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Sample records for plastics additives part

  1. Biobased additive plasticizing Polylactic acid (PLA

    Directory of Open Access Journals (Sweden)

    Mounira Maiza

    2015-12-01

    Full Text Available Polylactic acid (PLA is an attractive candidate for replacing petrochemical polymers because it is from renewable resources. In this study, a specific PLA 2002D was melt-mixed with two plasticizers: triethyl citrate (TEC and acetyl tributyl citrate (ATBC. The plasticized PLA with various concentrations were analyzed by differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, melt flow index (MFI, thermogravimetric analysis (TGA, X-ray diffraction (XRD, UV-Visible spectroscopy and plasticizer migration test. Differential scanning calorimetry demonstrated that the addition of TEC and ATBC resulted in a decrease in glass transition temperature (Tg, and the reduction was the largest with the plasticizer having the lowest molecular weight (TEC. Plasticizing effect was also shown by decrease in the dynamic storage modulus and viscosity of plasticized mixtures compared to the treated PLA. The TGA results indicated that ATBC and TEC promoted a decrease in thermal stability of the PLA. The X-ray diffraction showed that the PLA have not polymorphic crystalline transition. Analysis by UV-Visible spectroscopy showed that the two plasticizers: ATBC and TEC have no effect on the color change of the films. The weight loss plasticizer with heating time and at 100°C is lesser than at 135 °C. Migration of TEC and ATBC results in cracks and changed color of material. We have concluded that the higher molecular weight of citrate in the studied exhibited a greater plasticizing effect to the PLA.

  2. Other solutions for the plastic residue from the automobile industry and used as additives in the asphaltic bitumens; Alternativas de los residuos plasticos de la automocion y su empleo como aditivos de los betunes asfalticos. Parte I

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Vidriero, E.; Castillo, F. [CEDEX. Ministerio de Fomento. Madrid (Spain)

    1999-08-01

    This article forms part of an investigation which aims to achieve two adjectives. The first is to cooperate in the improvement of the environment by decreasing the amount of plastic residue from the automobile industry. The second is to improve the characteristics of asphaltic bitumens used in roofing and waterproofing in civil engineering, through the addition of plastic residue from the automobile industry. (Author) 4 refs.

  3. Leaching of Plastic Additives to Marine Organisms

    NARCIS (Netherlands)

    Koelmans, A.A.; Besseling, E.; Foekema, E.M.

    2014-01-01

    It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of Areni

  4. Leaching of Plastic Additives to Marine Organisms

    NARCIS (Netherlands)

    Koelmans, A.A.; Besseling, E.; Foekema, E.M.

    2014-01-01

    It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of Areni

  5. Release of additives from packaging plastics

    NARCIS (Netherlands)

    Helmroth, I.E.

    2002-01-01

    Keywords : migration, diffusion, additives, polymer, low density polyethylene, polymer swelling, Fick, stochastic modellingThe diffusion of small molecules from polymers into food is studied. A better understanding of this process is important for the development of mathematical models to predict mi

  6. DETERMINATION OF DIPOLE MOMENTS IN PLASTICIZER ADDITIONS FOR CEMENT CONCRETES

    Directory of Open Access Journals (Sweden)

    P. I. Ioukhnevsky

    2010-01-01

    Full Text Available The paper contains a method for determination of dipole moments in chemical plasticizer addition molecules for cement concretes as in powder-state so in the form of aqueous solutions as well.The methodology is based on measuring dielectric substance  permittivity depending on temperature, construction of a diagram (ε – 1/(ε + 2 = f(1/T with subsequent calculation of the molecule dipole moment. The Ossipov’s formula has been used for aqueous solutions of super-plasticizer additions with the purpose to calculate a dipole moment of polar substance in the polar solvent.The obtained values of dipole moments in C-3 super-plasticizer addition molecule are in good agreement with the values obtained as a result of quantum-chemical calculations. 

  7. Part weight verification between simulation and experiment of plastic part in injection moulding process

    Science.gov (United States)

    Amran, M. A. M.; Idayu, N.; Faizal, K. M.; Sanusi, M.; Izamshah, R.; Shahir, M.

    2016-11-01

    In this study, the main objective is to determine the percentage difference of part weight between experimental and simulation work. The effect of process parameters on weight of plastic part is also investigated. The process parameters involved were mould temperature, melt temperature, injection time and cooling time. Autodesk Simulation Moldflow software was used to run the simulation of the plastic part. Taguchi method was selected as Design of Experiment to conduct the experiment. Then, the simulation result was validated with the experimental result. It was found that the minimum and maximum percentage of differential of part weight between simulation and experimental work are 0.35 % and 1.43 % respectively. In addition, the most significant parameter that affected part weight is the mould temperature, followed by melt temperature, injection time and cooling time.

  8. Performance of Hot Asphalt Mixtures Containing Plastic Bottles as Additive

    Directory of Open Access Journals (Sweden)

    Jan Hakeem

    2017-01-01

    Full Text Available This study focuses on evaluating the resistance of polymer modified asphalt mixes and the role played by asphalt in the realm of construction is undeniably important. Addition of polymers(PB as additives to asphalt helps to improve the strength and water repellent property of the mix and as well as helps environment in various ways and at the same time, analyzing its lower maintenance activities and service life is most important. The use of inexpensive polymers, in this case, waste polymers has without any doubt proven to be the most convenient way of reducing the cost of construction and at the same time maintaining quality. The main resolve for this research was to establish the effects of the use of plastic bottles on hot asphalt and its mixtures. In order to put this into perspective, varying percentages of asphalt mixtures were calculated and subjected to laboratory tests. The two-factor variance analysis (ANOVA was conducted to determine the significance at various confidence limits. The results indicate that the inclusion of Polyethylene Terephthalate (PET had a particularly substantial effect on the properties of asphalt. Consequently, it can encourage the re-utilization of waste in the manufacturing industry in an ecologically friendly and cost-effective way.

  9. Structure Property Studies for Additively Manufactured Parts

    Energy Technology Data Exchange (ETDEWEB)

    Milenski, Helen M [Univ. of Mexico, Los Alamos, NM (United States); Schmalzer, Andrew Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kelly, Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-17

    Since the invention of modern Additive Manufacturing (AM) processes engineers and designers have worked hard to capitalize on the unique building capabilities that AM allows. By being able to customize the interior fill of parts it is now possible to design components with a controlled density and customized internal structure. The creation of new polymers and polymer composites allow for even greater control over the mechanical properties of AM parts. One of the key reasons to explore AM, is to bring about a new paradigm in part design, where materials can be strategically optimized in a way that conventional subtractive methods cannot achieve. The two processes investigated in my research were the Fused Deposition Modeling (FDM) process and the Direct Ink Write (DIW) process. The objectives of the research were to determine the impact of in-fill density and morphology on the mechanical properties of FDM parts, and to determine if DIW printed samples could be produced where the filament diameter was varied while the overall density remained constant.

  10. Fibre Reinforced Plastic Concepts for Structural Chassis Parts

    OpenAIRE

    Deißer, Oliver; Friedrich, Horst E.; Kopp, Gundolf

    2014-01-01

    Abstract Fibre reinforced plastics (FRP) have a high potential for reducing masses of automotive parts, but are seldom used for structural parts in the chassis. If the whole chassis concept is adapted to the new material, then a high weight saving potential can be gained and new body concepts can result. DLR Institute of Vehicle Concepts designed and dimensioned a highly stressed structural part in FRP. A topology optimisation of a defined working space with the estimated loads was perform...

  11. Design consideration for design a flat and ring plastics part using Solidworks software

    Science.gov (United States)

    Amran, M. A. M.; Faizal, K. M.; Salleh, M. S.; Sulaiman, M. A.; Mohamad, E.

    2015-12-01

    Various considerations on design of plastic injection moulded parts were applied in initial stage to prevent any defects of end products. Therefore, the objective of this project is to design the plastic injection moulded part by taking consideration on several factors such as draft angle, corner radius and location of gate. In this project, flat plastic part, ring plastic part, core inserts for flat and ring plastic part were designed using SolidWorks software. The plastic part was drawn in sketching mode then the 3D modeling of solid part was generated using various commands. Considerations of plastic part such as draft angle and corner radius with location of gate was considered in the design stage. Finally, it was successfully designed the two plastic parts with their respectively insert by using SolidWorks software. The flat plastic part and ring plastic part were designed for the purpose for future researches for study the weld lines, meld lines, air trapped and geometrical size of the product. Thus, by designing the flat plastic part and ring plastic part having core insert on each part, the completed mould design of two plate mould can be considered. This is because, plastic injection parts are needed to be designed properly in order to neglect any defect when the mould was made.

  12. Simulation of the X-Ray Beam Absorption by the ABS-Plastic Filled with Different Metallic Additives

    Science.gov (United States)

    Miloichikova, I. A.; Stuchebrov, S. G.; Verigin, D. A.; Krasnykh, A. A.; Danilova, I. B.

    2016-11-01

    This article is a part of the work on developing new materials for manufacturing filaments for fused deposition modeling (FDM). The computations of depth dose distributions for gamma-radiation in ABS plastic filled with lead and zinc additives of various concentration were performed via Monte Carlo technique and are represented in graphic form.

  13. Predicting Color Output of Additive Manufactured Parts

    DEFF Research Database (Denmark)

    Eiríksson, Eyþór Rúnar; Pedersen, David Bue; Aanæs, Henrik

    2015-01-01

    In this paper we address the colorimetric performance of a multicolor additive manufacturing process. A method on how to measure and characterize color performance of said process is presented. Furthermore, a method on predicting the color output is demonstrated, allowing for previsualization...

  14. SIMULATION OF OPEN MECHANISMS FOR THE ADDITIVE PROCESS WELD PLASTICS

    Directory of Open Access Journals (Sweden)

    N. N. Hurski

    2016-01-01

    Full Text Available This article discusses: model of the two-link mechanism; generalized scheme of mechatronic simulation model of 3D-printer with the positioning units of electric DC; mathematical model of the actuator of the printer unit in the form of a system of differential equations; 3D-printer programming model implemented in the Matlab-Simulink environment using the c standard library blocks and SimMechanics library; virtual (animated 3D printer model on the basis of the library Simulink 3D Animation, supports the visualization of the movements of the designed mechanism of the basic units. We present the initial data and the results of simulation of 3D-printer type Scara as a waveform positioning actuator (extruder in the manufacture of test items by fusing plastic.

  15. Navy additive manufacturing: adding parts, subtracting steps

    OpenAIRE

    Cunningham, Victor; Schrader, Christopher A.; Young, James

    2015-01-01

    Approved for public release; distribution is unlimited This study examines additive manufacturing (AM) and describes its potential impact on the Navy’s Supply Chain Management processes. Included in the analysis is the implementation of 3D printing technology and how it could impact the Navy’s future procurement processes, specifically based on a conducted analysis of the automotive aerospace industry. Industry research and development has identified multiple dimensions of AM technology, i...

  16. Fabrication of Functional Plastic Parts Using Nanostructured Steel Mold Inserts

    Directory of Open Access Journals (Sweden)

    Nicolas Blondiaux

    2017-06-01

    Full Text Available We report on the fabrication of sub-micro and nanostructured steel mold inserts for the replication of nanostructured immunoassay biochips. Planar and microstructured stainless steel inserts were textured at the sub-micron and nanoscale by combining nanosphere lithography and electrochemical etching. This allowed the fabrication of structures with lateral dimensions of hundreds of nanometers and aspect ratios of up to 1:2. Nanostructured plastic parts were produced by means of hot embossing and injection molding. Surface nanostructuring was used to control wettability and increase the sensitivity of an immunoassay.

  17. 3D Rigid-Plastic Finite Element Analysis for Skew Rolling Process of the Stepped Part

    Institute of Scientific and Technical Information of China (English)

    Gang FANG; Pan ZENG

    2003-01-01

    Based on rigid-plastic finite element method, a skew rolling process of stepped part is simulated. Considering nodesaving and effective remeshing, the tetrahedron solid elements are used to discrete workpiece. The workpiece material adopts rigid-plastic m

  18. Anomaly Detection In Additively Manufactured Parts Using Laser Doppler Vibrometery

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Carlos A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-29

    Additively manufactured parts are susceptible to non-uniform structure caused by the unique manufacturing process. This can lead to structural weakness or catastrophic failure. Using laser Doppler vibrometry and frequency response analysis, non-contact detection of anomalies in additively manufactured parts may be possible. Preliminary tests show promise for small scale detection, but more future work is necessary.

  19. Multiple material additive manufacturing – Part 1:\\ud a review

    OpenAIRE

    Vaezi, Mohammad; Chianrabutra, Srisit; Mellor, Brian; Yang, Shoufeng

    2013-01-01

    Interest in multifunctional structures made automatically from multiple materials poses a challenge for today’s additive manufacturing (AM) technologies; however the ability to process multiple materials is a fundamental advantage to some AM technologies. The capability to fabricate multiple material parts can improve AM technologies by either optimizing the mechanical properties of the parts or providing additional functions to the final parts. The objective of this paper is to give an overv...

  20. Using magnetic levitation for non-destructive quality control of plastic parts.

    Science.gov (United States)

    Hennek, Jonathan W; Nemiroski, Alex; Subramaniam, Anand Bala; Bwambok, David K; Yang, Dian; Harburg, Daniel V; Tricard, Simon; Ellerbee, Audrey K; Whitesides, George M

    2015-03-04

    Magnetic levitation (MagLev) enables rapid and non-destructive quality control of plastic parts. The feasibility of MagLev as a method to: i) rapidly assess injection-molded plastic parts for defects during process optimization, ii) monitor the degradation of plastics after exposure to harsh environmental conditions, and iii) detect counterfeit polymers by density is demonstrated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Machining of Additively Manufactured Parts: Implications for Surface Integrity

    OpenAIRE

    Oyelola, O.; Crawforth, P.; M'Saoubi, R.; Clare, A.T.

    2016-01-01

    Additive manufacturing methods continue to move towards production ready technologies with the widely extolled virtues of rapid transition from design to part and enhanced design freedoms. However, due to fundamental limitations of laser based processes for metal additive manufacturing, there is a significant ongoing need for these parts to be subject to additional machining operations. This paper reports on a study to investigate the machining behavior and surface integrity of Ti-6Al-4 V com...

  2. Machining of Additively Manufactured Parts: Implications for Surface Integrity

    OpenAIRE

    Oyelola, O.; Crawforth, P.; M'Saoubi, R.; Clare, A.T.

    2016-01-01

    Additive manufacturing methods continue to move towards production ready technologies with the widely extolled virtues of rapid transition from design to part and enhanced design freedoms. However, due to fundamental limitations of laser based processes for metal additive manufacturing, there is a significant ongoing need for these parts to be subject to additional machining operations. This paper reports on a study to investigate the machining behavior and surface integrity of Ti-6Al-4 V com...

  3. Tactile and visual perception of injection moulded plastic parts

    DEFF Research Database (Denmark)

    Jensen, Jacob Tobias; Akbas, Erkan; Madsen, Mads

    switches the technology is almost the same for all manufactures and therefore the visual appeal is very important as a competition factor. Traditional light switches have the button made from plastic material. It is this button that is imagined to be examined to find a plastic surface with a good visual...... appeal (aesthetics) and tactile perception (ergonomics). From this the following thesis has been created: What plastic material and surface texture gives the best combination of aesthetics and ergonomics in the use for buttons on light switches? Throughout the report this thesis will be examined...

  4. Porosity of additive manufacturing parts for process monitoring

    Science.gov (United States)

    Slotwinski, J. A.; Garboczi, E. J.

    2014-02-01

    Some metal additive manufacturing processes can produce parts with internal porosity, either intentionally (with careful selection of the process parameters) or unintentionally (if the process is not well-controlled.) Material porosity is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants, since surface-breaking pores allow for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the process. We are developing an ultrasonic sensor for detecting changes in porosity in metal parts during fabrication on a metal powder bed fusion system, for use as a process monitor. This paper will describe our work to develop an ultrasonic-based sensor for monitoring part porosity during an additive build, including background theory, the development and detailed characterization of reference additive porosity samples, and a potential design for in-situ implementation.

  5. COMPARISON OF GEOMETRIC PRECISION OF PLASTIC COMPONENTS MADE BY SUBTRACTIVE AND ADDITIVE METHODS

    Directory of Open Access Journals (Sweden)

    Paweł Fudali

    2013-09-01

    Full Text Available The paper presents information on manufacturing processes of plastic components. Basic subtractive and additive methods are described. There were also manufactured elements of fan housing by using this two types of methods. Then, the elements were measured using a touch probe. The obtained results were analyzed, on which a comparison of components’ geometric accuracy was performed.

  6. Clean, agile alternative binders, additives and plasticizers for propellant and explosive formulations

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.M. [Lawrence Livermore National Lab., CA (United States); Hawkins, T.W. [Phillips Lab., Edwards AFB, CA (United States); Lindsay, G.A. [Naval Weapons Station, China Lake, CA (United States)] [and others

    1994-12-01

    As part of the Strategic Environmental Research and Development Program (SERDP) a clean, agile manufacturing of explosives, propellants and pyrotechniques (CANPEP) effort set about to identify new approaches to materials and processes for producing propellants, explosives and pyrotechniques (PEP). The RDX based explosive PBXN-109 and gun propellant M-43 were identified as candidates for which waste minimization and recycling modifications might be implemented in a short time frame. The binders, additives and plasticizers subgroup identified cast non-curable thermoplastic elastomer (TPE) formulations as possible replacement candidates for these formulations. Paste extrudable explosives were also suggested as viable alternatives to PBXN-109. Commercial inert and energetic TPEs are reviewed. Biodegradable and hydrolyzable binders are discussed. The applicability of various types of explosive formulations are reviewed and some issues associated with implementation of recyclable formulations are identified. It is clear that some processing and weaponization modifications will need to be made if any of these approaches are to be implemented. The major advantages of formulations suggested here over PBXN-109 and M-43 is their reuse/recyclability. Formulations using TPE or Paste could by recovered from a generic bomb or propellant and reused if they met specification or easily reprocessed and sold to the mining industry.

  7. A mathematical basis for strain-gradient plasticity theory. Part II: Tensorial plastic multiplier

    Science.gov (United States)

    Fleck, N. A.; Willis, J. R.

    2009-07-01

    A phenomenological, flow theory version of gradient plasticity for isotropic and anisotropic solids is constructed along the lines of Gudmundson [Gudmundson, P., 2004. A unified treatment of strain-gradient plasticity. J. Mech. Phys. Solids 52, 1379-1406]. Both energetic and dissipative stresses are considered in order to develop a kinematic hardening theory, which in the absence of gradient terms reduces to conventional J 2 flow theory with kinematic hardening. The dissipative stress measures, work-conjugate to plastic strain and its gradient, satisfy a yield condition with associated plastic flow. The theory includes interfacial terms: elastic energy is stored and plastic work is dissipated at internal interfaces, and a yield surface is postulated for the work-conjugate stress quantities at the interface. Uniqueness and extremum principles are constructed for the solution of boundary value problems, for both the rate-dependent and the rate-independent cases. In the absence of strain gradient and interface effects, the minimum principles reduce to the classical extremum principles for a kinematically hardening elasto-plastic solid. A rigid-hardening version of the theory is also stated and the resulting theory gives rise to an extension to the classical limit load theorems. This has particular appeal as previous trial fields for limit load analysis can be used to generate immediately size-dependent bounds on limit loads.

  8. 32 CFR Appendix A to Part 155 - Additional Procedural Guidance

    Science.gov (United States)

    2010-07-01

    ... Part 155 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE SECURITY DEFENSE INDUSTRIAL PERSONNEL SECURITY CLEARANCE PROGRAM Pt. 155, App. A Appendix A to Part 155—Additional Procedural... interest to grant or continue a security clearance for an applicant, the case will be promptly referred to...

  9. The use of plasticizing additives based on recycled raw materials in the petrochemical rubber mixtures

    Directory of Open Access Journals (Sweden)

    Z. S. Shashok

    2016-01-01

    Full Text Available At present, the development of alternative products for elastomers based on recycling petrochemical raw materials is a new trend of the rubber industry progress. Petrochemical raw materials include spent lubricants and motor oils are among such recycling products. In this context, the influence of the products of recycling waste engine oil (DVCH and RA in comparison with industrial oil (I-20 on the technological properties of filled elastomeric compositions was investigated. The elastomeric compositions were based on poly isoprene and divinyl rubbers. The plasticizing components were manufactured by IOOO “DVCH-Menedzhment”. They are mixture of hydro-carbons, C16–C20 and differ from each other in the content of linear and branched paraffin. Plastic-elastic properties of rubber compounds on the shear disk viscometer MV2000 in accordance with GOST 10722–76 was carried out. Kinetics of vulcanization on the rheometer ODR2000 according to GOST 12535–84 was defined. It is shown that the introduction of RA test plasticizing component provides a significant effect on Mooney viscosity, as compared to elastomeric compositions containing a plasticizer and I-20 and plasticizing additive DVCH. It revealed that the administration of all components in the studied plasticizing elastomer compositions based on a combination poly isoprene and divinyl rubbers has no significant effect on the rate of relaxation of stress of rubber compounds. It is found that elastomeric compositions containing as additives investigated processing waste oil products (DVCH and RA are characterized by a slightly smaller value of time to reach an optimal degree of vulcanization.

  10. Design of Test Parts to Characterize Micro Additive Manufacturing Processes

    DEFF Research Database (Denmark)

    Thompson, Mary Kathryn; Mischkot, Michael

    2015-01-01

    The minimum feature size and obtainable tolerances of additive manufacturing processes are linked to the smallest volumetric elements (voxels) that can be created. This work presents the iterative design of a test part to investigate the resolution of AM processes with voxel sizes at the micro...... manufacturing processes....

  11. COPPER/CARBON CORE SHELL NANOPARTICLES AS ADDITIVE FOR NATURAL FIBER/WOOD PLASTIC BLENDS

    Directory of Open Access Journals (Sweden)

    Qinglin Wu,

    2012-06-01

    Full Text Available Copper/carbon core/shell nanoparticles (CCCSNs recently have been introduced as an industrial material. In this paper, composites based on high density polyethylene (HDPE, bamboo fiber, CCCSNs, and coupling agent (MAPE were prepared by melt compounding. The influence of CCCSN content on the resulting composites’ mechanical, biological resistance, and thermal properties was investigated. It was found that CCCSNs within the carbon black matrix were processed well with bamboo fiber-plastic blends through mixing and injection molding. The materials enhanced composite strength and modulus-related properties. Composites with CCCSNs and natural fibers reduced heat capacity and thermal diffusivity. Composites with CCCSN materials also enhanced termite and mold performance. Thus, the material can be used as additive for plastics and other polymers to modify strength properties, biological resistance (e.g., mold and stain, and thermal conductivity properties.

  12. Additive manufacturing technology in spare parts supply chain

    DEFF Research Database (Denmark)

    Li, Yao; Jia, Guozhu; Yang, Cheng

    2017-01-01

    Additive Manufacturing (AM) technology has the potential to significantly improve supply chain dynamics. The purpose of this paper is to investigate the impact of AM on spare parts supply chain. Three supply chain scenarios are investigated in this paper, namely conventional supply chain......, centralised AM-based supply chain and distributed AM-based supply chain. Based on system dynamics simulations, this paper specifically compares three supply chain scenarios, in terms of total variable cost and carbon emission. The results show the spare part supply chain utilising AM is indeed superior...... to the traditional one in sustainable performance. It is also expected that AM can facilitate the spare parts supply chain to achieve more economic benefits along with its development. To our knowledge, this paper is one of the early studies that explores the impact of AM on supply chain performance...

  13. Additive manufacturing technology in spare parts supply chain

    DEFF Research Database (Denmark)

    Li, Yao; Jia, Guozhu; Yang, Cheng

    2016-01-01

    Additive Manufacturing (AM) technology has the potential to significantly improve supply chain dynamics. The purpose of this paper is to investigate the impact of AM on spare parts supply chain. Three supply chain scenarios are investigated in this paper, namely conventional supply chain......, centralised AM-based supply chain and distributed AM-based supply chain. Based on system dynamics simulations, this paper specifically compares three supply chain scenarios, in terms of total variable cost and carbon emission. The results show the spare part supply chain utilising AM is indeed superior...... to the traditional one in sustainable performance. It is also expected that AM can facilitate the spare parts supply chain to achieve more economic benefits along with its development. To our knowledge, this paper is one of the early studies that explores the impact of AM on supply chain performance...

  14. Modifications in concrete superficial properties due to the use of different formworkrelease agents and plastic additives

    Directory of Open Access Journals (Sweden)

    Beltramone, A.

    2003-06-01

    Full Text Available The actual research study, carried out in the Laboratory of Construction Materials of the ETSAM., analyses the modifications in superficial properties (regarding colour and texture of grey Portland cement mortars due to the use of different formworks release agents (car oil, mineral oil and paraffin and to the addition of plastic superplasticiser to the mixture (Bettor and Sika trademarks. Once the test samples were obtained, a digital registration was made by giving them values in terms of colour and texture observed changes using computer programmes, referring those values to the test specimen (only cement, no additives. A migration of the polymeric particles of the additives towards the surface was observed, presenting the following modifications: Colour: darker hues than those of the test specimen sample were registered in the specimens with additives. Texture: the texture of the test specimen containing additives such as modified polycarboxilic ethers, polycarboxilic ethers; modified organic polymers and modified synthetic melamine were much smoother than the one in test specimen. Test specimens containing melamine, condensed naftalensulphate and polycarboxilic derivatives were a bit rougher but still smoother than the test specimen. The same variation of results as for the colour properties was obtained for the texture as regards to the use of formworks release agents, varying from smoothest to roughest with the car oil.

    El presente estudio experimental, realizado en las instalaciones del Laboratorio de Materiales de Construcción de la ETSAM, analiza las modificaciones de las propiedades superficiales observadas (en cuanto a color y textura en morteros de cemento portland gris, por la utilización de desencofrantes diversos (aceite de automóvil, aceite mineral y desencofrante parafínico, y la incorporación de aditivos superfluidificantes plásticos en la mezcla (de las marcas Bettor y Sika. Una vez obtenidas las diferentes

  15. Determination of plastic additives in packaging by liquid chromatography coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Moreta, Cristina; Tena, María-Teresa

    2015-10-02

    A simple and sensitive analytical method for the determination of several plastic additives in multilayer packaging based on solid-liquid extraction (SLE) and ultra-high performance liquid chromatography (UHPLC) coupled to variable wavelength (VWD) and time of flight mass spectrometry (TOF-MS) detectors is presented. The proposed method allows the simultaneous determination of fourteen additives belonging to different families such as antioxidants, slip agents and light stabilizers, as well as two oxidation products in only 9min. The developed method was validated in terms of linearity, matrix effect error, detection and quantification limits, repeatability and intermediate precision. The instrumental method showed satisfactory repeatability and intermediate precision at concentrations closed to LOQ with RSDs less than 7 and 20%, respectively, and LODs until 5000 times more sensitive than other GC-FID and HPLC-VWD methods previously reported. Also, focused ultrasound solid-liquid extraction (FUSLE) was optimized and evaluated to extract plastic additives from packaging. Extraction results obtained by FUSLE and SLE were compared to those obtained by pressurized liquid extraction (PLE). All extraction methods showed excellent extraction efficiency for slip agents, however quantitative recovery of all analytes was achieved only by SLE with just 5ml of hexane for 10h. Finally, the selected method was applied to the analysis of packaging samples where erucamide, Irgafos 168, oxidized Irgafos 168, Irganox 1076 and Irganox 1010 were detected and quantified. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Inspection of additive manufactured parts using laser ultrasonics

    Science.gov (United States)

    Lévesque, D.; Bescond, C.; Lord, M.; Cao, X.; Wanjara, P.; Monchalin, J.-P.

    2016-02-01

    Additive manufacturing is a novel technology of high importance for global sustainability of resources. As additive manufacturing involves typically layer-by-layer fusion of the feedstock (wire or powder), an important characteristic of the fabricated metallic structural parts, such as those used in aero-engines, is the performance, which is highly related to the presence of defects, such as cracks, lack of fusion or bonding between layers, and porosity. For this purpose, laser ultrasonics is very attractive due to its non-contact nature and is especially suited for the analysis of parts of complex geometries. In addition, the technique is well adapted to online implementation and real-time measurement during the manufacturing process. The inspection can be performed from either the top deposited layer or the underside of the substrate and the defects can be visualized using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). In this work, a variety of results obtained off-line on INCONEL® 718 and Ti-6Al-4V coupons that were manufactured using laser powder, laser wire, or electron beam wire deposition are reported and most defects detected were further confirmed by X-ray micro-computed tomography.

  17. 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.

  18. A Stability Formula for Plastic-Tipped Bullets Part 2: Experimental Testing

    CERN Document Server

    Courtney, Michael W

    2014-01-01

    Part 1 of this paper describes a modification of the original Miller twist rule for computing gyroscopic bullet stability that is better suited to plastic-tipped bullets. The original Miller twist rule assumes a bullet of constant density, but it also works well for conventional copper (or gilding metal) jacketed lead bullets because the density of copper and lead are sufficiently close. However, the original Miller twist rule significantly underestimates the gyroscopic stability of plastic-tipped bullets, because the density of plastic is much lower than the density of copper and lead. Here, a new amended formula is developed for the gyroscopic stability of plastic-tipped bullets by substituting the length of just the metal portion for the total length in the (1 + L2) term of the original Miller twist rule. Part 2 describes experimental testing of this new formula on three plastic-tipped bullets. The new formula is relatively accurate for plastic-tipped bullets whose metal portion has nearly uniform density,...

  19. A Stability Formula for Plastic-Tipped Bullets Part 1: Motivation and Development of New Formula

    CERN Document Server

    Courtney, Michael W

    2014-01-01

    Part 1 of this paper describes a modification of the original Miller twist rule for computing gyroscopic bullet stability that is better suited to plastic-tipped bullets. The original Miller twist rule assumes a bullet of constant density, but it also works well for conventional copper (or gilding metal) jacketed lead bullets because the density of copper and lead are sufficiently close. However, the original Miller twist rule significantly underestimates the gyroscopic stability of plastic-tipped bullets, because the density of plastic is much lower than the density of copper and lead. Here, a new amended formula is developed for the gyroscopic stability of plastic-tipped bullets by substituting the length of just the metal portion for the total length in the $(1 + L^2)$ term of the original Miller twist rule. Part 2 describes experimental testing of this new formula on three plastic-tipped bullets. The new formula is relatively accurate for plastic-tipped bullets whose metal portion has nearly uniform densi...

  20. 49 CFR Appendix B to Part 173 - Procedure for Testing Chemical Compatibility and Rate of Permeation in Plastic Packaging and...

    Science.gov (United States)

    2010-10-01

    ... Rate of Permeation in Plastic Packaging and Receptacles B Appendix B to Part 173 Transportation Other... Plastic Packaging and Receptacles 1. The purpose of this procedure is to determine the chemical compatibility and permeability of liquid hazardous materials packaged in plastic packaging and...

  1. Effects of glass fibers on the properties of micro molded plastic parts

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Gasparin, Stefania

    2011-01-01

    of polymeric thin ribs. It investigates the effect of feature size and gate location on distribution of glass fibers inside the molded parts. The results from this work indicate that glass filled plastic materials have poor replication quality and nonhomogeneous mechanical properties due to the nonuniform...

  2. DEVELOPMENT OF AN INNOVATIVE LASER SCANNER FOR GEOMETRICAL VERIFICATION OF METALLIC AND PLASTIC PARTS

    DEFF Research Database (Denmark)

    Carmignato, Simone; De Chiffre, Leonardo; Fisker, Rune

    2008-01-01

    and plastic parts. A first prototype of the novel measuring system has been developed, using laser triangulation. The system, besides ensuring the automatic reconstruction of complete surface models, has been designed to guarantee user-friendliness, versatility, reliability and speed. The paper focuses mainly...... dimensional measurements with adequate accuracy for most industrial requirements....

  3. Joining technology for parts for plastic and thin sheet metal parts; Fuegetechniken fuer Bauteile aus Kunststoff und duennwandigem Metall

    Energy Technology Data Exchange (ETDEWEB)

    Ahlers-Hestermann, G. [BOELLHOFF, Bielefeld (Germany)

    2001-07-01

    With the ongoing application of new materials (Al, Mg, Plastic) as an alternative to steel in light-weight body in white construction it is necessary to develop and use other joining and fixing technologies than spot welding, bolt-and nut-welding. These new technologies for example are mechanical joining technology as clinching and self-pierce-riveting, blind-riveting and special elements to fix other parts as blind-rivets and self-piercing nuts and bolts. These products are mainly used for metal materials and mixed structures. To fix other parts to plastic-parts direct-screwing or the after-moulding-technology with metal or plastic inserts is used. (orig.) [German] Mit der verstaerkten Anwendung von weiteren Werkstoffen (Al, Mg, Kunststoffe) als Stahl im Automobilbau ist die Notwendigkeit erwachsen, alternative Fuege- und Befestigungstechniken zum Punktschweissen, Bolzen- und Mutternschweissen zu entwickeln. Hierzu gehoeren die mechanischen Fuegetechniken wie Stanznieten, Clinchen, Blindnieten sowie die sogenannten Funktionselemente zum Befestigen von Anbauteilen, wie Blind- und Stanznietmuttern und -bolzen. Diese Verfahren werden ueberwiegend fuer metallische Werkstoffe oder bei Mischbauweise angewandt. Fuer die Befestigung an Kunststoffbauteilen wird die Direktverschraubung oder die after-moulding-technik (AMTEC {sup registered}) verwendet. (orig.)

  4. Effects of Aluminum Addition on Tensile and Cup Forming Properties of Three Twinning Induced Plasticity Steels

    Science.gov (United States)

    Hong, Seokmin; Shin, Sang Yong; Kim, Hyoung Seop; Lee, Sunghak; Kim, Sung-Kyu; Chin, Kwang-Geun; Kim, Nack J.

    2012-06-01

    In the present study, a high Mn twinning induced plasticity (TWIP) steel and two Al-added TWIP steels were fabricated, and their microstructures, tensile properties, and cup formability were analyzed to investigate the effects of Al addition on deformation mechanisms in tensile and cup forming tests. In the high Mn steel, the twin formation was activated to increase the strain hardening rate and ultimate tensile strength, which needed the high punch load during the cup forming test. In the Al-added TWIP steels, the twin formation was reduced, while the slip activation increased, thereby leading to the decrease in strain hardening rate and ultimate tensile strength. As twins and slips were homogeneously formed during the tensile or cup forming test, the punch load required for the cup forming and residual stresses were relatively low, and the tensile ductility was sufficiently high even after the cup forming test. This indicated that making use of twins and slips simultaneously in TWIP steels by the Al addition was an effective way to improve overall properties including cup formability.

  5. Migration of antioxidant additives from various polyolefinic plastics into oleaginous vehicles.

    Science.gov (United States)

    Marcato, B; Guerra, S; Vianello, M; Scalia, S

    2003-05-12

    The migration of the antioxidant additives pentaerythrityl tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1010) and tris(2,4-di-tert-butylphenyl)phosphite (Irgafos 168) from polyolefinic packaging into oily vehicles was investigated. The polyolefins included in the study were from the following classes: isotactic polypropylene homopolymer (PP), ethylene-co-propylene random copolymer (RACO), ethylene-propylene heterophasic copolymer and ethylene-propylene amorphous copolymer blend (EP) and high-density polyethylene (HDPE). Each polymer was additioned with Irganox 1010 (0.15%, w/w) and Irgafos 168 (0.15%, w/w) and processed into blown bottles. To study the antioxidant release process, plastic sheets were cut from the bottles and dipped for various time intervals into a mixture of five oils (caprylic/capric triglyceride, cyclomethicone, dicaprylyl ether, isohexadecane and C(12-15) alkyl benzoate) representative of lipophilic excipients used in pharmaceutical and cosmetic formulations. After exposure to the oil medium, the non-migrated Irganox 1010 and Irgafos 168 were recovered from the polymeric matrices using microwave-assisted extraction with ethyl acetate-hexane and assayed by HPLC. The leaching of the two antioxidants varied remarkably depending on the polyolefin crystallinity and structure. The amount of Irganox 1010 transferred into the contact medium at 25 degrees C decreased in the order EP>RACO>PP>HDPE. The same polyolefin ranking was observed in the case of Irgafos 168, except for PP and HDPE which exhibited similar depletion of this additive. Migration of Irgafos 168 was greater than that of Irganox 1010 and the release of both antioxidants increased at higher temperature (50 degrees C). The obtained data are useful for the selection of polyolefinic matrices as raw-materials for the production of pharmaceutical and cosmetic containers.

  6. Part height control of laser metal additive manufacturing process

    Science.gov (United States)

    Pan, Yu-Herng

    Laser Metal Deposition (LMD) has been used to not only make but also repair damaged parts in a layer-by-layer fashion. Parts made in this manner may produce less waste than those made through conventional machining processes. However, a common issue of LMD involves controlling the deposition's layer thickness. Accuracy is important, and as it increases, both the time required to produce the part and the material wasted during the material removal process (e.g., milling, lathe) decrease. The deposition rate is affected by multiple parameters, such as the powder feed rate, laser input power, axis feed rate, material type, and part design, the values of each of which may change during the LMD process. Using a mathematical model to build a generic equation that predicts the deposition's layer thickness is difficult due to these complex parameters. In this thesis, we propose a simple method that utilizes a single device. This device uses a pyrometer to monitor the current build height, thereby allowing the layer thickness to be controlled during the LMD process. This method also helps the LMD system to build parts even with complex parameters and to increase material efficiency.

  7. Additive Manufacturing: Multi Material Processing and Part Quality Control

    DEFF Research Database (Denmark)

    Pedersen, David Bue

    -ended. What is to hope is that future research will tie these ends with the emerge of a fully developed system. Additive Multi Material Manufacturing Additive Manufacturing share close family bonds with CNC machine tools. State-of-the-art CNC machine tools of today are multi-axis hybrid machines....... Abendoflathes,mills,grindersinoneplatform. Ifhistoryrepeatitself, hybrid additive manufacturing machines will emerge as the field evolve. It is sought to fuel this, by developing a flexible multi material manufacturing platform that will permit fundamental research towards a second generation additive...... manufacturing system that truly will be a universally applicable manufacturing machine. A desktop sized factory. Not merely the development of such machine is undertaken, also examined is the possibility to additively manufacture complex electromechanical systems, as a step towards being able to autonomously...

  8. Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology.

    Science.gov (United States)

    Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

    2016-07-01

    Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece.

  9. Migration from food contact plastics. Part I. Establishment and aims of the PIRA project.

    Science.gov (United States)

    Tice, P A; McGuinness, J D

    1987-01-01

    In the European Community regulatory approaches adopted by individual Member States to the control of food contact plastics differ markedly and, as a result, the European Commission has identified a need for harmonized legislation in this sector. The Commission requested its Scientific Committee for Food to advise on the toxicity of monomers and other starting substances used in the production of such plastics and the Committee's report has recently been published. It is apparent that, although some monomers have been studied in depth, for many little or no information was available to the Committee on either the levels migrating into food or their likely toxic effects. The Committee has requested that such information be provided within 3 years. Following discussions between the UK Ministry of Agriculture, Fisheries and Food, PIRA and companies involved in either the manufacture or use of food contact plastics, a Project has been established at PIRA to develop sensitive analytical procedures for the relevant UK-required monomers and to provide the required migration data. As a second part to this project the methodology for determining overall migration is being examined with a view to resolving existing experimental difficulties. The first analytical methods to be developed in the project are those for the determination or terephthalic acid and isophthalic acid. Residual levels of these monomers in plastics and the quantities migrating into food simulants and food have been shown to be very low.

  10. ABOUT FOOD ADDITIVES AS IMPORTANT PART OF FUNCTIONAL FOOD

    OpenAIRE

    Umida Khodjaeva; Tatiana Bojňanská; Vladimír Vietoris; Oksana Sytar

    2013-01-01

    The main characteristics and classification of food additives, which are common in the food production, have been described in the present review. The ways of food additives classification, source of nature, main antioxidants, food colouring, flavours, flavor enhancers, bulking agents, stabilizers, sweeteners which were collected from literature based on structural and biochemical characteristics with description of source and possible effects on human, organisms and environment have been pre...

  11. The exponentiated Hencky-logarithmic strain energy: part III—coupling with idealized multiplicative isotropic finite strain plasticity

    Science.gov (United States)

    Neff, Patrizio; Ghiba, Ionel-Dumitrel

    2016-03-01

    We investigate an immediate application in finite strain multiplicative plasticity of the family of isotropic volumetric-isochoric decoupled strain energies F mapsto W_eH(F):= widehat{W}_eH(U) := μ/k e^{k | dev_n log {U}|^2}+κ/2 {widehat{k}} e^{widehat{k} [ tr(log U)]^2}&quad if& det F > 0, + ∞ & quad if & det F ≤ 0, based on the Hencky-logarithmic (true, natural) strain tensor {log U} . Here, {μ > 0} is the infinitesimal shear modulus, {κ=2 μ+3λ/3 > 0} is the infinitesimal bulk modulus with λ the first Lamé constant, {k,widehat{k}} are additional dimensionless material parameters, {F=nabla \\varphi} is the gradient of deformation, {U=√{F^T F}} is the right stretch tensor, and dev n {log {U} =log {U}-1/n tr(log {U})\\cdot{1}} is the deviatoric part of the strain tensor {log U} . Based on the multiplicative decomposition {F=F_e F_p} , we couple these energies with some isotropic elasto-plastic flow rules {F_p {dt}/[F_p^{-1}]in-partial χ(dev_3 Σe)} defined in the plastic distortion F p , where {partial χ} is the subdifferential of the indicator function {χ} of the convex elastic domain {E_e({Σe},1/3{σ}_{y}^2)} in the mixed-variant {Σe} -stress space, {Σe=F_e^T D_{F_e}W_iso(F_e)} , and {W_iso(F_e)} represents the isochoric part of the energy. While {W_eH} may loose ellipticity, we show that loss of ellipticity is effectively prevented by the coupling with plasticity, since the ellipticity domain of {W_eH} on the one hand and the elastic domain in {Σe} -stress space on the other hand are closely related. Thus, the new formulation remains elliptic in elastic unloading at any given plastic predeformation. In addition, in this domain, the true stress-true strain relation remains monotone, as observed in experiments.

  12. Evolution of plastic deformation and its effect on mechanical properties of laser additive repaired Ti64ELI titanium alloy

    Science.gov (United States)

    Zhao, Zhuang; Chen, Jing; Tan, Hua; Lin, Xin; Huang, Weidong

    2017-07-01

    In this paper, laser additive manufacturing (LAM) technology with powder feeding has been employed to fabricate 50%LAMed specimens (i.e. the volume fraction of the laser deposited zone was set to 50%). With aid of the 3D-DIC technique, the tensile deformation behavior of 50%LAMed Ti64ELI titanium alloy was investigated. The 50%LAMed specimen exhibits a significant characteristic of strength mismatch due to the heterogeneous microstructure. The tensile fracture of 50%LAMed specimen occurs in WSZ (wrought substrate zone), but the tensile strength is slightly higher and the plastic elongation is significantly lower than that of the wrought specimen. The 3D-DIC results shows that the 50%LAMed specimen exhibits a characteristic of dramatic plastic strain heterogeneity and the maximal strain is invariably concentrated in WSZ. The ABAQUS simulation indicates that, the LDZ (laser deposited zone) can constrain the plastic deformation of the WSZ and biaxial stresses develop at the interface after yielding.

  13. BIODEGRADABLE PLASTICS FROM A MIXTURE OF LOW DENSITY POLYETHYLENE (LDPE AND CASSAVA STARCH WITH THE ADDITION OF ACRYLIC ACID

    Directory of Open Access Journals (Sweden)

    Susilawati Susilawati

    2013-05-01

    Full Text Available A research of preparation biodegradable plastics, from LDPE and cassava starch mixture with the addition of acrylic acid, had been conducted. This research purpose to  studied compatibility properties of the material and percent weight loss during the biodegradation test. Optimum weight loss (59,26% was showed after 60 days witches LDPE and starch composition ratio 6 : 4 (w/w  while tensile strength  equal to 0,38 Kgf/mm2.  SEM characterization showed that biodegradation has occurred by  formation of hole in the biodegradable plastic surface. DTA test gave Tg = 130 °C, Tm = 230 °C and Td = 370-450 °C while FT-IR analysis showed that the biodegradable plastics have a chemistry interaction.

  14. Evaluation of Additive Manufacturing for Composite Part Molds

    Energy Technology Data Exchange (ETDEWEB)

    Duty, Chad E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Springfield, Robert M. [Tru Design, LLC, Knoxville, TN (United States)

    2015-02-01

    The ORNL Manufacturing Demonstration Facility (MDF) collaborated with Tru-Design to test the quality and durability of molds used for making fiber reinforced composites using additive manufacturing. The partners developed surface treatment techniques including epoxy coatings and machining to improve the quality of the surface finish. Test samples made using the printed and surface finished molds demonstrated life spans suitable for one-of-a-kind and low-volume applications, meeting the project objective.

