at the interface of the cavity surface and the compressed compound to produce a thermal front. This thermal front advances into the evacuated compound at mean right angles to the compression load and toward a thermal fence formed at the opposite surface of the compressed compound.

  18. POSSIBLE METHODS FOR PREVENTING PLASTIC WASTE FROM ENTERING THE MARINE ENVIRONMENT

    OpenAIRE

    David, Minodora-Florentina; Burdukovska, Valentina; Heng, Chen

    2013-01-01

    The widespread use of plastic has become a huge threat for the marine environment. With problems such as the oceanic garbage patches increasing more and more in scale, the focus is set on how could plastic waste be prevented from entering the oceans and adversely affecting the wildlife. Since the largest accumulation of plastic waste is found in the North Pacific Gyre, we have looked at the surrounding countries with the highest waste generation. By using the pyramid of waste as a starting po...

  19. Organophosphorus esters in the oceans and possible relation with ocean gyres

    International Nuclear Information System (INIS)

    Cheng, Wenhan; Xie, Zhouqing; Blais, Jules M.; Zhang, Pengfei; Li, Ming; Yang, Chengyun; Huang, Wen; Ding, Rui; Sun, Liguang

    2013-01-01

    Four organophosphorus esters (OPEs) were detected in aerosol samples collected in the West Pacific, the Indian Ocean and the Southern Ocean from 2009 to 2010, suggesting their circumpolar and global distribution. In general, the highest concentrations were detected near populated regions in China, Australia and New Zealand. OPE concentrations in the Southern Ocean were about two orders of magnitude lower than those near major continents. Additionally, relatively high OPE concentrations were detected at the Antarctic Peninsula, where several scientific survey stations are located. The four OPEs investigated here are significantly correlated with each other, suggesting they may derive from the same source. In the circumpolar transect, OPE concentrations were associated with ocean gyres in the open ocean. Their concentrations were positively related with average vorticity in the sampling area suggesting that a major source of OPEs may be found in ocean gyres where plastic debris is known to accumulate. -- Highlights: •We provide OPE concentrations in aerosols in a circumpolar expedition. •We find strong anthropogenic source of OPE pollution. •We suggest potential relationship between ocean gyres and OPE pollution. -- Our work provides a circumpolar investigation on OPEs in the Southern Ocean and we suggest a possibility that ocean currents and gyres may act as important roles in global transport of OPEs

  20. Liquid fuel obtain from polypropylene (PP-5) and high density polyethylene (HDPE-2) waste plastics mixture

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin; Rashid, Mohammad Mamunor; Rahman, Md. Sadikur; Molla, Mohammed [Department of Research and Development, Natural State Research Inc, Stamford, (United States)

    2011-07-01

    Plastics are made by combination of small based molecules to form monomers. The monomers are then joined together by chemical polymerization mechanism to form polymers also known as plastics. These plastics contain various elements such as carbon, hydrogen, oxygen, nitrogen, chlorine and sul fur. The use of plastics is vastly expanded and it is being used in every sector of the world. However, using plastics does have a negative aspect, after use they end up in our landfill as waste causing numerous health and environmental problems. Landfill waste plastics release harmful gases due to the presence of carbon, chlorine and sul fur in them into the atmosphere causing climates to change drastically, equivalent to the effects of greenhouse gases (GHG) emission. To overcome these environmental issues, scientists have already developed many methods to converting these waste plastics into energy and fuel . We developed one new methods thermal cracking conversion to convert these waste plastics into usable liquid fuel . Thermal cracking conversion is a process to shorten the long chain hydrocarbons to produce liquid fuel in the absence of a catalyst. The thermal degradation process of the waste plastics long chain hydrocarbon to makes short chain hydrocarbon fuel. The fuel produced has been analyzed and tested according to standard methods. Key words: fuel , hydrocarbon, waste plastic, thermal degradation, conversion, GC/MS.

  1. Liquid fuel obtain from polypropylene (PP-5) and high density polyethylene (HDPE-2) waste plastics mixture

    International Nuclear Information System (INIS)

    Sarker, Moinuddin; Rashid, Mohammad Mamunor; Rahman, Md. Sadikur; Molla, Mohammed

    2011-01-01

    Plastics are made by combination of small based molecules to form monomers. The monomers are then joined together by chemical polymerization mechanism to form polymers also known as plastics. These plastics contain various elements such as carbon, hydrogen, oxygen, nitrogen, chlorine and sul fur. The use of plastics is vastly expanded and it is being used in every sector of the world. However, using plastics does have a negative aspect, after use they end up in our landfill as waste causing numerous health and environmental problems. Landfill waste plastics release harmful gases due to the presence of carbon, chlorine and sul fur in them into the atmosphere causing climates to change drastically, equivalent to the effects of greenhouse gases (GHG) emission. To overcome these environmental issues, scientists have already developed many methods to converting these waste plastics into energy and fuel . We developed one new methods thermal cracking conversion to convert these waste plastics into usable liquid fuel . Thermal cracking conversion is a process to shorten the long chain hydrocarbons to produce liquid fuel in the absence of a catalyst. The thermal degradation process of the waste plastics long chain hydrocarbon to makes short chain hydrocarbon fuel. The fuel produced has been analyzed and tested according to standard methods. Key words: fuel , hydrocarbon, waste plastic, thermal degradation, conversion, GC/MS

  2. Solar thermal

    International Nuclear Information System (INIS)

    Jones, J.

    2006-01-01

    While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m 3 - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become increasingly important as

  3. Solar thermal

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J.

    2006-07-15

    While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m{sup 3} - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become

  4. Planet Ocean

    Science.gov (United States)

    Afonso, Isabel

    2014-05-01

    A more adequate name for Planet Earth could be Planet Ocean, seeing that ocean water covers more than seventy percent of the planet's surface and plays a fundamental role in the survival of almost all living species. Actually, oceans are aqueous solutions of extraordinary importance due to its direct implications in the current living conditions of our planet and its potential role on the continuity of life as well, as long as we know how to respect the limits of its immense but finite capacities. We may therefore state that natural aqueous solutions are excellent contexts for the approach and further understanding of many important chemical concepts, whether they be of chemical equilibrium, acid-base reactions, solubility and oxidation-reduction reactions. The topic of the 2014 edition of GIFT ('Our Changing Planet') will explore some of the recent complex changes of our environment, subjects that have been lately included in Chemistry teaching programs. This is particularly relevant on high school programs, with themes such as 'Earth Atmosphere: radiation, matter and structure', 'From Atmosphere to the Ocean: solutions on Earth and to Earth', 'Spring Waters and Public Water Supply: Water acidity and alkalinity'. These are the subjects that I want to develop on my school project with my pupils. Geographically, our school is located near the sea in a region where a stream flows into the sea. Besides that, our school water comes from a borehole which shows that the quality of the water we use is of significant importance. This project will establish and implement several procedures that, supported by physical and chemical analysis, will monitor the quality of water - not only the water used in our school, but also the surrounding waters (stream and beach water). The samples will be collected in the borehole of the school, in the stream near the school and in the beach of Carcavelos. Several physical-chemical characteristics related to the quality of the water will

  5. 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.

