WorldWideScience

Sample records for plastic v-shaped spatula

  1. Plastic spatula with narrow long tip provides higher satisfactory smears for Pap test

    Directory of Open Access Journals (Sweden)

    Pervinder Kaur

    2013-01-01

    Full Text Available Background: Ayre spatula for cervical smear collection is being used despite the suggestion that different modified spatulas provide more satisfactory sampling. Aims: To see whether the cytological pickup improves with the use of long tipped spatula. Setting and Design: Rurally based University Hospital; crossover study. Materials and Methods: Pap smear using Ayre spatula in 500 and with plastic narrow long tip (Szalay spatula in 500 clinic attending women was taken and analyzed. Crossover smears were taken with modified spatula in 163 and using Ayre spatula in 187 women after 2 weeks of initial smears. The same pathologist made cytological reporting for all smears and was unaware of the type of spatula used. Results: Smears from Ayre spatula had significantly higher reports of inadequate smears (94 of 500 vs. 68 of 500 for Ayre and Szalay, respectively; P = 0.032 and it remained so even after crossover (94 of 187 vs. 70 of 163 for Ayre and Szalay, respectively; P = 0.2. Cellular quality appeared better with smears taken using Szalay spatula, but the overall abnormal smear detection rate remained similar with either collection tool (χ2 = 1.5; P = 0.2. Conclusions: Proportion of satisfactory smears is higher when long tip plastic spatula is used for collection of sample.

  2. Plastic spatula with narrow long tip provides higher satisfactory smears for Pap test.

    Science.gov (United States)

    Kaur, Pervinder; Kushtagi, Pralhad

    2013-07-01

    Ayre spatula for cervical smear collection is being used despite the suggestion that different modified spatulas provide more satisfactory sampling. To see whether the cytological pickup improves with the use of long tipped spatula. Rurally based University Hospital; crossover study. Pap smear using Ayre spatula in 500 and with plastic narrow long tip (Szalay) spatula in 500 clinic attending women was taken and analyzed. Crossover smears were taken with modified spatula in 163 and using Ayre spatula in 187 women after 2 weeks of initial smears. The same pathologist made cytological reporting for all smears and was unaware of the type of spatula used. Smears from Ayre spatula had significantly higher reports of inadequate smears (94 of 500 vs. 68 of 500 for Ayre and Szalay, respectively; P = 0.032) and it remained so even after crossover (94 of 187 vs. 70 of 163 for Ayre and Szalay, respectively; P = 0.2). Cellular quality appeared better with smears taken using Szalay spatula, but the overall abnormal smear detection rate remained similar with either collection tool (χ(2) = 1.5; P = 0.2). Proportion of satisfactory smears is higher when long tip plastic spatula is used for collection of sample.

  3. Coffee Stirrers and Drinking Straws as Disposable Spatulas

    Science.gov (United States)

    Turano, Morgan A.; Lobuono, Cinzia; Kirschenbaum, Louis J.

    2015-01-01

    Although metal spatulas are damaged through everyday use and become discolored and corroded by chemical exposure, plastic drinking straws are inexpensive, sterile, and disposable, reducing the risk of cross-contamination during laboratory procedures. Drinking straws are also useful because they come in a variety of sizes; narrow sample containers…

  4. 'V' shaped predens space

    International Nuclear Information System (INIS)

    Bohrer, S.P.; Klein, A.; Martin, W.

    1985-01-01

    ''V'' shaped widening of the predens space (PDS) in flexion can be a worrisome finding in traume patients, possibly representing injury to the transverse ligament. These patients may also show widening of the C-1/C-2 interspinous distance. We think this appearance is usually due to increased flexion mobility at the atlantoaxial level with developmental elongation or laxity of the cranial end of the transverse ligament and/or the posterior ligamentous complex. Tearing of only the cranial end of the transverse ligament must be extremely rare, if it occurs at all; there is no reported proven case. Tearing of only posterior ligaments seems possible and should be evaluated clinically. (orig.)