  15. Determination of Polymer Additives-Antioxidants, Ultraviolet Stabilizers, Plasticizers and Photoinitiators in Plastic Food Package by Accelerated Solvent Extraction Coupled with High-Performance Liquid Chromatography.

    Science.gov (United States)

    Li, Bo; Wang, Zhi-Wei; Lin, Qin-Bao; Hu, Chang-Ying; Su, Qi-Zhi; Wu, Yu-Mei

    2015-07-01

    An analytical method for the quantitative determination of 4 antioxidants, 9 ultraviolet (UV) stabilizers, 12 phthalate plasticizers and 2 photoinitiators in plastic food package using accelerated solvent extraction (ASE) coupled with high-performance liquid chromatography-photodiode array detector (HPLC-PDA) has been developed. Parameters affecting the efficiency in the process such as extraction and chromatographic conditions were studied in order to determine operating conditions. The analytical method of ASE-HPLC showed good linearity with good correlation coefficients (R ≥ 0.9833). The limits of detection and quantification were between 0.03 and 0.30 µg mL(-1) and between 0.10 and 1.00 µg mL(-1) for 27 analytes. Average spiked recoveries for most analytes in samples were >70.4% at 10, 20 and 40 µg g(-1) spiked levels, except UV-9 and Irganox 1010 (58.6 and 64.0% spiked at 10 µg g(-1), respectively), the relative standard deviations were in the range from 0.4 to 15.4%. The methodology has been proposed for the analysis of 27 polymer additives in plastic food package. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Stochastic dynamics of Arctic sea ice Part I: Additive noise

    CERN Document Server

    Moon, Woosok

    2015-01-01

    We analyze the numerical solutions of a stochastic Arctic sea ice model with constant additive noise over a wide range of external heat-fluxes, $\\Delta F_0$, which correspond to greenhouse gas forcing. The variability that the stochasticity provides to the deterministic steady state solutions (perennial and seasonal ice states) is illustrated by examining both the stochastic paths and probability density functions (PDFs). The principal stochastic moments (standard deviation, mean and skewness) are calculated and compared with those determined from a stochastic perturbation theory described previously by Moon and Wettlaufer (2013). We examine in detail the competing roles of the destabilizing sea ice-albedo-feedback and the stabilizing long-wave radiative loss contributions to the variability of the ice cover under increased greenhouse-gas forcing. In particular, the variability of the stochastic paths at the end of summer shows a clear maximum, which is due to the combination of the increasing importance of t...

  17. The role of additive neurogenesis and synaptic plasticity in a hippocampal memory model with grid-cell like input.

    Directory of Open Access Journals (Sweden)

    Peter A Appleby

    Full Text Available Recently, we presented a study of adult neurogenesis in a simplified hippocampal memory model. The network was required to encode and decode memory patterns despite changing input statistics. We showed that additive neurogenesis was a more effective adaptation strategy compared to neuronal turnover and conventional synaptic plasticity as it allowed the network to respond to changes in the input statistics while preserving representations of earlier environments. Here we extend our model to include realistic, spatially driven input firing patterns in the form of grid cells in the entorhinal cortex. We compare network performance across a sequence of spatial environments using three distinct adaptation strategies: conventional synaptic plasticity, where the network is of fixed size but the connectivity is plastic; neuronal turnover, where the network is of fixed size but units in the network may die and be replaced; and additive neurogenesis, where the network starts out with fewer initial units but grows over time. We confirm that additive neurogenesis is a superior adaptation strategy when using realistic, spatially structured input patterns. We then show that a more biologically plausible neurogenesis rule that incorporates cell death and enhanced plasticity of new granule cells has an overall performance significantly better than any one of the three individual strategies operating alone. This adaptation rule can be tailored to maximise performance of the network when operating as either a short- or long-term memory store. We also examine the time course of adult neurogenesis over the lifetime of an animal raised under different hypothetical rearing conditions. These growth profiles have several distinct features that form a theoretical prediction that could be tested experimentally. Finally, we show that place cells can emerge and refine in a realistic manner in our model as a direct result of the sparsification performed by the dentate gyrus

  18. Preliminary Comparison of Properties between Ni-electroplated Stainless Steel Parts Fabricated with Laser Additive Manufacturing and Conventional Machining

    Science.gov (United States)

    Mäkinen, Mika; Jauhiainen, Eeva; Matilainen, Ville-Pekka; Riihimäki, Jaakko; Ritvanen, Jussi; Piili, Heidi; Salminen, Antti

    Laser additive manufacturing (LAM) is a fabrication technology, which enables production of complex parts from metallic materials with mechanical properties comparable to those of conventionally machined parts. These LAM parts are manufactured via melting metallic powder layer by layer with laser beam. Aim of this study is to define preliminarily the possibilities of using electroplating to supreme surface properties. Electrodeposited nickel and chromium as well as electroless (autocatalytic) deposited nickel was used to enhance laser additive manufactured and machined parts properties, like corrosion resistance, friction and wearing. All test pieces in this study were manufactured with a modified research AM equipment, equal to commercial EOS M series. The laser system used for tests was IPG 200 W CW fiber laser. The material used in this study for additive manufacturing was commercial stainless steel powder grade named SS316L. This SS316L is not equal to AISI 316L grade, but commercial name of this kind of powder is widely known in additive manufacturing as SS316L. Material used for fabrication of comparison test pieces (i.e. conventionally manufactured) was AISI 316L stainless steel bar. Electroplating was done in matrix cell and electroless was done in plastic sink properties of plated parts were tested within acetic acid salt spray corrosion chamber (AASS, SFS-EN-ISO 9227 standard). Adhesion of coating, friction and wearing properties were tested with Pin-On-Rod machine. Results show that in these preliminary tests, LAM parts and machined parts have certain differences due to manufacturing route and surface conditions. These have an effect on electroplated and electroless parts features on adhesion, corrosion, wearing and friction. However, further and more detailed studies are needed to fully understand these phenomena.

  19. Design of the Mould for Plastic Cap-Shaped Parts%塑料帽模具设计

    Institute of Scientific and Technical Information of China (English)

    高银变

    2001-01-01

    The design of the small thin- wall deep- cavity plastic part with a groove outside was introduced. And the structure characteristics of the mould for the part was stated. It is of certain reference value to the design of the moulds for similar plastic parts of telecommunication products.%介绍了薄壁深腔且外表有凹槽的小塑件的设计思路及对应的模具结构特点,对于通讯产品中类似塑件的模具设计有一定参考价值。

  20. Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants. Final report, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

    1997-07-01

    Part one of this research provides manufacturers of components of air-conditioning and refrigeration equipment with a useful list of lubricant additives, sources, functional properties and chemical species. The list in part one is comprised of domestic lubricant additive suppliers and the results of a literature search that was specifically targeted for additives reported to be useful in polyolester chemistry.

  1. Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part II. Defects.

    Science.gov (United States)

    Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

    2016-07-01

    Synchrotron X-ray tomography (SXRT) has been applied to the study of defects within three-dimensional printed titanium parts. These parts were made using the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V) as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. The samples represent a selection of complex shapes with a variety of internal morphologies. Inspection via SXRT has revealed a number of defects which may not otherwise have been seen. The location and nature of such defects combined with detailed knowledge of the process conditions can contribute to understanding the interplay between design and manufacturing strategy. This fundamental understanding may subsequently be incorporated into process modelling, prediction of properties and the development of robust methodologies for the production of defect-free parts.

  2. Plastic wrinkling prediction in thin-walled part forming process:A review

    Institute of Scientific and Technical Information of China (English)

    Liu Nan; Yang He; Li Heng; Yan Siliang

    2016-01-01

    The precision forming of thin-walled components has been urgently needed in aviation and aerospace field. However, the wrinkling induced by the compressive instability is one of the major defects in thin-walled part forming. The initiation and growth of the wrinkles are interac-tively affected by many factors such as stress states, mechanical properties of the material, geometry of the workpiece and boundary conditions. Especially when the forming process involves compli-cated boundary conditions such as multi-dies constrains, the perturbation of clearances between workpiece and dies and the contact conditions changing in time and space, etc., the predication of the wrinkling is further complicated. In this paper, the current prediction methods were summa-rized including the static equilibrium method, the energy method, the initial imperfection method, the eigenvalue buckling analysis method, the static-implicit finite element method and the dynamic-explicit finite element method. Then, a systematical comparison and summary of these methods in terms of their advantages and limitations are presented. By using a combination of explicit FE method, initial imperfection and energy conservation, a hybrid method is recommended to predict plastic wrinkling in thin-walled part forming. Finally, considering the urgent requirements of com-plex thin-walled structures’ part in aviation and aerospace field, the trends and challenges in wrin-kling prediction under complicated boundary conditions are presented.

  3. 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.

  4. 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

  5. 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.

  6. A COMPARISON OF THE TENSILE STRENGTH OF PLASTIC PARTS PRODUCED BY A FUSED DEPOSITION MODELING DEVICE

    Directory of Open Access Journals (Sweden)

    Juraj Beniak

    2015-12-01

    Full Text Available Rapid Prototyping systems are nowadays increasingly used in many areas of industry, not only for producing design models but also for producing parts for final use. We need to know the properties of these parts. When we talk about the Fused Deposition Modeling (FDM technique and FDM devices, there are many possible settings for devices and models which could influence the properties of a final part. In addition, devices based on the same principle may use different operational software for calculating the tool path, and this may have a major impact. The aim of this paper is to show the tensile strength value for parts produced from different materials on the Fused Deposition Modeling device when the horizontal orientation of the specimens is changed.

  7. Catalytic thermal cracking of post-consumer waste plastics to fuels: Part 1 - Kinetics and optimization

    Science.gov (United States)

    Thermogravimetric analysis (TGA) was used to investigate thermal and catalytic pyrolysis of waste plastics such as prescription bottles (polypropylene/PP), high density polyethylene, landfill liners (polyethylene/PE), packing materials (polystyrene/PS), and foams (polyurethane/PU) into crude plastic...

  8. Improving the quality of polymer-coated urea with recycled plastic, proper additives, and large tablets.

    Science.gov (United States)

    Yang, Yue-Chao; Zhang, Min; Li, Yuncong; Fan, Xiao-Hui; Geng, Yu-Qing

    2012-11-14

    Polymer-coated urea (PCU) has great potential for increasing crop production and enhancing nitrogen (N) fertilizer use efficiency, benefiting the ecosystem. However, current PCUs are used only in a limited market, and the main obstacle to the wider use of PCUs is high cost compared to that of conventional N fertilizers. In this study, the low cost PCU and large tablet polymer-coated urea (LTPCU) were prepared by using recycling polystyrene foam and various sealants as the coating materials. The structural and chemical characteristics of the coating shells of the coated fertilizers were examined. The N release characteristics of coated fertilizers were determined in 25 °C water under laboratory conditions. The relationship between the N release longevity and the amount of coating material and the percentage of different sealants were evaluated. The results indicated that recycling polystyrene foam was the ideal coating material of the controlled release fertilizer. The polyurethane that was synthesized by the reaction of castor oil and isocyanate was better than the wax as the additive to delay the N release rate of coated urea. The coating material used for LTPCU was 70-80% less than those used for commercial PCUs under the same N release longevity. The cost of the recycling polystyrene foam used for coating one ton of pure N of the LTPCU was about one-seventh to one-eighth of the cost of the traditional polymer used for the commercial PCU. The experimental data showed that the LTPCU with good controlled-release capacities, being economical and eco-friendly, could be promising for wide use in agriculture and horticulture.

  9. Generalized requirements and decompositions for the design of test parts for micro additive manufacturing research

    DEFF Research Database (Denmark)

    Thompson, Mary Kathryn; Clemmensen, Line Katrine Harder

    2015-01-01

    level decompositions for the design of test parts and the design of experiments to characterize micro additive manufacturing processes. While the test parts and the experiments described are still work in progress, the generic requirements derived from them can serve as a starting point for the design......The design of experimental test parts to characterize micro additive manufacturing (AM) processes is challenging due to the influence of the manufacturing and metrology processes. This work builds on the lessons learned from a case study in the literature to derive generalized requirements and high...... of other micro additive manufacturing related studies and their decompositions can help structure future work....

  10. Parametric and non-parametric modeling of short-term synaptic plasticity. Part II: Experimental study.

    Science.gov (United States)

    Song, Dong; Wang, Zhuo; Marmarelis, Vasilis Z; Berger, Theodore W

    2009-02-01

    This paper presents a synergistic parametric and non-parametric modeling study of short-term plasticity (STP) in the Schaffer collateral to hippocampal CA1 pyramidal neuron (SC) synapse. Parametric models in the form of sets of differential and algebraic equations have been proposed on the basis of the current understanding of biological mechanisms active within the system. Non-parametric Poisson-Volterra models are obtained herein from broadband experimental input-output data. The non-parametric model is shown to provide better prediction of the experimental output than a parametric model with a single set of facilitation/depression (FD) process. The parametric model is then validated in terms of its input-output transformational properties using the non-parametric model since the latter constitutes a canonical and more complete representation of the synaptic nonlinear dynamics. Furthermore, discrepancies between the experimentally-derived non-parametric model and the equivalent non-parametric model of the parametric model suggest the presence of multiple FD processes in the SC synapses. Inclusion of an additional set of FD process in the parametric model makes it replicate better the characteristics of the experimentally-derived non-parametric model. This improved parametric model in turn provides the requisite biological interpretability that the non-parametric model lacks.

  11. A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing, Part II: Additive Manufacturing and Characterization of Polymer Composites

    Science.gov (United States)

    Chuang, Kathy C.; Grady, Joseph E.; Arnold, Steven M.; Draper, Robert D.; Shin, Eugene; Patterson, Clark; Santelle, Tom; Lao, Chao; Rhein, Morgan; Mehl, Jeremy

    2015-01-01

    This publication is the second part of the three part report of the project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing" funded by NASA Aeronautics Research Institute (NARI). The objective of this project was to conduct additive manufacturing to produce aircraft engine components by Fused Deposition Modeling (FDM), using commercially available polyetherimides-Ultem 9085 and experimental Ultem 1000 mixed with 10% chopped carbon fiber. A property comparison between FDM-printed and injection molded coupons for Ultem 9085, Ultem 1000 resin and the fiber-filled composite Ultem 1000 was carried out. Furthermore, an acoustic liner was printed from Ultem 9085 simulating conventional honeycomb structured liners and tested in a wind tunnel. Composite compressor inlet guide vanes were also printed using fiber-filled Ultem 1000 filaments and tested in a cascade rig. The fiber-filled Ultem 1000 filaments and composite vanes were characterized by scanning electron microscope (SEM) and acid digestion to determine the porosity of FDM-printed articles which ranged from 25 to 31%. Coupons of Ultem 9085, experimental Ultem 1000 composites and XH6050 resin were tested at room temperature and 400F to evaluate their corresponding mechanical properties. A preliminary modeling was also initiated to predict the mechanical properties of FDM-printed Ultem 9085 coupons in relation to varied raster angles and void contents, using the GRC-developed MAC/GMC program.

  12. On estimating the phase of a periodic waveform in additive Gaussian noise, part 3

    Science.gov (United States)

    Rauch, L. L.

    1991-01-01

    Motivated by advances in signal processing technology that support more complex algorithms, researchers have taken a new look at the problem of estimating the phase and other parameters of a nearly periodic waveform in additive Gaussian noise, based on observation during a given time interval. Parts 1 and 2 are very briefly reviewed. In part 3, the actual performances of some of the highly nonlinear estimation algorithms of parts 1 and 2 are evaluated by numerical simulation using Monte Carlo techniques.

  13. Femtosecond Laser Post-Processing of Metal Parts Produced by Laser Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Mingareev Ilya

    2013-11-01

    Full Text Available High-repetition rate femtosecond laser radiation was utilized to improve surface quality of metal parts manufactured by laser additive techniques. This novel approach can be used to postprocess parts made of heat-sensitive materials, and to attain the designed net shape with micrometer precision.

  14. A novel method to fabricate TiAl intermetallic alloy 3D parts using additive manufacturing

    Directory of Open Access Journals (Sweden)

    J.J.S. Dilip

    2017-04-01

    Full Text Available The present work explores the feasibility of fabricating porous 3D parts in TiAl intermetallic alloy directly from Ti–6Al–4V and Al powders. This approach uses a binder jetting additive manufacturing process followed by reactive sintering. The results demonstrate that the present approach is successful for realizing parts in TiAl intermetallic alloy.

  15. Effect of addition of butyl benzyl phthalate plasticizer and zinc oxide nanoparticles on mechanical properties of cellulose acetate butyrate/organoclay biocomposite

    Science.gov (United States)

    Putra, B. A. P.; Juwono, A. L.; Rochman, N. T.

    2017-07-01

    Plastics as packaging materials and coatings undergo increasing demands globally each year. This pose a serious problem to the environment due to its difficulty to degrade. One solution to addressing the problem of plastic wastes is the use of bioplastics. According to the European Organization Bioplastic, one of the biodegradable plastics is derivative of cellulose. To improve mechanical properties of bioplastic, biocomposites are made with the addition of certain additives and fillers. The aim of this study is to investigate the effect of butyl benzyl phthalate plasticizer (BBP) and ZnO nanoparticles addition on mechanical properties of cellulose acetate butyrate (CAB) / organoclay biocomposite. ZnO nanoparticles synthesized from commercial ZnO precursor by using sol-gel size reduction method. ZnO was dissolved in a solution of citric acid in the ratio 1:1 to 1:5 to form zinc citrate. Zinc citrate then decomposed by calcination at temperature of 600oC. ZnO nanoparticles with an average size of 44.4 nm is obtained at a ratio of 1: 2. The addition of ZnO nanoparticles and BBP plasticizer was varied to determine the effect on the mechanical properties of biocomposite. The addition of 10 - 15 %wt ZnO nanoparticles and 30 - 40 %wt BBP plasticizer was studied to determine the effect on the tensile strength, elongation, and modulus elasticity of the biocomposites. Biocomposite films were made by using solution casting method with acetone as solvent. The addition of plasticizer BBP and ZnO nanoparticles by 30% and 10% made biocomposite has a tensile strength of 2.223 MPa.

  16. The synthesis and characterization of hydrogel chitosan-alginate with the addition of plasticizer lauric acid for wound dressing application

    Science.gov (United States)

    Izak Rudyardjo, Djony; Wijayanto, Setiawan

    2017-05-01

    The writers conducted a study about the synthesis and characterization of hydrogel chitosan-alginate by addition plasticizer lauric acid for wound dressing application. The purpose was to find out the impact of lauric acid concentration variation on hydrogel chitosan-alginate to get the best mechanical and physical properties to be applied as wound dressing in accordance with existing standards. This study used commercially chitosan from extract of shells crab, commercially-available alginate from the extract of sargassum sp, and commercial lauric acid from palm starch. The addition of lauric acid was aimed to repair mechanical properties of hydrogel. The composition of chitosan-alginate is 4:1 (v/v), while the lauric acid concentration variations are 0%, 1%, 2%, 3%, 4%, and 5% w/v. The characterization of mechanical properties test (Tensile strength and Elongation at break) at hydrogel showed the hydrogel chitosan-alginate-lauric acid have the characteristic which meets the standard of mechanical properties for human skin. The best performance of hydrogel chitosan-alginate-lauric acid was obtained by increasing luric acid concentration by 4%, which has a thickness value of 125.46±0.63 µm, elongation 28.89±1.01 %, tensile strength (9.01±0.65) MPa, and ability to absorb liquids (601.45 ±1.24) %.

  17. A new pair of hard-soft plastic combination for precision manufacturing of two component plastic parts

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Marhöfer, David Maximilian

    2011-01-01

    Two component (2k) injection moulding is growing rapidly even in the field of precision micro moulding. Besides combining different material properties in the same product, two component moulding can eliminate many assembly steps in manufacturing process chain. One of the biggest technical...... challenges associated with 2k moulding is the unavailability of suitable two component material combinations which can meet the diverse requirement from product and process point of view. This paper presents a new pair of commercial polymer materials (BASF Ultramid A3EG10 and Kraiburg TPE Thermolast K TC5PCZ......-of-the-art two component micro moulding machine named Formica Plast from Desma Tec. The tests performed on the demonstrator showed potential for the material pair to be used in high precision two component moulding applications. The adhesion between the two materials, replication quality of the 2k part, sealing...

  18. Inelastic deformation of metal matrix composites: Plasticity and damage mechanisms, part 2

    Science.gov (United States)

    Majumdar, B. S.; Newaz, G. M.

    1992-01-01

    The inelastic deformation mechanisms for the SiC (SCS-6)/Ti-15-3 system were studied at 538 C (1000 F) using a combination of mechanical measurements and detailed microstructural examinations. The objectives were to evaluate the contributions of plasticity and damage to the overall MMC response, and to compare the room temperature and elevated temperature deformation behaviors. Four different laminates were studied: (0)8, (90)8,(+ or -45)2s, and (0/90)2s, with the primary emphasis on the unidirectional (0)8, and (90)8 systems. The elevated temperature responses were similar to those at room temperature, involving a two-stage elastic-plastic type of response for the (0)8 system, and a characteristic three-stage deformation response for the (90)8 and (+ or -45)2s systems. The primary effects of elevated temperatures included: (1) reduction in the 'yield' and failure strengths; (2) plasticity through diffused slip rather than concentrated planar slip (which occurred at room temperature); and (3) time-dependent deformation. The inelastic deformation mechanism for the (0)8 MMC was dominated by plasticity at both temperatures. For the (90)8 and (+ or -45)2s MMCs, a combination of damage and plasticity contributed to the deformation at both temperatures.

  19. Facilitated Leaching of Additive-Derived PBDEs from Plastic by Seabirds' Stomach Oil and Accumulation in Tissues.

    Science.gov (United States)

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

    2015-10-06

    Our previous study suggested the transfer of polybrominated diphenyl ether (PBDE) flame retardants from ingested plastics to seabirds' tissues. To understand how the PBDEs are transferred, we studied leaching from plastics into digestive fluids. We hypothesized that stomach oil, which is present in the digestive tract of birds in the order Procellariiformes, acts as an organic solvent, facilitating the leaching of hydrophobic chemicals. Pieces of plastic compounded with deca-BDE were soaked in several leaching solutions. Trace amounts were leached into distilled water, seawater, and acidic pepsin solution. In contrast, over 20 times as much material was leached into stomach oil, and over 50 times as much into fish oil (a major component of stomach oil). Analysis of abdominal adipose, liver tissue, and ingested plastics from 18 wild seabirds collected from the North Pacific Ocean showed the occurrence of deca-BDE or hexa-BDEs in both the tissues and the ingested plastics in three of the birds, suggesting transfer from the plastic to the tissues. In birds with BDE209 in their tissues, the dominance of BDE207 over other nona-BDE isomers suggested biological debromination at the meta position. Model calculation of PBDE exposure to birds based on the results of the leaching experiments combined with field observations suggested the dominance of plastic-mediated internal exposure to BDE209 over exposure via prey.

  20. Synthesis and characterization of an additive type super plasticizers obtained from plastics cups of polystyrene; Sintese e caracterizacao de um aditivo tipo superplastificantes obtido a partir de copos plasticos de poliestireno

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Carolina G.L.; Freire, Carolina B.; Tello, Cledola C. de O., E-mail: carolina_gabriela316@yahoo.com.br, E-mail: cbf@cdtn.br, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-BH), Belo Horizonte, MG (Brazil)

    2013-07-01

    This paper aims to describe the synthesis of an additive type superplasticizer from alternative material - plastic cups used of polystyrene - and characterize it physically and chemically in order to verify their efficiency and compare it with a commercial use superplasticizer. Following the search, the synthesized superplasticizer is used in mortars to assess their efficiency.

  1. Wood plastic composites from modified wood. Part 3. Durability of WPCs with bioderived matrix

    NARCIS (Netherlands)

    Westin, M.; Larsson-Brelid, P.; Segerholm, B.K.; Oever, van den M.J.A.

    2008-01-01

    The decay resistance of fully bio-derived wood plastic composites, WPCs, was tested in both laboratory and field tests. The laboratory tests were performed according to modified versions of AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils) and the field tests according to EN 2

  2. Inelastic Deformation of Metal Matrix Composites. Part 1; Plasticity and Damage Mechanisms

    Science.gov (United States)

    Majumdar, B. S.; Newaz, G. M.

    1992-01-01

    The deformation mechanisms of a Ti 15-3/SCS6 (SiC fiber) metal matrix composite (MMC) were investigated using a combination of mechanical measurements and microstructural analysis. The objectives were to evaluate the contributions of plasticity and damage to the overall inelastic response, and to confirm the mechanisms by rigorous microstructural evaluations. The results of room temperature experiments performed on 0 degree and 90 degree systems primarily are reported in this report. Results of experiments performed on other laminate systems and at high temperatures will be provided in a forthcoming report. Inelastic deformation of the 0 degree MMC (fibers parallel to load direction) was dominated by the plasticity of the matrix. In contrast, inelastic deformations of the 90 degree composite (fibers perpendicular to loading direction) occurred by both damage and plasticity. The predictions of a continuum elastic plastic model were compared with experimental data. The model was adequate for predicting the 0 degree response; however, it was inadequate for predicting the 90 degree response largely because it neglected damage. The importance of validating constitutive models using a combination of mechanical measurements and microstructural analysis is pointed out. The deformation mechanisms, and the likely sequence of events associated with the inelastic deformation of MMCs, are indicated in this paper.

  3. Effects of build parameters on linear wear loss in plastic part produced by fused deposition modeling

    Science.gov (United States)

    Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal

    2017-07-01

    Fused Deposition Modeling (FDM) is one of the prominent additive manufacturing technologies for producing polymer products. FDM is a complex additive manufacturing process that can be influenced by many process conditions. The industrial demands required from the FDM process are increasing with higher level product functionality and properties. The functionality and performance of FDM manufactured parts are greatly influenced by the combination of many various FDM process parameters. Designers and researchers always pay attention to study the effects of FDM process parameters on different product functionalities and properties such as mechanical strength, surface quality, dimensional accuracy, build time and material consumption. However, very limited studies have been carried out to investigate and optimize the effect of FDM build parameters on wear performance. This study focuses on the effect of different build parameters on micro-structural and wear performance of FDM specimens using definitive screening design based quadratic model. This would reduce the cost and effort of additive manufacturing engineer to have a systematic approachto make decision among the manufacturing parameters to achieve the desired product quality.

  4. Application of Snap Fit in Plastic Parts%搭扣配合在塑胶件中的应用

    Institute of Scientific and Technical Information of China (English)

    何佳林; 王新科; 汤庆儒

    2016-01-01

    搭扣配合在塑胶产品中的应用非常广泛,搭扣配合可以在不使用粘合剂或铆接等方法的情况下实现塑胶零件之间的连接紧固。文中阐明了悬臂搭扣、环形搭扣和扭转搭扣3种搭扣配合形式,并通过对这3种搭扣配合形式的基本设计要点进行归纳总结,提炼具体参数,为塑胶件搭扣设计提供理论基础,达到降低制造模具过程中模具返修率的目的。%Snap fit is widely used in the plastic products. Snap fit can realize fastening connection among the plastic parts without the use of an adhesive or caulking. The paper introduces 3 snap fit forms, including the boom snap, the snap ring, and the snap-fit twist clasp. Through these 3 forms of snap fit, summarize the basic design elements, extract specific parameters, provide a theoretical basis for the design of plastic parts snap fit, and reduce mould repair rate in mould manufacturing process.

  5. Coding Teaching for Simultaneity and Connections: Examining Teachers' Part-Whole Additive Relations Instruction

    Science.gov (United States)

    Ekdahl, Anna-Lena; Venkat, Hamsa; Runesson, Ulla

    2016-01-01

    In this article, we present a coding framework based on simultaneity and connections. The coding focuses on microlevel attention to three aspects of simultaneity and connections: between representations, within examples, and between examples. Criteria for coding that we viewed as mathematically important within part-whole additive relations…

  6. 基于Siemens NX软件对塑件产品的分模设计%Based on Siemens NX Software Parting Design of Plastic Product

    Institute of Scientific and Technical Information of China (English)

    苏丹娅

    2016-01-01

    本文通过实例分析塑料模具的分型面设计,分析塑料模具分型面的设计方法、分类,总结手工分模和自动分模时对于复杂分型面的应对方法。%In this paper, through an example analysis of plastic mold parting surface design, analysis of plastic mold parting surface design method, classiifcation, summary manual parting and automatic parting of the complex parting surface of the response method.

  7. 77 FR 54930 - Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics...

    Science.gov (United States)

    2012-09-06

    ... Employment and Training Administration Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A... plastic parts. New information shows that Fortis Plastics is now called Carlyle Plastics and Resins. In... of Carlyle Plastics and Resins, formerly known as Fortis Plastics, a subsidiary of...

  8. Reduction of Surface Roughness by Means of Laser Processing over Additive Manufacturing Metal Parts

    Directory of Open Access Journals (Sweden)

    Vittorio Alfieri

    2016-12-01

    Full Text Available Optimization of processing parameters and exposure strategies is usually performed in additive manufacturing to set up the process; nevertheless, standards for roughness may not be evenly matched on a single complex part, since surface features depend on the building direction of the part. This paper aims to evaluate post processing treating via laser surface modification by means of scanning optics and beam wobbling to process metal parts resulting from selective laser melting of stainless steel in order to improve surface topography. The results are discussed in terms of roughness, geometry of the fusion zone in the cross-section, microstructural modification, and microhardness so as to assess the effects of laser post processing. The benefits of beam wobbling over linear scanning processing are shown, as heat effects in the base metal are proven to be lower.

  9. Antiplasticization and plasticization of Matrimid® asymmetric hollow fiber membranes. Part B. Modeling

    KAUST Repository

    Lee, Jong Suk

    2010-03-15

    A previous paper characterized effects of exposure of Matrimid® asymmetric fibers to either toluene or n-heptane or a combination of both contaminants during permeation. In all cases, reductions in the carbon dioxide permeance and the carbon dioxide/methane selectivity were observed for both annealed and non-annealed samples. In this paper, the respective potential impacts of competitive sorption, fiber compaction, and antiplasticization/plasticization on membrane performance during contaminant exposure are quantified and analyzed. The combined impact of competitive sorption and antiplasticization/plasticization are shown to account for the loss in membrane performance observed during exposure to highly sorbing feed stream contaminants. The dual mode transport model for penetrant mixtures was used to explain reduction in CO2 permeance due to competitive sorption effects, while free volume-based modeling explained decrease in CO2 permeance due to antiplasticization. Finally, the impact on CO2 permeance during exposure of the annealed Matrimid® fibers to contaminants is analyzed. The analysis is based on reduction in segmental mobility expected due to reduction of residual unrelaxed volume as compared to unanealed sample. © 2010.

  10. Mechanism of plasticity Development for Ceramic Dough (Part 2). Investigation on Plasticity by Particle Packing Structure; Seramiku nendo no kasakusei hatsugen mekanizumu 2. Nendo juten kozo to kasakusei

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Shuji. [Wet Forming of Ceramics Technology Research Association, Aichi (Japan); Ichikawa, Yukari.; Ishida, Hideki. [INAX Corporation, Aichi (Japan); Shibasaki, Yasuo.; Oda, Kiichi. [National Industrial Research Institute of Nagoya, Aichi (Japan)

    1999-01-01

    Plasticity and packing structure of clay and alumina dough, and of alumina mixed with water-soluble and non-water-soluble plasticizers were investigated. It was found that both plastic clay dough and alumina dough with plasticizers showed a two-peak pore population. When the larger-sized pores increased in volume, the fluidity of the dough was improved. On the otherhand, when the smaller-sized pores decreased in volume, a high rigidity was showed. An aggregate structure was observed in the clay and the dough mixed with water-soluble plasticizer like methyl cellulose. Plasticity was generated when the aggregates were deformed by using the larger-sized pores among each aggregate. The non-water-soluble curdlan did not dissolve in the dough and remained in gel. The larger-sized pores were formed by the gel, whose deformation produced plasticity. It was understood that plasticity is fenerated when either the aggregates or the gel act as a buffer in the dough and enhance deformation of the dough. (author)

  11. 薄壁塑料件注塑模具设计%PLASTIC MOULD DESIGN OF THIN-WALL PLASTIC PARTS

    Institute of Scientific and Technical Information of China (English)

    苏瞧忠

    2011-01-01

    The design process of thin-wall plastic was analyzed, gate style and position was choosen according to the mould structure, plastic injection molding process, plastic surface quality etc. Producing reliable and dimensinally stable product was realized by optimizing plastic wall thickness and the mould structure, and the product could meet the quality requirement. These plastic mould design essentials were summarized.%分析薄壁塑料件的设计过程,重点阐述根据模具结构、塑料件成型工艺、塑料件表面质量等来选择进胶方式和位置.通过优化塑料件壁厚和模具结构,实现生产可靠、尺寸稳定,质量满足要求,并总结此类塑料件的模具设计要点.

  12. Experimental Investigation into Suitable Process Conditions for Plastic Injection Molding of Thin-Sheet Parts

    Directory of Open Access Journals (Sweden)

    Dyi-Cheng Chen

    2014-04-01

    Full Text Available This study performs an experimental investigation into the effects of the process parameters on the surface quality of injection molded thin-sheet thermoplastic components. The investigations focus specifically on the shape, number and position of the mold gates, the injection pressure and the injection rate. It can be seen that the gravity force entering point improved filling of the cavity for the same forming time and injection pressure. Moreover, it shows the same injection pressure and packing time, the taper-shape gate yields a better surface appearance than the sheet-shape gate. The experimental results provide a useful source of reference in suitable the process conditions for the injection molding of thin-sheet plastic components.

  13. Integration of additive manufacturing and inkjet printed electronics: a potential route to parts with embedded multifunctionality

    Directory of Open Access Journals (Sweden)

    Stringer Jonathan

    2016-01-01

    Full Text Available Additive manufacturing, an umbrella term for a number of different manufacturing techniques, has attracted increasing interest recently for a number of reasons, such as the facile customisation of parts, reduced time to manufacture from initial design, and possibilities in distributed manufacturing and structural electronics. Inkjet printing is an additive manufacturing technique that is readily integrated with other manufacturing processes, eminently scalable and used extensively in printed electronics. It therefore presents itself as a good candidate for integration with other additive manufacturing techniques to enable the creation of parts with embedded electronics in a timely and cost effective manner. This review introduces some of the fundamental principles of inkjet printing; such as droplet generation, deposition, phase change and post-deposition processing. Particular focus is given to materials most relevant to incorporating structural electronics and how post-processing of these materials has been able to maintain compatibility with temperature sensitive substrates. Specific obstacles likely to be encountered in such an integration and potential strategies to address them will also be discussed.

  14. Electron Backscatter Diffraction Analysis of Inconel 718 Parts Fabricated by Selective Laser Melting Additive Manufacturing

    Science.gov (United States)

    Wang, Xiaoqing; Chou, Kevin

    2017-02-01

    In this study, the crystallographic texture of an Inconel 718 part fabricated by selective laser melting was investigated. The front surface (X-Z plane) microstructure is characterized by the columnar grains growing along the build direction, and the width of columnar grains is in the range of about 75-150 µm, with the bottom layers having narrower grains as a result of a higher cooling rate. In addition to equiaxed grains, the top surface (X-Y plane) has a feature of patch patterns resulting from the laser scanning strategy. Based on the electron backscatter diffraction results, there appears only weak crystallographic texture in both the X-Z plane and the X-Y plane of the part. From the grain boundary map, the microstructures are composed of high-angle boundaries with a larger fraction of subgrain boundaries.

  15. Electron Backscatter Diffraction Analysis of Inconel 718 Parts Fabricated by Selective Laser Melting Additive Manufacturing

    Science.gov (United States)

    Wang, Xiaoqing; Chou, Kevin

    2016-11-01

    In this study, the crystallographic texture of an Inconel 718 part fabricated by selective laser melting was investigated. The front surface (X-Z plane) microstructure is characterized by the columnar grains growing along the build direction, and the width of columnar grains is in the range of about 75-150 µm, with the bottom layers having narrower grains as a result of a higher cooling rate. In addition to equiaxed grains, the top surface (X-Y plane) has a feature of patch patterns resulting from the laser scanning strategy. Based on the electron backscatter diffraction results, there appears only weak crystallographic texture in both the X-Z plane and the X-Y plane of the part. From the grain boundary map, the microstructures are composed of high-angle boundaries with a larger fraction of subgrain boundaries.

  16. Scanning laser ultrasound and wavenumber spectroscopy for in-process inspection of additively manufactured parts

    Science.gov (United States)

    Koskelo, EliseAnne C.; Flynn, Eric B.

    2016-04-01

    We present a new in-process laser ultrasound inspection technique for additive manufacturing. Ultrasonic energy was introduced to the part by attaching an ultrasonic transducer to the printer build-plate and driving it with a single-tone, harmonic excitation. The full-field response of the part was measured using a scanning laser Doppler vibrometer after each printer layer. For each scan, we analyzed both the local amplitudes and wavenumbers of the response in order to identify defects. For this study, we focused on the detection of delamination between layers in a fused deposition modeling process. Foreign object damage, localized heating damage, and the resulting delamination between layers were detected in using the technique as indicated by increased amplitude and wavenumber responses within the damaged area.

  17. Applicability of chemical vapour polishing of additive manufactured parts to meet production-quality

    DEFF Research Database (Denmark)

    Pedersen, D. B.; Hansen, H. N.; Nielsen, J. S.

    2014-01-01

    The Fused Deposition Modelling (FDM) method is the most rapidly growing Additive Manufacturing (AM) method[1]. FDM employs a 2.5D deposition scheme which induce a step-ladder shaped surface definition [2], with seams of the individual layers clearly visible[3]. This paper investigate to which...... extend chemical vapour polishing can be applied to eliminate the layered surfaces from FDM, so that a polished surface quality is obtained. It is quantified to what extend parts can be vapour polished and how geometrical and mechanical properties alter. The fundamental question is whether the surfaces...

  18. Risk reduction in dimension inspection of the plastic injection-molded parts from mechatronic devices by using optical 3D measuring techniques

    Directory of Open Access Journals (Sweden)

    Braga Ion Cristian

    2017-01-01

    Full Text Available As of the definition presented by Harashima, Tomizuka, and Fukada in 1996, the mechatronics is the synergistic combination of precision mechanical engineering, electronic control and systems thinking in the design of products and manufacturing processes. The most of the mechatronic devices need the precise dimensions of the plastic parts, as long as the combination of those parts leads to a final haptic characteristic defined within specific limits or when the certain travel way is linked with an electrical contact. The increasing of the risks to produce bad mechatronic devices are directly related to the combination of the plastic injectionmolded parts out of different cavities. The paper’s aim is to present reducing of the risks to have bad final parts assembled with the components out of plastic injection-molded parts by using optical 3D measuring techniques at first validation of the parts out of the tool and setting parameters in the injection machines. The shrinkage and the warpage are more easily detected in that way and this will support first article inspection, but also during the entire production process. A case study presents the analysis of the data coming from the measurements of the plastic parts from each cavity and the combination of those parts, by using the ATOS inspection software. The CAD data are compared with the measured ones and the differences will be visible in the colored plotted areas, also the differences of the parts out of distinct cavities will be also displayed by overlaying of the measurements.

  19. STUDY CONCERNING THE INFLUENCE OF CERTAIN HYDROPHILIC AUXILIARIES ON THE PROPERTIES OF THE PLASTICIZED POLYVINYL CHLORIDE POROUS FILMS Part II-HYGIENIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    BĂLĂU MÎNDRU Tudorel

    2015-05-01

    Full Text Available The purpose of this paper was to obtain certain PVC films with improved hygienic properties, with applications both in the artificial leather industry and in other domains. This was done by introducing certain hydrophilic auxiliaries with free chemical functions into the chemical structure of the PVC films, such as: collagen hydrolysates (CH, hydroxyl-terminated polydimethylsiloxane (HTPDMS and nonylphenol ethoxylate (NPE. The use of these hydrophilic auxiliaries combined with the action of the high frequency electric fields (H.F.E.F. allows the attainment of cellular structures where the walls of the cells obtained from the expanding process display an enhanced humidity absorption. The collagen hydrolysates used to obtain the plasticized PVC porous films was obtained by electrolytic hydrolysis starting from Chamois leather powder waste resulting from buffing operation, according to a methodology described in a previous paper. The first part of this study was concerned with the influence of the addition of hydrophilic agents upon the moisture sorption of the plasticized PVC porous films. In this paper, there was investigated the water vapour and air permeability as well as the water vapour absorption of the porous films expanded in the H.F.E.F. in correlation with the nature and the recipe variant of the hydrophilic auxiliaries. The results highlighted the fact that the use of certain combinations of hydrophilic agents led to obtaining materials with adequate hygienic properties.

  20. DLP-based light engines for additive manufacturing of ceramic parts

    Science.gov (United States)

    Hatzenbichler, M.; Geppert, M.; Gruber, S.; Ipp, E.; Almedal, R.; Stampfl, J.

    2012-03-01

    In the framework of the European research project PHOCAM (http://www.phocam.eu) the involved partners are developing systems and materials for lithography-based additive manufacturing technologies (AMT) which are used for shaping advanced ceramic materials. In this approach a ceramic-filled photosensitive resin is selectively exposed layer by layer. By stacking up the individual layers with a typical layer thickness between 25 and 50μm, a three-dimensional part is built up. After structuring, a solid part consisting of a ceramic filled polymer is obtained. The polymer is afterwards burnt off and in a last step the part is sintered to obtain a fully dense ceramic part. The developed systems are based on selective exposure with DLP projection (Digital Light Processing). A key element of the developed systems is a light engine which uses digital mirror devices (DMD) in combination light emitting diodes (460nm) as light source. In the current setup DMDs with 1920x1080 pixels are used. The use of LEDs in combination with a customized optical projection system ensures a spatial and temporal homogeneity of the intensity at the build platform which is significantly better than with traditionally used light engines. The system has a resolution of 40μm and a build size of 79x43x100mm. It could be shown that this system can fabricate dense ceramic parts with excellent strength. In the case of alumina densities up to 99.6% of the theoretical density were achieved, yielding a biaxial strength of 510MPa. Besides technical ceramics like alumina it is also possible to structure bioceramics, e.g. tricalcium phosphate.

  1. A study on the applications of AI in finishing of additive manufacturing parts

    Science.gov (United States)

    Fathima Patham, K.

    2017-06-01

    Artificial intelligent and computer simulation are the technological powerful tools for solving complex problems in the manufacturing industries. Additive Manufacturing is one of the powerful manufacturing techniques that provide design flexibilities to the products. The products with complex shapes are directly manufactured without the need of any machining and tooling using Additive Manufacturing. However, the main drawback of the components produced using the Additive Manufacturing processes is the quality of the surfaces. This study aims to minimize the defects caused during Additive Manufacturing with the aid of Artificial Intelligence. The developed AI system has three layers, each layer is trying to eliminate or minimize the production errors. The first layer of the AI system optimizes the digitization of the 3D CAD model of the product and hence reduces the stair case errors. The second layer of the AI system optimizes the 3D printing machine parameters in order to eliminate the warping effect. The third layer of AI system helps to choose the surface finishing technique suitable for the printed component based on the Degree of Complexity of the product and the material. The efficiency of the developed AI system was examined on the functional parts such as gears.

  2. Characterization of fiberglass-filled diallyl phthalate plastic molding resins and molded parts

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, R.B.; Glaub, J.E.; Bonekowski, N.R.; Gillham, P.D.

    1980-12-01

    Characterization of diallyl phthalate (DAP) molding resins was undertaken by differential scanning calorimetry (DSC) and by combined size exclusion chromatography (SEC)/low angle laser light scattering (LALLS) in order to better predict moldability and storage life limits. Completeness of cure of molded parts, before and after any post-curing, was also determined by thermal analysis. Molecular weights and molecular weight distributions of the DAP molding resins by SEC/LALLS indicated that the better molding resins have lower M/sub w//M/sub n/ ratios. Association effects were observed, which could not be overcome by solvent modification alone. Determination of DAP molding resin heats of reaction by DSC indicated a linear relation between ..delta..H/sub R/ and weight percent filler for the good molding resins. DSC analyses of molded DAP parts showed that 95% cure was achieved in some as-molded parts, with a post-cure temperature of 165/sup 0/C being required to complete the cure to 100%. Thickness of the parts was a factor, with the thicker parts being 100% cured as molded. The glass transition temperature (T/sub g/) of the molded parts increased as cure was completed, to approx. 160 to 165/sup 0/C maximum. These results are consistent with a model of thermoset resin curing behavior which states that 100% cure can be achieved only if a post-curing operation is conducted above the T/sub g infinity/ (T/sub g/ at complete cure) of the polymer.