  6. 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.

  7. 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.)

  8. 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?

  9. 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.

  10. A Plastic Menagerie

    Science.gov (United States)

    Hadley, Mary Jane

    2010-01-01

    Bobble heads had become quite popular, depicting all sorts of sports figures, animals, and even presidents. In this article, the author describes how her fourth graders made bobble head sculptures out of empty plastic drink bottles. (Contains 1 online resource.)

  11. 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.

  12. Microbial biotechnology addressing the plastic waste disaster.

    Science.gov (United States)

    Narancic, Tanja; O'Connor, Kevin E

    2017-09-01

    Oceans are a major source of biodiversity, they provide livelihood, and regulate the global ecosystem by absorbing heat and CO 2 . However, they are highly polluted with plastic waste. We are discussing here microbial biotechnology advances with the view to improve the start and the end of life of biodegradable polymers, which could contribute to the sustainable use of marine and coastal ecosystems (UN Sustainability development goal 14). © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  13. 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.

  14. 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)

  15. The pollution of the marine environment by plastic debris: a review.

    Science.gov (United States)

    Derraik, José G B

    2002-09-01

    The deleterious effects of plastic debris on the marine environment were reviewed by bringing together most of the literature published so far on the topic. A large number of marine species is known to be harmed and/or killed by plastic debris, which could jeopardize their survival, especially since many are already endangered by other forms of anthropogenic activities. Marine animals are mostly affected through entanglement in and ingestion of plastic litter. Other less known threats include the use of plastic debris by "invader" species and the absorption of polychlorinated biphenyls from ingested plastics. Less conspicuous forms, such as plastic pellets and "scrubbers" are also hazardous. To address the problem of plastic debris in the oceans is a difficult task, and a variety of approaches are urgently required. Some of the ways to mitigate the problem are discussed.

  16. Temperature-dependent growth and photophysiology of prokaryotic and eukaryotic oceanic picophytoplankton

    NARCIS (Netherlands)

    Kulk, G.; de Vries, P.; van de Poll, W.H.; Visser, R.J.W.; Buma, A.G.J.

    2012-01-01

    It is expected that climate change will expand the open oligotrophic oceans by enhanced thermal stratification. Because temperature defines the geographic distribution of picophytoplankton in open-ocean ecosystems and regulates photophysiological responses, it is important to understand how

  17. Ocean Uses: Hawaii (PROUA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Pacific Regional Ocean Uses Atlas (PROUA) Project is an innovative partnership between NOAA and the Bureau of Ocean Energy Management (BOEM) designed to...

  18. Solar Thermal Power.

    Science.gov (United States)

    McDaniels, David K.

    The different approaches to the generation of power from solar energy may be roughly divided into five categories: distributed collectors; central receivers; biomass; ocean thermal energy conversion; and photovoltaic devices. The first approach (distributed collectors) is the subject of this module. The material presented is designed to…

  19. 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.

  20. 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

  1. Occurrence and effects of plastic additives on marine environments and organisms: A review.

    Science.gov (United States)

    Hermabessiere, Ludovic; Dehaut, Alexandre; Paul-Pont, Ika; Lacroix, Camille; Jezequel, Ronan; Soudant, Philippe; Duflos, Guillaume

    2017-09-01

    Plastics debris, especially microplastics, have been found worldwide in all marine compartments. Much research has been carried out on adsorbed pollutants on plastic pieces and hydrophobic organic compounds (HOC) associated with microplastics. However, only a few studies have focused on plastic additives. These chemicals are incorporated into plastics from which they can leach out as most of them are not chemically bound. As a consequence of plastic accumulation and fragmentation in oceans, plastic additives could represent an increasing ecotoxicological risk for marine organisms. The present work reviewed the main class of plastic additives identified in the literature, their occurrence in the marine environment, as well as their effects on and transfers to marine organisms. This work identified polybrominated diphenyl ethers (PBDE), phthalates, nonylphenols (NP), bisphenol A (BPA) and antioxidants as the most common plastic additives found in marine environments. Moreover, transfer of these plastic additives to marine organisms has been demonstrated both in laboratory and field studies. Upcoming research focusing on the toxicity of microplastics should include these plastic additives as potential hazards for marine organisms, and a greater focus on the transport and fate of plastic additives is now required considering that these chemicals may easily leach out from plastics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Plastic ingestion by sea turtles in Paraíba State, Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Camila Poli

    2015-09-01

    Full Text Available ABSTRACT Currently, plastics are recognized as a major pollutant of the marine environment, representing a serious threat to ocean wildlife. Here, we examined the occurrence and effects of plastic ingestion by sea turtles found stranded along the coast of Paraíba State, Brazil from August 2009 to July 2010. Ninety-eight digestive tracts were examined, with plastic found in 20 (20.4%. Sixty five percent (n = 13 of turtles with plastic in the digestive tract were green turtles (Chelonia mydas, 25% (n = 5 were hawksbills (Eretmochelys imbricata, and 10% (n = 2 were olive ridley (Lepidochelys olivacea. More plastic was found in the intestine (85% than in other parts of the gastrointestinal tract. We observed complete blockage of the gastrointestinal tract due to the presence of plastic in 13 of the 20 turtles that had ingested plastic. No correlation was found between the curved carapace length (CCL and the number or mass of the plastic ingested items. Significant differences were found between the intake of hard and soft plastic and the ingestion of white/transparent and colored plastic, with soft and white/transparent plastics being more commonly ingested. This study reveals the serious problem of plastic pollution to sea turtles at the area.

  3. River Export of Plastic from Land to Sea: A Global Modeling Approach

    Science.gov (United States)

    Siegfried, Max; Gabbert, Silke; Koelmans, Albert A.; Kroeze, Carolien; Löhr, Ansje; Verburg, Charlotte

    2016-04-01

    Plastic is increasingly considered a serious cause of water pollution. It is a threat to aquatic ecosystems, including rivers, coastal waters and oceans. Rivers transport considerable amounts of plastic from land to sea. The quantity and its main sources, however, are not well known. Assessing the amount of macro- and microplastic transport from river to sea is, therefore, important for understanding the dimension and the patterns of plastic pollution of aquatic ecosystems. In addition, it is crucial for assessing short- and long-term impacts caused by plastic pollution. Here we present a global modelling approach to quantify river export of plastic from land to sea. Our approach accounts for different types of plastic, including both macro- and micro-plastics. Moreover, we distinguish point sources and diffuse sources of plastic in rivers. Our modelling approach is inspired by global nutrient models, which include more than 6000 river basins. In this paper, we will present our modelling approach, as well as first model results for micro-plastic pollution in European rivers. Important sources of micro-plastics include personal care products, laundry, household dust and car tyre wear. We combine information on these sources with information on sewage management, and plastic retention during river transport for the largest European rivers. Our modelling approach may help to better understand and prevent water pollution by plastic , and at the same time serves as 'proof of concept' for future application on global scale.