  5. Novel spatula and dissector for safer deep anterior lamellar keratoplasty

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    Gustavo ,2,3 Bonfadini

    2014-10-01

    Full Text Available Objective: We describe a novel spatula and dissector to facilitate the big-bubble technique in deep anterior lamellar keratoplasty (DALK. Methods: A 29-year-old man who was diagnosed with bilateral keratoconus underwent deep anterior lamellar keratoplasty (DALK. After 350μm partial thickness incision of the recipient cornea, the Bonfadini dissector was inserted at the deepest point in the peripheral incision and could be advanced to the center of the cornea safely because of its "semi-sharp" tip. After achieving the big-bubble (BB separation of Descemet membrane (DM from the overlying stroma, the anterior stromal disc was removed. Viscoelastic material was placed on the stromal bed to prevent uncontrolled collapse and perforation of DM during the paracentesis blade incision into the BB. We could detect the safe opening of the BB using the Bonfadini dissector by the leakage of air bubbles into the viscoelastic material. After injecting viscoelastic material into the BB space, we inserted the Bonfadini spatula into the bigbubble safely because of its curved profile and blunt edges. The groove along the length of the Bonfadini spatula enables safe and efficient incision or the residual stromal tissue using the pointed end of a sharp blade while protecting the underlying DM. After removal of posterior stroma, the donor button was sutured with 16 interrupted 10-0 nylon sutures. Results: This technique and the use of the Bonfadini spatula and dissector facilitate exposure of Descemet membrane. Conclusion: The smooth Bonfadini DALK spatula and dissector facilitate safe and efficient completion of DALK surgery.

  6. Spatula scaffold: An iris-sparing technique for lensectomy.

    Science.gov (United States)

    Narang, Priya; Agarwal, Amar

    2017-12-01

    Lensectomy with vitrectomy is often performed for crystalline lenticular subluxation. We report a new technique and a practical approach that involves the placement of a spatula beneath the iris tissue that facilitates retroiridial removal of subluxated lens and acts as a scaffold by protecting the iris tissue from being accidentally trapped into the vitrectomy cutter port. Our technique facilitates management of the lens and vitreous without any trauma to the iris and secondarily obviates the need to perform an iris repair procedure that may arise due to iatrogenic reasons.

  7. Plastic

    International Nuclear Information System (INIS)

    Jeong Gi Hyeon

    1987-04-01

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

  8. V-shaped resonators for addition of broad-area laser diode arrays

    Science.gov (United States)

    Liu, Bo; Liu, Yun; Braiman, Yehuda Y.

    2012-12-25

    A system and method for addition of broad-area semiconductor laser diode arrays are described. The system can include an array of laser diodes, a V-shaped external cavity, and grating systems to provide feedback for phase-locking of the laser diode array. A V-shaped mirror used to couple the laser diode emissions along two optical paths can be a V-shaped prism mirror, a V-shaped stepped mirror or include multiple V-shaped micro-mirrors. The V-shaped external cavity can be a ring cavity. The system can include an external injection laser to further improve coherence and phase-locking.

  9. [Low urinary tract symptoms after Thierry's spatula delivery at first pregnancy].

    Science.gov (United States)