  3. Modification of water absorption capacity of a plastic based on bean protein using gamma irradiated starches as additives

    Energy Technology Data Exchange (ETDEWEB)

    Koeber, E. [Facultad de Ingenieria, Grupo de Ingenieria Bioquimica, Universidad de Buenos Aires, Paseo Colon 850, 1063, Buenos Aires (Argentina); Gonzalez, M.E. [Comision Nacional Energia Atomica, Av. Del Libertador 8250, Buenos Aires (Argentina); Gavioli, N. [Facultad de Ingenieria, Grupo de Ingenieria Bioquimica, Universidad de Buenos Aires, Paseo Colon 850, 1063, Buenos Aires (Argentina); Salmoral, E.M. [Facultad de Ingenieria, Grupo de Ingenieria Bioquimica, Universidad de Buenos Aires, Paseo Colon 850, 1063, Buenos Aires (Argentina)]. E-mail: esalmor@fi.uba.ar

    2007-01-15

    Some properties of a bean protein-starch plastic were modified by irradiation of the starch. Two kinds of starch from bean and cassava were irradiated with doses until 50 kGy before their inclusion in the composite. Water absorption of the resultant product was reduced by 36% and 60% in materials containing bean and cassava starch, respectively. A large decline in the elongation is observed till 10 kGy in both materials, while tensile strength diminished by 11% in the cassava composite.

  4. Functional nanostructures on injection molded plastic

    DEFF Research Database (Denmark)

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

    Nanotechnology can be used to make inexpensive plastic parts with functional surfaces. The plastic parts can be molded using a standard injection molding process. The nanostructures are directly transferred from the surface of the molding tool to the surface of the molded plastic part during...... the molding process. The main advantage with this method is that surface treatments and chemical additives are avoided, which minimizes health risks and simplifies recycling. Another advantage is that the unique technology enables nanostructuring of free form molded parts. The functional surfaces can have...

  5. Plasticity in allocation of nicotine to reproductive parts inNicotiana attenuata.

    Science.gov (United States)

    Baldwin, I T; Karb, M J

    1995-07-01

    Although little is known about the patterns of chemical defense allocation in reproductive tissues, optimal defense theory predicts a high constitutive allocation due to the tissues' high fitness value. To examine this prediction, we quantified the short- and long-term changes in the nicotine pools of reproductive tissues in response to both floral and leaf damage. Recently opened flowers (stage 5 capsules) do not alter their nicotine pools within a day in response to herbivory byManduca sexta larvae or mechanical damage to the corolla. Similarly, leaf damage during both vegetative and reproductive growth does not influence the nicotine pools of the first three stage-5 capsules produced. However, the nicotine pools of capsules produced later in reproductive growth were significantly larger (1.2- to 1.9-fold) on plants with leaf damage. These differences in floral nicotine pools were a result of both increases in nicotine pools of capsules on damaged plants and decreases in the nicotine pools of capsules on undamaged plants during reproductive growth. Leaf damage did not affect the rate of capsule maturation or the mass of stage-5 capsules at any time during reproductive growth. An allometric analysis of nicotine pools and biomass of reproductive parts in all stages of development from damaged and undamaged plants demonstrates that damaged plants allocated a significantly larger quantity of nicotine to reproductive parts in all stages of development than did undamaged plants. Given that nicotine is thought to be synthesized in the roots and transported to leaves and reproductive parts, nicotine could be allocated to reproductive parts in proportion to the number of developing capsules on a plant. We excised the first 27 stage-5 capsules on plants with and without leaf damage, with the expectation that plants with fewer capsules would allocate a larger amount of nicotine to the remaining capsules. In contrast to the prediction of this passive allocation model, floral

  6. The effect of thiolated additives on the properties of wheat gluten based plastics, aqueous solutions and electrospun fibers

    Science.gov (United States)

    Dong, Jing

    Wheat gluten (WG) is a promising substitute for petroleum-based plastics due to its unique ability to form a cohesive blend with viscoelastic properties once plasticized. Previous work blending WG with thiolated poly(vinyl alcohol) (TPVA) showed that both the strength and elongation of compression molded native WG bars can be improved via thiol/disulfide interchange reactions between WG and TPVA. In this study, the morphology of WG/TPVA blends was investigated by atomic force (AFM) and transmission electron microscopy (TEM), as well as by modulated dynamic scanning calorimetry (MDSC). Consistent with our earlier results, AFM and TEM imaging clearly indicated that TPVA is much more compatible with WG compared with poly(vinyl alcohol) (PVA) although there are still two phases in the blend: one WG rich phase and another TPVA rich phase. TPVA was also blended with WG in an aqueous solvent (1/1 (v/v) water/1-propanol mixture) to improve its solubility and spinnability. Control experiments were conducted with PVA and dithiothreitol (DTT) for comparison purposes. The concentration and the thiolation level of TPVA were also varied to explore the parameter space. The interactions of thiol groups from TPVA and soluble WG were found to be important during electrospinning. The fiber diameter became more uniform and the fiber quality increased very noticeably when TPVA was included. Furthermore, the time-dependent rheology behaviors of TPVA/WG and DTT/WG electrospinning solutions were investigated by using steady shear sweeps, oscillatory frequency sweeps, SE-HPLC and free -SH content determination. A two-step mechanism of interaction was proposed for DTT/WG and TPVA/WG solutions based on current results and other earlier studies. In comparison with WG and PVA/WG solutions, the reduction and reformation of disulfide linkages in both TPVA/WG and DTT/WG solutions were believed to play a key role in determining the rheological properties and molecular weight distribution of WG

  7. Looking at plastic surgery through Google Glass: part 1. Systematic review of Google Glass evidence and the first plastic surgical procedures.

    Science.gov (United States)

    Davis, Christopher R; Rosenfield, Lorne K

    2015-03-01

    Google Glass has the potential to become a ubiquitous and translational technological tool within clinical plastic surgery. Google Glass allows clinicians to remotely view patient notes, laboratory results, and imaging; training can be augmented via streamed expert master classes; and patient safety can be improved by remote advice from a senior colleague. This systematic review identified and appraised every Google Glass publication relevant to plastic surgery and describes the first plastic surgical procedures recorded using Google Glass. A systematic review was performed using PubMed National Center for Biotechnology Information, Ovid MEDLINE, and the Cochrane Central Register of Controlled Trials, following modified Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Key search terms "Google" and "Glass" identified mutually inclusive publications that were screened for inclusion. Eighty-two publications were identified, with 21 included for review. Google Glass publications were formal articles (n = 3), editorial/commentary articles (n = 7), conference proceedings (n = 1), news reports (n = 3), and online articles (n = 7). Data support Google Glass' positive impact on health care delivery, clinical training, medical documentation, and patient safety. Concerns exist regarding patient confidentiality, technical issues, and limited software. The first plastic surgical procedure performed using Google Glass was a blepharoplasty on October 29, 2013. Google Glass is an exciting translational technology with the potential to positively impact health care delivery, medical documentation, surgical training, and patient safety. Further high-quality scientific research is required to formally appraise Google Glass in the clinical setting.

  8. Evaluation of a local exhaust system used in the manufacture of small parts made of reinforced plastic.

    Science.gov (United States)

    Lazure, L P

    2000-09-01

    Fiber-reinforced plastics are used to manufacture a large variety of products, particularly for the transportation sector. Hand lay-up molding and projection molding are the main methods of manufacture. The users of these processes are exposed to appreciable emissions of styrene; in Quebec, more than 3000 workers work in this industry. A statistical analysis of styrene concentrations measured over a five-year period by the Institut de recherche en santé et en sécurité du travail (IRSST, Occupational Health and Safety Research Institute) reveals that for all of the main manufacturing sectors involved, between 40 percent and 78 percent of the results exceed the exposure standard of 50 ppm. This study evaluated the effectiveness of a ventilated table in controlling worker exposure to styrene and acetone in a shop that manufactures fiber-reinforced plastics parts. The evaluated local extraction system consists of a ventilated table with a surface area of 1.2 m x 1.2 m. During molding, the styrene emissions are exhausted through the ventilated table as well as through the slots in a lateral hood. Replacement air, introduced vertically through a supply air shower located above the worker, limits the diffusion of contaminants toward the worker's breathing zone. The reduction in worker exposure to styrene and acetone during hand lay-up molding was measured in the breathing zone for two sizes of molds. The results show that exhaust ventilation reduced the styrene concentrations by 91 percent and that the introduction of replacement air increased the efficiency of the ventilated table to 96 percent. The evaluation performed indicates that the ventilated table adequately controls worker exposure to styrene and acetone during the molding of small components.

  9. Isogeometric Boundary Element Analysis with elasto-plastic inclusions. Part 1: Plane problems

    CERN Document Server

    Beer, Gernot; Zechner, Jürgen; Dünser, Christian; Fries, Thomas-Peter

    2015-01-01

    In this work a novel approach is presented for the isogeometric Boundary Element analysis of domains that contain inclusions with different elastic properties than the ones used for computing the fundamental solutions. In addition the inclusion may exhibit inelastic material behavior. In this paper only plane stress/strain problems are considered. In our approach the geometry of the inclusion is described using NURBS basis functions. The advantage over currently used methods is that no discretization into cells is required in order to evaluate the arising volume integrals. The other difference to current approaches is that Kernels of lower singularity are used in the domain term. The implementation is verified on simple finite and infinite domain examples with various boundary conditions. Finally a practical application in geomechanics is presented.

  10. A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing Part I: System Analysis, Component Identification, Additive Manufacturing, and Testing of Polymer Composites

    Science.gov (United States)

    Grady, Joseph E.; Haller, William J.; Poinsatte, Philip E.; Halbig, Michael C.; Schnulo, Sydney L.; Singh, Mrityunjay; Weir, Don; Wali, Natalie; Vinup, Michael; Jones, Michael G.; Patterson, Clark; Santelle, Tom; Mehl, Jeremy

    2015-01-01

    The research and development activities reported in this publication were carried out under NASA Aeronautics Research Institute (NARI) funded project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing." The objective of the project was to conduct evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. The results of the activities are described in three part report. The first part of the report contains the data and analysis of engine system trade studies, which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. The technical scope of activities included an assessment of the feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composites, which were accomplished by fabricating prototype engine components and testing them in simulated engine operating conditions. The manufacturing process parameters were developed and optimized for polymer and ceramic composites (described in detail in the second and third part of the report). A number of prototype components (inlet guide vane (IGV), acoustic liners, engine access door) were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included turbine nozzle components. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

  11. DESIGN AND FEM STATIC ANALYSIS OF AN INSTRUMENT FOR SURFACE PLASTIC DEFORMATION OF NON-PLANAR FUNCTIONAL SURFACES OF MACHINE PARTS

    Directory of Open Access Journals (Sweden)

    STOYAN SLAVOV

    2015-12-01

    Full Text Available The paper presents the design of a specialized instrument for formation different types of regular microshape roughness on functional surfaces of parts with non-planar macroshape by using the process, called “surface plastic deformation”. The elements of which it is constructed are explained and the results from carried out strength and deformation analysis, obtained by Finite Element Method, conducted using the Simulation module of the SolidWorks are also represented. On this basis some advantages and limitations of some of the surface plastic deformation process technological parameters are identified and recommendations for its implementation are given.

  12. 17 CFR Appendix B to Part 4 - Adjustments for Additions and Withdrawals in the Computation of Rate of Return

    Science.gov (United States)

    2010-04-01

    ... Withdrawals in the Computation of Rate of Return B Appendix B to Part 4 Commodity and Securities Exchanges... Appendix B to Part 4—Adjustments for Additions and Withdrawals in the Computation of Rate of Return This... trading advisors may calculate the rate of return information required by Rules 4.25(a)(7)(i)(F) and...

  13. A study on the effect of halloysite nanoparticle addition on the strength of glass fiber reinforced plastic

    Science.gov (United States)

    Kim, Yun-Hae; Park, Soo-Jeong; Lee, Jin-Woo; Moon, Kyung-Man

    2015-03-01

    Halloysite nanotube, which has been used in the polymer, has been spotlighted as a useful functional materials in the improvement of mechanical properties. In the current study, we established the optimal nanoparticle dispersion and analyzed the mechanical characteristics and the behavior of composites reinforced by HNTs have been synthesized by dispersing HNTs to the unsaturated polyester resin (UPR) and their mechanical characteristics, especially the tensile strength, interlaminar shear strength have been analyzed. Additionally, the reinforcement effect and its variation according to the amount of HNTs was also studied.

  14. Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE Addition

    Directory of Open Access Journals (Sweden)

    Yun Lu

    2013-06-01

    Full Text Available This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs. The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%–8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

  15. Additions to the National Wilderness Preservation System : Part 6 [Bosque del Apache Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  16. Proposed additions to the National Wilderness Preservation System : Part 24 : Fort Niobrara Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  17. Proposed additions to the National Wilderness Preservation System : Part 16 : Lacassine Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  18. Additions to the National Wilderness Preservation System : Part 16 : Blackbeard Island Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  19. Proposed additions to the National Wilderness Preservation System : Part 20 : J. N. "Ding" Darling Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  20. Proposed additions to the National Wilderness Preservation System : Part 28 : Lake Woodruff Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  1. Additions to the National Wilderness Preservation System : Part 14 : Chase Lake Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  2. Proposed additions to the National Wilderness Preservation System : Part 25 : Medicine Lake Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  3. Proposals for 12 additions to the National Wilderness Preservation System : Part 12 : Valentine National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  4. Additions to the National Wilderness Preservation System : Part 13 : Lostwood Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  5. Proposed additions to the National Wilderness Preservation System : Part 29 : Anaho Island Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  6. Proposed additions to the National Wilderness Preservation System : Part 12 : Big Lake Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  7. Proposed additions to the National Wilderness Preservation System : Part 32 : Bombay Hook Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  8. Proposed additions to the National Wilderness Preservation System : Part 4 : Agassiz Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  9. Proposed additions to the National Wilderness Preservation System : Part 33 : Back Bay Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  10. Proposed additions to the National Wilderness Preservation System : Part 22 : Assateague Island Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  11. Proposed additions to the National Wilderness Preservation System : Part 2 : Kenai Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  12. Proposed additions to the National Wilderness Preservation System : Part 13 : Aleutian Islands Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  13. Additions to the National Wilderness Preservation System : Part 1 [Cape Romain National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  14. Additive Manufacturing: Which DLA-Managed Legacy Parts are Potential AM Candidates

    Science.gov (United States)

    2016-07-01

    Prescreening R&D Tool Appendix C Military Service and DLA Supply Chain Points of Contact Appendix D DLA Legacy Parts AM Prescreening R&D Tool User Guide...detailed discussions with our DLA stakeholders in the Aviation, Land and Maritime, and Troop Sup- port supply management organizations, who deal daily...Code (AMSC) Direct query EBS Acquisition Advice Code (AAC) Direct query EBS DLA Supply Chain Direct query EBS DLA Profit Center Direct query EBS

  15. Analysis on Basic Points for Plastic Parts Design of Wall Switch%墙壁开关塑胶件设计基本要点分析

    Institute of Scientific and Technical Information of China (English)

    何秀峰

    2014-01-01

    Plastic parts are the important material of wall switch; and the key point to realize the automatic produc-tion of wall switch. This paper detailedly analyzes the basic points for the plastic parts design of wall switch. And it proposes the design key points and matters needing attention to realize automatic production in wall switch industry according to the actual situation.%塑胶件是墙壁开关材料的重要组成部分,也是实现墙壁开关自动化生产的关键点,本文详细分析了墙壁开关塑胶件设计的基本要点,并根据实际情况提出了墙壁开关行业实现自动化生产的设计要点和注意事项。

  16. APPROACHES TO GEOMETRIC DATA ANALYSIS ON BIG AREA ADDITIVELY MANUFACTURED (BAAM) PARTS

    Energy Technology Data Exchange (ETDEWEB)

    Dreifus, Gregory D [ORNL; Ally, Nadya R [ORNL; Post, Brian K [ORNL; Jin, Yuan [ORNL

    2016-01-01

    The promise of additive manufacturing is that a user can design and print complex geometries that are very difficult, if not impossible, to machine. The capabilities of 3D printing are restricted by a number of factors, including properties of the build material, time constraints, and geometric design restrictions. In this paper, a thorough accounting and study of the geometric restrictions that exist in the current iteration of additive manufacturing (AM) fused deposition modeling (FDM) technologies are discussed. Offline and online methodologies for collecting data sets for qualitative analysis of large scale AM, in particular Oak Ridge National Laboratory s (ORNL) big area additive manufacturing (BAAM) system, are summarized. In doing so, a survey of tools for designers and software developers is provided. In particular, strategies in which geometric data can be used as training sets for smarter AM technologies in the future are explained as well.

  17. Additive manufacturing of ITER first wall panel parts by two approaches: Selective laser melting and electron beam melting

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yuan [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm (Sweden); Rännar, Lars-Erik [Department of Quality Technology, Mechanical Engineering and Mathematics, Sports Tech Research Centre, Mid Sweden University, SE-831 25 Östersund (Sweden); Wikman, Stefan [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Koptyug, Andrey [Department of Quality Technology, Mechanical Engineering and Mathematics, Sports Tech Research Centre, Mid Sweden University, SE-831 25 Östersund (Sweden); Liu, Leifeng; Cui, Daqing [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm (Sweden); Shen, Zhijian, E-mail: shen@mmk.su.se [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm (Sweden)

    2017-03-15

    Highlights: • A novel way using additive manufacturing to fabricated ITER First Wall Panel parts is proposed. • ITER First Wall Panel parts successfully manufactured by both SLM and EBM are compared. • Physical and mechanical properties of SLM and EBM SS316L are clearly compared. • Problems encountered for large scale part building were discussed and possible solutions are given. - Abstract: Fabrication of ITER First Wall (FW) Panel parts by two additive manufacturing (AM) technologies, selective laser melting (SLM) and electron beam melting (EBM), was supported by Fusion for Energy (F4E). For the first time, AM is applied to manufacture ITER In-Vessel parts with complex design. Fully dense SS316L was prepared by both SLM and EBM after developing optimized laser/electron beam parameters. Characterizations on the density, magnetic permeability, microstructure, defects and inclusions were carried out. Tensile properties, Charpy-impact properties and fatigue properties of SLM and EBM SS316L were also compared. ITER FW Panel parts were successfully fabricated by both SLM and EBM in a one-step building process. The SLM part has smoother surface, better size accuracy while the EBM part takes much less time to build. Issues with removing support structures might be solved by slightly changing the design of the internal cooling system. Further investigation of the influence of neutron irradiation on materials properties between the two AM technologies is needed.

  18. 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......, for example, gutters, window frames, car parts and transportation boxes have long lifetimes and thus appear as waste only many years after they have been introduced on the market. Plastic is constantly being used for new products because of its attractive material properties: relatively cheap, easy to form......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  19. Evaluation of the effect of sodium silicate addition to mine backfill, Gelfill − Part 1

    Directory of Open Access Journals (Sweden)

    M. Kermani

    2015-06-01

    Full Text Available In this paper, the mechanical properties of sodium silicate-fortified backfill, called Gelfill, were investigated by conducting a series of laboratory experiments. Two configurations were tested, i.e. Gelfill and cemented hydraulic fill (CHF. The Gelfill has an alkali activator such as sodium silicate in its materials in addition to primary materials of mine backfill which are tailings, water and binders. Large numbers of samples of Gelfill and CHF with various mixture designs were cast and cured for over 28 d. The mechanical properties of samples were investigated using uniaxial compression test, and the results were compared with those of reference samples made without sodium silicate. The test results indicated that the addition of an appropriate amount of an alkali activator such as sodium silicate can enhance the mechanical (uniaxial compressive strength and physical (water retention properties of backfill. The microstructure analysis conducted by mercury intrusion porosimetry (MIP revealed that the addition of sodium silicate can modify the pore size distribution and total porosity of Gelfill, which can contribute to the better mechanical properties of Gelfill. It was also shown that the time and rate of drainage in the Gelfill specimens are less than those in CHF specimens made without sodium silicate. Finally, the study showed that the addition of sodium silicate can reduce the required setting time of mine backfill, which can contribute to increase mine production in accordance with the mine safety.

  20. Evaluation of the effect of sodium silicate addition to mine backfill, Gelfill L Part 1

    Institute of Scientific and Technical Information of China (English)

    M. Kermani; F.P. Hassani; E. Aflaki; M. Benzaazoua; M. Nokken

    2015-01-01

    In this paper, the mechanical properties of sodium silicate-fortified backfill, called Gelfill, were investi-gated by conducting a series of laboratory experiments. Two configurations were tested, i.e. Gelfill and cemented hydraulic fill (CHF). The Gelfill has an alkali activator such as sodium silicate in its materials in addition to primary materials of mine backfill which are tailings, water and binders. Large numbers of samples of Gelfill and CHF with various mixture designs were cast and cured for over 28 d. The me-chanical properties of samples were investigated using uniaxial compression test, and the results were compared with those of reference samples made without sodium silicate. The test results indicated that the addition of an appropriate amount of an alkali activator such as sodium silicate can enhance the mechanical (uniaxial compressive strength) and physical (water retention) properties of backfill. The microstructure analysis conducted by mercury intrusion porosimetry (MIP) revealed that the addition of sodium silicate can modify the pore size distribution and total porosity of Gelfill, which can contribute to the better mechanical properties of Gelfill. It was also shown that the time and rate of drainage in the Gelfill specimens are less than those in CHF specimens made without sodium silicate. Finally, the study showed that the addition of sodium silicate can reduce the required setting time of mine backfill, which can contribute to increase mine production in accordance with the mine safety.

  1. High performance poly(etherketoneketone) (PEKK) composite parts fabricated using Big Area Additive Manufacturing (BAAM) processes

    Energy Technology Data Exchange (ETDEWEB)

    Kunc, Vlastimil [ORNL; Kishore, Vidya [ORNL; Chen, Xun [ORNL; Ajinjeru, Christine [ORNL; Duty, Chad [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Hassen, Ahmed A [ORNL

    2016-09-01

    ORNL collaborated with Arkema Inc. to investigate poly(etherketoneketone) (PEKK) and its composites as potential feedstock material for Big Area Additive Manufacturing (BAAM) system. In this work thermal and rheological properties were investigated and characterized in order to identify suitable processing conditions and material flow behavior for BAAM process.

  2. The role of dissipation and defect energy in variational formulations of problems in strain-gradient plasticity. Part 2: single-crystal plasticity

    Science.gov (United States)

    Reddy, B. D.

    2011-11-01

    Variational formulations are constructed for rate-independent problems in small-deformation single-crystal strain-gradient plasticity. The framework, based on that of Gurtin (J Mech Phys Solids 50: 5-32, 2002), makes use of the flow rule expressed in terms of the dissipation function. Provision is made for energetic and dissipative microstresses. Both recoverable and non-recoverable defect energies are incorporated into the variational framework. The recoverable energies include those that depend smoothly on the slip gradients, the Burgers tensor, or on the dislocation densities (Gurtin et al. J Mech Phys Solids 55:1853-1878, 2007), as well as an energy proposed by Ohno and Okumura (J Mech Phys Solids 55:1879-1898, 2007), which leads to excellent agreement with experimental results, and which is positively homogeneous and therefore not differentiable at zero slip gradient. Furthermore, the variational formulation accommodates a non-recoverable energy due to Ohno et al. (Int J Mod Phys B 22:5937-5942, 2008), which is also positively homogeneous, and a function of the accumulated dislocation density. Conditions for the existence and uniqueness of solutions are established for the various examples of defect energy, with or without the presence of hardening or slip resistance.

  3. MECHANICAL PROPERTIES OF PARTS OF MEDICAL PRODUCTS PRODUCED USING ADDITIVE MANUFACTURING TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Filip Górski

    2017-06-01

    Full Text Available The paper presents results of tests conducted on the elements of medical devices - slings used with medical lifts - manufactured using additive technologies. Project assumptions were: to produce 100 samples of clips with varying design, material and orientation parameter. Samples were manufactured using FDM and SLA processes and then tested for mechanical strength, load transmission and functionality, using certified equipment. Paper shows full methodology and obtained test results.

  4. Part 1. Approaches to the total synthesis of the diterpene marrubin. Part II. Ligand assisted nucleophilic additions. Part III. Coal processing in a non-dissolving medium

    Energy Technology Data Exchange (ETDEWEB)

    Lipscombe, J.; Charles, W. II

    1987-01-01

    The total synthesis of the diterpene marrubiin was attempted using methodology previously developed in the Liotta laboratories. Ligand Assisted Nucleophilic Additions (LANA) comprise a new class of synthetic reactions involving the stereoselective addition of some group, usually in an intramolecular conjugate fashion. This group is itself derived from an earlier nucleophilic addition to a carbonyl moiety. Exchange of the original metal of the alkoxide with a second metal (which must be at least divalent) having a transferrable group demands that the stereochemistry of the first addition control the second. The general features of these types of processes are discussed. Initial work with substituted quinones is presented, and some mechanistic rationales are given. A novel method of coal processing at modest temperatures and hydrogen pressures (250-300/sup 0/C, 8.0 MPa) is discussed. Coals reacted with small amounts of tetrahydroquinoline in the presence of fluorocarbons or other non-dissolving media underwent astounding increases in pyridine solubility, a common standard in coal liquefaction studies. Several additives were employed, although only tetrahydroquinoline was found to effectively increase coal solubility. Coals having vastly different individual properties behaved similarly under these conditions. Kinetic and model studies were used in an attempt to clarify the reactions occurring under these novel conditions.

  5. Additional antiprotozoal flavonol glycosides of the aerial parts of Helianthemum glomeratum.

    Science.gov (United States)

    Calzada, Fernando; Alanís, Alma Delia

    2007-01-01

    Bioassay-guided fractionation of the methanol extract of aerial parts from Helianthemum glomeratum afforded five antiprotozoal flavonol glycosides: tiliroside, kaempferol-3-O-(3'',6''di-O-E-p-coumaroyl)-betad-glucopyranoside, astragalin, quercitrin and isoquercitrin. The in vitro antiprotozoal assay showed that tiliroside was the most potent antiamoebic and antigiardial compound with IC(50) values of 17.5 microg/mL for Entamoeba histolytica and 17.4 microg/mL for G. lamblia. Isoquercitrin showed selectivity against E. histolytica (IC(50) 14.7 microg/mL) and quercitrin toward G. lamblia (IC(50) 24.3 microg/mL). All isolated compounds were less active than metronidazole and emetine, two antiprotozoal drugs used as positive controls.

  6. Development of procedures for the acquisition of metal Additive Manufacturing (AM) parts for use in the CSIR's wind tunnel models

    CSIR Research Space (South Africa)

    Johnston, C

    2015-11-04

    Full Text Available The first Additive Manufacturing (AM) non-load-bearing, client furnished part was used in the CSIR’s wind tunnels in 2007. The advent of metal-grown materials, and the acquisition of machines to grow them in South Africa, has made it feasible...

  7. A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing of Ceramic Composites. Part III; Additive Manufacturing and Characterization of Ceramic Composites

    Science.gov (United States)

    Halbig, Michael C.; Grady, Joseph E.; Singh, Mrityunjay; Ramsey, Jack; Patterson, Clark; Santelle, Tom

    2015-01-01

    This publication is the third part of a three part report of the project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing" funded by NASA Aeronautics Research Institute (NARI). The objective of this project was to conduct additive manufacturing to produce ceramic matrix composite materials and aircraft engine components by the binder jet process. Different SiC powders with median sizes ranging from 9.3 to 53.0 microns were investigated solely and in powder blends in order to maximize powder packing. Various infiltration approaches were investigated to include polycarbosilane (SMP-10), phenolic, and liquid silicon. Single infiltrations of SMP-10 and phenolic only slightly filled in the interior. When the SMP-10 was loaded with sub-micron sized SiC powders, the infiltrant gave a much better result of filling in the interior. Silicon carbide fibers were added to the powder bed to make ceramic matrix composite materials. Microscopy showed that the fibers were well distributed with no preferred orientation on the horizontal plane and fibers in the vertical plane were at angles as much as 45deg. Secondary infiltration steps were necessary to further densify the material. Two to three extra infiltration steps of SMP-10 increased the density by 0.20 to 0.55 g/cc. However, the highest densities achieved were 2.10 to 2.15 g/cc. Mechanical tests consisting of 4 point bend tests were conducted. Samples from the two CMC panels had higher strengths and strains to failure than the samples from the two nonfiber reinforced panels. The highest strengths were from Set N with 65 vol% fiber loading which had an average strength of 66 MPa. Analysis of the fracture surfaces did not reveal pullout of the reinforcing fibers. Blunt fiber failure suggested that there was not composite behavior. The binder jet additive manufacturing method was used to also demonstrate the fabrication of turbine engine vane components of two different designs and sizes. The

  8. Plastic Surgery

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A A ... forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word "plastic" ...

  9. 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.

  10. Elastic-Plastic Nonlinear Response of a Space Shuttle External Tank Stringer. Part 1; Stringer-Feet Imperfections and Assembly

    Science.gov (United States)

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

    2012-01-01

    Elastic-plastic, large-deflection nonlinear stress analyses are performed for the external hat-shaped stringers (or stiffeners) on the intertank portion of the Space Shuttle s external tank. These stringers are subjected to assembly strains when the stringers are initially installed on an intertank panel. Four different stringer-feet configurations including the baseline flat-feet, the heels-up, the diving-board, and the toes-up configurations are considered. The assembly procedure is analytically simulated for each of these stringer configurations. The location, size, and amplitude of the strain field associated with the stringer assembly are sensitive to the assumed geometry and assembly procedure. The von Mises stress distributions from these simulations indicate that localized plasticity will develop around the first eight fasteners for each stringer-feet configuration examined. However, only the toes-up configuration resulted in high assembly hoop strains.

  11. 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

  12. Injection Mold Design of Automotive Jointing Plastic Parts%汽车接头塑料件注塑模设计

    Institute of Scientific and Technical Information of China (English)

    苏慧祎

    2015-01-01

    The lateral concave structure is often used in the plastic mould design,and it is often used in connection with another parts and installing sealing rings and so on. Such plastic parts using slide block core-pulling mechanism was detailed by way of example. This design can solve demoulding problems of lateral parts through the working principle of telescopic core and designing method. The mechanism in the actual production runs smoothly,and it hasn't catching phenomenon, which indicated that the design principles are reliability and agency is validity.%侧凹结构在塑料模具产品设计中经常被用到,它常用于与另一零件的连接、安装密封圈等情况.通过实例详细论述了利用滑块抽芯机构成型该类塑料件,通过"伸缩型芯"的工作原理及设计方法,解决了在模具设计中侧凹零件的脱模问题,并且该机构在实际生产中运行平稳,无卡滞现象,说明了该机构的可靠性及设计原理的正确性.

  13. 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...

  14. Geometric Limitation and Tensile Properties of Wire and Arc Additive Manufacturing 5A06 Aluminum Alloy Parts

    Science.gov (United States)

    Geng, Haibin; Li, Jinglong; Xiong, Jiangtao; Lin, Xin; Zhang, Fusheng

    2017-02-01

    Wire and arc additive manufacture (WAAM), as an emerging and promising technology of metal additive manufacturing, it lacks of experimental works to clarify the feature of geometrical configuration, microstructure and tensile properties, which can be used for further evaluating whether the as-deposited part can be used directly, and providing design reference for structure optimization. Taking 5A06 aluminum alloy additive manufacturing for example, in this paper, the geometric limitation and tensile property criteria are characterized using experimental method. The minimum angle and curvature radius that can be made by WAAM are 20° and 10 mm when the layer width is 7.2 mm. It shows isotropy when loading in build direction and perpendicular one. When loading in the direction of parallel and perpendicular to texture orientation, the tensile properties are anisotropic. The difference between them is 22 MPa.

  15. Invited Review Article: Review of post-process optical form metrology for industrial-grade metal additive manufactured parts.

    Science.gov (United States)

    Stavroulakis, P I; Leach, R K

    2016-04-01

    The scope of this review is to investigate the main post-process optical form measurement technologies available in industry today and to determine whether they are applicable to industrial-grade metal additive manufactured parts. An in-depth review of the operation of optical three-dimensional form measurement technologies applicable to metal additive manufacturing is presented, with a focus on their fundamental limitations. Looking into the future, some alternative candidate measurement technologies potentially applicable to metal additive manufacturing will be discussed, which either provide higher accuracy than currently available techniques but lack measurement volume, or inversely, which operate in the appropriate measurement volume but are not currently accurate enough to be used for industrial measurement.

  16. Invited Review Article: Review of post-process optical form metrology for industrial-grade metal additive manufactured parts

    Science.gov (United States)

    Stavroulakis, P. I.; Leach, R. K.

    2016-04-01

    The scope of this review is to investigate the main post-process optical form measurement technologies available in industry today and to determine whether they are applicable to industrial-grade metal additive manufactured parts. An in-depth review of the operation of optical three-dimensional form measurement technologies applicable to metal additive manufacturing is presented, with a focus on their fundamental limitations. Looking into the future, some alternative candidate measurement technologies potentially applicable to metal additive manufacturing will be discussed, which either provide higher accuracy than currently available techniques but lack measurement volume, or inversely, which operate in the appropriate measurement volume but are not currently accurate enough to be used for industrial measurement.

  17. Deposition Time and Thermal Cycles of Fabricating Thin-wall Steel Parts by Double Electrode GMAW Based Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Yang Dongqing

    2017-01-01

    Full Text Available The deposition time for fabricating the thin-wall part as well as the peak temperature of the substrate during the process was analyzed in the double electrode gas metal arc welding (DE-GMAW based additive manufacturing (AM. The total deposition time and the interlayer idle time of the manufacturing process decreased with the increasing of the bypass current under the same interlayer temperature and the same deposition rate. The thermal cycling curves illustrated that the peak temperature of the substrate was lower in the DE-GMAW base AM under the same conditions. When depositing the thin-wall parts, the DE-GMAW based AM can reduce the heat input to the substrate and improve the fabrication efficiency, compared with the GMAW based AM.

  18. Possibilities of the Technology of Additive Production for Making Complex-Shape Parts and Depositing Functional Coatings from Metallic Powders

    Science.gov (United States)

    Grigor'ev, S. N.; Tarasova, T. V.

    2016-01-01

    The aspects of terminology, definitions and classification in the technology of additive production are considered. The principal possibility of fabrication of complex-shape parts from a refractory cobalt alloy by the method of selective laser melting and deposition of hard and wear-resistant coatings from Ti and SiC powders by coaxial laser surfacing is shown. The technological possibility of microlaser surfacing with lateral resolution about 100 μm in the production of parts from aluminum alloys is considered. The mechanisms of formation of structure in the studied alloys typical for selective laser melting, laser surfacing and microlaser surfacing are determined. The physical and mechanical properties of the alloys are investigated.

  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. Microelectronics plastic molded packaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R. [Ktech Corp., Albuquerque, NM (United States); Palmer, D.W.; Peterson, D.W. [Sandia National Lab., Albuquerque, NM (United States)] [and others

    1997-02-01

    The use of commercial off-the-shelf (COTS) microelectronics for nuclear weapon applications will soon be reality rather than hearsay. The use of COTS for new technologies for uniquely military applications is being driven by the so-called Perry Initiative that requires the U.S. Department of Defense (DoD) to accept and utilize commercial standards for procurement of military systems. Based on this philosophy, coupled with several practical considerations, new weapons systems as well as future upgrades will contain plastic encapsulated microelectronics. However, a conservative Department of Energy (DOE) approach requires lifetime predictive models. Thus, the focus of the current project is on accelerated testing to advance current aging models as well as on the development of the methodology to be used during WR qualification of plastic encapsulated microelectronics. An additional focal point involves achieving awareness of commercial capabilities, materials, and processes. One of the major outcomes of the project has been the definition of proper techniques for handling and evaluation of modern surface mount parts which might be used in future systems. This program is also raising the familiarity level of plastic within the weapons complex, allowing subsystem design rules accommodating COTS to evolve. A two year program plan is presented along with test results and commercial interactions during this first year.

  1. Design and development of a layer-based additive manufacturing process for the realization of metal parts of designed mesostructure

    Science.gov (United States)

    Williams, Christopher Bryant

    Low-density cellular materials, metallic bodies with gaseous voids, are a unique class of materials that are characterized by their high strength, low mass, good energy absorption characteristics, and good thermal and acoustic insulation properties. In an effort to take advantage of this entire suite of positive mechanical traits, designers are tailoring the cellular mesostructure for multiple design objectives. Unfortunately, existing cellular material manufacturing technologies limit the design space as they are limited to certain part mesostructure, material type, and macrostructure. The opportunity that exists to improve the design of existing products, and the ability to reap the benefits of cellular materials in new applications is the driving force behind this research. As such, the primary research goal of this work is to design, embody, and analyze a manufacturing process that provides a designer the ability to specify the material type, material composition, void morphology, and mesostructure topology for any conceivable part geometry. The accomplishment of this goal is achieved in three phases of research: (1) Design---Following a systematic design process and a rigorous selection exercise, a layer-based additive manufacturing process is designed that is capable of meeting the unique requirements of fabricating cellular material geometry. Specifically, metal parts of designed mesostructure are fabricated via three-dimensional printing of metal oxide ceramic powder followed by post-processing in a reducing atmosphere. (2) Embodiment ---The primary research hypothesis is verified through the use of the designed manufacturing process chain to successfully realize metal parts of designed mesostructure. (3) Modeling & Evaluation ---The designed manufacturing process is modeled in this final research phase so as to increase understanding of experimental results and to establish a foundation for future analytical modeling research. In addition to an analysis of

  2. 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 plasti...... as a knowledge handbook for laser welding of plastic components. This document should provide the information for all aspects of plastic laser welding and help the design engineers to take all critical issues into consideration from the very beginning of the design phase....

  3. Comparison between Palm Oil Derivative and Commercial Thermo-Plastic Binder System on the Properties of the Stainless Steel 316L Sintered Parts

    Science.gov (United States)

    Ibrahim, R.; Azmirruddin, M.; Wei, G. C.; Fong, L. K.; Abdullah, N. I.; Omar, K.; Muhamad, M.; Muhamad, S.

    2010-03-01

    Binder system is one of the most important criteria for the powder injection molding (PIM) process. Failure in the selection of the binder system will affect on the final properties of the sintered parts. The objectives of this studied is to develop a novel binder system based on the local natural resources and environmental friendly binder system from palm oil derivative which is easily available and cheap in our country of Malaysia. The novel binder that has been developed will be replaced the commercial thermo-plastic binder system or as an alternative binder system. The results show that the physical and mechanical properties of the final sintered parts fulfill the Metal Powder Industries Federation (MPIF) standard 35 for PIM parts. The biocompatibility test using cell osteosarcoma (MG63) and vero fibroblastic also shows that the cell was successfully growth on the sintered stainless steel 316L parts indicate that the novel binder was not toxic. Therefore, the novel binder system based on palm oil derivative that has been developed as a binder system fulfills the important criteria for the binder system in PIM process.

  4. MIGRATION OF PHTHALATES FROM PLASTIC TANK TO VEGETABLE OIL AS A PART OF FEEDING MIXTURES USED FOR CHICKEN BROILERS FATTENING

    Directory of Open Access Journals (Sweden)

    Pavel Suchý

    2010-05-01

    Full Text Available The concentrations of phthalic acid esters (PAEs as di-n-butyl phthalate (DBP and di-2-ethylhexyl phthalate (DEHP were measured in samples of rapeseed oil, which was used as a feed. First samples were collected during the production process and second after the storage in plastic tank (21 days. The results of measurements are that there is 2.93-10.10 mg PAEs.kg-1 in the oil before storage and 22.73-61.55 mg PAEs.kg-1 after storage. For the monitoring of distribution and accumulation of PAEs in animal tissues and organs (muscles, adipose tissue, skin and liver broiler chicks ROSS 308 were used. The chicks were divided into 4 groups (50 chicks each. All the chicks were fed by commercial diets (complete feed, KKS for broiler chicks (starter – BR1; grower – BR2 and finisher – BR3. The experimental diets were supplemented with vegetable oil (RO with low (group N or high (group V phthalate content, or animal fat with high phthalate content (group Z. Neither the control diets (K nor the grower (BR1 diets contained vegetable oil or animal fat. DBP and DEHP were found in all tissues of all chicks. The highest concentration of DBP of 1.28 1.00 mg.kg-1 of fresh sample (an average value from 8 chicks was determined in the adipose tissue of V chicks. The highest concentration of DEHP of 3.27 2.87 mg.kg-1 of fresh sample (average of 8 chicks was also determined in the V group. doi:10.5219/49

  5. Informative document waste plastics

    NARCIS (Netherlands)

    Nagelhout D; Sein AA; Duvoort GL

    1989-01-01

    This "Informative document waste plastics" forms part of a series of "informative documents waste materials". These documents are conducted by RIVM on the indstruction of the Directorate General for the Environment, Waste Materials Directorate, in behalf of the program of

  6. Hebbian plasticity requires compensatory processes on multiple timescales

    Science.gov (United States)

    Gerstner, Wulfram

    2017-01-01

    We review a body of theoretical and experimental research on Hebbian and homeostatic plasticity, starting from a puzzling observation: while homeostasis of synapses found in experiments is a slow compensatory process, most mathematical models of synaptic plasticity use rapid compensatory processes (RCPs). Even worse, with the slow homeostatic plasticity reported in experiments, simulations of existing plasticity models cannot maintain network stability unless further control mechanisms are implemented. To solve this paradox, we suggest that in addition to slow forms of homeostatic plasticity there are RCPs which stabilize synaptic plasticity on short timescales. These rapid processes may include heterosynaptic depression triggered by episodes of high postsynaptic firing rate. While slower forms of homeostatic plasticity are not sufficient to stabilize Hebbian plasticity, they are important for fine-tuning neural circuits. Taken together we suggest that learning and memory rely on an intricate interplay of diverse plasticity mechanisms on different timescales which jointly ensure stability and plasticity of neural circuits. This article is part of the themed issue ‘Integrating Hebbian and homeostatic plasticity’. PMID:28093557

  7. Reversible addition of the OH radical to p-cymene in the gas phase: multiple adduct formation. Part 2.

    Science.gov (United States)

    Alarcón, Paulo; Bohn, Birger; Zetzsch, Cornelius; Rayez, Marie-Thérèse; Rayez, Jean-Claude

    2014-08-28

    A flash photolysis-resonance fluorescence (FP-RF) system was used to study the p-cymene (PC) + OH reaction at temperatures between 299 and 349 K in helium. Triexponential functions were fitted to groups of observed OH decay curves according to a model considering a reversible addition to form two adducts as thermolabile reservoirs of OH. Compared to Part 1 of this paper, consideration of a second adduct strongly improved the fits to our measurements, and the rate constants for the major pathways were optimized between 299 and 349 K. The Arrhenius expression for the rate constant of the sum of OH addition and H-atom abstraction pathways was found to be kOH = 1.9 × 10(-12) exp[(610 ± 210) K/T] cm(3) s(-1). Rate constants of unimolecular decomposition reactions of the adducts were similar to other aromatic compounds with the following Arrhenius expressions: 1 × 10(12) exp[(-7600 ± 800) K/T] s(-1) for adduct 1 and 4 × 10(11) exp[(-8000 ± 300) K/T] s(-1) for adduct 2. Adduct yields increased and decreased with temperature for adduct 1 and 2, respectively, but were similar (∼0.4) around room temperature. Equilibrium constants yielded values for reaction enthalpies and entropies of adduct formations. While for one adduct reasonable agreement was obtained with theoretical predictions, there were significant deviations for the other adduct. This indicates the presence of more than two adduct isomers that were not accounted for in the reaction model. Quantum chemical calculations (DFT M06-2X/6-31G(d,p)) and RRKM kinetics were employed with the aim of clarifying the mechanism of the OH addition to PC. These calculations show that formation of adducts with OH in ortho positions to the isopropyl and methyl substituents is predominant (55% and 24%) to those with OH in ipso positions (21% and 3%). A large fraction (>90%) of the ipso-C3H7 adduct is predicted to react by dealkylation forming p-cresol (in the absence of oxygen) and isopropyl radicals. These theoretical

  8. Plastic Jellyfish.

    Science.gov (United States)

    Moseley, Christine

    2000-01-01

    Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

  9. Ranking hospitals for outcomes in total hip replacement - administrative data with or without additional patient surveys? - Part 1: Administrative data

    Directory of Open Access Journals (Sweden)

    Dörning, Hans

    2007-03-01

    Full Text Available Background: Many hospital rankings rely on the frequency of adverse outcomes and are based on administrative data. In the study presented here, we tried to find out, to what extent available administrative data of German Sickness Funds allow for an adequate hospital ranking and compared this with rankings based on additional information derived from a patient survey. Total hip replacement was chosen as an example procedure. In part I of the publication, we present the results of the approach based on administrative data. Methods: We used administrative data from the AOK-Lower Saxony of the years 2000, 2001 and 2002. The study population comprised all beneficiaries, who received total hip replacement in the years 2000 or 2001. Performance indicators used where “critical incident (Mortality or revision” and “number of revisions” within the first year. Hospitals were ranked if they performed at least 20 procedures on AOK-beneficiaries in each of the two years. Multivariate modelling (logistic and poisson regression was used to estimate the performance indicators by case-mix variables (age, sex, co-diagnoses and hospital characteristics (hospital size, surgical volume. The actual ranking was based on these multivariate models, excluding hospital variables and adding dummy-variables for each hospital. Hospitals were ranked by their case-mix adjusted odds ratio or SMR respectively with respect to a pre-selected reference hospital. The resulting rankings were compared with each other, with regard to temporal stability, and the impact of case-mix variables.Results: About 4500 beneficiaries received total hip replacement in each year (n2000: 4482; n2001: 4579. The ranking included 65 hospitals. Comparing the years 2000 and 2001, the temporal stability of the rankings based on a single performance indicator was low (Spearman rang correlation coefficients 0.158 and 0.191. The agreement of rankings based on different performance indicators in the

  10. 42 CFR 408.21 - Reduction in Medicare Part B premium as an additional benefit under Medicare+Choice plans.