  4. Plastic ingestion by sea turtles in Paraíba State, Northeast Brazil

    OpenAIRE

    Camila Poli; Daniel Oliveira Mesquita; Cinthia Saska; Rita Mascarenhas

    2015-01-01

    ABSTRACT Currently, plastics are recognized as a major pollutant of the marine environment, representing a serious threat to ocean wildlife. Here, we examined the occurrence and effects of plastic ingestion by sea turtles found stranded along the coast of Paraíba State, Brazil from August 2009 to July 2010. Ninety-eight digestive tracts were examined, with plastic found in 20 (20.4%). Sixty five percent (n = 13) of turtles with plastic in the digestive tract were green turtles (Chelonia mydas...

  5. Incidence of plastic fragments among burrow-nesting seabird colonies on offshore islands in northern New Zealand.

    Science.gov (United States)

    Buxton, Rachel T; Currey, Caitlin A; Lyver, Philip O'B; Jones, Christopher J

    2013-09-15

    Marine plastic pollution is ubiquitous throughout the world's oceans, and has been found in high concentrations in oceanic gyres of both the northern and southern hemispheres. The number of studies demonstrating plastic debris at seabird colonies and plastic ingestion by adult seabirds has increased over the past few decades. Despite the recent discovery of a large aggregation of plastic debris in the South Pacific subtropical gyre, the incidence of plastics at seabird colonies in New Zealand is unknown. Between 2011 and 2012 we surveyed six offshore islands on the northeast coast of New Zealand's North Island for burrow-nesting seabird colonies and the presence of plastic fragments. We found non-research related plastic fragments (0.031 pieces/m(2)) on one island only, Ohinau, within dense flesh-footed shearwater (Puffinus carneipes) colonies. On Ohinau, we found a linear relationship between burrow density and plastic density, with 3.5 times more breeding burrows in areas with plastic fragments found. From these data we conclude that plastic ingestion is a potentially a serious issue for flesh-footed shearwaters in New Zealand. Although these results do not rule out plastic ingestion by other species, they suggest the need for further research on the relationship between New Zealand's pelagic seabirds and marine plastic pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. All is not lost: deriving a top-down mass budget of plastic at sea

    Science.gov (United States)

    Koelmans, Albert A.; Kooi, Merel; Lavender Law, Kara; van Sebille, Erik

    2017-11-01

    Understanding the global mass inventory is one of the main challenges in present research on plastic marine debris. Especially the fragmentation and vertical transport processes of oceanic plastic are poorly understood. However, whereas fragmentation rates are unknown, information on plastic emissions, concentrations of plastics in the ocean surface layer (OSL) and fragmentation mechanisms is available. Here, we apply a systems engineering analytical approach and propose a tentative ‘whole ocean’ mass balance model that combines emission data, surface area-normalized plastic fragmentation rates, estimated concentrations in the OSL, and removal from the OSL by sinking. We simulate known plastic abundances in the OSL and calculate an average whole ocean apparent surface area-normalized plastic fragmentation rate constant, given representative radii for macroplastic and microplastic. Simulations show that 99.8% of the plastic that had entered the ocean since 1950 had settled below the OSL by 2016, with an additional 9.4 million tons settling per year. In 2016, the model predicts that of the 0.309 million tons in the OSL, an estimated 83.7% was macroplastic, 13.8% microplastic, and 2.5% was < 0.335 mm ‘nanoplastic’. A zero future emission simulation shows that almost all plastic in the OSL would be removed within three years, implying a fast response time of surface plastic abundance to changes in inputs. The model complements current spatially explicit models, points to future experiments that would inform critical model parameters, and allows for further validation when more experimental and field data become available.

  7. 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.

  8. 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.

  9. Finite element analysis of large elasto-plastic deformation for sealing ring in nuclear pressure vessel

    International Nuclear Information System (INIS)

    Xiao Xuejian; Chen Ruxin

    1995-02-01

    Based on the R. Hills incremental virtual power principle and the elasto-plastic constitution equation for large deformation and by considering physical nonlinear, geometric nonlinear and thermal effects, a plane and axisymmetric finite element equation for thermal large elasto-plastic deformation has been established in the Euler description. The corresponding analysis program ATLEPD has been also complied for thermal large elasto-plastic deformation process of O-ring in RPV. The variations of stress, strain, contact specific pressure, mesh deformation and the aspects of spring back in upsetting and spring back process have been also investigated. Numerical results are fairly consistent with experimental ones. (5 figs., 4 tabs.)

  10. Plastics in the marine environment: the dark side of a modern gift.

    Science.gov (United States)

    Hammer, Jort; Kraak, Michiel H S; Parsons, John R

    2012-01-01

    Plastics are cheap, strong, and durable and offer considerable benefits to humanity. They potentially can enhance the benefits that both medical and scientific technology will bestow to humankind. However, it has now been several decades since the use of plastics exploded, and we have evidence that our current approach to production, use, transport and disposal of plastic materials has caused, and is still causing serious effects on wildlife, and is not sustainable. Because of frequent inappropriate waste management practices, or irresponsible human behavior, large masses of plastic items have been released into the environment, and thereby have entered the world's oceans. Moreover, this process continues, and in some places is even increasing. Most plastic debris that now exists in the marine environment originated from ocean-based sources such as the fishing industry. Plastics accumulate in coastal areas, at the ocean surface and on the seabed. Because 70% of all plastics are known to eventually sink, it is suspected that ever increasing amounts of plastic items are accumulating in seabed sediments. Plastics do not biodegrade, although, under the influence of solar UV radiations, plastics do degrade and fragment into small particles, termed microplastics. Our oceans eventually serve as a sink for these small plastic particles and in one estimate, it is thought that 200,000 microplastics per km(2) of the ocean's surface commonly exist. The impact of plastic debris has been studied since the beginning of the 1960's. To date, more than 267 species in the marine environment are known to have been affected by plastic entanglement or ingestion. Marine mammals are among those species that are most affected by entanglement in plastic debris. By contrast, marine birds suffer the most from ingestion of plastics. Organisms can also be seriously absorbed by floating plastic debris, or the contaminants may derive from plastic additives that are leached to the environment

  11. Transgenerational acclimation of fishes to climate change and ocean acidification

    OpenAIRE

    Munday, Philip L.

    2014-01-01

    There is growing concern about the impacts of climate change and ocean acidification on marine organisms and ecosystems, yet the potential for acclimation and adaptation to these threats is poorly understood. Whereas many short-term experiments report negative biological effects of ocean warming and acidification, new studies show that some marine species have the capacity to acclimate to warmer and more acidic environments across generations. Consequently, transgenerational plasticity may be...

  12. Current meter data from moored current meter casts in the Caribbean Sea as part of the Ocean Thermal Energy Conversion (OTEC) project from 1979-09-27 to 1979-12-01 (NODC Accession 8100607)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Caribbean Sea from September 27, 1979 to December 1, 1979. Data were submitted by...

  13. Current meter data from moored current meter casts in the Caribbean Sea as part of the Ocean Thermal Energy Conversion (OTEC) project from 1979-02-15 to 1980-02-01 (NODC Accession 8100608)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Caribbean Sea from February 15, 1979 to February 1, 1980. Data were submitted by University...

  14. Current meter and other data from FIXED PLATFORMS from the Gulf of Mexico and other locations as part of the Ocean Thermal Energy Conversion (OTEC) and other projects from 24 October 1964 to 01 November 1977 (NODC Accession 7800586)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected from FIXED PLATFORMS from the Gulf of Mexico and Straits of Florida. Data were submitted by the Atlantic Oceanographic and...

  15. Current meter data from moored current meter casts in the Gulf of Mexico as part of the Ocean Thermal Energy Conversion (OTEC) project from 18 October 1977-10-18 to 1979-07-01 (NODC Accession 8000284)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Gulf of Mexico from October 18, 1977 to June 1, 1979. Data were submitted by Atlantic...

  16. REGRESSION ANALYSIS OF SEA-SURFACE-TEMPERATURE PATTERNS FOR THE NORTH PACIFIC OCEAN.

    Science.gov (United States)

    SEA WATER, *SURFACE TEMPERATURE, *OCEANOGRAPHIC DATA, PACIFIC OCEAN, REGRESSION ANALYSIS , STATISTICAL ANALYSIS, UNDERWATER EQUIPMENT, DETECTION, UNDERWATER COMMUNICATIONS, DISTRIBUTION, THERMAL PROPERTIES, COMPUTERS.

  17. Investigation into Plastic Cards

    Directory of Open Access Journals (Sweden)

    Neringa Stašelytė

    2015-03-01

    Full Text Available The article examines the strength of laminating plastic cards at different lamination temperatures. For investigation purposes, two types of plastic substrate and films have been used. Laminate strength has been tested (CMYK to establish the impact of colours on the strength of laminate. The paper compares inks supplied by two different producers. The colour characteristics of CIE L*a*b* space before and after the lamination process have been found. According to lamination strength and characteristics of the colours, the most suitable inks, temperature and films have been chosen.

  18. 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...

  19. Elastic plastic fracture mechanics

    International Nuclear Information System (INIS)

    Simpson, L.A.

    1978-07-01

    The application of linear elastic fracture mechanics (LEFM) to crack stability in brittle structures is now well understood and widely applied. However, in many structural materials, crack propagation is accompanied by considerable crack-tip plasticity which invalidates the use of LEFM. Thus, present day research in fracture mechanics is aimed at developing parameters for predicting crack propagation under elastic-plastic conditions. These include critical crack-opening-displacement methods, the J integral and R-curve techniques. This report provides an introduction to these concepts and gives some examples of their applications. (author)

  20. Cladding failure by local plastic instability

    International Nuclear Information System (INIS)

    Kramer, J.M.; Deitrich, L.W.

    1977-01-01

    Cladding failure is one of the major considerations in analysis of fast-reactor fuel pin behavior during hypothetical accident transients since time, location and nature of failure govern the early post-failure material motion and reactivity feedback. Out-of-Pile transient burst tests of both irradiated and unirradiated fast-reactor cladding show that local plastic instability, or bulging, often precedes rupture. To investigate the details of cladding bulging, a perturbation analysis of the equations governing the large deformation of a cylindrical shell has been developed. The overall deformation history is assumed to consist of a small perturbation epsilon of the radial displacement superimposed on large axisymmetric displacements. Computations have been carried out using high temperature properties of stainless steel in conjunction with various constitutive theories, including a generalization of the Endochronic Theory of Plasticity in which both time-independent and time-dependent plastic strains are modeled. Although the results of the calculations are all qualitatively similar, it appears that modeling of both time-independent and time-dependent plastic strains is necessary to interpret the transient burst test results. Sources for bulge formation that have been considered include initial geometric imperfections and thermal perturbations due to either eccentric fuel pellets or non-symmetric cooling. (Auth.)

  1. Ocean Prediction Center

    Science.gov (United States)

    Social Media Facebook Twitter YouTube Search Search For Go NWS All NOAA Weather Analysis & Forecasts of Commerce Ocean Prediction Center National Oceanic and Atmospheric Administration Analysis & Unified Surface Analysis Ocean Ocean Products Ice & Icebergs NIC Ice Products NAIS Iceberg Analysis

  2. Ocean climate and seal condition

    Directory of Open Access Journals (Sweden)

    Crocker Daniel E

    2005-03-01

    Full Text Available Abstract Background The condition of many marine mammals varies with fluctuations in productivity and food supply in the ocean basin where they forage. Prey is impacted by physical environmental variables such as cyclic warming trends. The weaning weight of northern elephant seal pups, Mirounga angustirostris, being closely linked to maternal condition, indirectly reflects prey availability and foraging success of pregnant females in deep waters of the northeastern Pacific. The aim of this study was to examine the effect of ocean climate on foraging success in this deep-diving marine mammal over the course of three decades, using cohort weaning weight as the principal metric of successful resource accrual. Results The mean annual weaning weight of pups declined from 1975 to the late 1990s, a period characterized by a large-scale, basin-wide warm decadal regime that included multiple strong or long-duration El Niños; and increased with a return to a cool decadal regime from about 1999 to 2004. Increased foraging effort and decreased mass gain of adult females, indicative of reduced foraging success and nutritional stress, were associated with high ocean temperatures. Conclusion Despite ranging widely and foraging deeply in cold waters beyond coastal thermoclines in the northeastern Pacific, elephant seals are impacted significantly by ocean thermal dynamics. Ocean warming redistributes prey decreasing foraging success of females, which in turn leads to lower weaning mass of pups. Annual fluctuations in weaning mass, in turn, reflect the foraging success of females during the year prior to giving birth and signals changes in ocean temperature cycles.