    Science.gov (United States)

    2010-10-01

    .... After determining the Medicare Part B premium reduction amount for each eligible beneficiary, CMS will— (1) Transmit this information to the Social Security Administration, Railroad Retirement Board,...

  11. ARE PLASTIC GROCERY BAGS SACKING THE ENVIRONMENT?

    OpenAIRE

    Mangal Gogte

    2009-01-01

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

  12. 78 FR 51744 - Digital Trade in the U.S. and Global Economies, Part 2; Scheduling of an Additional Public Hearing

    Science.gov (United States)

    2013-08-21

    ... COMMISSION Digital Trade in the U.S. and Global Economies, Part 2; Scheduling of an Additional Public Hearing..., Digital Trade in the U.S. and Global Economies, Part 2 at the NASA Ames Research Center in Moffett Field... role of digital trade in the U.S. and global economies at the request of the U.S. Senate Committee...

  13. Selective laser melting additive manufactured Inconel 718 superalloy parts: High-temperature oxidation property and its mechanisms

    Science.gov (United States)

    Jia, Qingbo; Gu, Dongdong

    2014-10-01

    This work presented a comprehensive study of high-temperature oxidation behaviors and mechanisms of Selective laser melting (SLM) processed Inconel 718 superalloy parts using different methods including isothermal oxidation testing, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The experimental results revealed that the oxidation process of the tested parts processed at a lower volumetric laser energy density experienced the severe spallation. On reasonably increasing the applied volumetric laser energy density, the oxidation kinetics of the as-produced parts obeyed a parabolic law, exhibiting the significantly improved oxidation resistance performance. The constitutional phases within the oxidation film were identified and the corresponding formation mechanisms were elucidated in detail according to the thermodynamic principles. The cross-sectional morphologies of oxidized Inconel 718 parts indicated that the oxidation microstructure mainly consisted of an external oxidation layer and an internal oxidation zone. The oxidation process was controlled by the outward diffusion of oxide forming elements and inward penetration of oxygen, by which the interaction mechanisms between the microstructures and internal oxidation zones were clarified. On the basis of the experimental results and theoretical analyses, the physical oxidation mechanisms were accordingly established to illustrate the oxidation behaviors of SLM-processed Inconel 718 parts at elevated operative temperatures.

  14. Comparability of the performance of in-line computer vision for geometrical verification of parts, produced by Additive Manufacturing

    DEFF Research Database (Denmark)

    Pedersen, David B.; Hansen, Hans N.

    2014-01-01

    in order to verify geometrical tolerances, The paper addresses to which precision, tolerance verification has been achieved, by assessing the reconstruction capability against reference 3D scanning by a selected number of AM processes. Geometrical verification was achieved down to a precision of 20μm......-customized parts with narrow geometrical tolerances require individual verification whereas many hyper-complex parts simply cannot be measured by traditional means such as by optical or mechanical measurement tools. This paper address the challenge by detailing how in-line computer vision has been employed...

  15. Proposals for 12 additions to the National Wilderness Preservation System : Part 9 : White River National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  16. Proposals for 12 additions to the National Wilderness Preservation System : Part 15 : Klamath Forest National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  17. Proposed additions to the National Wilderness Preservation System : Part 18 : Mattamuskeet Wilderness - Swanquarter Wilderness - Cedar Island Wilderness - Pea Island Wilderness

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  18. Design of wear-out-failure in-situ repair parts by environment-friendly nanocopper additive

    Institute of Scientific and Technical Information of China (English)

    YU He-long; XU Bin-shi; XU Yi; WANG Xiao-li; LIU Qian

    2005-01-01

    Oleic acid surface-modified Cu nanoparticles with an average size of 20 nm were prepared by liquid phase reducing reaction. The tribological performance and mechanism of nanocopper as additive were studied by means of tribotester, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and nanoindentation instrument. The results indicate that the modified nanocopper additive can significantly improve the wear resistance and reduce friction coefficient of base oil. A copper protective film is formed and contributes to the excellent tribological properties of nanocopper additive. On the basis of the film forming mechanism, a new in-situ repair method was designed and used to repair wear-out-failure injection pump plunger and barrel. Furthermore, the current research progress of nanoparticles as green energy-saving lubricating oil additives were presented.

  19. The Pabst's method: an effective and low-budget tool for the forensic comparison of opaque thermoplastics--part 1: Additional discrimination of black electrical tapes.

    Science.gov (United States)

    Henning, Siegfried; Schönberger, Torsten; Simmross, Ulrich

    2013-12-10

    For many years now, Pabst's micro-press has been used in German forensic science laboratories as a valuable addition to methods of comparative analysis of plastic trace evidence. However, it is as yet hardly known in laboratories outside of Germany. The principal reproducibility is demonstrated by a homogeneity check of a raw backing material of defined origin. The illustrated results of a proficiency test emphasise the applicability of the Pabst method for forensic comparisons. The discrimination power of the Pabst method was tested by taking 90 black PVC-backings provided by the FBI Laboratory, i.e. those that could not be discriminated by standard methods. In this way further discriminations could be achieved. In the following, the Pabst method is therefore introduced as a straightforward, inexpensive and useful tool.

  20. Development of plastic surgery

    Directory of Open Access Journals (Sweden)

    Pećanac Marija Đ.

    2015-01-01

    Full Text Available Introduction. 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.

  1. Reinforced plaster by means of the synergic action between concrete additives (superfluidifiers, fluidiflers and airing-plasticizers and E glass fibres

    Directory of Open Access Journals (Sweden)

    del Río Merino, M.

    2000-12-01

    Full Text Available Through the analysis of the different compounds (plaster + additives + E glass fibres we pretend to demostrate that a synergic action is present between certain concrete additives (superfluidifiers, fluidiflers, and airingplasticizers and E glass fibre, on the basis of the flection resistance of plaster matrix based compound materials.

    Mediante el análisis de diferentes compuestos (escayola + aditivos + fibras de vidrio E se pretende demostrar que existe una acción sinérgica entre ciertos aditivos del hormigón (superfluidificantes, fluidificantes y aireantes-plastificantes y los refuerzos a base de fibras de vidrio E, sobre la resistencia a flexión de los materiales compuestos de matriz principal escayola.

  2. Developmental plasticity and evolution--quo vadis?

    National Research Council Canada - National Science Library

    Moczek, A P

    2015-01-01

    The role of developmental (phenotypic) plasticity in ecology and evolution is receiving a growing appreciation among the biologists, and many plasticity-specific concepts have become well established as part of the mainstream evolutionary...

  3. Plastics Technology.

    Science.gov (United States)

    Barker, Tommy G.

    This curriculum guide is designed to assist junior high schools industrial arts teachers in planning new courses and revising existing courses in plastics technology. Addressed in the individual units of the guide are the following topics: introduction to production technology; history and development of plastics; safety; youth leadership,…

  4. Comparability of the performance of in-line computer vision for geometrical verification of parts, produced by Additive Manufacturing

    DEFF Research Database (Denmark)

    Pedersen, David B.; Hansen, Hans N.

    2014-01-01

    The field of Additive Manufacturing is growing at an accelerated rate, as prototyping is left in favor of direct manufacturing of components for the industry and consumer. A consequence of masscustomization and component complexity is an adverse geometrical verification challenge. Mass...

  5. Rendering of surface-geometries at job-generation level for camouflaging the layered nature of Additively Manufactured parts

    DEFF Research Database (Denmark)

    Pedersen, D. B.; Hansen, H. N.; Nielsen, J. S.

    2014-01-01

    . An often used method for visualization of complex geometries within CGI is by producing a geometrical primitive after which the primitive is passed through a renderer.[2] Examples can be geometries with hair, leather structure and their like. Should the entire geometry including surface definition sought......] It is proposed to camouflage these layers in order to produce parts with a better visual appeal, and to add functional surface structures. In order to generate such surface structures without adding a challenging computational overhead at job-generation, inspiration from Computer Generated Imaging (CGI) is found...

  6. An Investigation into the Comparative Costs of Additive Manufacture vs. Machine from Solid for Aero Engine Parts

    Science.gov (United States)

    2006-05-01

    Shape Processing (Rentabilite de fabrication par un traitement de finition immediate), The original document contains color images. 14. ABSTRACT 15...removal of surface finish effects and to allow for slight thermal distortion effects on cooling. 1.2.2 Additive Manufacturing Process The method of...its forming temperature. A machining allowance is also provided to allow surface effects such as skin stresses and oxidation caused by the forging

  7. Tips for a physician in getting the right job, part VIII: additional types of questions during an executive interview.

    Science.gov (United States)

    Harolds, Jay A

    2014-03-01

    The applicant for an administrative position may be asked situational and stress questions on an interview. Some possible questions and answers for these types of queries are included in this article. In addition, the candidate may be required to answer some odd or unusual questions to test his/her ability to be creative or respond to an unexpected question. Some suggestions regarding those queries are also given in this article.

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

    Science.gov (United States)

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

    2017-12-01

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

  9. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  10. Mechanical plasticity of cells

    Science.gov (United States)

    Bonakdar, Navid; Gerum, Richard; Kuhn, Michael; Spörrer, Marina; Lippert, Anna; Schneider, Werner; Aifantis, Katerina E.; Fabry, Ben

    2016-10-01

    Under mechanical loading, most living cells show a viscoelastic deformation that follows a power law in time. After removal of the mechanical load, the cell shape recovers only incompletely to its original undeformed configuration. Here, we show that incomplete shape recovery is due to an additive plastic deformation that displays the same power-law dynamics as the fully reversible viscoelastic deformation response. Moreover, the plastic deformation is a constant fraction of the total cell deformation and originates from bond ruptures within the cytoskeleton. A simple extension of the prevailing viscoelastic power-law response theory with a plastic element correctly predicts the cell behaviour under cyclic loading. Our findings show that plastic energy dissipation during cell deformation is tightly linked to elastic cytoskeletal stresses, which suggests the existence of an adaptive mechanism that protects the cell against mechanical damage.

  11. 5 CFR 1001.101 - In addition to this part, what other rules of conduct apply to Office of Personnel Management...

    Science.gov (United States)

    2010-01-01

    ... rules of conduct apply to Office of Personnel Management employees? 1001.101 Section 1001.101 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) REGULATIONS GOVERNING EMPLOYEES OF THE OFFICE OF PERSONNEL MANAGEMENT OPM EMPLOYEE RESPONSIBILITIES AND CONDUCT § 1001.101 In addition to this part...

  12. Informative document waste plastics

    NARCIS (Netherlands)

    Nagelhout D; Sein AA; Duvoort GL

    1989-01-01

    This "Informative document waste plastics" forms part of a series of "informative documents waste materials". These documents are conducted by RIVM on the indstruction of the Directorate General for the Environment, Waste Materials Directorate, in behalf of the program of acti

  13. Plastic bronchitis

    National Research Council Canada - National Science Library

    Singhi, Anil Kumar; Vinoth, Bharathi; Kuruvilla, Sarah; Sivakumar, Kothandam

    2015-01-01

    Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics...

  14. Injection Mold Design with Thread Rotating Demoulding Mechanism of Plastic Part with Internal Thread%螺纹旋转脱模内螺纹塑件注塑模设计

    Institute of Scientific and Technical Information of China (English)

    王成

    2013-01-01

    The injection mold with thread rotating demoulding mechanism was designed by taking acrylonitrile-butadiene -styrene plastic bottle cap as example. Without external unscrewing power plant attached to the mold, the plastic part can be automatically rotating demoulded by using opening force of the injection molding machine, so the problems of time-consuming being long and plastic part thread being scuffed when thread was demoulded were solved and the quality of the plastic part was ensured. The gating system, small rod limitting structure and thread rotating demoulding mechanism were designed and analyzed, the overall structure, working process of the mold and demoulding step exploded view were introduced also. The mold has the advantages of simple, compact structure and small size, is suitable for large-scale production.%以ABS塑料瓶盖为例,设计了螺纹旋转脱模内螺纹塑件注塑模.该模具无需外接脱螺纹动力装置,利用注塑机的开模力实现塑件自动旋转脱模顶出,保证了内螺纹塑件的质量,解决了现有技术中螺纹脱模耗时、易拉伤塑件螺纹的问题.对浇注系统、小拉杆限位结构、螺纹旋转脱模结构等进行了设计分析,介绍了模具的整体结构和开、合模工作过程及脱模步骤分解图.该模具结构简单、紧凑、体积小,适用于大批量生产.

  15. 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.

  16. Plastic Bridge

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Already ubiquitous in homes and cars, plastic is now appearing inbridges. An academic-industrial consortium based at the University ofCalifornia in San Diego is launching a three-year research program aimed atdeveloping the world’s first plastic highway bridge, a 450-foot span madeentirely from glass-,carbon,and polymer-fiber-reinforced composite mate-rials, the stuff of military aircraft. It will cross Interstate 5 to connect thetwo sides of the school’s campus.

  17. Plastic Surgery and Suicide: A Clinical Guide for Plastic Surgeons.

    Science.gov (United States)

    Reddy, Vikram; Coffey, M Justin

    2016-08-01

    Several studies have identified an increased risk of suicide among patient populations which a plastic surgeon may have a high risk of encountering: women undergoing breast augmentation, cosmetic surgery patients, and breast cancer patients. No formal guidelines exist to assist a plastic surgeon when faced with such a patient, and not every plastic surgery team has mental health clinicians that are readily accessible for consultation or referral. The goal of this clinical guide is to offer plastic surgeons a set of practical approaches to manage potentially suicidal patients. In addition, the authors review a screening tool, which can assist surgeons when encountering high-risk patients.

  18. 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...

  19. Impact factors and publication times for plastic surgery journals.

    Science.gov (United States)

    Labanaris, Apostolos P; Vassiliadu, Agapi P; Polykandriotis, Elias; Tjiawi, Jimmy; Arkudas, Andreas; Horch, Raymund E

    2007-12-01

    The purposes of the authors' analysis were to assess the values that plastic surgical journals demonstrate in terms of the standardized measures created by the Institute for Scientific Information's Journal Citation Report, and to assess the relationship between these values and the turnaround time of these journals. The overall indexes of surgical journals were compared with those of journals in other fields of medicine using the following parameters: highest impact factor, average impact factor, cited half-life, immediacy index, and number of journals. Similarly, plastic surgery journals were compared with the highest ranking journals from various fields of surgery. In addition, an evaluation of all original articles published in 2005, assessing the time intervals from submission to publication, submission to acceptance, and acceptance to publication, was conducted for all plastic surgical journals and the highest ranking journals from various surgical fields listed in the Journal Citation Report. Plastic surgical journals demonstrated low overall index values and a greater elongation of their turnaround time in comparison to journals in other fields of surgery and medicine. The fact that the field of plastic surgery targets a rather specific and limited medical audience, and that plastic surgical articles usually get quoted by this audience, partly explains these values. Furthermore, the elongated turnaround time contributes to their endurance. Since plastic surgical journals cannot attract a broader medical audience, journals should speed up their publication times to help these values rise.

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

    Science.gov (United States)

    Gunderson, Alex R; Stillman, Jonathon H

    2015-06-07

    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.

  1. Biodegradability of degradable plastic waste.

    Science.gov (United States)

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  2. ARE PLASTIC GROCERY BAGS SACKING THE ENVIRONMENT?

    Directory of Open Access Journals (Sweden)

    Mangal Gogte

    2009-12-01

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

  3. Plastic Bronchitis.

    Science.gov (United States)

    Rubin, Bruce K

    2016-09-01

    Plastic bronchitis is an uncommon and probably underrecognized disorder, diagnosed by the expectoration or bronchoscopic removal of firm, cohesive, branching casts. It should not be confused with purulent mucous plugging of the airway as seen in patients with cystic fibrosis or bronchiectasis. Few medications have been shown to be effective and some are now recognized as potentially harmful. Current research directions in plastic bronchitis research include understanding the genetics of lymphatic development and maldevelopment, determining how abnormal lymphatic malformations contribute to cast formation, and developing new treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Polishing compound for plastic surfaces

    Science.gov (United States)

    Stowell, Michael S.

    1995-01-01

    A polishing compound for plastic surfaces. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS.TM., LEXAN.TM., LUCITE.TM., polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  5. Polishing compound for plastic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stowell, M.S.

    1993-01-01

    A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains colloidal silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{sup TM}, LEXAN{sup TM}, LUCITE{sup TM}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  6. Plastic zonnecellen

    NARCIS (Netherlands)

    Roggen, Marjolein

    1998-01-01

    De zonnecel van de toekomst is in de maak. Onderzoekers van uiteenlopend pluimage werken eendrachtig aan een plastic zonnecel. De basis is technisch gelegd met een optimale, door invallend licht veroorzaakte, vorming van ladingdragers binnen een composiet van polymeren en buckyballs. Nu is het zaak

  7. Density of Additively-Manufactured, 316L SS Parts Using Laser Powder-Bed Fusion at Powers Up to 400W

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, Chandrika [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); El-dasher, Bassem [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gallegos, Gilbert F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); King, Wayne E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sisto, Aaron [Stanford Univ., CA (United States)

    2013-12-19

    Selective laser melting is a powder-based, additive-manufacturing process where a threedimensional part is produced, layer by layer, by using a high-energy laser beam to fuse the metallic powder particles. A particular challenge in this process is the selection of appropriate process parameters that result in parts with desired properties. In this study, we describe an approach to selecting parameters for high density (>99%) parts using 316L stainless steel. Though there has been significant success in achieving near-full density for 316L parts, this work has been limited to laser powers <225W. We discuss how we can exploit prior knowledge, design of computational experiments using a simple model of laser melting, and single-track experiments to determine the process parameters for use at laser powers up to 400W. Our results show that, at higher power values, there is a large range of scan speeds over which the relative density remains >99%, with the density reducing rapidly at high speeds due to insufficient melting, and less rapidly at low speeds due to the effect of voids created as the process enters keyhole mode.

  8. Phenotypic Plasticity and Species Coexistence.

    Science.gov (United States)

    Turcotte, Martin M; Levine, Jonathan M

    2016-10-01

    Ecologists are increasingly interested in predicting how intraspecific variation and changing trait values impact species interactions and community composition. For many traits, much of this variation is caused by phenotypic plasticity, and thus the impact of plasticity on species coexistence deserves robust quantification. Partly due to a lack of sound theoretical expectations, empirical studies make contradictory claims regarding plasticity effects on coexistence. Our critical review of this literature, framed in modern coexistence theory, reveals that plasticity affects species interactions in ways that could impact stabilizing niche differences and competitive asymmetries. However, almost no study integrates these measures to quantify the net effect of plasticity on species coexistence. To address this challenge, we outline novel empirical approaches grounded in modern theory.

  9. Plastic Surgery Statistics

    Science.gov (United States)

    ... PSN PSEN GRAFT Contact Us News Plastic Surgery Statistics Plastic surgery procedural statistics from the American Society of Plastic Surgeons. Statistics by Year Print 2016 Plastic Surgery Statistics 2015 ...

  10. COMPUTER MODELING IN DEFORM-3D FOR ANALYSIS OF PLASTIC FLOW IN HIGH-SPEED HOT EXTRUSION OF BIMETALLIC FORMATIVE PARTS OF DIE TOOLING

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2015-01-01

    Full Text Available The modern development of industrial production is closely connected with the use of science-based and high technologies to ensure competitiveness of the manufactured products on the world market. There is also much tension around an energy- and resource saving problem which can be solved while introducing new technological processes and  creation of new materials that provide productivity increase through automation and improvement of tool life. Development and implementation of such technologies are rather often considered as time-consuming processes  which are connected with complex calculations and experimental investigations. Implementation of a simulation modelling for materials processing using modern software products serves an alternative to experimental and theoretical methods of research.The aim of this paper is to compare experimental results while obtaining bimetallic samples of a forming tool through the method of speed hot extrusion and the results obtained with the help of computer simulation using DEFORM-3D package and a finite element method. Comparative analysis of plastic flow of real and model samples has shown that the obtained models provide high-quality and reliable picture of plastic flow during high-speed hot extrusion. Modeling in DEFORM-3D make it possible to eliminate complex calculations and significantly reduce a number of experimental studies while developing new technological processes.

  11. Wire-based laser metal deposition for additive manufacturing of TiAl6V4: basic investigations of microstructure and mechanical properties from build up parts

    Science.gov (United States)

    Klocke, Fritz; Arntz, Kristian; Klingbeil, Nils; Schulz, Martin

    2017-02-01

    The wire-based laser metal deposition (LMD-W) is a new technology which enables to produce complex parts made of titanium for the aerospace and automotive industry. For establishing the LMD-W as a new production process it has to be proven that the properties are comparable or superior to conventional produced parts. The mechanical properties were investigated by analysis of microstructure and tensile test. Therefore, specimens were generated using a 4.5 kW diode laser cladding system integrated in a 5-Axis-machining center. The structural mechanical properties are mainly influence by crystal structure and thereby the thermal history of the work piece. Especially the high affinity to oxide, distortion and dual phase microstructure make titanium grade 5 (TiAl6V4) one of the most challenging material for additive manufacturing. By using a proper local multi-nozzle shielding gas concept the negative influence of oxide in the process could be eliminated. The distortion being marginal at a single bead, accumulated to a macroscopic effect on the work piece. The third critical point for additive processing of titanium, the bimodal microstructure, could not be cleared by the laser process alone. All metallurgical probes showed α-martensitic-structure. Therefore, a thermal treatment became a necessary production step in the additive production chain. After the thermal treatment the microstructure as well as the distortion was analyzed and compared with the status before. Although not all technical issues could be solved, the investigation show that LMD-W of titanium grade 5 is a promising alternative to other additive techniques as electronic beam melting or plasma deposition welding.

  12. Plastic bronchitis

    Directory of Open Access Journals (Sweden)

    Anil Kumar Singhi

    2015-01-01

    Full Text Available Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics. They are ominous with poor prognosis. Sometimes, infection or airway reactivity may provoke cast bronchitis as a two-step insult on a vulnerable vascular bed. In such instances, aggressive management leads to longer survival. This report of cast bronchitis discusses its current understanding.

  13. Analysisi and Discussion on Structure of Plastic Part for Lithium Battery Pack%浅谈直流工具用锂电池包注塑件结构

    Institute of Scientific and Technical Information of China (English)

    房加强

    2016-01-01

    From the view of the structure of plastic part, this paper analyzes the structural characteristics of the lithium battery pack comprehensively on the market. Based on the application and enclosure type of the built-in lithium battery pack and external lithium battery pack, combined with the problems encountered in the actual production, this paper analyzes the matters what should be pay attention to in the design of the plastic parts of lithium battery pack.%从注塑件结构角度浅述直流工具用锂电池包的结构特点,以内置式锂电池包和外置式锂电池包的分类、应用特点与外壳分型,结合在实际生产中遇到的问题,分析锂电池包各注塑件在设计时应注意的相关事项。

  14. Polishing compound for plastic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stowell, M.S.

    1991-01-01

    This invention is comprised of a polishing compound for plastic materials. The compound includes approximately by approximately by weight 25 to 80 parts at least one petroleum distillate lubricant, 1 to 12 parts mineral spirits, 50 to 155 parts abrasive paste, and 15 to 60 parts water. Preferably, the compound includes approximately 37 to 42 parts at least one petroleum distillate lubricant, up to 8 parts mineral spirits, 95 to 110 parts abrasive paste, and 50 to 55 parts water. The proportions of the ingredients are varied in accordance with the particular application. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC), and similar plastic materials whenever a smooth, clear polished surface is desired.

  15. Procedural Portfolio Planning in Plastic Surgery, Part 1: Strategic Changes in Clinical Practice to Increase Physician Revenue, Improve Operative Throughput, and Maintain Patient Satisfaction.

    Science.gov (United States)

    Hultman, Charles Scott

    2016-06-01

    Portfolio planning in health care represents the strategic prioritization of services that permits an organization to better achieve its goals of margin and mission. Because of recent volatility in the economy, declining reimbursement, and rising costs of providing care, such strategic planning has become increasingly important if physicians want to remain leaders in health care. This project assesses the financial impact of procedural portfolio planning on an academic plastic surgery practice from the physician's perspective. We tracked the top 50 procedures, defined as total charges per CPT code, that were performed in our baseline year, for 6 providers in a stable plastic surgery practice. At the end of the first year, we implemented 3 types of strategic changes: growth of areas with high contribution margin (laser resurfacing of burn scars), curtailment of high-risk procedures with negative contribution margin (panniculectomy in smokers), and improved efficiency of mission-critical services with high resource consumption (free-flap breast reconstruction). During the 2-year study period, we had no turnover in faculty, did not pursue any formal marketing, did not change our surgical fees or billing system, provided care independent of payer mix, and maintained our commitment to indigent care. Outcome measures included procedural charges and revenue, collection rates, work relative value units, operating room times, idle times (room time less case time), receipts/minute in operating room, uncompensated charity care, and patient satisfaction (Press-Gainey scores). Before the study period, annual incremental growth in our practice was 1% to 2%, in terms of charges and receipts. After implementation of the portfolio planning project, the financial position of our division improved significantly, with patient satisfaction rates increasing from 85.5% to 94.1% and charity care remaining constant at US $400,000 per year. Encounters, work relative value units, charges

  16. Study of 3-D stress development in parent and twin pairs of a hexagonal close-packed polycrystal: Part II - Crystal plasticity finite element modeling

    DEFF Research Database (Denmark)

    Abdolvand, Hamidreza; Majkut, Marta; Oddershede, Jette

    2015-01-01

    -of-mass positions and volumes as measured by three-dimensional X-ray diffraction (3DXRD) microscopy. The constructed microstructure is meshed with different element densities and for different numbers of grains. Then a selected group of twin and parent pairs are studied. It is shown that the measured average stress...... each grain, stresses in the parent and twin are quite different if they are plotted in the global coordinate system. However, if the stress tensor is rotated into the local coordinate system of the twin habit plane, all the stress components averaged over the presented population are close, except......Stress heterogeneity within each individual grain of polycrystalline Zircaloy-2 is studied using a crystal plasticity finite element (CPFE) model. For this purpose, the weighted Voronoi tessellation method is used to construct 3D geometries of more than 2600 grains based on their center...

  17. Plastics recycling: challenges and opportunities.

    Science.gov (United States)

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-07-27

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

  18. Plastics recycling: challenges and opportunities

    Science.gov (United States)

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-01-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

  20. 双色高光成型塑件的结构设计技术%Structure Design Technique of Double-injection High-gloss Surface Plastic Parts

    Institute of Scientific and Technical Information of China (English)

    陈茂顺; 孙玲; 辛勇; 沙华

    2012-01-01

    According to the requirements of double-injection and high gloss plastics injection on structure design, the design methodology of structure with double color and high gloss surface including the main struc ture and join way, shut-off design, bosses, ribs, fillets, hole, etc, were been studied based on conven tional design method. The research lead to the conclusion that three main rules-correspondence of structure, sturdiness of connection and uniformity of wall-thickness, should be followed based on the outstanding charac teristic of double-decker and high-gloss surface of high gloss double-injection plastic part. Finally study used a LCD TV front shell and electrical appliance shell as an example to illustrate structure design of double color high gloss plastic products.%根据双色注塑和高光注塑成型对塑件结构的双重要求,基于和普通塑件结构设计方法的对比,针对双色高光塑件的整体结构、连接方式、防溢设计及凸起、加强筋、圆角、孔等进行研究.结合双色高光塑件的双层结构及表面高光的突出特点,得出其结构设计需遵守结构协调、黏结牢固及壁厚均匀三项原则.并以某液晶电视机前壳和电器外壳结构设计为例,对双色高光塑料制品的结构设计做了具体阐述.

  1. Circadian Regulation of Synaptic Plasticity

    Directory of Open Access Journals (Sweden)

    Marcos G. Frank

    2016-07-01

    Full Text Available Circadian rhythms refer to oscillations in biological processes with a period of approximately 24 h. In addition to the sleep/wake cycle, there are circadian rhythms in metabolism, body temperature, hormone output, organ function and gene expression. There is also evidence of circadian rhythms in synaptic plasticity, in some cases driven by a master central clock and in other cases by peripheral clocks. In this article, I review the evidence for circadian influences on synaptic plasticity. I also discuss ways to disentangle the effects of brain state and rhythms on synaptic plasticity.

  2. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 3: Michael addition reactions and miscellaneous transformations.

    Science.gov (United States)

    Aceña, José Luis; Sorochinsky, Alexander E; Soloshonok, Vadim

    2014-09-01

    The major goal of this review is a critical discussion of the literature data on asymmetric synthesis of α-amino acids via Michael addition reactions involving Ni(II)-complexes of amino acids. The material covered is divided into two conceptually different groups dealing with applications of: (a) Ni(II)-complexes of glycine as C-nucleophiles and (b) Ni(II)-complexes of dehydroalanine as Michael acceptors. The first group is significantly larger and consequently subdivided into four chapters based on the source of stereocontrolling element. Thus, a chiral auxiliary can be used as a part of nucleophilic glycine Ni(II) complex, Michael acceptor or both, leading to the conditions of matching vs. mismatching stereochemical preferences. The particular focus of the review is made on the practical aspects of the methodology under discussion and mechanistic considerations.

  3. 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.

  4. 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.

  5. Cooling simulation of plastic injection molding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Analyses the cooling of mold and plastic part during injectionmolding and the continued cooling of plastic part after being ejected from mold using the heat transfer theory and Boundary Element Method (BEM) to predict the temperature distribution in both mold and plastic part,and presents the experiments carried out with plates of ABS (Acrylonitrile-Butadiene-Styrene) to verify the validity of the cooling analysis software used to simulate the temperature distribution in ABS plate parts, and concludes that the analysis software agree qualitatively well with actual experimental findings.

  6. Environmental evaluation of plastic waste management scenarios

    DEFF Research Database (Denmark)

    Rigamonti, L.; Grosso, M.; Møller, Jacob

    2014-01-01

    The management of the plastic fraction is one of the most debated issues in the discussion on integrated municipal solid waste systems. Both material and energy recovery can be performed on such a waste stream, and different separate collection schemes can be implemented. The aim of the paper...... is to contribute to the debate, based on the analysis of different plastic waste recovery routes. Five scenarios were defined and modelled with a life cycle assessment approach using the EASEWASTE model. In the baseline scenario (P0) the plastic is treated as residual waste and routed partly to incineration...... with energy recovery and partly to mechanical biological treatment. A range of potential improvements in plastic management is introduced in the other four scenarios (P1–P4). P1 includes a source separation of clean plastic fractions for material recycling, whereas P2 a source separation of mixed plastic...

  7. Improvement Design for the Gating of the Annularity Plastic Parts Based on Moldflow%基于Moldflow的环状塑件浇注系统改进设计

    Institute of Scientific and Technical Information of China (English)

    陆宝山

    2012-01-01

    以Moldflow为工具,针对环形塑件生产成本高的问题,改进浇注系统设计和成型工艺参数,在保证制品质量的前提下,使废料占注射重量由原先的35%降至18%,节约成本,取得了很好的经济效益.%In this paper,the gating and moulding process were reformed with the Moldflow to improve the problem of high cost for annular plastic parts,and with the quality guarantee the wastage is dropped from the original 35% to 18%,which obtained good economic benefits.

  8. Overcoming maladaptive plasticity through plastic compensation

    Directory of Open Access Journals (Sweden)

    Matthew R.J. MORRIS, Sean M. ROGERS

    2013-08-01

    Full Text Available Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments. This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity, two of which involve genetic changes (standing genetic variation, genetic compensation and two of which do not (standing epigenetic variation, plastic compensation. Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity. In particular, plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence. We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change [Current Zoology 59 (4: 526–536, 2013].

  9. Overcoming maladaptive plasticity through plastic compensation

    Institute of Scientific and Technical Information of China (English)

    Matthew R.J.MORRIS; Sean M.ROGERS

    2013-01-01

    Most species evolve within fluctuating environments,and have developed adaptations to meet the challenges posed by environmental heterogeneity.One such adaptation is phenotypic plasticity,or the ability of a single genotype to produce multiple environmentally-induced phenotypes.Yet,not all plasticity is adaptive.Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution,much less is known about maladaptive plasticity.However,maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments.This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity,two of which involve genetic changes (standing genetic variation,genetic compensation) and two of which do not (standing epigenetic variation,plastic compensation).Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity.In particular,plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence.We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change.

  10. 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.

  11. 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......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  12. Tree plastic bark

    OpenAIRE

    Casado Arroyo, Carlos

    2016-01-01

    “Tree plastic bark" consiste en la realización de una intervención artística en un entorno natural concreto, generando de esta manera un Site Specific(1). Como hace alusión Rosalind Krauss en sus reflexiones “La escultura en el campo expandido”(2), comenta que su origen esta claramente ligado con el concepto de monumentalidad. La escultura es un monumento, se crea para conmemorar algún hecho o personaje relevante y está realizada para una ubicación concreta. La investigación parte de la id...

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

    Science.gov (United States)

    Haryono, Agus; Triwulandari, Evi; Jiang, Pingping

    2017-01-01

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

  14. Constraints on the evolution of phenotypic plasticity: limits and costs of phenotype and plasticity.

    Science.gov (United States)

    Murren, C J; Auld, J R; Callahan, H; Ghalambor, C K; Handelsman, C A; Heskel, M A; Kingsolver, J G; Maclean, H J; Masel, J; Maughan, H; Pfennig, D W; Relyea, R A; Seiter, S; Snell-Rood, E; Steiner, U K; Schlichting, C D

    2015-10-01

    Phenotypic plasticity is ubiquitous and generally regarded as a key mechanism for enabling organisms to survive in the face of environmental change. Because no organism is infinitely or ideally plastic, theory suggests that there must be limits (for example, the lack of ability to produce an optimal trait) to the evolution of phenotypic plasticity, or that plasticity may have inherent significant costs. Yet numerous experimental studies have not detected widespread costs. Explicitly differentiating plasticity costs from phenotype costs, we re-evaluate fundamental questions of the limits to the evolution of plasticity and of generalists vs specialists. We advocate for the view that relaxed selection and variable selection intensities are likely more important constraints to the evolution of plasticity than the costs of plasticity. Some forms of plasticity, such as learning, may be inherently costly. In addition, we examine opportunities to offset costs of phenotypes through ontogeny, amelioration of phenotypic costs across environments, and the condition-dependent hypothesis. We propose avenues of further inquiry in the limits of plasticity using new and classic methods of ecological parameterization, phylogenetics and omics in the context of answering questions on the constraints of plasticity. Given plasticity's key role in coping with environmental change, approaches spanning the spectrum from applied to basic will greatly enrich our understanding of the evolution of plasticity and resolve our understanding of limits.

  15. Part I: Reverse-docking studies of a squaramide-catalyzed conjugate addition of a diketone to a nitro-olefin Part II: The development of ChemSort: an education game for organic chemistry

    Science.gov (United States)

    Granger, Jenna Christine

    Part 1: Reverse-docking studies of a squaramide-catalyzed conjugate addition of a diketone to a nitro-olefin. Asymmetric organocatalysis, the catalysis of asymmetric reactions by small organic molecules, is a rapidly growing field within organic synthesis. The ability to rationally design organocatalysts is therefore of increasing interest to organic chemists. Computational chemistry is quickly proving to be an extremely successful method for understanding and predicting the roles of organocatalysts, and therefore is certain to be of use in the rational design of such catalysts. A methodology for reverse-docking flexible organocatalysts to rigid transition state models of asymmetric reactions has been previously developed by the Deslongchamps group. The investigation of Rawal's squaramide-based organocatalyst for the addition of a diketone to a nitro-olefin is described, and the results of the reverse docking of Rawal's catalyst to the geometry optimized transition state models of the uncatalyzed reaction for both the R and S-product enantiomers are presented. The results of this study indicate a preference for binding of the organocatalyst to the R-enantiomer transition state model with a predicted enantiomeric excess of 99%, which is consistent with the experimental results. A plausible geometric model of the transition state for the catalyzed reaction is also presented. The success of this study demonstrates the credibility of using reverse docking methods for the rational design of asymmetric organocatalysts. Part 2: The development of ChemSort: an educational game for organic chemistry. With the advent of the millennial learner, we need to rethink traditional classroom approaches to science learning in terms of goals, approaches, and assessments. Digital simulations and games hold much promise in support of this educational shift. Although the idea of using games for education is not a new one, well-designed computer-based "serious games" are only beginning to

  16. Effect of Rapid Prototyping Technique on Mechanical Properties of Plastic Parts Through FDM Process%FDM快速成型工艺对成型件力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘亚; 何冰; 陈鹏飞; 赵海超; 薄夫祥

    2017-01-01

    Taking ABS-M30,PPSF and Ultem 9085 3D printing materials as three typical cases,the plastic parts were formed through a fused deposition modeling (FDM) method,and the effect of raw materials,setting angles and printer nozzles on the mechanical properties of the parts were investigated.The results indicated that the tensile and impact strength increased at first and tended to decrease afterwards when the setting angels of printer varied from 0 ° to 90 °,and they achieved maximum values at the setting angel of 45 °.The flexural strength increased with an increase of setting angel.Moreover,the plastic parts formed by T16-type printer nozzle gained better mechanical properties than that formed by T12-type nozzle at the same position angle.%基于熔融沉积成型(FDM)技术,研究了不同材料、成型件放置角度和喷嘴型号对成型件力学性能的影响,得到具有最佳力学性能的打印工艺.分别以美国Stratasys公司生产的ABS-M30、PPSF和Ultem 9085打印材料为研究对象,采用常规填充方式,以xy平面为基准面,0°~90°范围内分别设置不同放置角度打印并测试其力学性能.结果表明,45°角放置样件的拉伸和冲击强度最佳;随着放置角度的增加,样件弯曲强度也随之增大;采用相同放置方式成型测试样件,T16喷嘴打印成型件较T12喷嘴打印成型件的力学性能更佳.

  17. Plasticity Theory of Fillet Welds

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper deals with simple methods for calculation of fillet welds based on the theory of plasticity. In developing the solutions the lower-bound theorem is used. The welding material and parts of the base material are subdivided into triangular regions with homogeneous stress fields; thereby...

  18. Proposals for the addition of fifteen new areas to the National Wilderness Preservation System : Part 2 : Havasu National Wildlife Refuge and additions to previously submitted proposals : Pinnacles National Monument and Sequoia-Kings Canyon National Park

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  19. Corrosion of metals and alloys - Corrosion and fouling in industrial cooling water systems - Part 1: Guidelines for conducting pilot-scale evaluation of corrosion and fouling control additives for open recirculating cooling water systems

    CERN Document Server

    International Organization for Standardization. Geneva

    2006-01-01

    Corrosion of metals and alloys - Corrosion and fouling in industrial cooling water systems - Part 1: Guidelines for conducting pilot-scale evaluation of corrosion and fouling control additives for open recirculating cooling water systems

  20. 49 CFR 192.375 - Service lines: Plastic.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Plastic. 192.375 Section 192.375... § 192.375 Service lines: Plastic. (a) Each plastic service line outside a building must be installed... terminate above ground level and outside the building, if— (i) The above ground level part of the...

  1. Brain Plasticity, Intelligence and Schizophrenia: influence of genes and environment

    NARCIS (Netherlands)

    Hedman, A.M.

    2013-01-01

    This thesis shows that the adult human brain has plastic properties. These plastic properties are at least in part heritable and have functional significance. Identifying genes and environmental factors implicated in brain plasticity is an important next step to optimize brain development in health

  2. A review of plastic waste biodegradation.

    Science.gov (United States)

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

    2005-01-01

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

  3. Recycling and recovery of post-consumer plastic solid waste in a European context

    Directory of Open Access Journals (Sweden)

    Dewil Raf

    2012-01-01

    Full Text Available The disposal of waste plastics has become a major worldwide environmental problem. The USA, Europe and Japan generate annually about 50 million tons of post-consumer plastic waste, previously landfilled, generally considered as a non-sustainable and environmentally questionable option. Landfill sites and their capacity are, moreover, decreasing rapidly, and legislation is stringent. Several European Directives and US legislation concern plastic wastes and the required management. They are briefly discussed in this paper. New processes have emerged, i.e., advanced mechanical recycling of plastic waste as virgin or second grade plastic feedstock, and thermal treatments to recycle the waste as virgin monomer, as synthetic fuel gas, or as heat source (incineration with energy recovery. These processes avoid land filling, where the non-biodegradable plastics remain a lasting environmental burden. The paper reviews these alternative options through mostly thermal processing (pyrolysis, gasification and waste-to-energy. Additional research is, however, still needed to confirm the potential on pilot and commercial scale. [Acknowledgments. The research was partly funded by the Fundamental Research Funds for the Central Universities RC1101 (PR China and partly funded by Project KP/09/005 (SCORES4CHEM Knowledge Platform of the Industrial Research Council of the KU Leuven (Belgium.

  4. Part 3. Triethylborane-air: a suitable initiator for intermolecular radical additions of S-2-oxoalkyl-thionocarbonates (S-xanthates to olefins

    Directory of Open Access Journals (Sweden)

    Nguyen Van Tai

    2007-12-01

    Full Text Available Abstract Under carefully controlled conditions, the triethylborane-air combination proves to be an efficient radical initiator that allows intermolecular radical additions of S-2-oxoalkyl-thionocarbonates (S-xanthates to olefins. Depending on both the structures of the xanthate and the olefin, the addition process can be achieved at room temperature or slightly higher.

  5. Polychlorinated biphenyls and organochlorine pesticides in plastics ingested by seabirds.

    Science.gov (United States)

    Colabuono, Fernanda Imperatrice; Taniguchi, Satie; Montone, Rosalinda Carmela

    2010-04-01

    The occurrence of plastic objects in the digestive tract was assessed in eight species of Procellariiformes collected in southern Brazil and the occurrence of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the ingested plastics pellets and plastic fragments was evaluated. PCBs were detected in plastic pellets (491 ng g(-1)) and plastic fragments (243-418 ng g(-1)). Among the OCPs, p,p'-DDE had the highest concentrations, ranging from 68.0 to 99.0 ng g(-1). The occurrence of organic pollutants in post-consumer plastics supports the fact that plastics are an important source carrying persistent organic pollutants in the marine environment. Although transfer through the food chain may be the main source of exposure to POPs to seabirds, plastics could be an additional source for the organisms which ingest them, like Procellariiformes which are the seabirds most affected by plastic pollution.

  6. Use of recycled plastics in concrete: A critical review.

    Science.gov (United States)

    Gu, Lei; Ozbakkaloglu, Togay

    2016-05-01

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

  7. Research Papers Sponsored by the Commission on Private Philanthropy and Public Needs. Volume II: Philanthropic Fields of Interest, Part II-Additional Perspectives.

    Science.gov (United States)

    Department of the Treasury, Washington, DC.

    Twelve papers discuss future changes and trends in philanthropic giving and activities. The report is Volume II, Part II of a five volume series examining the relationship between nonprofit institutions and their donors. The opening paper reviews the needs for better definition of the government's role in contracting and grant making, and for…

  8. Proposals for the addition of fifteen new areas to the National Wilderness Preservation System : Part 5 : Crab Orchard National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  9. Proposals for the addition of fifteen new areas to the National Wilderness Preservation System : Part 8 : Mille Lacs and Rice Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  10. Proposals for the addition of fifteen new areas to the National Wilderness Preservation System : Part 4 : Hawaiian Islands National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  11. Influence of Injection-Molding Process Parameters on Part Replication of Microstructures with Additively-Manufactured Soft Tooling Inserts WCMNM 2017 No

    DEFF Research Database (Denmark)

    Mischkot, Michael; Zhang, Yang; Segebrecht Gøtje, Asger

    2017-01-01

    The objective of this research is to investigate the influence of injection molding parameters on the dimensional replication of microstructure surfaces in injection molding with additively manufactured soft tooling inserts in a photopolymer material. The replication degree of micropillars...... diameter and decreases the replication degree of the pillar height. A high melt temperature increases the pillar diameter independently from the pillar height. A higher injection speed affects both pillar diameter and height negatively. In addition, the study showed a significant difference...