  3. Modelling global distribution, risk and mitigation strategies of floating plastic pollution

    Science.gov (United States)

    van Sebille, Erik; Wilcox, Chris; Sherman, Peter; Hardesty, Britta Denise; Lavender Law, Kara

    2016-04-01

    Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on the North Pacific and North Atlantic accumulation zones, with much sparser coverage elsewhere. Here, we use the largest dataset of microplastic measurements assembled to date to assess the confidence we can have in global estimates of microplastic abundance and mass. We use a rigorous statistical framework to standardise a global dataset of plastic marine debris measured using surface-trawling plankton nets and couple this with three different ocean circulation models to spatially interpolate the observations. Our estimates show that the accumulated number of microplastic particles in 2014 ranges from 15 to 51 trillion particles, weighing between 93 and 236 thousand metric tons. A large fraction of the uncertainty in these estimates comes from sparse sampling in coastal and Southern Hemisphere regions. We then use this global distribution of small floating plastic debris to map out where in the ocean the risk to marine life (in particular seabirds and plankton growth) is greatest, using a quantitative risk framework. We show that the largest risk occurs not necessarily in regions of high plastic concentration, but rather in regions of extensive foraging with medium-high plastic concentrations such as coastal upwelling regions and the Southern Ocean. Finally, we use the estimates of distribution to investigate where in the ocean plastic can most optimally be removed, assuming hypothetical clean-up booms following the ideas from The Ocean Cleanup project. We show that mitigation of the plastic problem can most aptly be done near coastlines, particularly in Asia, rather than in the centres of the gyres. Based on these results, we propose more focus on the coastal zones when

  4. Characters of chlorine isotopic composition in ocean water

    Digital Repository Service at National Institute of Oceanography (India)

    Xiao, Y.; Zhou, Y.; Liu, W.G.; Hong, A.; Wang, Q.; Wang, Y.; Wei, H.; Shirodkar, P.V.

    The chlorine isotopic composition of ocean water was determined using thermal ionization mass spectrometry based on the measurement of Cs sub(2) Cl sup(+) ion. The results show that the sup(37) Cl/ sup(35) Cl ratios are basically homogeneous...

  5. Plastic flashtube chambers

    International Nuclear Information System (INIS)

    Frisken, W.R.

    1977-01-01

    A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

  6. Plastic Surgery: Tackling Misconceptions

    African Journals Online (AJOL)

    will succeed. First impressions tend to last, and if young people's first impression of plastic surgeons is that they spend much of their time doing cosmetic surgery then this is a first impression that might be long ... Res 2014;4 Suppl S3:169‑70. Access this article online. Quick Response Code: Website: www.amhsr.org. DOI:.

  7. Biobased Plastics 2012

    NARCIS (Netherlands)

    Bolck, C.H.; Ravenstijn, J.; Molenveld, K.; Harmsen, P.F.H.

    2011-01-01

    Dit boek geeft inzicht in de huidige op de markt verkrijgbare biobased plastics en de te verwachten ontwikkelingen. Er wordt gekeken naar zowel thermoplastische als thermohardende materialen. Het boek biedt inzicht in de productie, verwerking en eigenschappen van de verschillende types. Daarnaast

  8. New plastic recycling technology

    Science.gov (United States)

    Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy de...

  9. Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    1989-01-01

    In the paper it is shown how upper and lower bounds for the reliability of plastic slabs can be determined. For the fundamental case it is shown that optimal bounds of a deterministic and a stochastic analysis are obtained on the basis of the same failure mechanisms and the same stress fields....

  10. 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

  11. Strand Plasticity Governs Fatigue in Colloidal Gels

    Science.gov (United States)

    van Doorn, Jan Maarten; Verweij, Joanne E.; Sprakel, Joris; van der Gucht, Jasper

    2018-05-01

    The repeated loading of a solid leads to microstructural damage that ultimately results in catastrophic material failure. While posing a major threat to the stability of virtually all materials, the microscopic origins of fatigue, especially for soft solids, remain elusive. Here we explore fatigue in colloidal gels as prototypical inhomogeneous soft solids by combining experiments and computer simulations. Our results reveal how mechanical loading leads to irreversible strand stretching, which builds slack into the network that softens the solid at small strains and causes strain hardening at larger deformations. We thus find that microscopic plasticity governs fatigue at much larger scales. This gives rise to a new picture of fatigue in soft thermal solids and calls for new theoretical descriptions of soft gel mechanics in which local plasticity is taken into account.

  12. Radiation processing of plastics for decorative purposes

    International Nuclear Information System (INIS)

    Knizhnik, R.I.; Onisko, A.D.

    1982-01-01

    Methods are reviewed for the radiation processing of polymeric films, sheets, plates and panels to form patterns, drawings, images and decorative finishing which have been recently developed in various countries. Methods of beam and radiation processing of transparent plastics are described for making a decorative article with a pattern inside the volume; advantages and shortcomings of the methods are shown. The method of radiation processing of transparent dielectric plastics by electron beam of a Microtron is considered in detail. It provides an economical method of fabrication of large-size highly artistic decorative articles with an original pattern inside the volume. Radiation processing operations are presented which are aimed at creation and visualization of regions of extended thermalized electron space charges stored by irradiation of dielectric. Examples are presented of large-size highly artistic decorative articles of polymethylmethacrylate which were used in interior of buildings and demonstrated at home and international exhibitions. (author)

  13. Circular economy measures to keep plastics and their value in the economy, avoid waste and reduce marine litter

    OpenAIRE

    ten Brink, Patrick; Schweitzer, Jean-Pierre; Watkins, Emma; Janssens, Charlotte; De Smet, Michiel; Leslie, Heather; Galgani, François

    2018-01-01

    We live in the plastic age (the “plasticene”), producing over 300 million tonnes (mt) of plastic every year globally, 5–15 mt of which flow into already polluted oceans. Plastic remains a key material in the global economy, but low rates of collection, reuse and recycling, emissions of microplastic from product wear and tear, and often insufficient disposal measures are leading to far-reaching environmental, health, social and economic impacts. The costs of inaction are unacceptably high. Glo...

  14. Circular economy measures to keep plastics and their value in the economy, avoid waste and reduce marine litter

    OpenAIRE

    Ten Brink, Patrick; Schweitzer, Jean-pierre; Watkins, Emma; De Smet, Michel; Leslie, Heather; Galgani, Francois

    2017-01-01

    We live in the plastic age (the “plasticene”), producing over 300 million tonnes (mt) of plastic every year globally, 5-15 mt of which flow into already polluted oceans. Plastic remains a key material in the global economy, but low rates of collection, reuse and recycling, emissions of microplastic from product wear and tear, and often insufficient disposal measures are leading to far-reaching environmental, health, social and economic impacts. The costs of inaction are unacceptably high. Glo...

  15. Determining the amount of waste plastics in the feed of Austrian waste-to-energy facilities.

    Science.gov (United States)

    Schwarzböck, Therese; Van Eygen, Emile; Rechberger, Helmut; Fellner, Johann

    2017-02-01

    Although thermal recovery of waste plastics is widely practiced in many European countries, reliable information on the amount of waste plastics in the feed of waste-to-energy plants is rare. In most cases the amount of plastics present in commingled waste, such as municipal solid waste, commercial, or industrial waste, is estimated based on a few waste sorting campaigns, which are of limited significance with regard to the characterisation of plastic flows. In the present study, an alternative approach, the so-called Balance Method, is used to determine the total amount of plastics thermally recovered in Austria's waste incineration facilities in 2014. The results indicate that the plastics content in the waste feed may vary considerably among different plants but also over time. Monthly averages determined range between 8 and 26 wt% of waste plastics. The study reveals an average waste plastics content in the feed of Austria's waste-to-energy plants of 16.5 wt%, which is considerably above findings from sorting campaigns conducted in Austria. In total, about 385 kt of waste plastics were thermally recovered in all Austrian waste-to-energy plants in 2014, which equals to 45 kg plastics cap -1 . In addition, the amount of plastics co-combusted in industrial plants yields a total thermal utilisation rate of 70 kg cap -1  a -1 for Austria. This is significantly above published rates, for example, in Germany reported rates for 2013 are in the range of only 40 kg of waste plastics combusted per capita.