  12. Training manual for precision hand deburring, Part 3

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1981-03-01

    This publication is Part 3 of a 4 part training manual to be used by machinist trainees, production workers, and others removing burrs from precision miniature parts. The manuals are written to be self-teaching and are intended to be used with two hours of training each day along with six additional hours of bench work in deburring. This part describes mounted stones, scrapers, hand stones, abrasive filled rubber and cotton tools, abrasive paper products, felt bobs and lapping compounds, mandrels and arbors, miscellaneous tools, personal techniques for assuring quality, cleaning parts, and deburring gears and plastic parts.

  13. Our plastic age

    National Research Council Canada - National Science Library

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

    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...

  14. Weinig plastic in vissenmaag

    NARCIS (Netherlands)

    Foekema, E.M.

    2012-01-01

    Waar de magen van sommige zeevogels vol plastic zitten, lijken vissen in de Noordzee nauwelijks last te hebben van kunststofafval. Onderzoekers die plastic resten zochten in vissenmagen vonden ze in elk geval nauwelijks.

  15. Ear Plastic Surgery

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  16. VISCO-ELASTIC (PLASTIC) EFFECTS AND FAILURE BEHAVIOR OF PUR FOAMED PLASTICS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The viscous effects and failure behavior of PUR foamed plastics are investigated by the cycling loading and preloading experiments. On the basis of static and dynamic compressive experiments, the SEM analysis is given for the PUR foamed plastics specimens which have been tested and the deformation as well as failure mechanisms are determined at the same time. In addition, the relaxation characteristics and the failure criterion of foamed plastics are discussed adequately.

  17. 76 FR 51922 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Adoption of Plastic...

    Science.gov (United States)

    2011-08-19

    ... of Plastic Parts and Business Machines Coating Standards AGENCY: Environmental Protection Agency (EPA... Coating, and adds new COMAR 26.11.19.07-2, Plastic Parts and Business Machines Coating. Maryland's SIP... by EPA's Control Techniques Guidelines (CTG) for Miscellaneous Metal and Plastic Parts Coatings...

  18. Biodegradability of Plastics

    OpenAIRE

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

    2009-01-01

    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 ...

  19. Shaping frequency response of a vibrating plate for passive and active control applications by simultaneous optimization of arrangement of additional masses and ribs. Part I: Modeling

    Science.gov (United States)

    Wrona, Stanislaw; Pawelczyk, Marek

    2016-03-01

    An ability to shape frequency response of a vibrating plate according to precisely defined demands has a very high practical potential. It can be applied to improve acoustic radiation of the plate for required frequencies or enhance acoustic isolation of noise barriers and device casings by using both passive and active control. The proposed method is based on mounting severaladditional ribs and masses (passive and/or active) to the plate surface at locations followed from an optimization process. This paper, Part I, concerns derivation of a mathematical model of the plate with attached elements in the function of their shape and placement. The model is validated by means of simulations and laboratory experiments, and compared with models known from the literature. This paper is followed by a companion paper, Part II, where the optimization process is described. It includes arrangement of passive elements as well as actuators and sensors to improve controllability and observability measures, if active control is concerned.

  20. Chemical Recycle of Plastics

    Directory of Open Access Journals (Sweden)

    Sara Fatima

    2014-11-01

    Full Text Available Various chemical processes currently prevalent in the chemical industry for plastics recycling have been discussed. Possible future scenarios in chemical recycling have also been discussed. Also analyzed are the effects on the environment, the risks, costs and benefits of PVC recycling. Also listed are the various types of plastics and which plastics are safe to use and which not after rcycle

  1. 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...

  2. Characterization and evaluation physical properties biodegradable plastic composite from seaweed (Eucheuma cottonii)

    Science.gov (United States)

    Deni, Glar Donia; Dhaningtyas, Shalihat Afifah; Fajar, Ibnu; Sudarno

    2015-12-01

    The characterization and evaluation of biodegradable plastic composed of a mixture PVA - carrageenan - chitosan was conducted in this study. Obtained data were then compared to commercial biodegradable plastic. Characteristic of plastic was mechanical tested such as tensile - strength and elongation. Plastic degradation was studied using composting method for 7 days and 14 days. The results showed that the increase carrageenan will decrease tensile-strength and elongation plastic composite. In addition, increase carrageenan would increase the degraded plastics composite.

  3. Influência da adição de plastificante do processo de reticulação na morfologia, absorção de aguá e propriedades mecânicas de filmes de alginato de sódio Influence of plasticizer addition and crosslinking process on morohology, water absoption and mechanical properties of sodium alginate films

    Directory of Open Access Journals (Sweden)

    Aline Margarete Furuyama Lima

    2007-08-01

    Full Text Available The effects of sorbitol and formaldehyde on the morphology, water absorption and mechanical properties of sodium alginate films were analyzed. The morphology of the films indicated the presence of small aggregates in the surface of uncrosslinked films, which disappeared with the crosslinking process. The water uptake and percentage of elongation increased with the addition of sorbitol in uncrosslinked films. At the same time, a decrease in tensile strength and Young's modulus occurred. The swelling ratio and water uptake of crosslinked alginate/sorbitol films decreased with an increase in sorbitol content suggesting an enhanced crosslinking density due to the presence of plasticizer.

  4. Comparative investigation of optical techniques for topography measurement of rough plastic surfaces

    DEFF Research Database (Denmark)

    Bariani, Paolo; Hansen, Hans Nørgaard; Arlø, Uffe Rolf

    2003-01-01

    polypropylene parts manufactured by injection moulding. The mould was equipped with inserts with EDM machined surfaces (Sa  3.5 µm) in order to represent a typical tool surface for injection moulding. A focus detection laser scanning profiler, a confocal scanning laser microscope, a white light interferometer...... and, in addition, a scanning electron microscope, have been used in the analysis of plastic surfaces. This investigation has shown that topography assessment of rough plastic surfaces is critical to both white light interference microscope and confocal microscope while the focus detection laser...

  5. Comparative investigation of optical techniques for topography measurement of rough plastic surfaces

    DEFF Research Database (Denmark)

    Bariani, Paolo; Hansen, Hans Nørgaard; Arlø, Uffe Rolf

    2003-01-01

    polypropylene parts manufactured by injection moulding. The mould was equipped with inserts with EDM machined surfaces (Sa  3.5 µm) in order to represent a typical tool surface for injection moulding. A focus detection laser scanning profiler, a confocal scanning laser microscope, a white light interferometer...... and, in addition, a scanning electron microscope, have been used in the analysis of plastic surfaces. This investigation has shown that topography assessment of rough plastic surfaces is critical to both white light interference microscope and confocal microscope while the focus detection laser...

  6. BIOFILTERS IN WASTEWATER TREATMENT AFTER RECYCLED PLASTIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Irena Kania-Surowiec

    2014-10-01

    Full Text Available In this paper the possibility of using biological deposits in wastewater treatment of recycled plastics were presented. There are many aspects of this issue that should be considered to be able to use information technology solutions in the industry. This includes, inter alia, specify the types of laboratory tests based on the analysis of changes in the fluid during the wastewater treatment process, knowledge and selection factors for proper growth of biofilm in the deposit and to develop the right concept and a prototype for a particular processing plant, plastic processing plant. It is possible to determine the parameters that will increase the efficiency of sewage treatment while minimizing the financial effort on the part of the Company. Selection methods of wastewater treatment is also associated with the environmental strategy of the country at the enterprise level specified in the Environmental Policy. This is an additional argument for the use of biological methods in the treatment of industrial waste water.

  7. 汽车注塑件3D 打印快速成型机控制系统设计%Design of 3D Printer Control System for Automotive Plastic Parts

    Institute of Scientific and Technical Information of China (English)

    谢彤; 张米雅; 姚建飞

    2016-01-01

    The 3D printer control system for automotive plastic parts is designed according to the demand of the me-chanical system.It use ST STM32F103VCT6 microcontroller which is based on ARM Corxtex -M3 high efficiency core to communicate with the host computer ,process data ,acquisite&convert analog to digital , control the MOS .STM32F103VCT6 also signals the stepper driving IC A4988.It runs a PID algorithm software to precisely control the temperature of the ex-truder.This paper discusses the main hardware circuit and software realization process of the control system .The system testing shows good performance.%针对汽车注塑件3D打印快速成型机机械部分的控制需求,设计了一款汽车注塑件3D打印快速成型机控制系统。控制系统采用意法半导体公司推出的高效ARM Corxtex-M3核心的STM32F103VCT6微控制器,由该控制器完成与上位机通信、数据处理、模拟量采集与模数转换、MOS管控制,并控制A4988两相步进电机驱动芯片以实现步进电机驱动等工作,软件采用PID算法准确控制物料喷头的加热温度。论述了控制系统主要硬件电路设计和软件的实现流程,系统测试表明性能良好。

  8. 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.

  9. 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....

  10. 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.

  11. Journal of CHINA PLASTICS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Journal of CHINA PLASTICS was authorized and approved by The State Committee of Science and Technology of China and The Bureau of News Press of China, and published by The China Plastics Processing Industry Association,Beijing Technology and Business University and The Institute of Plastics Processing and Application of Light Industry, distributed worldwide. Since its birth in 1987, CHINA PLASTICS has become a leading magazine in plastics industry in China, a national Chinese core journal and journal of Chinese scientific and technological article statistics. It is covered by CA.

  12. Integrating Hebbian and homeostatic plasticity: introduction.

    Science.gov (United States)

    Fox, Kevin; Stryker, Michael

    2017-03-05

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

  13. Bomb reduction of uranium tetrafluoride. Part II: Influence of the addition elements in the reduction process; Reduccion del tetrafluoruro de uranio en bomba cerrada. Parte II: Influencia de elementos de adicion en la reducion

    Energy Technology Data Exchange (ETDEWEB)

    Anca Abati, R.; Lopez Rodriguez, M.

    1962-07-01

    This work shows the influence of uranium oxide and uranyl fluoride in the reduction of uranium with Ca and Mg. These additions are more harmful when using smaller bombs. The uranyl fluoride has influence in the reduction process; the curves yield-concentration shows two regions depending upon the salt concentration. The behaviour of this addition in these regions can be explained following the different decompositions that can take place during the reduction process. (Author) 9 refs.

  14. Characterization of Ultra High Temperature Ceramics via Transmission Electron Microscopy. Part 2: UHTCs sintered with addition of TaSi2

    Science.gov (United States)

    2010-01-21

    hafnium diborides and carbides belong to the class of materials defined UHTCs (Ultra-High-Temperature-Ceramics). These materials are of particular...are finally compared to composites sintered with addition of the same amount of MoSi2. FA8655-09-M-4002 8 1. Introduction Zirconium, hafnium ... alloying elements. High temperatures decrease the liquid surface tension and promote wettability. Also, the spreading rate towards equilibrium is enhanced

  15. BOOK REVIEW: Introduction to Computational Plasticity

    Science.gov (United States)

    Hartley, P.

    2006-04-01

    The use of computational modelling in all areas of science and engineering has in recent years escalated to the point where it underpins much of current research. However, the distinction must be made between computer systems in which no knowledge of the underlying computer technology or computational theory is required and those areas of research where the mastery of computational techniques is of great value, almost essential, for final year undergraduates or masters students planning to pursue a career in research. Such a field of research in the latter category is continuum mechanics, and in particular non-linear material behaviour, which is the core topic of this book. 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. Any lack of knowledge in this area however, is of no disadvantage as it serves only as an introduction and the book moves on quickly to continuum plasticity

  16. Ion radiation damage in plastic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, M

    2006-07-01

    Plastic detectors are widely used for particle identification, micro pore and nano pore technology, neutron, gamma, radon and electron dosimeters. For some applications, plastic detectors have unique advantages among electronic detectors as 4 solid angles for ion identification in nuclear and cosmic ray physics; low-cost for massive use in indoors radon and neutron dosimeters; wide dose-range response for gamma and electron dosimetry; easy to use detectors in active geological faults in prospecting geothermal energy etc. There is a grate diversity of plastic detectors, which further improves their use in a particular application. However, the comparison test between different kinds of plastics can be time consuming, being therefore necessary to have methods for rapidly assessing plastic detectors properties. This invited talk deals in the first part with overview applications in Mexico of plastic detectors mentioned in the first paragraph. In the second part presents a general experimental relationship between the diameter-grow of positive ions tracks in several plastics for light ions, that allow to compare their energy resolution and to predict the track diameter of isotopes beams, as well as to predict the uniformity of micro pores. The formation of Nano pores produced by {sup 238} U ions is also discussed. (Author)

  17. Glassy metallic plastics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper reports a class of bulk metallic glass including Ce-, LaCe-, CaLi-, Yb-, and Sr-based metallic glasses, which are regarded as glassy metallic plastics because they combine some unique properties of both plastics and metallic alloys. These glassy metallic plastics have very low glass transition temperature (Tg~25oC to 150oC) and low Young’s modulus (~20 GPa to 35 GPa). Similar to glassy plastics, these metallic plastics show excellent plastic-like deformability on macro-, micro- and even nano-scale in their supercooled liquid range and can be processed, such as elongated, compressed, bent, and imprinted at low temperatures, in hot water for instance. Under ambient conditions, they display such metallic properties as high thermal and electric conductivities and excellent mechanical properties and other unique properties. The metallic plastics have potential applications and are also a model system for studying issues in glass physics.

  18. PHASE EQUILIBRIA INVESTIGATIONS OF BINARY, TERNARY, AND HIGHER ORDER SYSTEMS. PART 2. EFFECT OF RHENIUM AND ALUMINUM ADDITIONS ON THE METAL-RICH EQUILIBRIA IN THE TITANIUM-MOLYBDENIUM-CARBON AND TITANIUM-NIOBIUM-CARBON SYSTEMS

    Science.gov (United States)

    The solid state phase equilibria of the metal-rich regions of the Titanium-Molybdenum-Carbon and Titanium-Niobium-Carbon systems with up to 12 At...Rhenium and 10 At.% Aluminum additions, respectively, have been determined on hot pressed, heat treated, and in part arc melted alloys. The phase ... equilibria in the metal-rich regions, with these additions, is practically unchanged over that of the ternary Titanium-Molybdenum-Carbon and Titanium

  19. Motor cortical plasticity in Parkinson's disease.

    Science.gov (United States)

    Udupa, Kaviraja; Chen, Robert

    2013-09-04

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

  20. 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.

  1. 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.

  2. 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.

  3. Plastic Deformation of Metal Surfaces

    DEFF Research Database (Denmark)

    Hansen, Niels; Zhang, Xiaodan; Huang, Xiaoxu

    2013-01-01

    parameters by TEM and EBSD and apply strength-structural relationships established for the bulk metal deformed to high strains. This technique has been applied to steel deformed by high energy shot peening and a calculated stress gradient at or near the surface has been successfully validated by hardness......Plastic deformation of metal surfaces by sliding and abrasion between moving parts can be detrimental. However, when the plastic deformation is controlled for example by applying different peening techniques hard surfaces can be produced which can increase the fracture resistance and fatigue life...... of metal components. An optimization of processes and material parameters must be based on a quantification of stress and strain gradients at the surface and in near surface layer where the structural scale can reach few tens of nanometers. For such fine structures it is suggested to quantify structural...

  4. Plastics - the sustainable way to use Oil and Gas

    Energy Technology Data Exchange (ETDEWEB)

    Siebourg, Wolfgang

    2009-07-01

    Conclusions (drawn by the author): Plastics are a sustainable use of oil and gas - Plastic products enable significant savings of energy and GHG emissions particularly in the use phase; - Plastic products help use resources in the most efficient way. Restricting plastics relative growth would result in increased energy consumption. Diversion from landfill would increase resource efficiency. Waste-to-Energy is an additional resource and is complementary to mechanical recycling. Plastics producers and the Oil and Gas industry should cooperate to produce reliable consumption data. Oil and Gas industry should develop and maintain European (world) eco-profiles (cradle to gate) for their respective industry. (author)

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

    Directory of Open Access Journals (Sweden)

    Mery Apriyani

    2016-05-01

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

  6. Neural Plasticity: For Good and Bad

    Science.gov (United States)

    Møller, A. R.

    The brain's ability to change its organization and function is necessary for normal development of the nervous system and it makes it possible to adapt to changing demands but it can also cause disorders when going awry. This property, known as neural plasticity, is only evident when induced, very much like genes. Plastic changes may be programmed and providing a ``midcourse correction" during childhood development. If that is not executed in the normal way severe developmental disorders such as autism may results. Normal development of functions and anatomical organization of the brain and the spinal cord depend on appropriate sensory stimulation and motor activations. So-called enriched sensory environments have been shown to be beneficial for cognitive development and enriched acoustic environment may even slow the progression of age-related hearing loss. It is possible that the beneficial effect of physical exercise is achieved through activation of neural plasticity. The beneficial effect of training after trauma to the brain or spinal cord is mainly achieved through shifting functions from damaged brain area to other parts of the central nervous system and adapting these parts to take over the functions that are lost. This is accomplished through activation of neural plasticity. Plastic changes can also be harmful and cause symptoms and signs of disorders such as some forms of chronic pain (central neuropathic pain) and severe tinnitus. We will call such disorders ``plasticity disorders".

  7. Propelling plastics into the circular economy - weeding out the toxics first.

    Science.gov (United States)

    Leslie, H A; Leonards, P E G; Brandsma, S H; de Boer, J; Jonkers, N

    2016-09-01

    The Stockholm Convention bans toxic chemicals on its persistent organic pollutants (POPs) list in order to promote cleaner production and prevent POPs accumulation in the global environment. The original 'dirty dozen' set of POPs has been expanded to include some of the brominated diphenyl ether flame retardants (POP-BDEs). In addition to cleaner production, there is an urgent need for increased resource efficiency to address the finite amount of raw materials on Earth. Recycling plastic enhances resource efficiency and is part of the circular economy approach, but how clean are the materials we are recycling? With the help of a new screening method and detailed analyses, we set out to investigate where these largely obsolete BDEs were showing up in Dutch automotive and electronics waste streams, calculate mass flows and determine to what extent they are entering the new product chains. Our study revealed that banned BDEs and other toxic flame retardants are found at high concentrations in certain plastic materials destined for recycling markets. They were also found in a variety of new consumer products, including children's toys. A mass flow analysis showed that 22% of all the POP-BDE in waste electrical and electronic equipment (WEEE) is expected to end up in recycled plastics because these toxic, bioaccumulative and persistent substances are currently not effectively separated out of plastic waste streams. In the automotive sector, this is 14%, while an additional 19% is expected to end up in second-hand parts (reuse). These results raise the issue of delicate trade-offs between consumer safety/cleaner production and resource efficiency. As petroleum intensive materials, plastic products ought to be repaired, reused, remanufactured and recycled, making good use of the 'inner circles' of the circular economy. Keeping hazardous substances - whether they are well known POPs or emerging contaminants - out of products and plastic waste streams could make these

  8. EFFECT OF UNEQUAL DEFORMATION IN DEVELOPMENT OF ADVANCED PLASTIC PROCESSING TECHNOLOGIES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An effect of unequal deformation in development of advanced plastic processing technologies is researched by studying an in-plane bending process of strip metal under unequal compressing. The research results show the following: If appropriately controlled, unequal plastic deformation can play an important role not only in the improvement of quality of parts obtained by plastic processing technologies, but also in the development of new processes for advanced plastic working technologies. A coordinated growth of unequal plastic deformation can develop the deformation potentiality of material to the full. The degree of unequal plastic deformation can be used as bases for optimization design of processes and dies of plastic forming.

  9. UTILIZATION OF WASTE PLASTIC BOTTLES IN ASPHALT MIXTURE

    Directory of Open Access Journals (Sweden)

    TAHER BAGHAEE MOGHADDAM

    2013-06-01

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

  10. Halos of Plastic

    Institute of Scientific and Technical Information of China (English)

    Maya Reid

    2012-01-01

    The halos that span South Africa's coastline are anything but angelic. Fanning out around four major urban centers-Cape Town, Port Elizabeth, East London and Durban-they are made up of innumerable bits and pieces of plastic. As a form of pollution, their shelflife is unfathomable. Plastic is essentially chemically inactive. It's designed to never break down.

  11. Biodegradation of plastics.

    Science.gov (United States)

    Shimao, M

    2001-06-01

    Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes.

  12. MODULATING EXCITATION THROUGH PLASTICITY AT INHIBITORY SYNAPSES

    Directory of Open Access Journals (Sweden)

    Vivien eChevaleyre

    2014-03-01

    Full Text Available Learning is believed to depend on lasting changes in synaptic efficacy such as long-term potentiation and long-term depression. As a result, a profusion of studies has tried to elucidate the mechanisms underlying these forms of plasticity. Traditionally, experience-dependent changes at excitatory synapses were assumed to underlie learning and memory formation. However, with the relatively more recent investigation of inhibitory transmission, it had become evident that inhibitory synapses are not only plastic, but also provide an additional way to modulate excitatory transmission and the induction of plasticity at excitatory synapses.Thanks to recent technological advances, progress has been made in understanding synaptic transmission and plasticity from particular interneuron subtypes. In this review article, we will describe various forms of synaptic plasticity that have been ascribed to two fairly well characterized populations of interneurons in the hippocampus, those expressing cholecystokinin (CCK and parvalbumin (PV. We will discuss the resulting changes in the strength and plasticity of excitatory transmission that occur in the local circuit as a result of the modulation of inhibitory transmission. We will focus on the hippocampus because this region has a relatively well-understood circuitry, numerous forms of activity-dependent plasticity and a multitude of identified interneuron subclasses.

  13. 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...... answered the first Danish national survey, PD13[1], investigating the importance of industrial designers’ knowledge in plastics and the collaboration between designers and the polymer industry. The plastics industry and the industrial designers collaborate well, but both groups frequently experience...... that the designers’ lack of knowledge concerning polymer materials and manufacturing methods can be problematic or annoying, and design students from most Danish design universities express the need for more contact with the industry and more competencies and tools to handle even simple topics when designing plastic...

  14. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    In contemporary consciousness studies the phenomenon of neural plasticity has received little attention despite the fact that neural plasticity is of still increased interest in neuroscience. We will, however, argue that neural plasticity could be of great importance to consciousness studies....... If consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather...... the relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can...

  15. Computational Strain Gradient Crystal Plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2011-01-01

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

  16. Development of recycled plastic composites for structural applications from CEA plastics

    Science.gov (United States)

    Bhalla, Agrim

    Plastic waste from consumer electronic appliances (CEAs) such as computer and printer parts including Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polystyrene (PS) and PC/ABS were collected using handheld FTIR Spectrophotometer. The blends of these plastics with High Density Polyethylene (HDPE) are manufactured under special processing conditions in a single screw compounding injection molding machine. The blends are thermoplastics have high stiffness and strength, which may enhance the mechanical properties of HDPE like tensile modulus, ultimate tensile strength, tensile break and tensile yield. These composites have a potential to be used for the future application of recycled plastic lumber, thus replacing the traditional wood lumber.

  17. Additive Manufacturing: Reproducibility of Metallic Parts

    Directory of Open Access Journals (Sweden)

    Konda Gokuldoss Prashanth

    2017-02-01

    Full Text Available The present study deals with the properties of five different metals/alloys (Al-12Si, Cu-10Sn and 316L—face centered cubic structure, CoCrMo and commercially pure Ti (CP-Ti—hexagonal closed packed structure fabricated by selective laser melting. The room temperature tensile properties of Al-12Si samples show good consistency in results within the experimental errors. Similar reproducible results were observed for sliding wear and corrosion experiments. The other metal/alloy systems also show repeatable tensile properties, with the tensile curves overlapping until the yield point. The curves may then follow the same path or show a marginal deviation (~10 MPa until they reach the ultimate tensile strength and a negligible difference in ductility levels (of ~0.3% is observed between the samples. The results show that selective laser melting is a reliable fabrication method to produce metallic materials with consistent and reproducible properties.

  18. Navy Additive Manufacturing: Adding Parts, Subtracting Steps

    Science.gov (United States)

    2015-06-01

    2013, para. 1). .............38  Figure 19.  Lockheed Martin Airship (from Lockheed Martin, n.d.). ................................39  Figure 20.  Bell...tunnel testing so more iterations can be tested in less time” (Rapid Prototyping, n.d., para 3). According to Aerodynamic Development Engineer...are used for early aerodynamic testing” (Rapid Prototyping, n.d., para 5). Along with providing higher quality prototypes, GM has been able to

  19. Equivalent Plastic Strain Gradient Plasticity with Grain Boundary Hardening and Comparison to Discrete Dislocation Dynamics

    CERN Document Server

    Bayerschen, E; Wulfinghoff, S; Weygand, D; Böhlke, T

    2015-01-01

    The gradient crystal plasticity framework of Wulfinghoff et al. [53] incorporating an equivalent plastic strain and grain boundary yielding, is extended with additional grain boundary hardening. By comparison to averaged results from many discrete dislocation dynamics (DDD) simulations of an aluminum type tricrystal under tensile loading, the new hardening parameter in the continuum model is calibrated. It is shown that although the grain boundaries (GBs) in the discrete simulations are impenetrable, an infinite GB yield strength corresponding to microhard GB conditions, is not applicable in the continuum model. A combination of a finite GB yield strength with an isotropic bulk Voce hardening relation alone also fails to model the plastic strain profiles obtained by DDD. Instead, a finite GB yield strength in combination with GB hardening depending on the equivalent plastic strain at the GBs is shown to give a better agreement to DDD results. The differences in the plastic strain profiles obtained in DDD simu...

  20. Self-Organization of Microcircuits in Networks of Spiking Neurons with Plastic Synapses.

    Directory of Open Access Journals (Sweden)

    Gabriel Koch Ocker

    2015-08-01

    Full Text Available The synaptic connectivity of cortical networks features an overrepresentation of certain wiring motifs compared to simple random-network models. This structure is shaped, in part, by synaptic plasticity that promotes or suppresses connections between neurons depending on their joint spiking activity. Frequently, theoretical studies focus on how feedforward inputs drive plasticity to create this network structure. We study the complementary scenario of self-organized structure in a recurrent network, with spike timing-dependent plasticity driven by spontaneous dynamics. We develop a self-consistent theory for the evolution of network structure by combining fast spiking covariance with a slow evolution of synaptic weights. Through a finite-size expansion of network dynamics we obtain a low-dimensional set of nonlinear differential equations for the evolution of two-synapse connectivity motifs. With this theory in hand, we explore how the form of the plasticity rule drives the evolution of microcircuits in cortical networks. When potentiation and depression are in approximate balance, synaptic dynamics depend on weighted divergent, convergent, and chain motifs. For additive, Hebbian STDP these motif interactions create instabilities in synaptic dynamics that either promote or suppress the initial network structure. Our work provides a consistent theoretical framework for studying how spiking activity in recurrent networks interacts with synaptic plasticity to determine network structure.

  1. Self-Organization of Microcircuits in Networks of Spiking Neurons with Plastic Synapses.

    Science.gov (United States)

    Ocker, Gabriel Koch; Litwin-Kumar, Ashok; Doiron, Brent

    2015-08-01

    The synaptic connectivity of cortical networks features an overrepresentation of certain wiring motifs compared to simple random-network models. This structure is shaped, in part, by synaptic plasticity that promotes or suppresses connections between neurons depending on their joint spiking activity. Frequently, theoretical studies focus on how feedforward inputs drive plasticity to create this network structure. We study the complementary scenario of self-organized structure in a recurrent network, with spike timing-dependent plasticity driven by spontaneous dynamics. We develop a self-consistent theory for the evolution of network structure by combining fast spiking covariance with a slow evolution of synaptic weights. Through a finite-size expansion of network dynamics we obtain a low-dimensional set of nonlinear differential equations for the evolution of two-synapse connectivity motifs. With this theory in hand, we explore how the form of the plasticity rule drives the evolution of microcircuits in cortical networks. When potentiation and depression are in approximate balance, synaptic dynamics depend on weighted divergent, convergent, and chain motifs. For additive, Hebbian STDP these motif interactions create instabilities in synaptic dynamics that either promote or suppress the initial network structure. Our work provides a consistent theoretical framework for studying how spiking activity in recurrent networks interacts with synaptic plasticity to determine network structure.

  2. Applications of Fiber-Reinforced Polymers in Additive Manufacturing

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David Bue; Tosello, Guido

    2017-01-01

    and Young's modulus. Key challenges in the field, as of now, are proper fiber placement, fiber seizing, an increased knowledge in the used materials and how they are applied into engineering solutions through proper control of the additive manufacturing process. The aim of this research is the improved...... understanding of fiber-reinforcement in additive manufacturing in terms of production and application. Vat polymerization and material extrusion techniques for composite additive manufacturing were investigated with respect of increasing adhesion between the matrix material and the fibers. Process optimization......Additive manufacturing technologies are these years entering the market of functional final parts. Initial research has been performed targeting the integration of fibers into additive manufactured plastic composites. Major advantages, among others, are for example increased tensile strength...

  3. Solving depressions formed during production of plastic molding

    Directory of Open Access Journals (Sweden)

    J. Dobránsky

    2015-07-01

    Full Text Available This article deals with improvement of design properties of molded plastic parts. It can be achieved by modifying construction of metal injection mold and optimization of parameters in injection process. The subject of our examination was depressions formed on molded plastic parts which are inacceptable in the process of approval. The problem which has arisen was solved in two phases. The first phase consisted in alteration of injection mold design – enlargement of injection molding gate. In the second phase, we have changed the location of injection molding gate. After performing constructional modifications, new molded plastic parts were manufactured and assessed.

  4. 全套方案实现汽车塑料件绿色化的研究%Research of a Comprehensive Plan to Achieve Greening of Automotive Plastic Parts

    Institute of Scientific and Technical Information of China (English)

    张友根

    2013-01-01

    A comprehensive plan to achieve the development of automotive plastics materials, products, molding, waste recycling in the green in all aspects of green technology is analysed. It is pointed that the health, environmental protection, resource utilization to maximize are the core of the automotive plastic green. The development of automotive plastic green health standards to create a good ecological environment is put forward.%分析了全套方案实现汽车塑料件绿色化中的材料、制品、成型加工、废弃物回收利用等各个环节绿色化技术的发展,指出健康化、环保化、资源利用率最大化是汽车塑料件绿色化的核心,提出制定汽车塑料件绿色化健康标准以达到营造良好的生态环境.

  5. From Oil to Plastic. Young Discovery Library Series.

    Science.gov (United States)

    Brice, Raphaelle

    This book is written for children ages 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume explains in text and pictures how plastic is made from oil, the problems with this nearly indestructible material, and the future of plastics. Topics include: (1) formation of oil; (2) history of…

  6. Screening Plastic-Encapsulated Solid-State Devices

    Science.gov (United States)

    Buldhaupt, L.

    1984-01-01

    Suitability of plastic-encapsulated solid-state electronic devices for use in spacecraft discussed. Conclusion of preliminary study was plasticencapsulated parts sufficiently reliable to be considered for use in lowcost equipment used at moderate temperature and low humidity. Useful to engineers as guides to testing or use of plastic encapsulated semiconductors in severe terrestrial environments.

  7. INJECTION MOLDING AND STRUCTURAL ANALYSIS IN METAL TO PLASTIC CONVERSION OF BOLTED FLANGE JOINT BY CAE

    Directory of Open Access Journals (Sweden)

    Marian Blaško

    2014-12-01

    Full Text Available Many metal parts in various applications are being replaced by plastic parts. There are several reasons for that depending on actual application - minimize part cost, enhance corrosion resistance, integrating more components into one part etc. Most important steps of metal to plastic conversion are material selection and design of plastic part. Plastic part has to withstand the same load as metal part. To fulfill this requirement fiber reinforced engineering plastics are often used. Also it is convenient to substitute heavy wall sections with ribbed structure to increase load-carrying ability of part and decrease cycle time, eliminate voids, sink marks etc. Mechanical properties of such part could be highly affected by fiber orientation. Results of fiber orientation from injection molding filling analysis can be used in stress analysis for better prediction of part response to mechanical load. Such coupled analysis is performed here in this case study on bolted flange joint.

  8. Comparative Analysis of Properties and Microstructure of the Plastically Deformed Alloy Inconel®718, Manufactured by Plastic Working and Direct Metal Laser Sintering

    Directory of Open Access Journals (Sweden)

    Żaba K.

    2016-03-01

    Full Text Available Nickel superalloys as Inconel® are materials widely used in the aerospace industry among others for diffusers, combustion chamber, shells of gas generators and other. In most cases, manufacturing process of those parts are used metal strips, produced by conventional plastic processing techniques, and thus by hot or cold rolling. An alternative technology allowing for manufacturing components for jet engines is the technique of 3D printing (additive manufacturing, and most of all Direct Metal Laser Sintering, which is one of the latest achievement in field of additive technologies.

  9. Determining biodegradability of plastic materials under controlled and natural composting environments.

    Science.gov (United States)

    Mohee, R; Unmar, G

    2007-01-01

    With the advent of recently promulgated Government regulations on plastics in Mauritius, a study was initiated to examine the biodegradability of two different types of plastic, namely Willow Ridge Plastics - PDQ-H additive (Plastic A) and Ecosafe Plastic - TDPA additive (Plastic B) under controlled and natural composting environments. The results obtained from the controlled composting environment showed that the cumulative carbon dioxide evolution for Plastic A was much higher than that for Plastic B. Plastic A therefore showed a higher level of biodegradation in terms of CO2 evolution than Plastic B. However, from the regression analysis, it was found that the level of CO2 varying with time fitted the sigmoid type curves with very high correlation coefficients (R2 values: 0.9928, 0.9921 and 0.9816, for reference material, inoculum and Plastic A, respectively). The corresponding F-values obtained from the ANOVA analysis together with significance levels of pbiodegradability experiment were significant. The other experiment was undertaken to observe any physical change of Plastics A and B as compared to a reference plastic, namely, compostable plastic bag (Mater-Bi product-Plastic C), when exposed to a natural composting environment. Thermophilic temperatures were obtained for about 3-5 days of composting and the moisture content was in the range of 60-80% throughout the degradation process. It was observed that after 55 days of composting, Plastic C degraded completely while Plastic A and Plastic B did not undergo any significant degradation. It can be concluded that naturally based plastic made of starch would degrade completely in a time frame of 60 days, whereas plastics with biodegradable additive would require a longer time.

  10. Plastic deformation modelling of tempered martensite steel block structure by a nonlocal crystal plasticity model

    Directory of Open Access Journals (Sweden)

    Martin Boeff

    2014-01-01

    Full Text Available The plastic deformations of tempered martensite steel representative volume elements with different martensite block structures have been investigated by using a nonlocal crystal plasticity model which considers isotropic and kinematic hardening produced by plastic strain gradients. It was found that pronounced strain gradients occur in the grain boundary region even under homogeneous loading. The isotropic hardening of strain gradients strongly influences the global stress–strain diagram while the kinematic hardening of strain gradients influences the local deformation behaviour. It is found that the additional strain gradient hardening is not only dependent on the block width but also on the misorientations or the deformation incompatibilities in adjacent blocks.

  11. Challenges of randomized controlled trial design in plastic surgery.

    Science.gov (United States)

    Hassanein, Aladdin H; Herrera, Fernando A; Hassanein, Omar

    2011-01-01

    Randomized controlled trials are the gold standard of evidence-based medicine. In the field of plastic surgery, designing these studies is much more challenging than in pharmaceutical medicine. Randomized trials in plastic surgery encompass several road blocks including problems shared with other surgical trials: equipoise, high cost, placebo issues and learning curves following the establishment of a novel approach. In addition, plastic surgery has more subjective outcomes, thus making study design even more difficult in assessing the end result.

  12. 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.)

  13. Cortical plasticity and rehabilitation.

    Science.gov (United States)

    Moucha, Raluca; Kilgard, Michael P

    2006-01-01

    The brain is constantly adapting to environmental and endogenous changes (including injury) that occur at every stage of life. The mechanisms that regulate neural plasticity have been refined over millions of years. Motivation and sensory experience directly shape the rewiring that makes learning and neurological recovery possible. Guiding neural reorganization in a manner that facilitates recovery of function is a primary goal of neurological rehabilitation. As the rules that govern neural plasticity become better understood, it will be possible to manipulate the sensory and motor experience of patients to induce specific forms of plasticity. This review summarizes our current knowledge regarding factors that regulate cortical plasticity, illustrates specific forms of reorganization induced by control of each factor, and suggests how to exploit these factors for clinical benefit.

  14. Targeting tumour Cell Plasticity

    Institute of Scientific and Technical Information of China (English)

    Elizabeth D. WILLIAMS

    2009-01-01

    @@ Her research is focused on understanding the mechanisms of tumour progression and metastasis, particularly in uro-logical carcinomas (bladder and prostate). Tumour cell plasticity, including epithelial-mesenchymal transition, is a cen-tral theme in Dr Williams' work.

  15. Effect of Various Additives on the Physical Properties of Polyvinylchloride Resin

    Directory of Open Access Journals (Sweden)

    Imran Nazir Unar

    2010-12-01

    Full Text Available The compounding of Polyvinylchloride (PVC with some additives was studied for the enhancement of physical and mechanical properties. Two categories of formulations (un-plasticized and plasticized PVC were prepared with PVC (K value ranging from 60 to 70 taking as base polymer. Different additives generally categorized as plasticizers, fillers, stabilizers, pigments and processing aids, were mixed in the standard concentration unit “parts per hundred resins (phr” with base polymer. Cable compound and shoe compound were prepared in plasticized-PVC category containing mainly plasticizing additives like diisooctyl phthalate (DIOP (40 phr and epoxidized soybean oil (2-3 phr with general plasticizer (50-80 phr respectively. Whereas the rigid pipe and sheet compounds were prepared as un-plasticized PVC category containing different fillers/stabilizers like tribasic lead sulphate (6 phr, lead stearate (1 phr, glyceryl monostearate (0.4 phr in rigid pipe and butylin mercaptides (2-2.5 phr, fatty alcohol and fatty acid ester (0.5-0.8 phr in rigid sheet compound. Experimental investigation was carried out for analyzing the mechanical properties like tensile strength, elongation at break, hardness and physical property i.e. specific gravity for the compounded samples. An appreciable increase was observed in tensile strength from 460 Kg/cm2 (base PVC-polymer to a range of 550 Kg/cm2 for un-plasticized PVC compounds (rigid PVC-pipe and sheet with little increase in elongation at break from 56% (base polymer to 124.33% and 150% (for Pipe and Sheet compounds respectively. On the other side the elongation at break for plasticized PVC compounds was increased from 56% to 250.67% (for cable compound and 351.33% (for shoe compound, where as the tensile strength was decreased from 460 Kg/cm2 to 150.33 Kg/cm2 (for cable compound and 120.33 Kg/cm2 (for shoe compound. The hardness (shore A, D was increased from 40 to 80 for all the compounds except shoe compound

  16. 金属零件自动超轻结构化设计及激光增材制造%Automatic design and laser additive manufacturing of super-light structure of metal part

    Institute of Scientific and Technical Information of China (English)

    吴伟辉; 肖冬明; 毛星

    2016-01-01

    为解决金属超轻结构零件设计技术复杂、设计周期长、难添加蒙皮进行增材制造等难题,提出一种基于激光选区熔化增材制造工艺的金属零件自动超轻结构化设计方法:根据激光选区熔化工艺特点,编制程序将原始零件CAD模型自动转化为设定孔隙率的带蒙皮类蜂窝状超轻结构零件模型,且其数据可直接驱动设备实现零件增材制造.研究了带蒙皮超轻结构的构造形式及设计方法;探讨了合适的成型棱长及合理蒙皮结构形式;成功实现复杂零件自动带蒙皮超轻结构化设计及增材制造,所得零件孔隙率误差2.79%,表明能较准确按预期减重.该方法能根据原始零件CAD模型自动、快速地构建带蒙皮金属超轻结构零件模型,大大减轻该类零件设计负担及提高其实用性.%In order to solve the problems when designing super-light structure part such as needing complex design techniques, long design cycle, difficult to add skin if making it by additive manufacturing technology, based on selective laser melting technology, a method which can automatically add skinned super-light structure to traditional metal part CAD model was put forward in this paper. Considering the selective laser melting process characteristics, through an algorithm, a skinned super-light quasi-honeycomb structure part model with a preset porosity can be automatically designed by transforming an original CAD model. And the new part model data format can direct drive a selective laser melting machine for additive manufacturing without any data format transformation. The construction and design method of the skinned super-light structure of metal part were studied. Through process analysis, appropriate processing unit length and reasonable skin tissue of super-light structure metal part were gotten. The above method was tested successfully on a part model with complex shape in a selective laser melting experiment. The error of

  17. Laser cutting plastic materials

    Energy Technology Data Exchange (ETDEWEB)

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  18. Localization of plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Rice, J R

    1976-04-01

    The localization of plastic deformation into a shear band is discussed as an instability of plastic flow and a precursor to rupture. Experimental observations are reviewed, a general theoretical framework is presented, and specific calculations of critical conditions are carried out for a variety of material models. The interplay between features of inelastic constitutive description, especially deviations from normality and vertex-like yielding, and the onset of localization is emphasized.

  19. Additivity dominance

    Directory of Open Access Journals (Sweden)

    Paul Rozin

    2009-10-01

    Full Text Available Judgments of naturalness of foods tend to be more influenced by the process history of a food, rather than its actual constituents. Two types of processing of a ``natural'' food are to add something or to remove something. We report in this study, based on a large random sample of individuals from six countries (France, Germany, Italy, Switzerland, UK and USA that additives are considered defining features of what makes a food not natural, whereas ``subtractives'' are almost never mentioned. In support of this, skim milk (with major subtraction of fat is rated as more natural than whole milk with a small amount of natural vitamin D added. It is also noted that ``additives'' is a common word, with a synonym reported by a native speaker in 17 of 18 languages, whereas ``subtractive'' is lexicalized in only 1 of the 18 languages. We consider reasons for additivity dominance, relating it to omission bias, feature positive bias, and notions of purity.

  20. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita

    2010-01-01

    Full Text Available Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions - machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness. The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

  1. Wood-plastic composites as promising green-composites for automotive industries!

    Science.gov (United States)

    Ashori, Alireza

    2008-07-01

    Wood-plastic composite (WPC) is a very promising and sustainable green material to achieve durability without using toxic chemicals. The term WPCs refers to any composites that contain plant fiber and thermosets or thermoplastics. In comparison to other fibrous materials, plant fibers are in general suitable to reinforce plastics due to relative high strength and stiffness, low cost, low density, low CO2 emission, biodegradability and annually renewable. Plant fibers as fillers and reinforcements for polymers are currently the fastest-growing type of polymer additives. Since automakers are aiming to make every part either recyclable or biodegradable, there still seems to be some scope for green-composites based on biodegradable polymers and plant fibers. From a technical point of view, these bio-based composites will enhance mechanical strength and acoustic performance, reduce material weight and fuel consumption, lower production cost, improve passenger safety and shatterproof performance under extreme temperature changes, and improve biodegradability for the auto interior parts.

  2. Sorting Plastic Waste in Hydrocyclone

    Directory of Open Access Journals (Sweden)

    Ernestas Šutinys

    2011-02-01

    Full Text Available The article presents material about sorting plastic waste in hydrocyclone. The tests on sorting plastic waste were carried out. Also, the findings received from the performed experiment on the technology of sorting plastic waste are interpreted applying an experimental model of the equipment used for sorting plastics of different density.Article in Lithuanian

  3. Constitutive modelling and identification of parameters of the plastic strain-induced martensitic transformation in 316L stainless steel at cryogenic temperatures

    CERN Document Server

    Garion, C; Sgobba, Stefano

    2006-01-01

    The present paper is focused on constitutive modelling and identification of parameters of the relevant model of plastic strain- induced martensitic transformation in austenitic stainless steels at low temperatures. The model used to describe the FCCrightward arrow BCC phase transformation in austenitic stainless steels is based on the assumption of linearization of the most intensive part of the transformation curve. The kinetics of phase transformation is described by three parameters: transformation threshold (p/sub xi/), slope (A) and saturation level (xi/sub L/). It is assumed that the phase transformation is driven by the accumulated plastic strain p. In addition, the intensity of plastic deformation is strongly coupled to the phase transformation via the description of mixed kinematic /isotropic linear plastic hardening based on the Mori-Tanaka homogenization. The theory of small strains is applied. Small strain fields, corresponding to phase transformation, are decomposed into the volumic and the shea...

  4. Fifty Years of Innovation in Plastic Surgery

    Directory of Open Access Journals (Sweden)

    Richard M Kwasnicki

    2016-03-01

    Full Text Available BackgroundInnovation has molded the current landscape of plastic surgery. However, documentation of this process only exists scattered throughout the literature as individual articles. The few attempts made to profile innovation in plastic surgery have been narrative, and therefore qualitative and inherently biased. Through the implementation of a novel innovation metric, this work aims to identify and characterise the most prevalent innovations in plastic surgery over the last 50 years.MethodsPatents and publications related to plastic surgery (1960 to 2010 were retrieved from patent and MEDLINE databases, respectively. The most active patent codes were identified and grouped into technology areas, which were subsequently plotted graphically against publication data. Expert-derived technologies outside of the top performing patents areas were additionally explored.ResultsBetween 1960 and 2010, 4,651 patents and 43,118 publications related to plastic surgery were identified. The most active patent codes were grouped under reconstructive prostheses, implants, instruments, non-invasive techniques, and tissue engineering. Of these areas and other expert-derived technologies, those currently undergoing growth include surgical instruments, implants, non-invasive practices, transplantation and breast surgery. Innovations related to microvascular surgery, liposuction, tissue engineering, lasers and prostheses have all plateaued.ConclusionsThe application of a novel metric for evaluating innovation quantitatively outlines the natural history of technologies fundamental to the evolution of plastic surgery. Analysis of current innovation trends provides some insight into which technology domains are the most active.

  5. [The history of pediatric plastic surgery].

    Science.gov (United States)

    Glicenstein, J

    2016-10-01

    The history of pediatric plastic surgery is linked to that of paediatrics. Until the early 19th century, there was no children's hospital. Only some operations were performed before the discovery of anesthesia, aseptic and antisepsis: cleft lip repair, amputation for polydactyly. Many operations were described in the 19th century for cleft lip and palate repair, hypospadias, syndactylies. The first operation for protruding ears was performed in 1881. Pediatric plastic surgery is diversified in the 2nd half of the 20th century: cleft lip and palate, burns, craniofacial surgery, hand surgery become separate parts of the speciality.

  6. Potlining Additives

    Energy Technology Data Exchange (ETDEWEB)

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  7. Additivity dominance

    OpenAIRE

    2009-01-01

    Judgments of naturalness of foods tend to be more influenced by the process history of a food, rather than its actual constituents. Two types of processing of a ``natural'' food are to add something or to remove something. We report in this study, based on a large random sample of individuals from six countries (France, Germany, Italy, Switzerland, UK and USA) that additives are considered defining features of what makes a food not natural, whereas ``subtractives'' are almost never mentioned....

  8. Sulfite Additives

    OpenAIRE

    1988-01-01

    The CMA recommends that sulfites be banned as food preservatives when satisfactory and safe alternatives are available. When there is no suitable substitute strict labelling requirements on foods should be imposed for sulfite additives. The association supports the efforts of the Health Protection Branch of the Department of National Health and Welfare to regulate sulfites in the food and drug industry to prevent adverse reactions in people sensitive to sulfites. The CMA recommends that the D...

  9. A Calcium-Dependent Plasticity Rule for HCN Channels Maintains Activity Homeostasis and Stable Synaptic Learning

    Science.gov (United States)

    Honnuraiah, Suraj; Narayanan, Rishikesh

    2013-01-01

    Theoretical and computational frameworks for synaptic plasticity and learning have a long and cherished history, with few parallels within the well-established literature for plasticity of voltage-gated ion channels. In this study, we derive rules for plasticity in the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, and assess the synergy between synaptic and HCN channel plasticity in establishing stability during synaptic learning. To do this, we employ a conductance-based model for the hippocampal pyramidal neuron, and incorporate synaptic plasticity through the well-established Bienenstock-Cooper-Munro (BCM)-like rule for synaptic plasticity, wherein the direction and strength of the plasticity is dependent on the concentration of calcium influx. Under this framework, we derive a rule for HCN channel plasticity to establish homeostasis in synaptically-driven firing rate, and incorporate such plasticity into our model. In demonstrating that this rule for HCN channel plasticity helps maintain firing rate homeostasis after bidirectional synaptic plasticity, we observe a linear relationship between synaptic plasticity and HCN channel plasticity for maintaining firing rate homeostasis. Motivated by this linear relationship, we derive a calcium-dependent rule for HCN-channel plasticity, and demonstrate that firing rate homeostasis is maintained in the face of synaptic plasticity when moderate and high levels of cytosolic calcium influx induced depression and potentiation of the HCN-channel conductance, respectively. Additionally, we show that such synergy between synaptic and HCN-channel plasticity enhances the stability of synaptic learning through metaplasticity in the BCM-like synaptic plasticity profile. Finally, we demonstrate that the synergistic interaction between synaptic and HCN-channel plasticity preserves robustness of information transfer across the neuron under a rate-coding schema. Our results establish specific physiological roles

  10. Design for additive manufacturing of composite materials and potential alloys: a review

    OpenAIRE

    2016-01-01

    As a first step of applying additive manufacturing (AM) technology, plastic prototypes have been produced using various AM Process such as Fusion Deposition Modeling (FDM), Stereolithography (SLA) and other processes. After more research and development, AM has become capable of producing complex net shaped in materials which can be used in applicable parts. These materials include metals, ceramics, and composites. Polymers and metals are considered as commercially available materials for AM ...

  11. Design for additive manufacturing of composite materials and potential alloys: a review

    OpenAIRE

    Hegab Hussien A.

    2016-01-01

    As a first step of applying additive manufacturing (AM) technology, plastic prototypes have been produced using various AM Process such as Fusion Deposition Modeling (FDM), Stereolithography (SLA) and other processes. After more research and development, AM has become capable of producing complex net shaped in materials which can be used in applicable parts. These materials include metals, ceramics, and composites. Polymers and metals are considered as commercially available materials for AM ...

  12. Neural plasticity and behavior - sixty years of conceptual advances.

    Science.gov (United States)

    Sweatt, J David

    2016-10-01

    This brief review summarizes 60 years of conceptual advances that have demonstrated a role for active changes in neuronal connectivity as a controller of behavior and behavioral change. Seminal studies in the first phase of the six-decade span of this review firmly established the cellular basis of behavior - a concept that we take for granted now, but which was an open question at the time. Hebbian plasticity, including long-term potentiation and long-term depression, was then discovered as being important for local circuit refinement in the context of memory formation and behavioral change and stabilization in the mammalian central nervous system. Direct demonstration of plasticity of neuronal circuit function in vivo, for example, hippocampal neurons forming place cell firing patterns, extended this concept. However, additional neurophysiologic and computational studies demonstrated that circuit development and stabilization additionally relies on non-Hebbian, homoeostatic, forms of plasticity, such as synaptic scaling and control of membrane intrinsic properties. Activity-dependent neurodevelopment was found to be associated with cell-wide adjustments in post-synaptic receptor density, and found to occur in conjunction with synaptic pruning. Pioneering cellular neurophysiologic studies demonstrated the critical roles of transmembrane signal transduction, NMDA receptor regulation, regulation of neural membrane biophysical properties, and back-propagating action potential in critical time-dependent coincidence detection in behavior-modifying circuits. Concerning the molecular mechanisms underlying these processes, regulation of gene transcription was found to serve as a bridge between experience and behavioral change, closing the 'nature versus nurture' divide. Both active DNA (de)methylation and regulation of chromatin structure have been validated as crucial regulators of gene transcription during learning. The discovery of protein synthesis dependence on the

  13. Supercritical Water Process for the Chemical Recycling of Waste Plastics

    Science.gov (United States)

    Goto, Motonobu

    2010-11-01

    The development of chemical recycling of waste plastics by decomposition reactions in sub- and supercritical water is reviewed. Decomposition reactions proceed rapidly and selectively using supercritical fluids compared to conventional processes. Condensation polymerization plastics such as PET, nylon, and polyurethane, are relatively easily depolymerized to their monomers in supercritical water. The monomer components are recovered in high yield. Addition polymerization plastics such as phenol resin, epoxy resin, and polyethylene, are also decomposed to monomer components with or without catalysts. Recycling process of fiber reinforced plastics has been studied. Pilot scale or commercial scale plants have been developed and are operating with sub- and supercritical fluids.

  14. Production of Methane and Water from Crew Plastic Waste

    Science.gov (United States)

    Captain, Janine; Santiago, Eddie; Parrish, Clyde; Strayer, Richard F.; Garland, Jay L.

    2008-01-01

    Recycling is a technology that will be key to creating a self sustaining lunar outpost. The plastics used for food packaging provide a source of material that could be recycled to produce water and methane. The recycling of these plastics will require some additional resources that will affect the initial estimate of starting materials that will have to be transported from earth, mainly oxygen, energy and mass. These requirements will vary depending on the recycling conditions. The degredation products of these plastics will vary under different atmospheric conditions. An estimate of the the production rate of methane and water using typical ISRU processes along with the plastic recycling will be presented.

  15. Crystallinity in starch plastics: consequences for material properties

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Soest, J.J.G. van

    1997-01-01

    The processing of starches with biodegradable additives has made biodegradable plastics suitable for a number of applications. Starch plastics are partially crystalline as a result of residual crystallinity and the recrystallization of amylose and amylopectin. Such crystallinity is a key determinant

  16. Benzotriazole-type ultraviolet stabilizers and antioxidants in plastic marine debris and their new products.

    Science.gov (United States)

    Rani, Manviri; Shim, Won Joon; Han, Gi Myung; Jang, Mi; Song, Young Kyoung; Hong, Sang Hee

    2017-02-01

    Ultraviolet stabilizers (UVSs) and antioxidants are the most widely used additives in plastics to enhance the lifetime of polymeric materials. There is growing interest in the roles of plastic marine debris and microplastics as source or vector of toxic substances to marine environment and organisms. However, there is limited information available on plastic associated chemicals, particularly additive chemicals. Therefore, to evaluate their extent of exposure from plastics to the marine environment, we determined UVSs and antioxidants in plastic debris (n=29) collected from beaches along with their corresponding new plastic products in markets (n=27) belonging to food, fisheries, and general use. Antioxidants were present at higher concentrations than UVSs in both plastic debris and new plastics, indicative of their high use over UVSs. Irganox 1076 and Irganox 1010 were more commonly used than other chemicals investigated. The irregular use with high concentration of additive chemicals was observed in short-term use plastic products. Except for Irganox 1076 and UV 326, most antioxidants and UVSs were relatively high in new plastics compared to corresponding plastic marine debris, implying their potential leaching or degradation during use or after disposal. The present study provides quantitative information about additive chemicals contained in plastic marine debris and their new products. These results could be useful for better understanding of environmental exposure to hazardous chemicals through plastic pollution.

  17. Thermal Viscoelastic Analysis of Plastic Components Considering Residual Stress

    Science.gov (United States)

    Choi, Chel Woo; Jeoung, Kab Sik; Moon, Hyung-Il; Kim, Heon Young

    Plastics is commonly used in consumer electronics because of it is high strength per unit mass and good productivity, but plastic components may often become distorted after injection molding due to residual stress after the filling, packing, and cooling processes. In addition, plastic deteriorates depending on various temperature conditions and the operating time, which can be characterized by stress relaxation and creep. The viscoelastic behavior of plastic materials in the time domain can be expressed by the Prony series using the ABAQUS commercial software package. This paper suggests a process for predicting post-production deformation under cyclic thermal loading. The process was applied to real plastic panels, and the deformation predicted by the analysis was compared to that measured in actual testing, showing the possibility of using this process for predicting the post-production deformation of plastic products under thermal loading.

  18. Ultrasonic Assembly of Thermoplastic Parts

    Energy Technology Data Exchange (ETDEWEB)

    Schurman, W. R.

    1970-03-31

    Four ultrasonic methods were evaluated for assembly of experimental plastic parts for detonators: (1) welding, (2) crimping and staking, (3) insertion, and (4) reactivation of adhesives. For welding, staking and insertion, plastics with low elastic moduli, such as acrylics and polycarbonate, produced the best results. Thermosetting, hot-melt, and solution adhesives could all be activated ultrasonically to form good bonds on plastics and other materials. This evaluation indicated that thermoplastic detonator parts could be assembled ultrasonically in shorter times than by present production techniques with high bond strengths and high product acceptance rates.

  19. Microglia in neuronal plasticity: Influence of stress.

    Science.gov (United States)

    Delpech, Jean-Christophe; Madore, Charlotte; Nadjar, Agnes; Joffre, Corinne; Wohleb, Eric S; Layé, Sophie

    2015-09-01

    The central nervous system (CNS) has previously been regarded as an immune-privileged site with the absence of immune cell responses but this dogma was not entirely true. Microglia are the brain innate immune cells and recent findings indicate that they participate both in CNS disease and infection as well as facilitate normal CNS function. Microglia are highly plastic and play integral roles in sculpting the structure of the CNS, refining neuronal circuitry and connectivity, and contribute actively to neuronal plasticity in the healthy brain. Interestingly, psychological stress can perturb the function of microglia in association with an impaired neuronal plasticity and the development of emotional behavior alterations. As a result it seemed important to describe in this review some findings indicating that the stress-induced microglia dysfunction may underlie neuroplasticity deficits associated to many mood disorders. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.

  20. Plasticity in the Drosophila larval visual System

    Directory of Open Access Journals (Sweden)

    Abud J Farca-Luna

    2013-07-01

    Full Text Available The remarkable ability of the nervous system to modify its structure and function is mostly experience and activity modulated. The molecular basis of neuronal plasticity has been studied in higher behavioral processes, such as learning and memory formation. However, neuronal plasticity is not restricted to higher brain functions, but may provide a basic feature of adaptation of all neural circuits. The fruit fly Drosophila melanogaster provides a powerful genetic model to gain insight into the molecular basis of nervous system development and function. The nervous system of the larvae is again a magnitude simpler than its adult counter part, allowing the genetic assessment of a number of individual genetically identifiable neurons. We review here recent progress on the genetic basis of neuronal plasticity in developing and functioning neural circuits focusing on the simple visual system of the Drosophila larva.

  1. Recycling bin concepts for hotels on Zanzibar Island : - Efficient and sustainable recycling for one of Zanrec Plastics Ltd. customer groups

    OpenAIRE

    Gobena, Elina; Lundén, Hanna

    2012-01-01

    This report presents a developed recycling bin concept for Zanrec Plastics Ltd. (Zanrec Plastics in this report), a Swedish company that is about to implement a solid waste recycling system on Zanzibar Island, Tanzania. Zanrec Plastics will negotiate waste management with the hotels, that produce a large part of the recyclable garbage on the island, and the project aim is to develop a concept that will help Zanrec Plastics in these negotiations. Zanrec Plastics requirements on the concepts re...

  2. 40 CFR Table 2 to Subpart Wwww of... - Compliance Dates for New and Existing Reinforced Plastic Composites Facilities

    Science.gov (United States)

    2010-07-01

    ... Reinforced Plastic Composites Facilities 2 Table 2 to Subpart WWWW of Part 63 Protection of Environment...: Reinforced Plastic Composites Production Pt. 63, Subpt. WWWW, Table 2 Table 2 to Subpart WWWW of Part 63—Compliance Dates for New and Existing Reinforced Plastic Composites Facilities As required in §§ 63.5800...

  3. Multi-scale modeling and experimental study of twin inception and propagation in hexagonal close-packed materials using a crystal plasticity finite element approach; part II: Local behavior

    Science.gov (United States)

    Abdolvand, Hamidreza; Daymond, Mark R.

    2013-03-01

    In-situ tensile tests are performed on Zircaloy-2 samples with various grain sizes to study twin inception and propagation. Orientation maps of some areas at the surface are measured before and after deformation, using the Electron BackScattered Diffraction (EBSD) technique. Strain fields of the same areas are determined using the digital image correlation technique and are compared with results from Crystal Plasticity Finite Element (CPFE) simulations. Different assumptions are made within the CPFE code to simulate twin propagation. It is observed that the predictions of different models does not really change from one model to another when statistical information on the twins is compared, yet local predictions for each grain, i.e. twin direction, twin variant selection, and twin inception site, do change. Also, it is shown that the twin Schmid factor can vary drastically within grains and that for those grains with a low tendency for twinning this variation may make them susceptible to twinning.

  4. Astrocyte-Synapse Structural Plasticity

    Directory of Open Access Journals (Sweden)

    Yann Bernardinelli

    2014-01-01

    Full Text Available The function and efficacy of synaptic transmission are determined not only by the composition and activity of pre- and postsynaptic components but also by the environment in which a synapse is embedded. Glial cells constitute an important part of this environment and participate in several aspects of synaptic functions. Among the glial cell family, the roles played by astrocytes at the synaptic level are particularly important, ranging from the trophic support to the fine-tuning of transmission. Astrocytic structures are frequently observed in close association with glutamatergic synapses, providing a morphological entity for bidirectional interactions with synapses. Experimental evidence indicates that astrocytes sense neuronal activity by elevating their intracellular calcium in response to neurotransmitters and may communicate with neurons. The precise role of astrocytes in regulating synaptic properties, function, and plasticity remains however a subject of intense debate and many aspects of their interactions with neurons remain to be investigated. A particularly intriguing aspect is their ability to rapidly restructure their processes and modify their coverage of the synaptic elements. The present review summarizes some of these findings with a particular focus on the mechanisms driving this form of structural plasticity and its possible impact on synaptic structure and function.

  5. SABIC Innovative Plastics: Be the World Best Plastic Resin Manufacturer

    Institute of Scientific and Technical Information of China (English)

    Jenny Du

    2007-01-01

    @@ "SABIC Innovative Plastics is a global supplier of plastic resins, manufacturing and compounding polycarbonate, ABS, SAN, ASA, PPE, PC/ABS, PBT and PEI resins, as well as the LNP* line of high performance specialty compounds," said Hiroshi Yoshida, the Global Market Director for Electronics of SABIC Innovative Plastics based in Tokyo at the press conference held by SABIC Innovative Plastics, November 8th 2007, Shanghai.

  6. Health effects models for nuclear power plant accident consequence analysis. Modification of models resulting from addition of effects of exposure to alpha-emitting radionuclides: Revision 1, Part 2, Scientific bases for health effects models, Addendum 2

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamson, S. [Wisconsin Univ., Madison, WI (United States); Bender, M.A. [Brookhaven National Lab., Upton, NY (United States); Boecker, B.B.; Scott, B.R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.; Gilbert, E.S. [Pacific Northwest Lab., Richland, WA (United States)

    1993-05-01

    The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled {open_quotes}Health Effects Models for Nuclear Power Plant Consequence Analysis{close_quotes}, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled {open_quotes}Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,{close_quotes} was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model.

  7. Preserving in Plastic.

    Science.gov (United States)

    Wahla, James

    1985-01-01

    Outlines steps for casting insects in permanent molds prepared from commercially available liquid plastic. Also describes dry mountings in glass, acrylic, and petri dishes. The rationale for specimen use, hints for producing quality results, purchasing information, and safety precautions are considered. (DH)

  8. Discrete dislocation plasticity

    NARCIS (Netherlands)

    van der Giessen, E.; Finel, A; Maziere, D; Veron, M

    2003-01-01

    Conventional continuum mechanics models of inelastic deformation processes axe size scale independent. In contrast, there is considerable experimental evidence that plastic flow in crystalline materials is size dependent over length scales of the order of tens of microns and smaller. At present ther

  9. Progress in neural plasticity

    Institute of Scientific and Technical Information of China (English)

    POO; Mu-Ming

    2010-01-01

    One of the properties of the nervous system is the use-dependent plasticity of neural circuits.The structure and function of neural circuits are susceptible to changes induced by prior neuronal activity,as reflected by short-and long-term modifications of synaptic efficacy and neuronal excitability.Regarded as the most attractive cellular mechanism underlying higher cognitive functions such as learning and memory,activity-dependent synaptic plasticity has been in the spotlight of modern neuroscience since 1973 when activity-induced long-term potentiation(LTP) of hippocampal synapses was first discovered.Over the last 10 years,Chinese neuroscientists have made notable contributions to the study of the cellular and molecular mechanisms of synaptic plasticity,as well as of the plasticity beyond synapses,including activity-dependent changes in intrinsic neuronal excitability,dendritic integration functions,neuron-glia signaling,and neural network activity.This work highlight some of these significant findings.

  10. 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...

  11. Persisting Plastic Addiction

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The policy on curbing plastic shopping bag use implemented three years ago has produced mixed results In a bustling farmers’market tucked in a narrow street in Xisanqi residential community in north Beijing,stalls selling vegetables,fruits and other foods line the sidewalk.

  12. Geotehnical Properties of Plastic Stabilized Lateritic Soil

    Directory of Open Access Journals (Sweden)

    Akinola Johnson Olarewaju

    2016-09-01

    Full Text Available Stabilization is the combination of soils and additives to change its properties and remain in its stable compacted state without undergoing any change under effect of exposure to weather and traffic. Soil stabilization through the reinforced soil construction is an efficient and reliable technique for improving the strength and stability of soils. The lateritic soil used in this study was taken along Papa-Ilaro road Ajegunle at Abalabi, Ogun State, Nigeria and the solid plastic wastes were taken from different locations in Ilaro. The plastics were grounded into pellets and substituted with laterite at 10%, 15%, 20%, 25% and 30% for compaction test and at 5%, 10%, 15%, 20%, 25% and 30% for California bearing ration (CBR test. The tests conducted in line with BS 1377 (1990 are the specific gravity, compaction and CBR. From the results, it was also observed that plastic pellets reduce the bulk densities and dry densities in the same proportion as the percentage water content increases. From the results, it is hereby suggested that plastic pellets could be mixed with lateritic material around underground pipes to mitigate the effects of accidental explosions. Consequently, environmental risk and hazards caused by plastic wastes and accidental explosions could be greatly reduced.

  13. Plastic Guidance Fins for Long Rod Projectiles .

    Directory of Open Access Journals (Sweden)

    Mark L. Bundy

    1997-10-01

    Full Text Available Projectile tail fins on long rod kinetic energy (KE penetrators serve the same purpose as fletchings (feathers on an arrow, namely, they help align the projectile axis with its velocity vector. This reduces the projectile's yaw and hence reduces its aerodynamic drag. In addition, a low yaw angle at target impact helps to maximise the projectile's target penetration. It is typical for projectiles to exit the gun muzzle and enter free flight at some ndn-zero yaw angle. Aerodynamic forces acting on yawed tail fins create a stabilising torque about the projectile's centre of gravity (CG. This torque can be increased by making the fin material lighter. Most conventional long rod penetrators fired from high performance guns have tail fins made from aluminium. However, aluminium can undergo catastrophic oxidation (rapid burning in-bore. Coating aluminium with Al/sub 2/O/sub 3/ {hardcoat prevents ignition of the substrate, provided solid propellant grain impacts do not chip the brittle hardcoat off the surface. Plastic is lighter than aluminium and less exothermic when oxidized. Therefore, other factors aside, it is conceivable that plastic fins could increase projectile stability while incurring less thermal erosion than aluminium. However, thermal loads are not the only concern when considering plastic as an alternative tail fin material. The mechanical strength of plastic is also a critical factor. This paper discusses some of the successes and failures of plastic fins, at least relatively thin fins, for use as KE stabilisers.

  14. Astrocyte and Neuronal Plasticity in the Somatosensory System.

    Science.gov (United States)

    Sims, Robert E; Butcher, John B; Parri, H Rheinallt; Glazewski, Stanislaw

    2015-01-01

    Changing the whisker complement on a rodent's snout can lead to two forms of experience-dependent plasticity (EDP) in the neurons of the barrel cortex, where whiskers are somatotopically represented. One form, termed coding plasticity, concerns changes in synaptic transmission and connectivity between neurons. This is thought to underlie learning and memory processes and so adaptation to a changing environment. The second, called homeostatic plasticity, serves to maintain a restricted dynamic range of neuronal activity thus preventing its saturation or total downregulation. Current explanatory models of cortical EDP are almost exclusively neurocentric. However, in recent years, increasing evidence has emerged on the role of astrocytes in brain function, including plasticity. Indeed, astrocytes appear as necessary partners of neurons at the core of the mechanisms of coding and homeostatic plasticity recorded in neurons. In addition to neuronal plasticity, several different forms of astrocytic plasticity have recently been discovered. They extend from changes in receptor expression and dynamic changes in morphology to alteration in gliotransmitter release. It is however unclear how astrocytic plasticity contributes to the neuronal EDP. Here, we review the known and possible roles for astrocytes in the barrel cortex, including its plasticity.

  15. Plastic theory for the multi-crystal metals-From infinitesimal deformation to finite deformation

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Multi-crystal metals have the property of volume conservation in the plastic state. In the infinitesimal deformation plasticity the strain tensor can be split into a deviator part and a volumetric part. The vanishing of the first variant of the strain tensor is equivalent to the volume conservation. Furthermore, the split of the strain into an elastic part and a plastic part is also adopted widely. The flow rule is thus established. These two splits are not confirmed in the finite deformation plasticity. The plasticity criterion and the flow rule are thus facing great challenge. There are various definitions of strain measures in the finite deformation theory. Though the choosing of strain measure is arbitrary in the elastic problem, it is strongly restricted in the plastic problem. By theoretical and experimental studies, it is shown that the logarithmic strain is the only suitable strain measure in the metal forming problem.

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

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2008-01-01

    The objective of this paper is to show the application of a novel approach to the rigid plastic hinge and yield line theory in post-buckling analysis of slender plates and columns. The upper bound theorem of plasticity theory and the associated flow law of plasticity are used to find...... of the post-buckling behaviour. The rigid plastic theory of plates, referred to as yield line theory, involves large rigid parts of the plate mutually rotating about yielding hinge lines, however in order to accommodate in plane plastic deformations area “collapse” yield lines have been introduced. The hinge...... yield lines accommodate differential rotations of rigid parts and the area “collapse” yield lines accommodate local area changes of the rigid parts thereby preserving compatibility of the rigid parts of a plate. The approach will be illustrated for rigid plastic column analysis and for a quadratic plate...

  17. Plastic ingestion by Masked booby, Sula dactylatra Lesson, 1831, on Biological Reserve of Rocas Atoll, RN, Brazil

    Directory of Open Access Journals (Sweden)

    Erich de Freitas Mariano

    2012-11-01

    Full Text Available Plastic particles are one of the most common pollutants in the marine environment and it is reaching regions with low human population density. These particles are frequently ingested by many marine organisms, causing digestive problems, which may lead to the weakening and death of the animal. In a research on the feeding of 631-masked boobies, Sula dactylatra from the Biological Reserve of Atol das Rocas, plastic particles were found in stomach contents of four adults. The artifacts found were made of transperant plastic, a piece of label of a mineral water bottle, two pieces of black plastic and a small hard and red piece. The flow of fishing and tourism boats on the Atol das Rocas Biological Reserve may be the source of origin of the plastic parts in both the stomach contents and those found on the islands of the reserve, which suggests that anthropogenic behaviour has already reached isolated areas which should have a high degree of biodiversity protection. Several measures can be taken to avoid deleterious events in the marine biota, but there is great difficulty in avoiding waste dumping from fishing and tourism ships/boats, in addition to that, there are many materials from the mainland, which requires an increase in awareness and supervision.

  18. A QSPR for the plasticization efficiency of polyvinylchloride plasticizers.

    Science.gov (United States)

    Chandola, Mridula; Marathe, Sujata

    2008-01-01

    A simple quantitative structure property relationship (QSPR) for correlating the plasticization efficiency of 25 polyvinylchloride (PVC) plasticizers was obtained using molecular modeling. The plasticizers studied were-aromatic esters (phthalate, terephthalate, benzoate, trimellitate), aliphatic esters (adipate, sebacate, azelate), citrates and a phosphate. The low temperature flex point, Tf, of plasticized polyvinylchloride resins was considered as an indicator of plasticization efficiency. Initially, we attempted to predict plasticization efficiency of PVC plasticizers from physical and structural descriptors derived from the plasticizer molecule alone. However, the correlation of these descriptors with Tf was not very good with R=0.78 and r2=0.613. This implied that the selected descriptors were unable to predict all the interactions between PVC and plasticizer. Hence, to account for these interactions, a model containing two polyvinylchloride (PVC) chain segments along with a plasticizer molecule in a simulation box was constructed, using molecular mechanics. A good QSPR equation correlating physical and structural descriptors derived from the model to Tf of the plasticized resins was obtained with R=0.954 and r2=0.909.

  19. PLASTIC LIMIT LOAD ANALYSIS OF DEFECTIVE PIPELINES

    Institute of Scientific and Technical Information of China (English)

    ChenGang; LiuYinghua; XuBingye

    2003-01-01

    The integrity assessment of defective pipelines represents a practically important task of structural analysis and design in various technological areas, such as oil and gas industry, power plant engineering and chemical factories. An iterative algorithm is presented for the kinematic limit analysis of 3-D rigid-perfectly plastic bodies. A numerical path scheme for radial loading is adopted to deal with complex multi-loading systems. The numerical procedure has been applied to carry out the plastic collapse analysis of pipelines with part-through slot under internal pressure, bending moment and axial force. The effects of various shapes and sizes of part-through slots on the collapse loads of pipelines are systematically investigated and evaluated. Some typical failure modes corresponding to different configurations of slots and loading forms are studied.

  20. Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

    Science.gov (United States)

    Rios, Pedro; Stuart, Julie Ann; Grant, Ed

    2003-12-01

    Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

  1. Sustainable reverse logistics for household plastic waste

    OpenAIRE

    Bing, X

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than that of virgin plastics. Therefore, it is environmentally and economically beneficial to improve the plastic recycling system to ensure more plastic waste from households is properly collected and pr...

  2. HOW DO DEGRADABLE/BIODEGRADABLE PLASTIC MATERIALS DECOMPOSE IN HOME COMPOSTING ENVIRONMENT?

    Directory of Open Access Journals (Sweden)

    Magdalena Vaverková

    2014-10-01

    Full Text Available This paper provides information about biodegradability of polymeric (biodegradable/degradable materials advertised as 100%-degradable or certified as compostable, which may be a part of biodegradable waste, in home composting conditions. It describes an experiment that took place in home wooden compost bins and contained 9 samples that are commonly available in retail chains in the Czech Republic and Poland. The experiment lasted for the period of 12 weeks. Based on the results thereof it can be concluded that polyethylene samples with additive (samples 2, 4, 7 have not decomposed, their color has not changed and that no degradation or physical changes have occurred. Samples 1, 3 and 5 certified as compostable have not decomposed. Sample 6 exhibited the highest decomposition rate. Samples 8, 9 (tableware exhibited high degree of decomposition. The main conclusion from this study is that degradable/biodegradable plastics or plastics certified as compostable are not suitable for home composting.

  3. 基于CAE技术大型注塑件浇注系统的设计%Design of Gating System for Large Injection Plastic Parts Based on CAE Technology

    Institute of Scientific and Technical Information of China (English)

    董金虎

    2011-01-01

    Take an automobile interior part for example, the gating system for large injection mold part was analyzed and evaluated accurately by using CAE technology. The rational design scheme of gating system was determined through analysis and comparison for four schemes.%以某汽车内饰件为例,采用CAE技术,较为准确地对大型注塑件浇注系统进行分析评估.通过对四个方案的分析对比,确定了合理的浇注系统设计方案.

  4. Plasticized protein for 3D printing by fused deposition modeling

    Science.gov (United States)

    Chaunier, Laurent; Leroy, Eric; Della Valle, Guy; Lourdin, Denis

    2016-10-01

    The developments of Additive Manufacturing (AM) by Fused Deposition Modeling (FDM) now target new 3D printable materials, leading to novel properties like those given by biopolymers such as proteins: degradability, biocompatibility and edibility. Plasticized materials from zein, a storage protein issued from corn, present interesting thermomechanical and rheological properties, possibly matching with AM-FDM specifications. Thus commercial zein plasticized with 20% glycerol has a glass transition temperature (Tg) at about 42°C, after storage at intermediate relative humidity (RH=59%). Its principal mechanical relaxation at Tα ≈ 50°C leads to a drop of the elastic modulus from about 1.1 GPa, at ambient temperature, to 0.6 MPa at Tα+100°C. These values are in the same range as values obtained in the case of standard polymers for AM-FDM processing, as PLA and ABS, although relaxation mechanisms are likely different in these materials. Such results lead to the setting up of zein-based compositions printable by AM-FDM and allow processing bioresorbable printed parts, with designed 3D geometry and structure.

  5. Low temperature creep plasticity

    Directory of Open Access Journals (Sweden)

    Michael E. Kassner

    2014-07-01

    Full Text Available The creep behavior of crystalline materials at low temperatures (T < 0.3Tm is discussed. In particular, the phenomenological relationships that describe primary creep are reviewed and analyzed. A discussion of the activation energy for creep at T < 0.3Tm is discussed in terms of the context of higher temperature activation energy. The basic mechanism(s of low temperature creep plasticity are discussed, as well.

  6. Structural Color for Additive Manufacturing: 3D-Printed Photonic Crystals from Block Copolymers.

    Science.gov (United States)

    Boyle, Bret M; French, Tracy A; Pearson, Ryan M; McCarthy, Blaine G; Miyake, Garret M

    2017-03-28

    The incorporation of structural color into 3D printed parts is reported, presenting an alternative to the need for pigments or dyes for colored parts produced through additive manufacturing. Thermoplastic build materials composed of dendritic block copolymers were designed, synthesized, and used to additively manufacture plastic parts exhibiting structural color. The reflection properties of the photonic crystals arise from the periodic nanostructure formed through block copolymer self-assembly during polymer processing. The wavelength of reflected light could be tuned across the visible spectrum by synthetically controlling the block copolymer molecular weight and manufacture parts that reflected violet, green, or orange light with the capacity to serve as selective optical filters and light guides.

  7. Gelatin films plasticized with a simulated biodiesel coproduct stream

    Directory of Open Access Journals (Sweden)

    2009-04-01

    Full Text Available In order to explore the possibility of substituting an unrefined biodiesel coproduct stream (BCS for refined glycerol as a polymer plasticizer we have prepared cast gelatin films plasticized with a simulated BCS, i.e., mixtures of glycerol and some of the typical components found in BCS (methyl linoleate, methyl oleate, linoleic acid, and oleic acid. We measured the tensile properties as a function of plasticizer composition, and analyzed the specific effect of each individual component on tensile properties. We found that it is the unrecovered alkyl esters that largely determine the tensile properties, and that BCS can be successfully used to plasticize cast gelatin films as long as the BCS contains 11 parts by weight, or less, of unrecovered alkyl esters per 100 parts glycerol.

  8. Phenotypic plasticity in sex pheromone production in Bicyclus anynana butterflies.

    Science.gov (United States)

    Dion, Emilie; Monteiro, Antónia; Yew, Joanne Y

    2016-12-14

    Phenotypic plasticity refers to the environmental control of phenotypes. Cues experienced during development (developmental plasticity) or during adulthood (acclimatization) can both affect adult phenotypes. Phenotypic plasticity has been described in many traits but examples of developmental plasticity in physiological traits, in particular, remain scarce. We examined developmental plasticity and acclimatization in pheromone production in the butterfly Bicyclus anynana in response to rearing temperature. B. anynana lives in the African tropics where warm rearing temperatures of the wet season produce active males that court and females that choose, whereas cooler temperatures of the dry season lead to choosy less active males and courting females. We hypothesized that if male pheromone production is costly, it should be reduced in the dry season form. After describing the ultrastructure of pheromone producing cells, we showed that dry season males produced significantly less sex pheromones than wet season males, partly due to acclimatization and partly due to developmental plasticity. Variation in levels of one of the compounds is associated with differential regulation of a pheromone biosynthetic enzyme gene. This plasticity might be an adaptation to minimize pheromone production costs during the stressful dry season.

  9. New perspectives in plastic biodegradation.

    Science.gov (United States)

    Sivan, Alex

    2011-06-01

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

  10. Deoxynivalenol impairs hepatic and intestinal gene expression of selected oxidative stress, tight junction and inflammation proteins in broiler chickens, but addition of an adsorbing agent shifts the effects to the distal parts of the small intestine.

    Science.gov (United States)

    Osselaere, Ann; Santos, Regiane; Hautekiet, Veerle; De Backer, Patrick; Chiers, Koen; Ducatelle, Richard; Croubels, Siska

    2013-01-01

    Broiler chickens are rather resistant to deoxynivalenol and thus, clinical signs are rarely seen. However, effects of subclinical concentrations of deoxynivalenol on both the intestine and the liver are less frequently studied at the molecular level. During our study, we investigated the effects of three weeks of feeding deoxynivalenol on the gut wall morphology, intestinal barrier function and inflammation in broiler chickens. In addition, oxidative stress was evaluated in both the liver and intestine. Besides, the effect of a clay-based mycotoxin adsorbing agent on these different aspects was also studied. Our results show that feeding deoxynivalenol affects the gut wall morphology both in duodenum and jejenum of broiler chickens. A qRT-PCR analysis revealed that deoxynivalenol acts in a very specific way on the intestinal barrier, since only an up-regulation in mRNA expression of claudin 5 in jejunum was observed, while no effects were seen on claudin 1, zona occludens 1 and 2. Addition of an adsorbing agent resulted in an up-regulation of all the investigated genes coding for the intestinal barrier in the ileum. Up-regulation of Toll-like receptor 4 and two markers of oxidative stress (heme-oxigenase or HMOX and xanthine oxidoreductase or XOR) were mainly seen in the jejunum and to a lesser extent in the ileum in response to deoxynivalenol, while in combination with an adsorbing agent main effect was seen in the ileum. These results suggest that an adsorbing agent may lead to higher concentrations of deoxynivalenol in the more distal parts of the small intestine. In the liver, XOR was up-regulated due to DON exposure. HMOX and HIF-1α (hypoxia-inducible factor 1α) were down-regulated due to feeding DON but also due to feeding the adsorbing agent alone or in combination with DON.

  11. Migration of plasticizers phthalates, bisphenol A and alkylphenols from plastic containers and evaluation of risk.

    Science.gov (United States)

    Guart, A; Bono-Blay, F; Borrell, A; Lacorte, S

    2011-05-01

    This study investigates the potential migration of plasticisers, plastic components and additives from several plastic water bottles. Compounds studied were phthalates (dimethyl phthalate, di-n-butyl phthalate, benzylbutyl phthalate, bis(2-ethylhexyl) phthalate), bis(2-ethylhexyl) adipate, octylphenol, 4-nonylphenol and bisphenol A. Polycarbonate (PC), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET) and polystyrene (PS) plastics used in the water bottling sector were tested using three kinds of total or specific migration tests: (1) standard method UNE-EN ISO 177; (2) ultrasonic forced extraction; and (3) standard method UNE-EN 13130-1. In addition, bottled waters contained in different plastic materials were analysed to determine the potential migration of target compounds in real conditions. In all cases, samples were solid-phase extracted using Oasis HLB 200 mg cartridges and analysed using GC-MS in scan-acquisition mode. Bisphenol A and 4-nonylphenol were detected in incubated samples, indicating that migration from food plastics can occur at the experimental conditions tested. The total daily intake was calculated according to the levels detected in bottled water and the assessment of the consumers' risk was evaluated taking into consideration toxicological and legislative values.

  12. Interfacial interactions between plastic particles in plastics flotation.

    Science.gov (United States)

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation.

  13. Structural plasticity of axon terminals in the adult.

    Science.gov (United States)

    Gogolla, Nadine; Galimberti, Ivan; Caroni, Pico

    2007-10-01

    There is now conclusive evidence for widespread ongoing structural plasticity of presynaptic boutons and axon side-branches in the adult brain. The plasticity complements that of postsynaptic spines, but axonal plasticity samples larger volumes of neuropil, and has a larger impact on circuit remodeling. Axons from distinct neurons exhibit unique ratios of stable (t1/2>9 months) and dynamic (t1/2 5-20 days) boutons, which persist as spatially intermingled subgroups along terminal arbors. In addition, phases of side-branch dynamics mediate larger scale remodeling guided by synaptogenesis. The plasticity is most pronounced during critical periods; its patterns and outcome are controlled by Hebbian mechanisms and intrinsic neuronal factors. Novel experience, skill learning, life-style, and age can persistently modify local circuit structure through axonal structural plasticity.

  14. Production, use, and fate of all plastics ever made

    Science.gov (United States)

    Geyer, Roland; Jambeck, Jenna R.; Law, Kara Lavender

    2017-01-01

    Plastics have outgrown most man-made materials and have long been under environmental scrutiny. However, robust global information, particularly about their end-of-life fate, is lacking. By identifying and synthesizing dispersed data on production, use, and end-of-life management of polymer resins, synthetic fibers, and additives, we present the first global analysis of all mass-produced plastics ever manufactured. We estimate that 8300 million metric tons (Mt) as of virgin plastics have been produced to date. As of 2015, approximately 6300 Mt of plastic waste had been generated, around 9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050. PMID:28776036

  15. Maladaptive synaptic plasticity in L-DOPA-induced dyskinesia

    Directory of Open Access Journals (Sweden)

    Qiang Wang

    2016-12-01

    Full Text Available The emergence of L-DOPA-induced dyskinesia (LID in patients with Parkinson disease (PD could be due to maladaptive plasticity of corticostriatal synapses in response to L-DOPA treatment. A series of recent studies has revealed that LID is associated with marked morphological plasticity of striatal dendritic spines, particularly cell type-specific structural plasticity of medium spiny neurons (MSNs in the striatum. In addition, evidence demonstrating the occurrence of plastic adaptations, including aberrant morphological and functional features, in multiple components of cortico-basal ganglionic circuitry, such as primary motor cortex (M1 and basal ganglia (BG output nuclei. These adaptations have been implicated in the pathophysiology of LID. Here, we briefly review recent studies that have addressed maladaptive plastic changes within the cortico-BG loop in dyskinetic animal models of PD and patients with PD.

  16. Developmental Plasticity in Child Growth and Maturation

    Directory of Open Access Journals (Sweden)

    Ze'ev eHochberg

    2011-09-01

    Full Text Available The ability of a given genotype to produce different phenotypes in response to different environments is termed "plasticity", and is part of the organism's "adaptability" to environmental cues. The expressions of suites of genes, particularly during development or life-history transitions, probably underlie the fundamental plasticity of an organism. Plasticity in developmental programming has evolved in order to provide the best chances of survival and reproductive success to organisms under changing environments. Environmental conditions that are experienced in early life can profoundly influence human biology, child growth and maturation, and long-term health and longevity. Developmental origins of health and disease and life history transitions are purported to use placental, nutritional, and endocrine cues for setting long-term biological, mental, and behavioral strategies for child growth and maturation in response to local ecological and/or social conditions. The window of developmental plasticity extends from conception to early childhood, and even beyond to the transition from juvenility to adoelscence, and could be transmitted transgenerationally. It involves epigenetic responses to environmental changes, which exert their effects during life history phase-transitions.

  17. Developmental plasticity in child growth and maturation.

    Science.gov (United States)

    Hochberg, Ze'ev

    2011-01-01

    The ability of a given genotype to produce different phenotypes in response to different environments is termed "plasticity," and is part of the organism's "adaptability" to environmental cues. The expressions of suites of genes, particularly during development or life history transitions, probably underlie the fundamental plasticity of an organism. Plasticity in developmental programming has evolved in order to provide the best chances of survival and reproductive success to organisms under changing environments. Environmental conditions that are experienced in early life can profoundly influence human biology, child growth and maturation, and long-term health and longevity. Developmental origins of health and disease and life history transitions are purported to use placental, nutritional, and endocrine cues for setting long-term biological, mental, and behavioral strategies for child growth and maturation in response to local ecological and/or social conditions. The window of developmental plasticity extends from conception to early childhood, and even beyond to the transition from juvenility to adolescence, and could be transmitted transgenerationally. It involves epigenetic responses to environmental changes, which exert their effects during life history phase transitions.

  18. The demise of plastic encapsulated microcircuit myths

    Science.gov (United States)

    Hakim, E. B.; Agarwal, R. K.; Pecht, M.

    1994-10-01

    Production of microelectronic devices encapsulated in solid, molded plastic packages has rapidly increased since the early 1980's. Today, millions of plastic-encapsulated devices are produced daily. On the other hand, only a few million hermetic (cavity) packages are produced per year. Reasons for the increased use of plastic-encapsulated packages include cost, availability, size, weight, quality, and reliability. Markets taking advantage of this technology range from computers and telecommunications to automotive uses. Yet, several industries, the military in particular, will not accept such devices. One reason for this reluctance to use the best available commercial parts is a perceived risk of poor reliability, derived from antiquated military specifications, standards, and handbooks; other common justifications cite differing environments; inadequate screens; inadequate test data, and required government audits of suppliers' processes. This paper describes failure mechanisms associated with plastic encapsulation and their elimination. It provides data indicating the relative reliability of cavity and solid-encapsulated packaging, and presents possible approaches to assuring quality and reliability in the procuring and applying this successful commercial technology.

  19. Finite element modelling of manufacturing processes for plastic deformation

    Directory of Open Access Journals (Sweden)

    Fernando Mejía Umaña

    2010-04-01

    Full Text Available The object of the Mechanical and Electrical Engineering Departament's computational mechanics of solids section is to offer industry solutions to problems requiring deeper knowledge regarding the mechanincs of solids and how they can be numerically modelled. This article summarises the foundations of plastic deformation, together with the results obtained during the experimental phase and from modelling two applications of plastic deformation processes being studied as part of mechanical engineering students' undergraduate projects.