  16. Reduction experiment of iron scale by adding waste plastics.

    Science.gov (United States)

    Zhang, Chongmin; Chen, Shuwen; Miao, Xincheng; Yuan, Hao

    2009-01-01

    The special features of waste plastics in China are huge in total amount, various in type and dispersive in deposition. Therefore, it is necessary to try some new ways that are fit to Chinese situation for disposing waste plastics as metallurgical raw materials more effectively and flexibly. Owing to its high ferrous content and less impurity, the iron scale became ideal raw material to produce pure iron powder. One of the methods to produce pure iron powder is Hoganas Method, by which, after one or multistage of reduction steps, the iron scale can be reduced pure iron powder. However, combining utilization of waste plastics and iron powder production, a series of reduction experiments were arranged and investigated, which is hoped to take use of both thermal and chemical energy contained in waste plastics as well as to improve the reducing condition of iron scale, and hence to develop a new metallurgical way of disposing waste plastics. The results show that under these experimental conditions, the thermal-decomposition of water plastics can conduce to an increase of porosity in the reduction systems. Moreover, better thermodynamics and kinetics conditions for the reduction of scale can be reached. As a result, the reduction rate is increased.

  17. Waste-to-energy: Dehalogenation of plastic-containing wastes.

    Science.gov (United States)

    Shen, Yafei; Zhao, Rong; Wang, Junfeng; Chen, Xingming; Ge, Xinlei; Chen, Mindong

    2016-03-01

    The dehalogenation measurements could be carried out with the decomposition of plastic wastes simultaneously or successively. This paper reviewed the progresses in dehalogenation followed by thermochemical conversion of plastic-containing wastes for clean energy production. The pre-treatment method of MCT or HTT can eliminate the halogen in plastic wastes. The additives such as alkali-based metal oxides (e.g., CaO, NaOH), iron powders and minerals (e.g., quartz) can work as reaction mediums and accelerators with the objective of enhancing the mechanochemical reaction. The dehalogenation of waste plastics could be achieved by co-grinding with sustainable additives such as bio-wastes (e.g., rice husk), recyclable minerals (e.g., red mud) via MCT for solid fuels production. Interestingly, the solid fuel properties (e.g., particle size) could be significantly improved by HTT in addition with lignocellulosic biomass. Furthermore, the halogenated compounds in downstream thermal process could be eliminated by using catalysts and adsorbents. Most dehalogenation of plastic wastes primarily focuses on the transformation of organic halogen into inorganic halogen in terms of halogen hydrides or salts. The integrated process of MCT or HTT with the catalytic thermal decomposition is a promising way for clean energy production. The low-cost additives (e.g., red mud) used in the pre-treatment by MCT or HTT lead to a considerable synergistic effects including catalytic effect contributing to the follow-up thermal decomposition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Concept for a hyperspectral remote sensing algorithm for floating marine macro plastics.

    Science.gov (United States)

    Goddijn-Murphy, Lonneke; Peters, Steef; van Sebille, Erik; James, Neil A; Gibb, Stuart

    2018-01-01

    There is growing global concern over the chemical, biological and ecological impact of plastics in the ocean. Remote sensing has the potential to provide long-term, global monitoring but for marine plastics it is still in its early stages. Some progress has been made in hyperspectral remote sensing of marine macroplastics in the visible (VIS) to short wave infrared (SWIR) spectrum. We present a reflectance model of sunlight interacting with a sea surface littered with macro plastics, based on geometrical optics and the spectral signatures of plastic and seawater. This is a first step towards the development of a remote sensing algorithm for marine plastic using light reflectance measurements in air. Our model takes the colour, transparency, reflectivity and shape of plastic litter into account. This concept model can aid the design of laboratory, field and Earth observation measurements in the VIS-SWIR spectrum and explain the results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Studying ocean acidification in the Arctic Ocean

    Science.gov (United States)

    Robbins, Lisa

    2012-01-01

    The U.S. Geological Survey (USGS) partnership with the U.S. Coast Guard Ice Breaker Healey and its United Nations Convention Law of the Sea (UNCLOS) cruises has produced new synoptic data from samples collected in the Arctic Ocean and insights into the patterns and extent of ocean acidification. This framework of foundational geochemical information will help inform our understanding of potential risks to Arctic resources due to ocean acidification.

  20. Marine microbe with potential to adhere and degrade plastic structures

    Directory of Open Access Journals (Sweden)

    Alka Kumari

    2017-10-01

    Full Text Available Extensive usages of plastics have led to their accumulation as a contaminant in natural environment worldwide. Plastic is an inert and non-biodegradable material, due to its complex structure and hydrophobic backbone [1]. Conventional methods for reduction of plastic waste such as burning, land-filling release unwanted toxic chemicals to the environment and harming living organism of land as well as the ocean. There is growing interest in development of strategies for the degradation of plastic wastes to clean the environment [2]. Marine bacteria have evolved with the capability to adapt and grow in the diverse environmental conditions [3]. We studied the ability of marine bacteria for destabilization and utilization of different plastic films (LDPE, HDPE, PVC and PET as a sole source of carbon. An active bacterial strain AIIW2 was selected based on the triphenyl tetrazolium chloride reduction assay, and it was identified as Bacillus species based on 16S rRNA gene sequence. The viability of the strain over the plastic surface was studied and confirmed by bacLight assay with fluorescent probes. Scanning Electron Microscope and Atomic Force Microscope images suggested that bacterial interaction over the plastic surface is causing deterioration and roughness with increasing bacterial incubation time. In Fourier transform infrared spectra of treated plastic film evidenced stretching of the (-CH alkane rock chain and (-CO carbonyl region, suggested the oxidative activities of the bacteria. The results revealed that ability of bacterial strain for instigating their colonization over plastic films and deteriorating the polymeric structure in the absence of other carbon sources [4]. Moreover, production of extracellular enzymes such as esterase, laccase, and dehalogenase which are reported to support utilization of plastics was confirmed by plate assays. In concise, our results suggested that the marine bacterial strain AIIW2 have the ability to utilize

  1. 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.

  2. 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....