  20. Composição bromatológica e produção de efluente de silagens de capim-tanzânia sob efeitos do emurchecimento, do tamanho de partícula e do uso de aditivos biológicos Chemical composition and effluent yield of Tanzaniagrass silages affected by wilting, particle size and enzymatic/microbial additive

    Directory of Open Access Journals (Sweden)

    Daniele Rebouças Santana Loures

    2005-06-01

    Full Text Available O presente trabalho foi conduzido para se avaliar o efeito do emurchecimento, da redução do tamanho das partículas e da adição de enzimas fibrolíticas (com ou sem inoculante bacteriano Lactobacillus plantarum sobre a composição bromatológica da silagem e a produção de efluente em silagens de capim-tanzânia (Panicum maximum Jacq. cv. Tanzânia. A forragem foi cortada aos 45 dias de crescimento vegetativo e armazenada em silos experimentais (50 L durante 136 dias. O efluente foi coletado e quantificado no 1º, 2º, 7º, 14º, 21º, 60º, 90º e 136º dias de armazenamento. A adição de enzimas fibrolíticas, associadas ou não ao inoculante bacteriano, promoveu redução da fração fibrosa (FDN, FDA, celulose e hemicelulose, que foi mais acentuada nas silagens emurchecidas. Contudo, não houve aumento da digestibilidade in vitro da MS com a adição de enzimas fibrolíticas. Embora tenha havido diferenças no tamanho de partícula, a amplitude alcançada não foi suficiente para provocar alterações significativas na composição química e no efluente das silagens. Observou-se que a quantidade total de efluente produzida foi maior (250L/t forragem ensilada em silagens não-emurchecidas e esporádica nas emurchecidas. A adição de enzimas com ou sem inoculante bacteriano não aumentou as perdas por efluente. Os valores médios de DBO (11.289 mg/L, DQO (36.279 mg/L, DQO/DBO (3, 35, pH (4, 9 e de sólidos totais (34.395 mg/L e sólidos totais fixos (16.533 mg/L foram observados no efluente das silagens não-emurchecidas. As silagens não-emurchecidas apresentaram efluente com elevado potencial poluidor para o meio ambiente.The present trial aimed to evaluate the effects of wilting (wet vs. wilted, particle size reduction (small vs. large and the addition of fibrolytic enzymes (alone vs. combined with Lactobacillus plantarum on the chemical composition and effluent yield of Tanzaniagrass silages (Panicum maximum Jacq. cv. Tanzania

  1. Mechanism of plasticity development for ceramic dough (5). Influence of the deformability of buffer domain on plasticity; Seramikku nendo no kasakusei hatsugen mekanizumu (5). Kanshoryoiki no henkeino no kasakusei eno eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, S. [Wet Forming of Ceramics Technology Research Association, Aichi (Japan); Ishida, H. [INAX Corporation, Aichi (Japan). Space Design Research Center; Shibasaki, Y; Oda, K. [National Industrial Research Institute of Nagoya, Aichi (Japan)

    1999-11-01

    Plasticity of ceramic dough is determined by the deformation of the buffer domain that consists of aggregate or gel. Effect of the deformability of each buffer domain on the plasticity of alumina dough, in presence of various additives, was investigated. Those additives were konjak, agar, curdlan and super-absorbent polymer. Moderately deformable additives such as konjak and agar worked as buffer domains, and plasticity was generated. However, soft and brittle additives such as curdlan and super-absorbent polymer could not improve plasticity because of their lower ability in generating the buffer domains. It was clarified that the deformability of buffer domain directly influences plasticity. (author)

  2. Motor cortical plasticity in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Kaviraja eUdupa

    2013-09-01

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

  3. Recycling of plastic waste: Screening for brominated flame retardants (BFRs).

    Science.gov (United States)

    Pivnenko, K; Granby, K; Eriksson, E; Astrup, T F

    2017-08-30

    Flame retardants are chemicals vital for reducing risks of fire and preventing human casualties and property losses. Due to the abundance, low cost and high performance of bromine, brominated flame retardants (BFRs) have had a significant share of the market for years. Physical stability on the other hand, has resulted in dispersion and accumulation of selected BFRs in the environment and receiving biota. A wide range of plastic products may contain BFRs. This affects the quality of waste plastics as secondary resource: material recycling may potentially reintroduce the BFRs into new plastic product cycles and lead to increased exposure levels, e.g. through use of plastic packaging materials. To provide quantitative and qualitative data on presence of BFRs in plastics, we analysed bromophenols (tetrabromobisphenol A (TBBPA), dibromophenols (2,4- and 2,6-DBP) and 2,4,6-tribromophenol (2,4,6-TBP)), hexabromocyclododecane stereoisomers (α-, β-, and γ-HBCD), as well as selected polybrominated diphenyl ethers (PBDEs) in samples of household waste plastics, virgin and recycled plastics. A considerable number of samples contained BFRs, with highest concentrations associated with acrylonitrile butadiene styrene (ABS, up to 26,000,000ngTBBPA/g) and polystyrene (PS, up to 330,000ng∑HBCD/g). Abundancy in low concentrations of some BFRs in plastic samples suggested either unintended addition in plastic products or degradation of higher molecular weight BFRs. The presence of currently restricted flame retardants (PBDEs and HBCD) identified in the plastic samples illustrates that circular material flows may be contaminated for extended periods. The screening clearly showed a need for improved documentation and monitoring of the presence of BFRs in plastic waste routed to recycling. Copyright © 2017. Published by Elsevier Ltd.

  4. Plastic ingestion in marine-associated bird species from the eastern North Pacific.

    Science.gov (United States)

    Avery-Gomm, S; Provencher, J F; Morgan, K H; Bertram, D F

    2013-07-15

    In addition to monitoring trends in plastic pollution, multi-species surveys are needed to fully understand the pervasiveness of plastic ingestion. We examined the stomach contents of 20 bird species collected from the coastal waters of the eastern North Pacific, a region known to have high levels of plastic pollution. We observed no evidence of plastic ingestion in Rhinoceros Auklet, Marbled Murrelet, Ancient Murrelet or Pigeon Guillemot, and low levels in Common Murre (2.7% incidence rate). Small sample sizes limit our ability to draw conclusions about population level trends for the remaining fifteen species, though evidence of plastic ingestion was found in Glaucous-Winged Gull and Sooty Shearwater. Documenting levels of plastic ingestion in a wide array of species is necessary to gain a comprehensive understanding about the impacts of plastic pollution. We propose that those working with bird carcasses follow standard protocols to assess the levels of plastic ingestion whenever possible.

  5. Life cycle assessment and additives: state of knowledge

    DEFF Research Database (Denmark)

    Concerns about possible toxic effects from additives/impurities accumulated in globally recycled waste/resources like paper and plastics was one of the main reasons for starting up the EU FP7 Coordination Action project RiskCycle (www.wadef.com/projects/riskcycle). A key aim of the project...... is to identify research needs within this area focusing on both risk assessment (RA) and life cycle assessment (LCA). Besides the sectors on paper and plastics also lubricants, textiles, electronics and leather are included in RiskCycle. On plastics a literature review regarding the state of knowledge...... on additives/impurities in LCA has been performed within RiskCycle. Several inventory databases (LCI data) have been investigated and the result shows that most LCI databases use PlasticsEurope data for plastics production. Most of these data are aggregated and do not include additives. Regarding...

  6. Reduce Plasticizer Migration by Modification of PVC during Reactive Processing

    Institute of Scientific and Technical Information of China (English)

    XING X S; SCOTT G

    2003-01-01

    Plasticizers in plasticized polyvinyl chloride (PVC) are generally physically added into PVC by compounding so that they can be rapidly leached from PVC articles during service. This results in their migration into the human environment with potentially serious consequences and lower effectiveness of the additives in PVC. Potentially the chemical modification of PVC during processing via reactive processing procedure is one of the most attractive solutions to these problems.In this paper, we will report our work in exploring an environmentally friendly and cost-effective reactive processing approach for chemically binding plasticizer into PVC chains.Our research results indicate that it is possible to reduce the plasticizer migration from a plasticized PVC by chemically binding of a certain plasticizer into PVC chains via reactive processing. Thus, high levels of binding of DBM, a maleate plasticizer, to PVC may be reached in less than 10 min under prevailing reactive processing conditions. The extent of binding of DBM as a function of the loading shows two peaks: one at a relatively low loading (less than 0.12 mol*kg-1 PVC) tends to 100%, the other in the high loading region (more than 1.5 mol*kg-1 PVC) approaches around 50%. The DBM modified PVC polymer exhibits behaviours as a plasticized PVC but its bound plasticising groups would not be leached by solvent extraction.

  7. Reduce Plasticizer Migration by Modification of PVC during Reactive Processing

    Institute of Scientific and Technical Information of China (English)

    XINGXS; SCOTTG

    2003-01-01

    Plasticizers in plasticized polyvinyl chloride (PVC) are generally physically added into PVC by compounding so that they can be rapidly leached from PVC articles during service. This results in their migration into the human environment with potentially serious consequences and lower effectiveness of the additives in PVC. Potentially the chemical modification of PVC during processing via reactive processing procedure is one of the most attractive solutions to these problems. In this paper, we will report our work in exploring an environmentally friendly and cost-effective reactive processing approach for chemically binding plasticizer into PVC chains. Our research results indicate that it is possible to reduce the plasticizer migration from a plasticized PVC by chemically binding of a certain plasticizer into PVC chains via reactive processing. Thus, high levels of binding of DBM,a maleate plasticizer, to PVC may be reached in less than 10 min under prevailing reactive processing conditions. The extent of binding of DBM as a function of the loading shows two peaks: one at a relatively low loading (less than 0.12 mol·kg-1 PVC) tends to 100%, the other in the high loading region (more than 1.5 mol·kg-1 PVC) approaches around 50%. The DBM modified PVC polymer exhibits behaviours as a plasticized PVC but its bound plasticising groups would not be leached by solvent extraction.

  8. Study on Mechanical Properties of Concrete Using Plastic Waste as an Aggregate

    Science.gov (United States)

    Jaivignesh, B.; Sofi, A.

    2017-07-01

    Disposal of large quantity of plastic causes land, water and air pollution etc.., so a study is conducted to recycle the plastic in concrete. This work investigates about the replacement of natural aggregate with non-biodegradable plastic aggregate made up of mixed plastic waste in concrete. Several tests are conducted such as compressive strength of cube, split tensile strength of cylinder, flexural strength test of prism to identify the properties and behavior of concrete using plastic aggregate. Replacement of fine aggregate weight by 10%, 15%, 20% with Plastic fine (PF) aggregate and for each replacement of fine aggregate 15%, 20%, 25% of coarse aggregate replacement also conducted with Plastic Coarse(PC) aggregate. In literatures reported that the addition of plastic aggregate in concrete causes the reduction of strength in concrete due to poor bonding between concrete and plastic aggregate, so addition of 0.3% of steel fiber by weight of cement in concrete is done to improve the concrete strength. Totally 60 cubes, 60 cylinders and 40 prisms are casted to identify the compressive strength, split tensile strength and flexural strength respectively. Casted specimens are tested at 7 and 28 days. The identified results from concrete using plastic aggregate are compared with conventional concrete. Result shows that reduction in mechanical properties of plastic aggregate added concrete. This reduction in strength is mainly due to poor bond strength between cement and plastic aggregate.

  9. Use of recycled plastics in wood plastic composites - a review.

    Science.gov (United States)

    Kazemi Najafi, Saeed

    2013-09-01

    The use of recycled and waste thermoplastics has been recently considered for producing wood plastic composites (WPCs). They have great potential for WPCs manufacturing according to results of some limited researches. This paper presents a detailed review about some essential properties of waste and recycled plastics, important for WPCs production, and of research published on the effect of recycled plastics on the physical and mechanical properties of WPCs.

  10. Doses de boro e crescimento radicular e da parte aérea de cultivares de arroz de terras altas Influence of boron addition on growth of roots and shoot of upland rice crops

    Directory of Open Access Journals (Sweden)

    Juliano Corulli Corrêa

    2006-12-01

    Full Text Available O crescimento radicular é favorecido em condições adequadas de disponibilidade de boro no solo e, por isto, a aplicação da dose correta desse micronutriente é de grande importância, para que não ocorra prejuízo no desenvolvimento e na produtividade da cultura de arroz de terras altas, de acordo com a variedade e tipo de solo. O presente trabalho teve como objetivo avaliar a influência das doses de boro no crescimento radicular e da parte aérea, em três cultivares de arroz de terras altas. O experimento foi realizado em casa de vegetação, em vaso com capacidade de 10 L, que continha 8 dm³ de solo Latossolo Vermelho distrófico, sendo o delineamento experimental inteiramente casualizado, em esquema fatorial 3 x 3, com quatro repetições. Os tratamentos consistiram de três cultivares (Caiapó, Primavera e Maravilha e três doses de boro (0, 3 e 6 mg dm-3, usando, como fonte, o bórax. A dose de 6 mg dm-3 foi prejudicial tanto à produção de matéria seca da parte aérea como de raiz para o arroz de terras altas. Além de apresentar maior capacidade de absorção de boro, o cultivar Maravilha apresentou-se mais tolerante à elevação da disponibilidade de B no solo, não ocorrendo alterações de comprimento, diâmetro e superfície radicular.Appropriate boron (B availability in soils favors root growth, and a sufficient supply of this micronutrient is very important for adequate rice development and yield in upland fields, depending on the cultivars and soil type. This study aimed at evaluating the influence of B addition on growth of roots and shoot of three upland rice cultivars. The experiment was carried out in a greenhouse, in 10 L pots containing 8 kg of an Hapludox; the experiment was in a completely random 3 x 3 factorial design, with four replications. The treatments consisted of three rice cultivars (Caiapó, Primavera, and Maravilha and three B rates (0, 3 and 6 mg dm-3, as borax. The B rate of 6 mg dm-3 boron was

  11. Direct liquefaction of plastics and coprocessing of coal with plastics

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

  12. Outcome-based residency education: teaching and evaluating the core competencies in plastic surgery.

    Science.gov (United States)

    Bancroft, Gregory N; Basu, C Bob; Leong, Mimi; Mateo, Carol; Hollier, Larry H; Stal, Samuel

    2008-06-01

    Through its oversight of residency education in the United States, the Accreditation Council for Graduate Medical Education has mandated new structural changes in resident education with its newly created core competencies and an emphasis on outcomes-based education. These core competencies represent the central areas in which the Accreditation Council for Graduate Medical Education believes a plastic surgery resident should receive adequate and appropriate education and training. In addition, as part of this outcomes-based education, residents are to be evaluated on their level of mastery in these core competencies. Increasingly, the Accreditation Council for Graduate Medical Education will assess the ability of residency programs to integrate the teaching and evaluating of the core competencies in their accreditation process of plastic surgery residency programs. This shift in residency evaluation initiated by the Outcomes Project by the Accreditation Council for Graduate Medical Education will have a significant impact in how plastic surgery residents are taught and, as importantly, evaluated in the coming years. The objectives of this work were as follows: (1) to outline the different methods available to foster a core competency-based plastic surgery training curriculum and (2) to serve as a primer to help both full-time academic and clinical faculty to further develop their curriculum to successfully teach and constructively evaluate their residents in the core competencies in accordance with the Accreditation Council for Graduate Medical Education guidelines. At the conclusion of this review, the reader should have a better understanding of what is necessary to formulate and help foster a plastic surgery core competency curriculum, particularly with an emphasis on the contemporary methods used for outcomes evaluations.

  13. 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.

  14. Geotehnical Properties of Plastic Stabilized Lateritic Soil

    OpenAIRE

    Akinola Johnson Olarewaju

    2016-01-01

    Stabilization is the combination of soils and additives to change its properties and remain in its stable compacted state without undergoing any change under effect of exposure to weather and traffic. Soil stabilization through the reinforced soil construction is an efficient and reliable technique for improving the strength and stability of soils. The lateritic soil used in this study was taken along Papa-Ilaro road Ajegunle at Abalabi, Ogun State, Nigeria and the solid plastic wastes were t...

  15. Fabrication of plastic biochips

    Energy Technology Data Exchange (ETDEWEB)

    Saaem, Ishtiaq; Ma, Kuo-Sheng; Alam, S. Munir; Tian Jingdong [Department of Biomedical Engineering and Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27708 (United States); Department of Medicine and Human Vaccine Institute, Duke University, Durham, North Carolina 27708 (United States); Department of Biomedical Engineering and Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27708 (United States)

    2010-07-15

    A versatile surface functionalization procedure based on rf magnetron sputtering of silica was performed on poly(methylmethacrylate), polycarbonate, polypropylene, and cyclic olefin copolymers (Topas 6015). The hybrid thermoplastic surfaces were characterized by x-ray photoelectron spectrometer analysis and contact angle measurements. The authors then used these hybrid materials to perform a sandwich assay targeting an HIV-1 antibody using fluorescent detection and biotinylated peptides immobilized using the bioaffinity of biotin-neutravidin. They found a limit of detection similar to arrays on glass surfaces and believed that this plastic biochip platform may be used for the development of disposable immunosensing and diagnostic applications.

  16. Developmental Plasticity and Language: A Comparative Perspective.

    Science.gov (United States)

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

    2016-04-01

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

  17. Chemical deactivation of V{sub 2}O{sub 5}/WO{sub 3}-TiO{sub 2} SCR catalysts by additives and impurities from fuels, lubrication oils, and urea solution. Part 1. Catalytic studies

    Energy Technology Data Exchange (ETDEWEB)

    Kroecher, Oliver; Elsener, Martin [Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)

    2008-01-10

    The influence of the combustion products of different lubrication oil additives (Ca, Mg, Zn, P, B, Mo) and impurities in Diesel fuel (K from raps methyl ester) or urea solution (Ca, K) on the activity and selectivity of vanadia-based SCR catalysts were investigated. Standard V{sub 2}O{sub 5}/WO{sub 3}-TiO{sub 2} catalysts coated on metal substrates (400 cpsi) were impregnated with water soluble compounds of these elements and calcined at 400 and 550 C, in order to investigate the chemical deactivation potential of different elements and combinations of them. It was found that potassium strongly reduced the adsorption equilibrium constant K{sub NH{sub 3}} of ammonia. At small ammonia concentrations in the feed, only part of the active sites were covered with ammonia resulting in a reduced SCR reaction rate. At high ammonia concentrations, the surface coverage and SCR reaction rate increased, but high SCR activity at concurrent low ammonia emissions was impossible. Calcium caused less deactivation than potassium and did not affect the ammonia adsorption to the same extent, but it lowered the intrinsic SCR reaction rate. Moreover, deactivation by calcium was much reduced if counter-ions of inorganic acids were present (order of improvement: SO{sub 4}{sup 2-} > PO{sub 4}{sup 3-} > BO{sub 3}{sup 3-}). Zinc was again less deactivating than calcium, but the positive effect of the counter-ions was weaker than in case of calcium. The degree of N{sub 2}O production at T > 500 C, which is typical for V{sub 2}O{sub 5}/WO{sub 3}-TiO{sub 2} catalysts, was not influenced by the different compounds, except for molybdenum, which induced a small increase in N{sub 2}O formation. (author)

  18. 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.

  19. Key Questions on the Role of Phenotypic Plasticity in Eco-Evolutionary Dynamics.

    Science.gov (United States)

    Hendry, Andrew P

    2016-01-01

    Ecology and evolution have long been recognized as reciprocally influencing each other, with recent research emphasizing how such interactions can occur even on very short (contemporary) time scales. Given that these interactions are mediated by organismal phenotypes, they can be variously shaped by genetic variation, phenotypic plasticity, or both. I here address 8 key questions relevant to the role of plasticity in eco-evolutionary dynamics. Focusing on empirical evidence, especially from natural populations, I offer the following conclusions. 1) Plasticity is--not surprisingly--sometimes adaptive, sometimes maladaptive, and sometimes neutral. 2) Plasticity has costs and limits but these constraints are highly variable, often weak, and hard to detect. 3) Variable environments favor the evolution of increased trait plasticity, which can then buffer fitness/performance (i.e., tolerance). 4) Plasticity sometimes aids colonization of new environments (Baldwin Effect) and responses to in situ environmental change. However, plastic responses are not always necessary or sufficient in these contexts. 5) Plasticity will sometimes promote and sometimes constrain genetic evolution. 6) Plasticity will sometimes help and sometimes hinder ecological speciation but, at present, empirical tests are limited. 7) Plasticity can show considerable evolutionary change in contemporary time, although the rates of this reaction norm evolution are highly variable among taxa and traits. 8) Plasticity appears to have considerable influences on ecological dynamics at the community and ecosystem levels, although many more studies are needed. In summary, plasticity needs to be an integral part of any conceptual framework and empirical investigation of eco-evolutionary dynamics.

  20. Research of High-gloss Injection Molding Technology in Thin Shell Plastic Parts with Holes%薄壳多孔塑料件高光注射成型工艺研究

    Institute of Scientific and Technical Information of China (English)

    赵苗; 黄翔; 辛勇

    2012-01-01

    对手机壳体塑料件进行了常规注射成型CAE研究,分析存在较为严重的表现质量问题.通过采用高光成型技术,以沉降指数、体积收缩率和翘曲变形为质量指标,利用正交试验和多目标综合平衡法分析研究得出该产品的最佳成型工艺参数组合.分析结果表明,高光注射成型技术在改善薄壳多孔塑料件缺陷方面比常规注射成型有着更大的优越性.%CAE research of conventional injection moulding on a mobile phone shell was carried out and the serious apparent quality problems were analyzed.Then through high-gloss injection molding technology, selecting sink index, volumetric shrinkage and warpage as the main quality indexes, the optimum injection molding parameters combination was obtained by using orthogonal experiment and multi-objective integral balance method.The analysis results showed that high-gloss injection molding had more advantages in improving defects of thin shell injection molding parts with holes compared with conventional injection molding.High-gloss injection molding ; thin shell injection molding parts with holes ; orthogonal experiment design;

  1. Structural features of plastic deformation in bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Scudino, S., E-mail: s.scudino@ifw-dresden.de; Shakur Shahabi, H.; Stoica, M.; Kühn, U. [IFW Dresden, Institut für Komplexe Materialien, D-01069 Dresden (Germany); Kaban, I.; Escher, B.; Eckert, J. [IFW Dresden, Institut für Komplexe Materialien, D-01069 Dresden (Germany); TU Dresden, Institut für Werkstoffwissenschaft, D-01062 Dresden (Germany); Vaughan, G. B. M. [European Synchrotron Radiation Facilities ESRF, BP220, 38043 Grenoble (France)

    2015-01-19

    Spatially resolved strain maps of a plastically deformed bulk metallic glass (BMG) have been created by using high-energy X-ray diffraction. The results reveal that plastic deformation creates a spatially heterogeneous atomic arrangement, consisting of strong compressive and tensile strain fields. In addition, significant shear strain is introduced in the samples. The analysis of the eigenvalues and eigenvectors of the strain tensor indicates that considerable structural anisotropy occurs in both the magnitude and direction of the strain. These features are in contrast to the behavior observed in elastically deformed BMGs and represent a distinctive structural sign of plastic deformation in metallic glasses.

  2. Plastic food packaging and health

    Directory of Open Access Journals (Sweden)

    Raika Durusoy

    2011-02-01

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

  3. The commercialization of plastic surgery.

    Science.gov (United States)

    Swanson, Eric

    2013-09-01

    The last decade has brought a major challenge to the traditional practice of plastic surgery from corporations that treat plastic surgery as a commercial product and market directly to the public. This corporate medicine model may include promotion of a trademarked procedure or device, national advertising that promises stunning results, sales consultants, and claims of innovation, superiority, and improved safety. This article explores the ethics of this business practice and whether corporate medicine is a desirable model for patients and plastic surgeons.

  4. Recyclability assessment of nano-reinforced plastic packaging

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez, C., E-mail: csanchez@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Hortal, M., E-mail: mhortal@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Aliaga, C., E-mail: caliaga@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Devis, A., E-mail: adevis@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Cloquell-Ballester, V.A., E-mail: cloquell@dpi.upv.es [Dpto. Proyectos de Ingeniería, Universitat Politècnica de València, Camino de Vera, 46022 Valencia (Spain)

    2014-12-15

    Highlights: • The study compares the recyclability of polymers with and without nanoparticles. • Visual appearance, material quality and mechanical properties are evaluated. • Minor variations in mechanical properties in R-PE and R-PP with nanoparticles. • Slight degradation of R-PET which affect mechanical properties. • Colour deviations in recycled PE, PP and PET in ranges higher that 0.3 units. - Abstract: Packaging is expected to become the leading application for nano-composites by 2020 due to the great advantages on mechanical and active properties achieved with these substances. As novel materials, and although there are some current applications in the market, there is still unknown areas under development. One key issue to be addressed is to know more about the implications of the nano-composite packaging materials once they become waste. The present study evaluates the extrusion process of four nanomaterials (Layered silicate modified nanoclay (Nanoclay1), Calcium Carbonate (CaCO{sub 3}), Silver (Ag) and Zinc Oxide (ZnO) as part of different virgin polymer matrices of polyethylene (PE), Polypropylene (PP) and Polyethyleneterephtalate (PET). Thus, the following film plastic materials: (PE–Nanoclay1, PE–CaCO{sub 3}, PP–Ag, PET–ZnO, PET–Ag, PET–Nanoclay1) have been processed considering different recycling scenarios. Results on recyclability show that for PE and PP, in general terms and except for some minor variations in yellowness index, tensile modulus, tensile strength and tear strength (PE with Nanoclay1, PP with Ag), the introduction of nanomaterial in the recycling streams for plastic films does not affect the final recycled plastic material in terms of mechanical properties and material quality compared to conventional recycled plastic. Regarding PET, results show that the increasing addition of nanomaterial into the recycled PET matrix (especially PET–Ag) could influence important properties of the recycled material, due to a

  5. Recyclability assessment of nano-reinforced plastic packaging.

    Science.gov (United States)

    Sánchez, C; Hortal, M; Aliaga, C; Devis, A; Cloquell-Ballester, V A

    2014-12-01

    Packaging is expected to become the leading application for nano-composites by 2020 due to the great advantages on mechanical and active properties achieved with these substances. As novel materials, and although there are some current applications in the market, there is still unknown areas under development. One key issue to be addressed is to know more about the implications of the nano-composite packaging materials once they become waste. The present study evaluates the extrusion process of four nanomaterials (Layered silicate modified nanoclay (Nanoclay1), Calcium Carbonate (CaCO3), Silver (Ag) and Zinc Oxide (ZnO) as part of different virgin polymer matrices of polyethylene (PE), Polypropylene (PP) and Polyethyleneterephtalate (PET). Thus, the following film plastic materials: (PE-Nanoclay1, PE-CaCO3, PP-Ag, PET-ZnO, PET-Ag, PET-Nanoclay1) have been processed considering different recycling scenarios. Results on recyclability show that for PE and PP, in general terms and except for some minor variations in yellowness index, tensile modulus, tensile strength and tear strength (PE with Nanoclay1, PP with Ag), the introduction of nanomaterial in the recycling streams for plastic films does not affect the final recycled plastic material in terms of mechanical properties and material quality compared to conventional recycled plastic. Regarding PET, results show that the increasing addition of nanomaterial into the recycled PET matrix (especially PET-Ag) could influence important properties of the recycled material, due to a slight degradation of the polymer, such as increasing pinholes, degradation fumes and elongation at break. Moreover, it should be noted that colour deviations were visible in most of the samples (PE, PP and PET) in levels higher than 0.3 units (limit perceivable by the human eye). The acceptance of these changes in the properties of recycled PE, PP and PET will depend on the specific applications considered (e.g. packaging applications are more

  6. Multiscale modeling and synaptic plasticity.

    Science.gov (United States)

    Bhalla, Upinder S

    2014-01-01

    Synaptic plasticity is a major convergence point for theory and computation, and the process of plasticity engages physiology, cell, and molecular biology. In its many manifestations, plasticity is at the hub of basic neuroscience questions about memory and development, as well as more medically themed questions of neural damage and recovery. As an important cellular locus of memory, synaptic plasticity has received a huge amount of experimental and theoretical attention. If computational models have tended to pick specific aspects of plasticity, such as STDP, and reduce them to an equation, some experimental studies are equally guilty of oversimplification each time they identify a new molecule and declare it to be the last word in plasticity and learning. Multiscale modeling begins with the acknowledgment that synaptic function spans many levels of signaling, and these are so tightly coupled that we risk losing essential features of plasticity if we focus exclusively on any one level. Despite the technical challenges and gaps in data for model specification, an increasing number of multiscale modeling studies have taken on key questions in plasticity. These have provided new insights, but importantly, they have opened new avenues for questioning. This review discusses a wide range of multiscale models in plasticity, including their technical landscape and their implications.

  7. Plastics recycling: challenges and opportunities

    National Research Council Canada - National Science Library

    Jefferson Hopewell; Robert Dvorak; Edward Kosior

    2009-01-01

    .... Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public...

  8. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-15

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

  9. Modeling plasticity of materials with nanostructure

    Science.gov (United States)

    Kudinova, N. R.

    2017-02-01

    A new approach to modeling of the plasticity of materials with the particle size in the range from 3 to 20 nm (nanostructure) has been proposed. It is based on classical thermodynamic approach employing the surface tension of nanoparticles. Its main advantage is the minimum number of physical parameters in use. In the context of the proposed model, we calculated the dependence of the melting temperature on the nanoparticle size which is consistent with experimental data. The volume density of the surface energy of nanoparticles was also determined. This energy is assumed to be a significant part of the internal energy during deformation Yield point was interpreted as the result of changes of grains surface energy during the deformation. The obtained yield point dependence on the grain size was related to the Hall–Petch law, and this resulted in confirmation of the hypothesis on the crucial role of surface tension forces in the initial stage of plastic deformation of nanomaterials.

  10. [Informed consent in aesthetic plastic surgery].

    Science.gov (United States)

    Fenger, H

    2006-02-01

    The informed consent plays a very decisive part in aesthetic plastic surgery. As there is often no medical indication in plastic surgery, the patient has to be informed about all the facts of an operation, especially about the possible risks. The legal requests for therapeutic and economic clarification gain in importance. The jurisdiction in Germany demands a merciless clarification for the patient. The patient needs to be clarified about all facts early enough so that he has a sufficient amount of time to weigh-up the pros und cons of the operation and if necessary to take advice from someone else. The sufficient documentation is very important at the sight of the extensive burden of proof at the expense of the physician.

  11. [Erythropoietin in plastic surgery].

    Science.gov (United States)

    Günter, C I; Rezaeian, F; Harder, Y; Lohmeyer, J A; Egert, S; Bader, A; Schilling, A F; Machens, H-G

    2013-04-01

    EPO is an autologous hormone, which is known to regulate erythropoiesis. For 30 years it has been used for the therapy of diverse forms of anaemia, such as renal anaemia, tumour-related anaemias, etc. Meanwhile, a multitude of scientific publications were able to demonstrate its pro-regenerative effects after trauma. These include short-term effects such as the inhibition of the "primary injury response" or apoptosis, and mid- and long-term effects for example the stimulation of stem cell recruitment, growth factor production, angiogenesis and re-epithelialisation. Known adverse reactions are increases of thromboembolic events and blood pressure, as well as a higher mortality in patients with tumour anaemias treated with EPO. Scientific investigations of EPO in the field of plastic surgery included: free and local flaps, nerve regeneration, wound healing enhancement after dermal thermal injuries and in chronic wounds.Acute evidence for the clinical use of EPO in the field of plastic surgery is still not satisfactory, due to the insufficient number of Good Clinical Practice (GCP)-conform clinical trials. Thus, the initiation of more scientifically sound trials is indicated.

  12. Optogenetics and synaptic plasticity.

    Science.gov (United States)

    Xie, Yu-feng; Jackson, Michael F; Macdonald, John F

    2013-11-01

    The intricate and complex interaction between different populations of neurons in the brain has imposed limits on our ability to gain detailed understanding of synaptic transmission and its integration when employing classical electrophysiological approaches. Indeed, electrical field stimulation delivered via traditional microelectrodes does not permit the targeted, precise and selective control of neuronal activity amongst a varied population of neurons and their inputs (eg, cholinergic, dopaminergic or glutamatergic neurons). Recently established optogenetic techniques overcome these limitations allowing precise control of the target neuron populations, which is essential for the elucidation of the neural substrates underlying complex animal behaviors. Indeed, by introducing light-activated channels (ie, microbial opsin genes) into specific neuronal populations, optogenetics enables non-invasive optical control of specific neurons with milliseconds precision. These approaches can readily be applied to freely behaving live animals. Recently there is increased interests in utilizing optogenetics tools to understand synaptic plasticity and learning/memory. Here, we summarize recent progress in applying optogenetics in in the study of synaptic plasticity.

  13. Scratch Performance Investigation on Injection Molding Visible Plastic Parts of Passenger Vehicle%乘用车注塑外观塑料零件刮擦性能研究

    Institute of Scientific and Technical Information of China (English)

    林秀玲

    2012-01-01

    Using Cross Hatch test method to evaluate the anti -scratch whitening performance, mainly test the talc filled PP which are molded into part or plaque and analyze effects caused by appearance definition, coloring approach, sample preparation, etc. in order to find the right solution and direction so that we can find solution for scratch performance improvement%主要针对采用十字划格的测试方法,对添加滑石粉改性PP类材料配色注塑而成的零件或样板进行抗刮擦发白性能的评估,从外观定义、配色过程、样品准备等方面分析其对刮擦测试结果产生的影响,以期找到耐刮性能影响因素和改进方向.

  14. Motor cortical plasticity induced by motor learning through mental practice.

    Directory of Open Access Journals (Sweden)

    Laura eAvanzino

    2015-04-01

    Full Text Available Several investigations suggest that actual and mental actions trigger similar neural substrates. Motor learning via physical practice results in long-term potentiation (LTP-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. However, whether this neuroplasticity process contributes to improve motor performance through mental practice remains to be determined. Here, we tested skill learning-dependent changes in primary motor cortex (M1 excitability and plasticity by means of transcranial magnetic stimulation in subjects trained to physically execute or mentally perform a sequence of finger opposition movements. Before and after physical practice and motor-imagery practice, M1 excitability was evaluated by measuring the input-output (IO curve of motor evoked potentials. M1 long-term potentiation (LTP and long-term depression (LTD-like plasticity was assessed with paired-associative stimulation (PAS of the median nerve and motor cortex using an interstimulus interval of 25 ms (PAS25 or 10 ms (PAS10, respectively. We found that even if after both practice sessions subjects significantly improved their movement speed, M1 excitability and plasticity were differentially influenced by the two practice sessions. First, we observed an increase in the slope of IO curve after physical but not after motor-imagery practice. Second, there was a reversal of the PAS25 effect from LTP-like plasticity to LTD-like plasticity following physical and motor-imagery practice. Third, LTD-like plasticity (PAS10 protocol increased after physical practice, whilst it was occluded after motor-imagery practice. In conclusion, we demonstrated that motor-imagery practice lead to the development of neuroplasticity, as it affected the PAS25- and PAS10- induced plasticity in M1. These results, expanding the current knowledge on how motor-imagery training shapes M1 plasticity, might have a potential impact in

  15. A two-surface plasticity model for stiff clay

    OpenAIRE

    2015-01-01

    This paper presents a constitutive model for describing some important features of the behavior of natural stiff clay evidenced experimentally such as the limited elastic zone, the presence of strain hardening and softening, and the smooth transition from elastic behavior to a plastic one. The model, namely ACC-2, is an adapted Modified Cam Clay model with two yield surfaces: similarly to bounding surface plasticity theory, an additional yield surface?namely Inner yield surface?was adopted to...

  16. The phenotypic plasticity of developmental modules

    Directory of Open Access Journals (Sweden)

    Aabha I. Sharma

    2016-08-01

    Full Text Available Abstract Background Organisms develop and evolve in a modular fashion, but how individual modules interact with the environment remains poorly understood. Phenotypically plastic traits are often under selection, and studies are needed to address how traits respond to the environment in a modular fashion. In this study, tissue-specific plasticity of melanic spots was examined in the large milkweed bug, Oncopeltus fasciatus. Results Although the size of the abdominal melanic bands varied according to rearing temperatures, wing melanic bands were more robust. To explore the regulation of abdominal pigmentation plasticity, candidate genes involved in abdominal melanic spot patterning and biosynthesis of melanin were analyzed. While the knockdown of dopa decarboxylase (Ddc led to lighter pigmentation in both the wings and the abdomen, the shape of the melanic elements remained unaffected. Although the knockdown of Abdominal-B (Abd-B partially phenocopied the low-temperature phenotype, the abdominal bands were still sensitive to temperature shifts. These observations suggest that regulators downstream of Abd-B but upstream of DDC are responsible for the temperature response of the abdomen. Ablation of wings led to the regeneration of a smaller wing with reduced melanic bands that were shifted proximally. In addition, the knockdown of the Wnt signaling nuclear effector genes, armadillo 1 and armadillo 2, altered both the melanic bands and the wing shape. Thus, the pleiotropic effects of Wnt signaling may constrain the amount of plasticity in wing melanic bands. Conclusions We propose that when traits are regulated by distinct pre-patterning mechanisms, they can respond to the environment in a modular fashion, whereas when the environment impacts developmental regulators that are shared between different modules, phenotypic plasticity can manifest as a developmentally integrated system.

  17. Sustainable reverse logistics for household plastic waste

    NARCIS (Netherlands)

    Bing, X.

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than th

  18. Sustainable reverse logistics for household plastic waste

    NARCIS (Netherlands)

    Bing, X.

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than

  19. Sustainable reverse logistics for household plastic waste

    NARCIS (Netherlands)

    Bing, X.

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than th

  20. Synaptic plasticity in inhibitory neurons of the auditory brainstem.

    Science.gov (United States)

    Bender, Kevin J; Trussell, Laurence O

    2011-04-01

    There is a growing appreciation of synaptic plasticity in the early levels of auditory processing, and particularly of its role in inhibitory circuits. Synaptic strength in auditory brainstem and midbrain is sensitive to standard protocols for induction of long-term depression, potentiation, and spike-timing-dependent plasticity. Differential forms of plasticity are operative at synapses onto inhibitory versus excitatory neurons within a circuit, and together these could serve to tune circuits involved in sound localization or multisensory integration. Such activity-dependent control of synaptic function in inhibitory neurons may also be expressed after hearing loss and could underlie persistent neuronal activity in patients with tinnitus. This article is part of a Special Issue entitled 'Synaptic Plasticity & Interneurons'.

  1. 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.

  2. Plastic in North Sea Fish

    NARCIS (Netherlands)

    Foekema, E.M.; Gruijter, de C.; Mergia, M.T.; Franeker, van J.A.; Murk, A.J.; Koelmans, A.A.

    2013-01-01

    To quantify the occurrence of ingested plastic in fish species caught at different geographical positions in the North Sea, and to test whether the fish condition is affected by ingestion of plastics, 1203 individual fish of seven common North Sea species were investigated: herring, gray gurnard, wh

  3. The scope of plastic surgery

    African Journals Online (AJOL)

    2013-08-03

    Aug 3, 2013 ... areas of surgery (especially general surgery), plastic surgeons are arguably the .... Who do you feel are experts in laparoscopic surgery? e (general surgeons) a. Maxillofacial .... of pressure sore. ORIF = open reduction internal fixation. ... Plastic versus cosmetic surgery: What's the difference? Plast Reconstr.

  4. New Life for Old Plastics

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Recycling joint venture utilizes innovative technology to reuse plastics Recycling,despite its green connotations,can be a messy business.In China,more than 400,000 companies are engaged in plastic recycling,but 70 percent of them are family enterprises,

  5. Computational strain gradient crystal plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2014-01-01

    of plane crystal plasticity are studied: pure shear of a single crystal between rigid platens as well as plastic deformation around cylindrical voids in hexagonal close packed and face centered cubic crystals. Effective in-plane constitutive slip parameters for plane strain deformation of specifically...

  6. Architecture of European Plastic Surgery

    NARCIS (Netherlands)

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

    2006-01-01

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

  7. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  8. Ultrasonography as a diagnostic method in addition to mammography

    Energy Technology Data Exchange (ETDEWEB)

    Otto, H.; Roer, E.

    1988-05-01

    By using ultrasonography in addition to mammography, experienced diagnosticians essentially enhance the safety of their diagnosis of mammary gland diseases. The same applies to gynecomastia, the condition after plastic surgery, and mastitis.

  9. Visual attentional load influences plasticity in the human motor cortex.

    Science.gov (United States)

    Kamke, Marc R; Hall, Michelle G; Lye, Hayley F; Sale, Martin V; Fenlon, Laura R; Carroll, Timothy J; Riek, Stephan; Mattingley, Jason B

    2012-05-16

    Neural plasticity plays a critical role in learning, memory, and recovery from injury to the nervous system. Although much is known about the physical and physiological determinants of plasticity, little is known about the influence of cognitive factors. In this study, we investigated whether selective attention plays a role in modifying changes in neural excitability reflecting long-term potentiation (LTP)-like plasticity. We induced LTP-like effects in the hand area of the human motor cortex using transcranial magnetic stimulation (TMS). During the induction of plasticity, participants engaged in a visual detection task with either low or high attentional demands. Changes in neural excitability were assessed by measuring motor-evoked potentials in a small hand muscle before and after the TMS procedures. In separate experiments plasticity was induced either by paired associative stimulation (PAS) or intermittent theta-burst stimulation (iTBS). Because these procedures induce different forms of LTP-like effects, they allowed us to investigate the generality of any attentional influence on plasticity. In both experiments reliable changes in motor cortex excitability were evident under low-load conditions, but this effect was eliminated under high-attentional load. In a third experiment we investigated whether the attentional task was associated with ongoing changes in the excitability of motor cortex, but found no difference in evoked potentials across the levels of attentional load. Our findings indicate that in addition to their role in modifying sensory processing, mechanisms of attention can also be a potent modulator of cortical plasticity.

  10. Universal features of amorphous plasticity

    Science.gov (United States)

    Budrikis, Zoe; Castellanos, David Fernandez; Sandfeld, Stefan; Zaiser, Michael; Zapperi, Stefano

    2017-07-01

    Plastic yielding of amorphous solids occurs by power-law distributed deformation avalanches whose universality is still debated. Experiments and molecular dynamics simulations are hampered by limited statistical samples, and although existing stochastic models give precise exponents, they require strong assumptions about fixed deformation directions, at odds with the statistical isotropy of amorphous materials. Here, we introduce a fully tensorial, stochastic mesoscale model for amorphous plasticity that links the statistical physics of plastic yielding to engineering mechanics. It captures the complex shear patterning observed for a wide variety of deformation modes, as well as the avalanche dynamics of plastic flow. Avalanches are described by universal size exponents and scaling functions, avalanche shapes, and local stability distributions, independent of system dimensionality, boundary and loading conditions, and stress state. Our predictions consistently differ from those of mean-field depinning models, providing evidence that plastic yielding is a distinct type of critical phenomenon.

  11. Imaging brain plasticity after trauma

    Institute of Scientific and Technical Information of China (English)

    Zhifeng Kou; Armin Iraji

    2014-01-01

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

  12. Size effects in crystal plasticity

    DEFF Research Database (Denmark)

    Borg, Ulrik

    2007-01-01

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

  13. Smart apps for the smart plastic surgeon

    Directory of Open Access Journals (Sweden)

    Aniketh Venkataram

    2015-01-01

    Full Text Available Smartphones have the ability to benefit plastic surgeons in all aspects of patient care and education. With the sheer number of applications available and more being created everyday, it is easy to miss out on apps which could be of great relevance. Moreover, the range of android applications available has not been extensively discussed in the literature. To this end, we have compiled an exhaustive list of android smartphone applications, which we feel can help our day to day functioning. The apps have been extensively reviewed and neatly described along with all their potential uses. In addition, we have made an effort to highlight ′non-medical′ or efficiency apps which can improve departmental functioning. These apps have not been described in prior articles, and their functionality might not be known to all. We believe that the technology savvy plastic surgeon can make maximum use of these apps to his benefit.

  14. Nano-Ceramic Coated Plastics

    Science.gov (United States)

    Cho, Junghyun

    2013-01-01

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

  15. Sulfur Distribution during Hydrothermal Liquefaction of Lignite, Wheat Straw and Plastic Waste in Sub-Critical Water

    Institute of Scientific and Technical Information of China (English)

    Wang Baofeng; Huang Yaru; Zhang Jinjun

    2015-01-01

    The distribution and transformation of sulfur in products during hydrothermal liquefaction of lignite, wheat straw and plastic waste in sub-critical water were investigated in an autoclave. The inlfuence of blending ratio, temperature, initial nitrogen pressure, residence time and additives on sulfur distribution was studied systematically. The results showed that most of sulfur existed as organic sulfur and transferred into the residue, and only a small part of sulfur transferred into oil and gas during hydrothermal liquefaction of lignite, wheat straw and plastic waste in sub-critical water. The results also showed that lower temperature (less than 300℃) was favorable for obtaining oil with low sulfur content. It can be also seen from the results that the best condition to obtain the oil with low sulfur content should be implemented at a lignite/wheat straw/plastic waste blending ratio of 5:4:1, an initial nitrogen pressure of 3 MPa and a residence time of 30 minutes. Fur-thermore, the results indicated that adding tourmaline during hydrothermal liquefaction of lignite, wheat straw and plastic waste was beneifcial to production of oil with low sulfur content.

  16. PENGARUH PLASTICIZER PADA KARAKTERISTIK EDIBLE FILM DARI PEKTIN

    Directory of Open Access Journals (Sweden)

    Sang Kompiang Wirawan

    2012-05-01

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

  17. Plastic shrinkage of mortars with shrinkage reducing admixture and lightweight aggregates studied by neutron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wyrzykowski, Mateusz, E-mail: mateusz.wyrzykowski@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Lodz University of Technology, Department of Building Physics and Building Materials, Lodz (Poland); Trtik, Pavel [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, Villigen (Switzerland); Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Münch, Beat [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Weiss, Jason [Purdue University, School of Civil Engineering, West Lafayette (United States); Vontobel, Peter [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, Villigen (Switzerland); Lura, Pietro [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); ETH Zurich, Institute for Building Materials (IfB), Zurich (Switzerland)

    2015-07-15

    Water transport in fresh, highly permeable concrete and rapid water evaporation from the concrete surface during the first few hours after placement are the key parameters influencing plastic shrinkage cracking. In this work, neutron tomography was used to determine both the water loss from the concrete surface due to evaporation and the redistribution of fluid that occurs in fresh mortars exposed to external drying. In addition to the reference mortar with a water to cement ratio (w/c) of 0.30, a mortar with the addition of pre-wetted lightweight aggregates (LWA) and a mortar with a shrinkage reducing admixture (SRA) were tested. The addition of SRA reduced the evaporation rate from the mortar at the initial stages of drying and reduced the total water loss. The pre-wetted LWA released a large part of the absorbed water as a consequence of capillary pressure developing in the fresh mortar due to evaporation.

  18. Life cycle perspective of plastic recycling

    Energy Technology Data Exchange (ETDEWEB)

    Ballhorn, R. [Targeted Research on Waste Minimization and Recycling Project, Darmstadt (Germany)

    2001-07-01

    Some recent European Union directives on recycling plastics are discussed, with particular reference to the automobile industry, highlighting developing chemical technologies such as selective solution/precipitation approaches, to increase the fraction of high quality recyclates. Some promising technologies, including separation by tribo-electrical charging, sorting by optical means, separation by gasification, dissolution, hydrogenation and co-processing with heavy oil residues are described, with examples involving the conversion of mixed plastic waste by gasification, and the production of PA6 monomer from carpet waste. Conclusion based on study results to date indicate that with regard to 'end of life' vehicles the driving force for dismantling is the recovery of resalable parts and metal, not plastic. Technologies for dismantling are seen as relatively crude. Moreover, the large investment required to construct a full dismantling facility and the lack of a well-developed 'after market' for recycled products makes it unlikely that such a facility will be built in the near future. The most promising way to cope with the economic and ecological challenges appears to be a combination of chemical recycling and energy recovery, accompanied by an aggressive effort to develop the 'after market' for the recycled products. 5 refs., 9 figs.

  19. Bio-Degradable Plastics Impact On Environment

    Directory of Open Access Journals (Sweden)

    T.SUBRAMANI

    2014-06-01

    Full Text Available The potential of biodegradable polymers and more particularly that of polymers obtained from renewable resources such as the polysaccharides (e.g., starch have long been recognized. However, these biodegradable polymers have been largely used in some applications (e.g., food industry and have not found extensive applications in the packaging industries to replace conventional plastic materials, although they could be an interesting way to overcome the limitation of the petrochemical resources in the future. The fossil fuel and gas could be partially replaced by greener agricultural sources, which should participate in the reduction of CO2 emissions. Bio-based and biodegradable plastics can form the basis for environmentally preferable, sustainable alternative to current materials based exclusively on petroleum feed stocks. These bio-based materials offer value in the sustainability/life-cycle equation by being a part of the biological carbon cycle, especially as it relates to carbon-based polymeric materials such as plastics, water soluble polymers and other carbon based products like lubricants, biodiesel, and detergents. Identification and quantification of bio based content uses radioactive C-14 signature. Biopolymers are generally capable of being utilized by living matter (biodegraded, and so can be disposed in safe and ecologically sound ways through disposal processes (waste management like composting, soil application, and biological wastewater treatment. Single use, short-life, disposable products can be engineered to be bio-based and biodegradable.

  20. Single gate optimization for plastic injection mold

    Institute of Scientific and Technical Information of China (English)

    LI Ji-quan; LI De-qun; GUO Zhi-ying; LV Hai-yuan

    2007-01-01

    This paper deals with a methodology for single gate location optimization for plastic injection mold. The objective of the gate optimization is to minimize the warpage of injection molded parts, because warpage is a crucial quality issue for most injection molded parts while it is influenced greatly by the gate location. Feature warpage is defined as the ratio of maximum displacement on the feature surface to the projected length of the feature surface to describe part warpage. The optimization is combined with the numerical simulation technology to find the optimal gate location, in which the simulated annealing algorithm is used to search for the optimum. Finally, an example is discussed in the paper and it can be concluded that the proposed method is effective.

  1. Plasticity and beyond microstructures, crystal-plasticity and phase transitions

    CERN Document Server

    Hackl, Klaus

    2014-01-01

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

  2. The Frontiers of Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-03

    Additive manufacturing, more commonly known as 3-D printing, has become a ubiquitous tool in science for its precise control over mechanical design. For additive manufacturing to work, a 3-D structure is split into thin 2D slices, and then different physical properties, such as photo-polymerization or melting, are used to grow the sequential layers. The level of control allows not only for devices to be made with a variety of materials: e.g. plastics, metals, and quantum dots, but to also have finely controlled structures leading to other novel properties. While 3-D printing is widely used by hobbyists for making models, it also has industrial applications in structural engineering, biological tissue scaffolding, customized electric circuitry, fuel cells, security, and more.

  3. Balancing noise and plasticity in eukaryotic gene expression

    Directory of Open Access Journals (Sweden)

    Bajić Djordje

    2012-07-01

    Full Text Available Abstract Background Coupling the control of expression stochasticity (noise to the ability of expression change (plasticity can alter gene function and influence adaptation. A number of factors, such as transcription re-initiation, strong chromatin regulation or genome neighboring organization, underlie this coupling. However, these factors do not necessarily combine in equivalent ways and strengths in all genes. Can we identify then alternative architectures that modulate in distinct ways the linkage of noise and plasticity? Results Here we first show that strong chromatin regulation, commonly viewed as a source of coupling, can lead to plasticity without noise. The nature of this regulation is relevant too, with plastic but noiseless genes being subjected to general activators whereas plastic and noisy genes experience more specific repression. Contrarily, in genes exhibiting poor transcriptional control, it is translational efficiency what separates noise from plasticity, a pattern related to transcript length. This additionally implies that genome neighboring organization –as modifier– appears only effective in highly plastic genes. In this class, we confirm bidirectional promoters (bipromoters as a configuration capable to reduce coupling by abating noise but also reveal an important trade-off, since bipromoters also decrease plasticity. This presents ultimately a paradox between intergenic distances and modulation, with short intergenic distances both associated and disassociated to noise at different plasticity levels. Conclusions Balancing the coupling among different types of expression variability appears as a potential shaping force of genome regulation and organization. This is reflected in the use of different control strategies at genes with different sets of functional constraints.

  4. Effects of plasticizers and their mixtures on estrogen Receptor and thyroid hormone functions

    DEFF Research Database (Denmark)

    Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    2009-01-01

    Plasticizers are additives used to increase the flexibility or plasticity of the material to which they are added, normally rigid plastic and as additives in paint and adhesives. They are suspected to interfere with the endocrine system, including the estrogen and the thyroid hormone (TH) systems...... was lower than predicted, suggesting a potential antagonizing effect of the mixture. In conclusion, the tested plasticizers and phenols elicited endocrine-disrupting potential that can be mediated via interference with the estrogen and TH systems. Moreover, the observed mixture effect stresses...

  5. Melt rheology and its applications in the plastics industry

    CERN Document Server

    Dealy, John M

    2013-01-01

    This is the second edition of Melt Rheology and its Role in Plastics Processing, although the title has changed to reflect its broadened scope. Advances in the recent years in rheometer technology and polymer science have greatly enhanced the usefulness of rheology in the plastics industry. It is now possible to design polymers having specific molecular structures and to predict the flow properties of melts having those structures. In addition, rheological properties now provide more precise information about molecular structure. This book provides all the information that is needed for the intelligent application of rheology in the development of new polymers, the determination of molecular structure and the correlation of processability with laboratory test data. Theory and equations are limited to what is essential for the use of rheology in the characterization of polymers, the development of new plastics materials and the prediction of plastics processing behavior. The emphasis is on information that wil...

  6. Stress-strain response of plastic waste mixed soil.

    Science.gov (United States)

    Babu, G L Sivakumar; Chouksey, Sandeep Kumar

    2011-03-01

    Recycling plastic waste from water bottles has become one of the major challenges worldwide. The present study provides an approach for the use plastic waste as reinforcement material in soil. The experimental results in the form of stress-strain-pore water pressure response are presented. Based on experimental test results, it is observed that the strength of soil is improved and compressibility reduced significantly with addition of a small percentage of plastic waste to the soil. The use of the improvement in strength and compressibility response due to inclusion of plastic waste can be advantageously used in bearing capacity improvement and settlement reduction in the design of shallow foundations. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Xanthos, Dirk; Walker, Tony R

    2017-02-18

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

  8. Fungal biodegradation of phthalate plasticizer in situ.

    Science.gov (United States)

    Pradeep, S; Faseela, P; Josh, M K Sarath; Balachandran, S; Devi, R Sudha; Benjamin, Sailas

    2013-04-01

    This unique study describes how Aspergillus japonicus, Penicillium brocae and Purpureocillium lilacinum, three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n-hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5% w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15-0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes.

  9. Fast convergence of learning requires plasticity between inferior olive and deep cerebellar nuclei in a manipulation task: a closed-loop robotic simulation.

    Science.gov (United States)

    Luque, Niceto R; Garrido, Jesús A; Carrillo, Richard R; D'Angelo, Egidio; Ros, Eduardo

    2014-01-01

    The cerebellum is known to play a critical role in learning relevant patterns of activity for adaptive motor control, but the underlying network mechanisms are only partly understood. The classical long-term synaptic plasticity between parallel fibers (PFs) and Purkinje cells (PCs), which is driven by the inferior olive (IO), can only account for limited aspects of learning. Recently, the role of additional forms of plasticity in the granular layer, molecular layer and deep cerebellar nuclei (DCN) has been considered. In particular, learning at DCN synapses allows for generalization, but convergence to a stable state requires hundreds of repetitions. In this paper we have explored the putative role of the IO-DCN connection by endowing it with adaptable weights and exploring its implications in a closed-loop robotic manipulation task. Our results show that IO-DCN plasticity accelerates convergence of learning by up to two orders of magnitude without conflicting with the generalization properties conferred by DCN plasticity. Thus, this model suggests that multiple distributed learning mechanisms provide a key for explaining the complex properties of procedural learning and open up new experimental questions for synaptic plasticity in the cerebellar network.

  10. Fast convergence of learning requires plasticity between inferior olive and deep cerebellar nuclei in a manipulation task: a closed-loop robotic simulation

    Science.gov (United States)

    Luque, Niceto R.; Garrido, Jesús A.; Carrillo, Richard R.; D'Angelo, Egidio; Ros, Eduardo

    2014-01-01

    The cerebellum is known to play a critical role in learning relevant patterns of activity for adaptive motor control, but the underlying network mechanisms are only partly understood. The classical long-term synaptic plasticity between parallel fibers (PFs) and Purkinje cells (PCs), which is driven by the inferior olive (IO), can only account for limited aspects of learning. Recently, the role of additional forms of plasticity in the granular layer, molecular layer and deep cerebellar nuclei (DCN) has been considered. In particular, learning at DCN synapses allows for generalization, but convergence to a stable state requires hundreds of repetitions. In this paper we have explored the putative role of the IO-DCN connection by endowing it with adaptable weights and exploring its implications in a closed-loop robotic manipulation task. Our results show that IO-DCN plasticity accelerates convergence of learning by up to two orders of magnitude without conflicting with the generalization properties conferred by DCN plasticity. Thus, this model suggests that multiple distributed learning mechanisms provide a key for explaining the complex properties of procedural learning and open up new experimental questions for synaptic plasticity in the cerebellar network. PMID:25177290

  11. 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.

  12. Conservative and esthetic cast gold fixed partial dentures-inlay, onlay, and partial veneer retainers, custom composite pontics, and stress breakers: part II: utilization of additional retentive features and fabrication of custom pontic facings.

    Science.gov (United States)

    Stevenson, Richard G; Refela, Jane A

    2009-01-01

    Although in today's dental world implant restorations are considered the standard of care in the replacement of missing teeth, clinical contraindications and patient nonacceptance of implant placement can be encountered. Several scenarios are discussed here in which a single missing tooth can be restored with conservative fixed partial dentures (FPD) that employ cast gold retainers; each with a customized design in order to preserve tooth structure, maintain esthetics, and provide a long-term prognosis. The abutment teeth are prepared for conservative partial coverage restorations by using Brasseler burs (Brasseler USA, Savannah, GA, USA). Impressions are taken of the preparations, along with any retentive features, utilizing either the Vented Pin Channel technique or the Shooshan Plastic Pin technique. The latter technique utilizes Kodex twist drills and corresponding impression pins (Coltene Whaledent Inc., Mahwah, NJ, USA). The conservative FPD with non-rigid connectors is fabricated by using type III gold alloy. The pontic cage portion is chemically prepared utilizing the Panavia F2.0 cement kit (Kuraray America Inc., Houston, TX, USA) or other dual-polymerizing resin cement and restored with any type of direct composite resin material. A palette of opaquers and tints are used for chairside characterization of the esthetic pontic facing. The final polish of the pontic is completed by using FlexiDisc and FlexiBuff discs (Cosmedent Inc., Chicago, IL, USA). CLINICAL SIGNIFICANCE In cases where an implant restoration is contraindicated for replacement of a single tooth, a semi-precision FPD is a conservative, functional, and esthetic alternative.

  13. Phenotypic plasticity, costs of phenotypes, and costs of plasticity

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  14. Biodegradable plastics from renewable sources.

    Science.gov (United States)

    Flieger, M; Kantorová, M; Prell, A; Rezanka, T; Votruba, J

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

  15. Plastics recycling: challenges and opportunities

    OpenAIRE

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-01-01

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

  16. PLASMA GASIFICATION OF WASTE PLASTICS

    Directory of Open Access Journals (Sweden)

    Tadeusz Mączka

    2013-01-01

    Full Text Available The article presents the process of obtaining liquid fuels and fuel gas in the process of plasma processing of organic materials, including waste plastics. The concept of plasma pyrolysis of plastics was presented and on its basis a prototype installation was developed. The article describes a general rule of operating the installation and its elements in the process and basic operation parameters determined during its start-up. Initial results of processing plastics and the directions further investigations are also discussed. The effect of the research is to be the design of effective technology of obtaining fuels from gasification/pyrolysis of organic waste and biomass.

  17. Proposal for the addition of fifteen new areas to the National Wilderness Preservation System : Part 16 : Deferred Areas : Cabeza Prieta Game Range : Desert National Wildlife Range : Glacier Bay National Monument

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  18. Proposed additions to the National Wilderness Preservation System : Part 35 : Deferred Areas : Kofa Game Range - Charles M. Russell National Wildlife Range - Lake Mead National Recreation Area - Nunivak National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is one of the Presidential Transmittals proposing additions to the National Wilderness Preservation System. This particular transmittal focuses on the...

  19. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation.

    Science.gov (United States)

    Li, Jia; Wu, Guiqing; Xu, Zhenming

    2015-01-01

    Plastic products can be found everywhere in people's daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (-)-PE-PS-PC-PVC-ABS-PP-(+), while the triboelectric series obtained by cyclone was (-)-PE-PS-PC-PVC-ABS-PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator.

  20. Recycling of Reinforced Plastics

    Science.gov (United States)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  1. Cancer stem cell plasticity and tumor hierarchy

    Institute of Scientific and Technical Information of China (English)

    Marina Carla Cabrera; Robert E Hollingsworth; Elaine M Hurt

    2015-01-01

    The origins of the complex process of intratumoralheterogeneity have been highly debated and differentcellular mechanisms have been hypothesized to accountfor the diversity within a tumor. The clonal evolution andcancer stem cell (CSC) models have been proposed asdrivers of this heterogeneity. However, the concept ofcancer stem cell plasticity and bidirectional conversionbetween stem and non-stem cells has added additionalcomplexity to these highly studied paradigms and may helpexplain the tumor heterogeneity observed in solid tumors.The process of cancer stem cell plasticity in which cancercells harbor the dynamic ability of shifting from a non-CSCstate to a CSC state and vice versa may be modulated byspecific microenvironmental signals and cellular interactionsarising in the tumor niche. In addition to promoting CSCplasticity, these interactions may contribute to the cellulartransformation of tumor cells and affect response tochemotherapeutic and radiation treatments by providingCSCs protection from these agents. Herein, we review theliterature in support of this dynamic CSC state, discussthe effectors of plasticity, and examine their role in thedevelopment and treatment of cancer.

  2. Environment, Leptin Sensitivity, and Hypothalamic Plasticity

    Directory of Open Access Journals (Sweden)

    Marco Mainardi

    2013-01-01

    Full Text Available Regulation of feeding behavior has been a crucial step in the interplay between leptin and the arcuate nucleus of the hypothalamus (ARC. On one hand, the basic mechanisms regulating central and peripheral action of leptin are becoming increasingly clear. On the other hand, knowledge on how brain sensitivity to leptin can be modulated is only beginning to accumulate. This point is of paramount importance if one considers that pathologically obese subjects have high levels of plasmatic leptin. A possible strategy for exploring neural plasticity in the ARC is to act on environmental stimuli. This can be achieved with various protocols, namely, physical exercise, high-fat diet, caloric restriction, and environmental enrichment. Use of these protocols can, in turn, be exploited to isolate key molecules with translational potential. In the present review, we summarize present knowledge about the mechanisms of plasticity induced by the environment in the ARC. In addition, we also address the role of leptin in extrahypothalamic plasticity, in order to propose an integrated view of how a single diffusible factor can regulate diverse brain functions.

  3. Environment, leptin sensitivity, and hypothalamic plasticity.

    Science.gov (United States)

    Mainardi, Marco; Pizzorusso, Tommaso; Maffei, Margherita

    2013-01-01

    Regulation of feeding behavior has been a crucial step in the interplay between leptin and the arcuate nucleus of the hypothalamus (ARC). On one hand, the basic mechanisms regulating central and peripheral action of leptin are becoming increasingly clear. On the other hand, knowledge on how brain sensitivity to leptin can be modulated is only beginning to accumulate. This point is of paramount importance if one considers that pathologically obese subjects have high levels of plasmatic leptin. A possible strategy for exploring neural plasticity in the ARC is to act on environmental stimuli. This can be achieved with various protocols, namely, physical exercise, high-fat diet, caloric restriction, and environmental enrichment. Use of these protocols can, in turn, be exploited to isolate key molecules with translational potential. In the present review, we summarize present knowledge about the mechanisms of plasticity induced by the environment in the ARC. In addition, we also address the role of leptin in extrahypothalamic plasticity, in order to propose an integrated view of how a single diffusible factor can regulate diverse brain functions.

  4. Transport and release of chemicals from plastics to the environment and to wildlife

    Science.gov (United States)

    Teuten, Emma L.; Saquing, Jovita M.; Knappe, Detlef R. U.; Barlaz, Morton A.; Jonsson, Susanne; Björn, Annika; Rowland, Steven J.; Thompson, Richard C.; Galloway, Tamara S.; Yamashita, Rei; Ochi, Daisuke; Watanuki, Yutaka; Moore, Charles; Viet, Pham Hung; Tana, Touch Seang; Prudente, Maricar; Boonyatumanond, Ruchaya; Zakaria, Mohamad P.; Akkhavong, Kongsap; Ogata, Yuko; Hirai, Hisashi; Iwasa, Satoru; Mizukawa, Kaoruko; Hagino, Yuki; Imamura, Ayako; Saha, Mahua; Takada, Hideshige

    2009-01-01

    Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2′-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g–1 to µg g–1. Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub µg l–1 to mg l–1 and were correlated with the level of economic development. PMID:19528054

  5. Colonic perforations caused by migrated plastic biliary stents

    Energy Technology Data Exchange (ETDEWEB)

    Virgilio, Edoardo; Pascarella, Agauido; Scandavini, Chiara Maria; Frezza, Barbara; Bocchetti, Tommaso; Balducci, Genoveffa [Faculty of Medicine and Psychology ' Sapienza' , St. Andrea Hospital, Rome (Italy)

    2015-04-15

    Endoscopic insertion of plastic endoprostheses has become an integral part of the management of many benign and malignant diseases affecting the hepatobiliary and pancreatic system. Clogging and dislocation into the duodenum are the most frequently described complications following stent placement. Distal migration with or without perforation of the colon is an exceedingly rare phenomenon and the treatment is not well defined, as discussed below.

  6. Successively refined models for crack tip plasticity in polymer blends

    NARCIS (Netherlands)

    Pijnenburg, KGW; Seelig, T; van der Giessen, E

    2005-01-01

    This paper is concerned with a comparative study of different, partly complementary micromechanical models for crack tip plasticity in polymer-rubber blends. It is experimentally well established that interspersion of micron-scale rubber particles into a polymer matrix can lead to a significantly en

  7. Fiber Glass/Plastics. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on methods of repairing damaged components and parts made of fiberglass/plastics is one of a series of texts and visual aids on operation, diagnosis, and repair of engine powered vehicles. Materials provide basic information with illustrations for use by vocational students and teachers as well as shop servicemen and laymen. Focusing…

  8. Persuasive Normative Messages: The Influence of Injunctive and Personal Norms on Using Free Plastic Bags

    OpenAIRE

    2013-01-01

    In this exploratory field-study, we examined how normative messages ( i.e. , activating an injunctive norm, personal norm, or both) could encourage shoppers to use fewer free plastic bags for their shopping in addition to the supermarket’s standard environmental message aimed at reducing plastic bags. In a one-way subjects-design ( N = 200) at a local supermarket, we showed that shoppers used significantly fewer free plastic bags in the injunctive, personal and combined normative message cond...

  9. Plasticity and creep of metals

    CERN Document Server

    Rusinko, Andrew

    2011-01-01

    Here is a systematic presentation of the postulates, theorems and principles of mathematical theories of plasticity and creep in metals, and their applications. Special attention is paid to analysis of the advantages and shortcomings of the classical theories.

  10. American Society of Plastic Surgeons

    Science.gov (United States)

    ... PRS PRS GO PSN PSEN GRAFT Contact Us Cosmetic Surgery New procedures and advanced technologies offer plastic surgery ... David Berman MD 14 Pidgeon Hill Drive Berman Cosmetic Surgery & S... Sterling, VA 20165 Website Franklin Richards MD Suite ...

  11. Plastic deformation of nanocrystalline nickel

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline (NC) Ni subject to cold rolling at liquid nitrogen temperature. The activation of grain-boundary-mediated-plasticity is evidenced in NC-Ni, including twinning and formation of stacking fault via partial dislocation slips from the grain boundary. The formation and storage of 60? full dislocations are observed inside NC-grains. The grain/twin boundaries act as the barriers of dislocation slips, leading to dislocation pile-up, severe lattice distortion, and formation of sub-grain boundary. The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation. The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

  12. Plastic deformation of nanocrystalline nickel

    Institute of Scientific and Technical Information of China (English)

    WU XiaoLei

    2009-01-01

    A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline(NC)Ni subject to cold rolling at liquid nitrogen temperature.The acti vation of grain-boundary-mediated-plasticity is evidenced in NC-Ni,including twinning and formation of stacking fault via partial dislocation slips from the grain boundary.The formation and storage of 60° full dislocations are observed inside NC-grains.The grain/twin boundaries act as the barriers of dislocation slips,leading to dislocation pile-up,severe lattice distortion,and formation of sub-grain boundary.The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation.The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

  13. Exceptional plasticity of silicon nanobridges

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Tadashi; Sato, Takaaki; Toshiyoshi, Hiroshi; Collard, Dominique; Fujita, Hiroyuki [University of Tokyo, Institute of Industrial Science, 4-6-1 Komaba Meguro, Tokyo 153-8505 (Japan); Cleri, Fabrizio [Institut d' Electronique Microelectronique et Nanotechnologie (CNRS UMR 8520), Universite de Lille I, Avenue Poincare BP60069 59652 Villeneuve d' Ascq (France); Kakushima, Kuniyuki [Tokyo Institute of Technology, 4259, Nagatsuda, Midori, Yokohama, Kanagawa 226-8502 (Japan); Mita, Makoto [Department of Spacecraft Engineering, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Miyata, Masaki; Itamura, Noriaki; Sasaki, Naruo [Department of Materials and Life Sciences, Seikei University, 3-3-1, Kitamachi, Kichijoji, Musashino, Tokyo 180-8633 (Japan); Endo, Junji, E-mail: tadashii@iis.u-tokyo.ac.jp [FK Optical laboratory, 1-13-4 Nakano Niiza Saitama, 352-0005 (Japan)

    2011-09-02

    The plasticity of covalently bonded materials is a subject at the forefront of materials science, bearing on a wide range of technological and fundamental aspects. However, covalent materials fracture in a brittle manner when the deformation exceeds just a few per cent. It is predicted that a macroscopically brittle material like silicon can show nanoscale plasticity. Here we report the exceptional plasticity observed in silicon nanocontacts ('nanobridges') at room temperature using a special experimental setup combining a transmission electron microscope and a microelectromechanical system. When accounting for surface diffusion, we succeeded in elongating the nanocontact into a wire-like structure, with a fivefold increase in volume, up to more than twenty times the original length. Such a large plasticity was caused by the stress-assisted diffusion and the sliding of the intergranular, amorphous-like material among the nanocrystals.

  14. Globally Oriented Chinese Plastics Industry

    Institute of Scientific and Technical Information of China (English)

    Liao Zhengpin

    2004-01-01

    @@ Through continued endeavor and persistent opening to the whole world the Chinese plastics industry has been developed into a comprehensive industrial system that forms the basic material industries side by side with the steel, cement and the timber industry.

  15. Borderline personality disorder and aesthetic plastic surgery.

    Science.gov (United States)

    Morioka, Daichi; Ohkubo, Fumio

    2014-12-01

    Borderline personality disorder (BPD) is a common axis II disorder associated with a high risk of impulsivity and self-injury. Several authors have suggested that individuals with BPD are poor candidates for plastic surgery. Recent changes in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for BPD may be confusing to surgeons. This article reviews the literature on BPD and discusses how important it is to recognize this condition and how difficult it is to treat patients, highlighting features and signs of this condition in plastic surgery settings. Illustrative case examples from our experience are also described. Our careful search of the literature revealed that individuals with BPD may seek treatment from plastic surgeons in two different patterns: as treatment for self-injury or as insatiable requests for aesthetic procedures. Individuals with BPD tend to request corrections of multiple body parts to avoid abandonment by the surgeon or due to their impulsivity, but such preoccupation with appearance is less profound and shifts from one body part to another over time. While flexible and individualized psychological approaches are required to minimize the patient's impulsivity and abandonment fears, surgeons should be inflexible to any unrealistic requests. It is best to avoid surgery on patients with BPD. Surgeons should be aware of the nuances of this condition so as not to miss the proper timing for a psychiatric referral. 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.

  16. Computational materials science: Nanoscale plasticity

    DEFF Research Database (Denmark)

    Jacobsen, Karsten Wedel; Schiøtz, Jakob

    2002-01-01

    How does plastic deformation of polycrystalline materials with grain sizes less than 100 nm look at the atomic scale? A large-scale molecular dynamics simulation of nanocrystalline alluminium reveals some surprising behaviour.......How does plastic deformation of polycrystalline materials with grain sizes less than 100 nm look at the atomic scale? A large-scale molecular dynamics simulation of nanocrystalline alluminium reveals some surprising behaviour....

  17. Sorting Techniques for Plastics Recycling

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper presents the basic principles of three different types of separating methods and a general guideline for choosing the most effective method for sorting plastic mixtures. It also presents the results of the tests carried out for separation of PVC, ABS and PET from different kinds of plastic mixtures in order to improve the grade of the raw input used in mechanical or feedstock recycling.

  18. [Modern neuroimaging of brain plasticity].

    Science.gov (United States)

    Kasprian, G; Seidel, S

    2010-02-01

    Modern neuroimaging methods offer new insights into the plasticity of the human brain. As the techniques of functional MRI and diffusion tensor imaging are increasingly being applied in a clinical setting, the examiner is now frequently confronted with the interpretation of imaging findings related to regenerative processes in response to lesions of the central and also of the peripheral nervous system. In this article individual results of modern neuroimaging studies are discussed in the context of structural and functional plasticity of the CNS.

  19. Plastic bronchitis: a management challenge.

    Science.gov (United States)

    Eberlein, Michael H; Drummond, Michael B; Haponik, Edward F

    2008-02-01

    Plastic bronchitis is an uncommon and underdiagnosed entity, characterized by recurrent expectoration of large, branching bronchial casts. We describe a 39-year-woman with no prior lung disease who had episodic wheezing, severe dyspnea with expectoration of large and thick secretions, branching in appearance, which she described as resembling squid. A comprehensive evaluation revealed no specific cause and a diagnosis of idiopathic plastic bronchitis was made. In plastic bronchitis the bronchial casts may vary in size from small segmental casts of a bronchus to casts filling the airways of an entire lung. Plastic bronchitis can therefore present as an acute life-threatening emergency if mechanical obstruction of major airways occurs. The casts are differentiated into type I, inflammatory casts, or type II, acellular casts. The type I inflammatory casts are often associated with bronchial disease and often have an acute presentation. The acellular type of cast production is often chronic or recurrent. Numerous systemic illnesses are associated with plastic bronchitis, but often, as in our patient, no underlying cause can be identified. The treatment of plastic bronchitis includes acute therapy to aid the removal and expectoration of casts, and specific short- or long-term treatments attempting to address the underlying hypersecretory process. The therapeutic options are supported only by anecdotal evidence based on case reports as the rarity and heterogeneity of plastic bronchitis confounds systematic investigations of its treatment. Improved understanding of the regulation of mucus production may allow for new treatment options in plastic bronchitis and other chronic lung diseases characterized by hypersecretion of mucus.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-28

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

  1. Injection Moulding of Plastic Parts with Surface Microstructures

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    2003-01-01

    structures with heights of 9 µm and aspect ratios from 0.2 to 1. For topographical characterisation a confocal laser scanning microscope was used. The injection moulding process conditions were varied over the recommended process window for the material, and the process was analysed using commercial...

  2. Injection Moulding of Plastic Parts with Surface Microstructures

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    2003-01-01

    structures with heights of 9 µm and aspect ratios from 0.2 to 1. For topographical characterisation a confocal laser scanning microscope was used. The injection moulding process conditions were varied over the recommended process window for the material, and the process was analysed using commercial...

  3. Elastic - Plastic Fracture Mechanics. A Critical Review. Part 1

    Science.gov (United States)

    1990-04-01

    Committee Naval Sea Systems Command U.S. Coast Guard (G-MTH) k Mwtlke Adminitation Ship 2100 Second Street S.W. Amercan Bureau of ShilP’ng Washington...Anderson (43) modeled the stress dependence of p with a modified power law- p - ([3.181V where (Y is the maximum principal stress at a point, and Yu, m

  4. Design of conformal cooling for plastic injection moulding by heat transfer simulation

    Directory of Open Access Journals (Sweden)

    Sabrina Marques

    2015-12-01

    Full Text Available The cooling channels of a mold for plastic injection have to be as close as possible to the part geometry in order to ensure fast and homogeneous cooling. However, conventional methods to manufacture cooling channels (drilling can only produce linear holes. Selective laser melting (SLM is an additive manufacturing technique capable to manufacture complex cooling channels (known as conformal cooling. Nevertheless, because of the high costs of SLM the benefits of conformal collings are still not clear. The current work investigates two designs of conformal coolings: i parallel circuit; ii serial circuit. Both coolings are evaluated against to traditional cooling circuits (linear channels by CAE simulation to produce parts of polypropylene. The results show that if the conformal cooling is not properly designed it cannot provide reasonable results. The deformation of the product can be reduced significantly after injection but the cycle time reduced not more than 6%.

  5. Effect of plasticizer type and concentration on physical properties of biodegradable films based on sugar palm (arenga pinnata) starch for food packaging.

    Science.gov (United States)

    Sanyang, M L; Sapuan, S M; Jawaid, M; Ishak, M R; Sahari, J

    2016-01-01

    In this study, sugar palm starch (SPS) films were developed using glycerol (G), sorbitol (S) or their combination (GS) as plasticizers at the ratio of 15, 30 and 45 (wt)% using casting technique. The addition of plasticizers to SPS film-forming solutions helped to overcome the brittle and fragile nature of unplasticized SPS films. Increased plasticizer concentration resulted to an increase in film thickness, moisture content and solubility. On the contrary, density and water absorption of plasticized films decreased with increasing plasticizer concentration. Raising the plasticizer content from 15 to 45 % showed less effect on the moisture content and water absorption of S-plasticized films. Films containing glycerol and glycerol-sorbitol plasticizer (G, and GS) demonstrated higher moisture content, solubility and water absorption capacity compared to S-plasticized films. The results obtained in this study showed that plasticizer type and concentration significantly improves film properties and enhances their suitability for food packaging applications.

  6. Plastic surgery-myths and realities in developing countries: experience from eastern Nepal.

    Science.gov (United States)

    Mishra, Brijesh; Koirala, Robin; Tripathi, Nalini; Shrestha, Kajan Raj; Adhikary, Buddhinath; Shah, Surendra

    2011-01-01

    B.P. Koirala Institute of Health Sciences, Dharan, Nepal, is the only tertiary care referral centre in the eastern region of Nepal. This paper discusses the author's experience of starting a plastic surgery unit in eastern Nepal regarding need and present status of plastic surgery care in Nepal. Methods. We analyzed the data of patients treated in Plastic surgery unit from July 2007 to February 2009. We did evaluation regarding type of patients, procedures, and their outcome. We also evaluated the limitations and their possible solutions to overcome the barriers to establish effective plastic surgical centers in developing countries. Results. Plastic surgery services were started as a unit in general surgery by single plastic surgeon and one general surgery resident on rotation. Total 848 patients were treated for different plastic-surgery-related conditions, which included 307 acute burn patients 541 general plastic surgery patients. Trauma constituted the major bulk 22%, followed by tumors 20%, while aesthetic surgery operations were only 10.1%. Conclusions. In developing countries, aesthetic procedures constitute very small part of plastic surgery interventions and plastic surgery units are primarily required for reconstructive needs for optimum management of patients.

  7. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-thomsen, Søren; Ditlevsen, Ove Dalager

    1996-01-01

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

  8. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-Thomsen, S.; Ditlevsen, Ove Dalager

    1999-01-01

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

  9. 49 CFR 192.281 - Plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe. 192.281 Section 192.281... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint...

  10. 49 CFR 192.59 - Plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe... specification; and (2) It is resistant to chemicals with which contact may be anticipated. (b) Used plastic...

  11. The Story of the Plastics Industry.

    Science.gov (United States)

    Masson, Don, Ed.

    This is an illustrated informative booklet, designed to serve members of the Society of the Plastics Industry, Inc., and the plastics industry as a whole. It provides basic information about the industry's history and growth, plastics raw materials, typical uses of plastics, properties, and methods of processing and fabricating. (Author/DS)

  12. Filling behaviour of wood plastic composites

    Science.gov (United States)

    Duretek, I.; Lucyshyn, T.; Holzer, C.

    2017-01-01

    Wood plastic composites (WPC) are a young generation of composites with rapidly growing usage within the plastics industry. The advantages are the availability and low price of the wood particles, the possibility of partially substituting the polymer in the mixture and sustainable use of the earth’s resources. The current WPC products on the market are to a large extent limited to extruded products. Nowadays there is a great interest in the market for consumer products in more use of WPC as an alternative to pure thermoplastics in injection moulding processes. This work presents the results of numerical simulation and experimental visualisation of the mould filling process in injection moulding of WPC. The 3D injection moulding simulations were done with the commercial software package Autodesk® Moldflow® Insight 2016 (AMI). The mould filling experiments were conducted with a box-shaped test part. In contrast to unfilled polymers the WPC has reduced melt elasticity so that the fountain flow often does not develop. This results in irregular flow front shapes in the moulded part, especially at high filler content.

  13. PLASTIC MATERIALS IN EUROPEAN AGRICULTURE: ACTUAL USE AND PERSPECTIVES

    Directory of Open Access Journals (Sweden)

    Giacomo Scarascia-Mugnozza

    2012-06-01

    Full Text Available The world consumption of plastics in agriculture amounts yearly to 6.5 million tons. In addition to conventional polymers used in agriculture for greenhouses and mulches such as PE, PVC, EVA, photo-selective and luminescent polymers have been used, in order to improve the quality of crops. For the same reason plastic nets are used mainly in countries with tropical and Mediterranean climates. For an environmentally friendly agricultural activity, an alternative strategy can be represented by bio-based agricultural raw materials. For low environmental impact applications, biodegradable materials for agricultural films are nowadays produced. An overview of the main methods for the disposal and recycling of plastic materials are presented with the results of mechanical and radiometric tests on recycled plastics. The strategies to reduce the burden of plastics in agriculture are: a correct procedure for the collection, disposal and recycling of post-consumption plastics; the increase of lifetime duration and performance; and the introduction and promotion of bio-based materials.

  14. Hormone signaling and phenotypic plasticity in nematode development and evolution.

    Science.gov (United States)

    Sommer, Ralf J; Ogawa, Akira

    2011-09-27

    Phenotypic plasticity refers to the ability of an organism to adopt different phenotypes depending on environmental conditions. In animals and plants, the progression of juvenile development and the formation of dormant stages are often associated with phenotypic plasticity, indicating the importance of phenotypic plasticity for life-history theory. Phenotypic plasticity has long been emphasized as a crucial principle in ecology and as facilitator of phenotypic evolution. In nematodes, several examples of phenotypic plasticity have been studied at the genetic and developmental level. In addition, the influence of different environmental factors has been investigated under laboratory conditions. These studies have provided detailed insight into the molecular basis of phenotypic plasticity and its ecological and evolutionary implications. Here, we review recent studies on the formation of dauer larvae in Caenorhabditis elegans, the evolution of nematode parasitism and the generation of a novel feeding trait in Pristionchus pacificus. These examples reveal a conserved and co-opted role of an endocrine signaling module involving the steroid hormone dafachronic acid. We will discuss how hormone signaling might facilitate life-history and morphological evolution.

  15. Mixed Elastico-Plasticity Problems with Partially Unknown Boundaries

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, we study mixed elastico-plasticity problems in which part of the boundary is known, while the other part of the boundary is unknown and is a free boundary. Under certain conditions, this problem can be transformed into a Riemann-Hilbert boundary value problem for analytic functions and a mixed boundary value problem for complex equations. Using the theory of generalized analytic functions, the solvability of the problem is discussed.

  16. Deformation mechanisms of plasticized starch materials.

    Science.gov (United States)

    Mikus, P-Y; Alix, S; Soulestin, J; Lacrampe, M F; Krawczak, P; Coqueret, X; Dole, P

    2014-12-19

    The aim of this paper is to understand the influence of plasticizer and plasticizer amount on the mechanical and deformation behaviors of plasticized starch. Glycerol, sorbitol and mannitol have been used as plasticizers. After extrusion of the various samples, dynamic mechanical analyses and video-controlled tensile tests have been performed. It was found that the nature of plasticizer, its amount as well as the aging of the material has an impact on the involved deformation mechanism. The variations of volume deformation could be explained by an antiplasticization effect (low plasticizer amount), a phase-separation phenomenon (excess of plasticizer) and/or by the retrogradation of starch.

  17. Recurrent plastic bronchitis in a child with 2009 influenza A (H1N1) and influenza B virus infection.

    Science.gov (United States)

    Kim, Sun; Cho, Hwa Jin; Han, Dong Kyun; Choi, Yoo Duk; Yang, Eun Seok; Cho, Young Kuk; Ma, Jae Sook

    2012-09-01

    Plastic bronchitis is an uncommon disorder characterized by the formation of bronchial casts. It is associated with congenital heart disease or pulmonary disease. In children with underlying conditions such as allergy or asthma, influenza can cause severe plastic bronchitis resulting in respiratory failure. A review of the literature showed nine cases of plastic bronchitis with H1N1 including this case. We report a case of a child with recurrent plastic bronchitis with eosinophilic cast associated with influenza B infection, who had recovered from plastic bronchitis associated with an influenza A (H1N1) virus infection 5 months previously. To the best of our knowledge, this is the first case of recurrent plastic bronchitis related to influenza viral infection. If patients with influenza virus infection manifest acute respiratory distress with total lung atelectasis, clinicians should consider plastic bronchitis and early bronchoscopy should be intervened. In addition, management for underlying disease may prevent from recurrence of plastic bronchitis.

  18. Lubricant for cold plastic metal working

    Energy Technology Data Exchange (ETDEWEB)

    Postolov, Yu.M.; Larina, N.F.; Osadchuk, Ye.S.; Proskuryakov, V.A.; Syroyezhko, A.M.; Vikhorev, A.A.; Yakovlev, V.I.

    1980-03-28

    A lubricant is proposed for cold plastic metal working based on fatty acids from the process of pyrolysis of castor oil (ZhKPM) with increased screening properties and which improve the quality of PV of finished parts. The lubricant contains (percent): cyclohexanol 0.5-60, levulinic and/or ketoenanthic acid 0.5-20, ZhKPM up to 100; the content of ketoenanthic acid in mixture with levulinic acid is 20-50 percent. Tests of the number of proposed lubricants were conducted for cold stampling of parts from a metal strip on a 10 ton mechanical press. Tool stability (number of pieces until adhesion) was 1200-1400, purity class Pv-7. In tests under a similar condition of vegetable oil, ZhKPM and a mixture of ZhKPM with esters (nonlubricant) tool stability was 1100, and the purity class Pv-6.

  19. Plastic Foam Withstands Greater Temperatures And Pressures

    Science.gov (United States)

    Cranston, John A.; Macarthur, Doug

    1993-01-01

    Improved plastic foam suitable for use in foam-core laminated composite parts and in tooling for making fiber/matrix-composite parts. Stronger at high temperatures, more thermally and dimensionally stable, machinable, resistant to chemical degradation, and less expensive. Compatible with variety of matrix resins. Made of polyisocyanurate blown with carbon dioxide and has density of 12 to 15 pounds per cubic feet. Does not contibute to depletion of ozone from atmosphere. Improved foam used in cores of composite panels in such diverse products as aircraft, automobiles, railroad cars, boats, and sporting equipment like surfboards, skis, and skateboards. Also used in thermally stable flotation devices in submersible vehicles. Machined into mandrels upon which filaments wound to make shells.

  20. Fontan-associated protein-losing enteropathy and plastic bronchitis.

    Science.gov (United States)

    Schumacher, Kurt R; Stringer, Kathleen A; Donohue, Janet E; Yu, Sunkyung; Shaver, Ashley; Caruthers, Regine L; Zikmund-Fisher, Brian J; Fifer, Carlen; Goldberg, Caren; Russell, Mark W

    2015-04-01

    To characterize the medical history, disease progression, and treatment of current-era patients with the rare diseases Fontan-associated protein-losing enteropathy (PLE) and plastic bronchitis. A novel survey that queried demographics, medical details, and treatment information was piloted and placed online via a Facebook portal, allowing social media to power the study. Participation regardless of PLE or plastic bronchitis diagnosis was allowed. Case control analyses compared patients with PLE and plastic bronchitis with uncomplicated control patients receiving the Fontan procedure. The survey was completed by 671 subjects, including 76 with PLE, 46 with plastic bronchitis, and 7 with both. Median PLE diagnosis was 2.5 years post-Fontan. Hospitalization for PLE occurred in 71% with 41% hospitalized ≥ 3 times. Therapy varied significantly. Patients with PLE more commonly had hypoplastic left ventricle (62% vs 44% control; OR 2.81, 95% CI 1.43-5.53), chylothorax (66% vs 41%; OR 2.96, CI 1.65-5.31), and cardiothoracic surgery in addition to staged palliation (17% vs 5%; OR 4.27, CI 1.63-11.20). Median plastic bronchitis diagnosis was 2 years post-Fontan. Hospitalization for plastic bronchitis occurred in 91% with 61% hospitalized ≥ 3 times. Therapy was very diverse. Patients with plastic bronchitis more commonly had chylothorax at any surgery (72% vs 51%; OR 2.47, CI 1.20-5.08) and seasonal allergies (52% vs 36%; OR 1.98, CI 1.01-3.89). Patient-specific factors are associated with diagnoses of PLE or plastic bronchitis. Treatment strategies are diverse without clear patterns. These results provide a foundation upon which to design future therapeutic studies and identify a clear need for forming consensus approaches to treatment. Copyright © 2015 Elsevier Inc. All rights reserved.