  3. Tracking plastics in the Mediterranean: 2D Lagrangian model.

    Science.gov (United States)

    Liubartseva, S; Coppini, G; Lecci, R; Clementi, E

    2018-04-01

    Drift of floating debris is studied with a 2D Lagrangian model with stochastic beaching and sedimentation of plastics. An ensemble of >10 10 virtual particles is tracked from anthropogenic sources (coastal human populations, rivers, shipping lanes) to environmental destinations (sea surface, coastlines, seabed). Daily analyses of ocean currents and waves provided by CMEMS at a horizontal resolution of 1/16° are used to force the plastics. High spatio-temporal variability in sea-surface plastic concentrations without any stable long-term accumulations is found. Substantial accumulation of plastics is detected on coastlines and the sea bottom. The most contaminated areas are in the Cilician subbasin, Catalan Sea, and near the Po River Delta. Also, highly polluted local patches in the vicinity of sources with limited circulation are identified. An inverse problem solution, used to quantify the origins of plastics, shows that plastic pollution of every Mediterranean country is caused primarily by its own terrestrial sources. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Phenotypic plasticity as an adaptive response to predictable and unpredictable environmental changes

    DEFF Research Database (Denmark)

    Manenti, Tommaso

    Phenotypic plasticity is the ability of a genotype to modify its phenotype in response to environmental changes as a consequence of an interaction between genes and environment (Bradshaw, 1965). Plasticity contributes to the vast phenotypic variation observed in natural populations. Many examples...... of a plastic response are expected to depend on the environmental conditions experienced by organisms. Thus, in populations exposed to a non-changing environment, the plastic machinery might be a waste of resources. Contrary, in populations experiencing varying environmental conditions, plasticity is expected...... such as anti-predator behaviours or the activation of mechanisms to prevent thermal stress injuries suggest that plasticity is an adaptive response, favoured by natural selection. At the same time, organisms do show limited plastic responses, indicating that this ability is not for free. Costs and benefits...

  5. Creating Methane from Plastic: Recycling at a Lunar Outpost

    Science.gov (United States)

    Santiago-Maldonado, Edgardo; Captain, Janine; Devor, Robert; Gleaton, Jeremy

    2010-01-01

    The high cost of re-supply from Earth demands resources to be utilized to the fullest extent for exploration missions. The ability to refuel on the lunar surface would reduce the vehicle mass during launch and provide excess payload capability. Recycling is a key technology that maximizes the available resources by converting waste products into useful commodities. One example of this is to convert crew member waste such as plastic packaging, food scraps, and human waste into fuel. This process thermally degrades plastic in the presence of oxygen producing CO2 and CO. The CO2 and CO are then reacted with hydrogen over catalyst (Sabatier reaction) producing methane. An end-to-end laboratory-scale system has been designed and built to produce methane from plastic, in this case polyethylene. This first generation system yields 12-16% CH4 by weight of plastic used.

  6. Determination of inorganic component in plastics by neutron activation analysis

    International Nuclear Information System (INIS)

    Mateus, Sandra Fonseca; Saiki, Mitiko

    1995-01-01

    In order to identify possible sources of heavy metals in municipal solid waste incinerator ashes, plastic materials originated mainly from household waste were analyzed by using instrumental neutron activation analysis method. Plastic samples and synthetic standards of elements were irradiated at the IEA-R1 nuclear reactor for 8 h under thermal neutron flux of about 10 13 n cm -2 s -1 . After adequate decay time, counting were carried out using a hyperpure Ge detector and the concentrations of the elements As, Ba, Br, Cd, Co, Cr, Fe, Sb, Sc, Se, Sn, Ti and Zn were determined. For some samples, not all these elements were detected. Besides, the range of concentrations determined in similar type and colored samples varied from a few ppb to percentage. In general, colored and opaque plastic samples presented higher concentrations of the elements than those obtained from transparent and milky plastics. Precision of the results was also evaluated. (author). 3 refs., 2 tabs

  7. 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 ...

  8. Characterization of plasticized PEO-PAM blend polymer electrolyte system

    Science.gov (United States)

    Dave, Gargi; Kanchan, Dinesh

    2017-05-01

    Present study reports characterization studies of NaCF3SO3 based PEO-PAM Blend Polymer Electrolyte (BPE) system with varying amount of EC+PC as plasticizer prepared by solution cast technique. Structural analysis and surface topography have been performed using FTIR and SEM studies. To understand, thermal properties, DSC studies have been undertaken in the present paper

  9. 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

  10. The mechanical and thermodynamical theory of plasticity

    CERN Document Server

    Negahban, Mehrdad

    2012-01-01

    ""an excellent text for a graduate-level course in plasticity…the approach and selection of topics are appropriate for the audience. ... Professor Negahban has done an excellent job in presenting a unified approach to include thermal effects in the theory of finite deformation of plastic solids. The simple thermo-mechanical analog presented at the beginning of the chapter is also very instructive to the reader. {presented figures are] particularly helpful in understanding the mechanisms in a simple (one-dimensional) setting … The learning features included in this chapter are excellent (the fi

  11. Investigations on fuel can plastic deformations

    International Nuclear Information System (INIS)

    Boutard, J.L.; Dupouy, J.M.

    1979-01-01

    To the extent where the elongation of claddings differs from the mean swelling, the diametral plastic deformation can include, apart from that due to fission gases or the mechanical oxide-cladding interaction, contributions due to swelling prevented along the axis or to growth phenomena. The high thermal activation of the creep of hyper quenched steel unlike cold rolled steel, gives rise to the problem of a contribution to creep in the reactor other than the term SIPA. The impact of mechanisms of diffusion deformation on the boundary decohesion criteria is discussed in conclusion [fr

  12. The Ocean Literacy Campaign

    Science.gov (United States)

    Schoedinger, S. E.; Strang, C.

    2008-12-01

    "Ocean Literacy is an understanding of the ocean's influence on you and your influence on the ocean." This simple statement captures the spirit of a conceptual framework supporting ocean literacy (COSEE et al., 2005). The framework comprises 7 essential principles and 44 fundamental concepts an ocean literate person would know (COSEE et al., 2005). The framework is the result of an extensive grassroots effort to reach consensus on (1) a definition for ocean literacy and (2) an articulation of the most important concepts to be understood by ocean-literate citizen (Cava et al., 2005). In the process of reaching consensus on these "big ideas" about the ocean, what began as a series of workshops has emerged as a campaign "owned" by an ever-expanding community of individuals, organizations and networks involved in developing and promoting the framework. The Ocean Literacy Framework has provided a common language for scientists and educators working together and serves as key guidance for the ocean science education efforts. This presentation will focus on the impact this Ocean Literacy Campaign has had to date as well as efforts underway to provide additional tools to enable educators and educational policy makers to further integrate teaching and learning about the ocean and our coasts into formal K-12 education and informal education. COSEE, National Geographic Society, NOAA, College of Exploration (2005). Ocean Literacy: The Essential Principles of Ocean Sciences Grades K-12, a jointly published brochure, URL: http://www.coexploration.org/oceanliteracy/documents/OceanLitChart.pdf Cava, F., S. Schoedinger , C. Strang, and P. Tuddenham (2005). Science Content and Standards for Ocean Literacy: A Report on Ocean Literacy, URL: http://www.coexploration.org/oceanliteracy/documents/OLit2004-05_Final_Report.pdf.

  13. Plasticity modeling & computation

    CERN Document Server

    Borja, Ronaldo I

    2013-01-01

    There have been many excellent books written on the subject of plastic deformation in solids, but rarely can one find a textbook on this subject. “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. It adopts a simple narrative style that is not mathematically overbearing, and has been written to emulate a professor giving a lecture on this subject inside a classroom. Each section is written to provide a balance between the relevant equations and the explanations behind them. Where relevant, sections end with one or more exercises designed to reinforce the understanding of the “lecture.” Color figures enhance the presentation and make the book very pleasant to read. For professors planning to use this textbook for their classes, the contents are sufficient for Parts A and B that can be taught in sequence over a period of two semesters or quarters.

  14. Oceans and Human Health: Microplastics and Harmful Algal Bloom

    International Nuclear Information System (INIS)

    Sombrito, Elvira Z.

    2015-01-01

    Traditionally the focus of research and concern of environmental studies in the marine system is the impact of human activities in the ocean: the sources, distribution and fate of pollutants resulting from human activities. More recently, there has been recognition of the potential direct impact health can come from eating contaminated seafood, swimming in polluted water, and exposure to toxins from harmful algal blooms. This paper will present two areas of concern that illustrates the fact that the health of the oceans and the health of humans go hand in hand: chemical pollution from plastics in the ocean and harmful alga bloom. The nuclear methodologies than can be useful in these areas will also be introduced. It is hoped that through the recognition of the inter-dependence of the health of both humans and the oceans, efforts will be made to restore and preserve the oceans. (author)

  15. Protected areas in the Atlantic facing the hazards of micro-plastic pollution: first diagnosis of three islands in the Canary Current.

    Science.gov (United States)

    Baztan, Juan; Carrasco, Ana; Chouinard, Omer; Cleaud, Muriel; Gabaldon, Jesús E; Huck, Thierry; Jaffrès, Lionel; Jorgensen, Bethany; Miguelez, Aquilino; Paillard, Christine; Vanderlinden, Jean-Paul

    2014-03-15

    Coastal zones and the biosphere as a whole show signs of cumulative degradation due to the use and disposal of plastics. To better understand the manifestation of plastic pollution in the Atlantic Ocean, we partnered with local communities to determine the concentrations of micro-plastics in 125 beaches on three islands in the Canary Current: Lanzarote, La Graciosa, and Fuerteventura. We found that, in spite of being located in highly-protected natural areas, all beaches in our study area are exceedingly vulnerable to micro-plastic pollution, with pollution levels reaching concentrations greater than 100 g of plastic in 1l of sediment. This paper contributes to ongoing efforts to develop solutions to plastic pollution by addressing the questions: (i) Where does this pollution come from?; (ii) How much plastic pollution is in the world's oceans and coastal zones?; (iii) What are the consequences for the biosphere?; and (iv) What are possible solutions? Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. The conversion of waste plastics/petroleum residue mixtures to transportation fuels

    International Nuclear Information System (INIS)

    Ali, M.F.; Siddiqui, M.N.

    2005-01-01

    Plastics have become the material of choice in the modern world and its applications in the industrial field are continually increasing. Presently the plastics are manufactured for various uses such as: consumer packaging, wires, pipes, containers, bottles, appliances, electrical/electronic parts, computers and automotive parts. Most of he post consumer, plastic products are discarded and end up as mixed plastic municipal waste. The disposal of his waste has become a major social concern. Mixed plastic waste (MPW) recycling is still very much in its infancy. Approximately 20 million tons of plastic waste is generated in the United States of America, while about 15 million tons is generated throughout the Europe. With existing recycle efforts, only 7% of the MPW are recycled to produce low-grade plastic products such as plastic sacks, pipes, plastic fencing, and garden furniture. The current plastic reclamation technology options are generally grouped into the following four types: (i) Primary: The processing of plastic for use comparable to the original application. (ii) Secondary: The processing of plastics waste into new products with a lower quality level. (iii) Tertiary: The chemical or thermal processing of plastic waste to their basic hydrocarbon feedstock. The resulting raw materials are then reprocessed into plastic material or other products of the oil refining process. (iv) Quaternary: The incineration of plastics waste to recover energy. This paper deals exclusively with tertiary recycling by pyrolysis and catalytic cracking of plastics waste alone and by coprocessing with petroleum residue or heavy oils to fuels and petrochemical feedstock for further processing in existing refinery and petrochemical units. (author)

  17. 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

  18. 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

  19. Plastic microfibre ingestion by deep-sea organisms

    Science.gov (United States)

    Taylor, M. L.; Gwinnett, C.; Robinson, L. F.; Woodall, L. C.

    2016-09-01

    Plastic waste is a distinctive indicator of the world-wide impact of anthropogenic activities. Both macro- and micro-plastics are found in the ocean, but as yet little is known about their ultimate fate and their impact on marine ecosystems. In this study we present the first evidence that microplastics are already becoming integrated into deep-water organisms. By examining organisms that live on the deep-sea floor we show that plastic microfibres are ingested and internalised by members of at least three major phyla with different feeding mechanisms. These results demonstrate that, despite its remote location, the deep sea and its fragile habitats are already being exposed to human waste to the extent that diverse organisms are ingesting microplastics.

  20. Compensatory plasticity: time matters

    Directory of Open Access Journals (Sweden)

    Latifa eLazzouni

    2014-06-01

    Full Text Available Plasticity in the human and animal brain is the rule, the base for development, and the way to deal effectively with the environment for making the most efficient use of all the senses. When the brain is deprived of one sensory modality, plasticity becomes compensatory: the exception that invalidates the general loss hypothesis giving the opportunity of effective change. Sensory deprivation comes with massive alterations in brain structure and function, behavioural outcomes, and neural interactions. Blind individuals do as good as the sighted and even more, show superior abilities in auditory, tactile and olfactory processing. This behavioural enhancement is accompanied with changes in occipital cortex function, where visual areas at different levels become responsive to non-visual information. The intact senses are in general used more efficiently in the blind but are also used more exclusively. New findings are disentangling these two aspects of compensatory plasticity. What is due to visual deprivation and what is dependent on the extended use of spared modalities? The latter seems to contribute highly to compensatory changes in the congenitally blind. Short term deprivation through the use of blindfolds shows that cortical excitability of the visual cortex is likely to show rapid modulatory changes after few minutes of light deprivation and therefore changes are possible in adulthood. However, reorganization remains more pronounced in the congenitally blind. Cortico-cortical pathways between visual areas and the areas of preserved sensory modalities are inhibited in the presence of vision, but are unmasked after loss of vision or blindfolding as a mechanism likely to drive cross-modal information to the deafferented visual cortex. Plasticity in the blind is also accompanied with neurochemical and morphological changes; both intrinsic connectivity and functional coupling at rest are altered but are likewise dependent on different sensory