    Provansal, M; Bretelle, F; Bannier, M; Gamerre, M; Mazouni, C

    2007-11-01

    This study was undertaken to evaluate prevalence of low urinary tract symptoms (LUTS) after Thierry's spatula delivery at first pregnancy. A retrospective study of 236 primiparous with instrumental delivery or spontaneous delivery who had delivered from January 2001 to December 2002. Low urinary tract symptoms (LUTS) were evaluated one year after delivery with a questionnaire. Incidence of LUTS was compared depending on mode of delivery. Of the 236 patients included, 88.1% replied to the questionnaire, 106 who delivered spontaneously and 102 who underwent Thierry's spatula delivery. The incidence of urinary incontinence was similar after instrumental deliveries and after spontaneous vaginal deliveries (34.9 versus 24.5%, p=0.10). In univariate analysis, symptoms of urinary urgency and urinary frequency were higher after instrumental delivery than after spontaneous delivery, respectively, 34.9 versus 22.5%, p=0.049 and 19.8 versus 8.8%, p=0.03. After controlling for confounding factors, no difference in LUTS was observed between the two groups; the respective adjusted odds-ratios (95% IC) were 1,5 (0.8-3) for urinary incontinence, 1.7 (0.9-3.5) for urgency and 2.5 (0.9-6.3) for urinary frequency. One year after delivery, one third of patients will present urinary incontinence and more than 50% will complain of bladder instability symptoms. Compared to spontaneous vaginal delivery, the use of Thierry's spatulas at first pregnancy does not induce higher risk of LUTS.

  10. Robust self-cleaning and micromanipulation capabilities of gecko spatulae and their bio-mimics

    Science.gov (United States)

    Xu, Quan; Wan, Yiyang; Hu, Travis Shihao; Liu, Tony X.; Tao, Dashuai; Niewiarowski, Peter H.; Tian, Yu; Liu, Yue; Dai, Liming; Yang, Yanqing; Xia, Zhenhai

    2015-11-01

    Geckos have the extraordinary ability to prevent their sticky feet from fouling while running on dusty walls and ceilings. Understanding gecko adhesion and self-cleaning mechanisms is essential for elucidating animal behaviours and rationally designing gecko-inspired devices. Here we report a unique self-cleaning mechanism possessed by the nano-pads of gecko spatulae. The difference between the velocity-dependent particle-wall adhesion and the velocity-independent spatula-particle dynamic response leads to a robust self-cleaning capability, allowing geckos to efficiently dislodge dirt during their locomotion. Emulating this natural design, we fabricate artificial spatulae and micromanipulators that show similar effects, and that provide a new way to manipulate micro-objects. By simply tuning the pull-off velocity, our gecko-inspired micromanipulators, made of synthetic microfibers with graphene-decorated micro-pads, can easily pick up, transport, and drop-off microparticles for precise assembling. This work should open the door to the development of novel self-cleaning adhesives, smart surfaces, microelectromechanical systems, biomedical devices, and more.

  11. Experimental Study of an SWH System with V-Shaped Plate

    Directory of Open Access Journals (Sweden)

    Jalaluddin

    2016-05-01

    Full Text Available Solar energy is known as an environmentally friendly energy source with a wide range of applications. This energy can be utilized in various applications such as domestic and industrial water heating using solar water heating (SWH systems. The thermal performance of an SWH system using a V-shaped absorber plate is presented in this study. Two SWH systems with different absorber plates, i.e. a flat-plate and a V-shaped plate, have been investigated experimentally. First, the absorptivity of the absorber plates was calculated analytically. The optimum V-shaped configuration with angle at β = 21° (V-shaped dimensions t = 4 cm and l = 4 cm was determined from various V-shaped plate absorbers based on their absorptivity and applied in the experimental study. Two SWH systems were installed and tested at a low flowrate of 0.5 L/min and at a high flowrate of 2 L/min. The results showed that the SWH system with V-shaped plate absorber had a 3.6-4.4% better performance compared with that of the system with flat-plate absorber.

  12. Investigation on the Crack Initiation of V-Shaped Notch Tip in Precision Cropping

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    Lijun Zhang

    2014-01-01

    Full Text Available The crack initiation of V-shaped notch tip has a very important influence on the cross-section quality and the cropping time for every segment of metal bar in course of low stress precision cropping. By the finite element method, the influence of machining precision of V-shaped notch bottom corner on the crack initiation location is analyzed and it is pointed out that the crack initiation point locates in the place at the maximal equivalent stress change rate on V-shaped notch surface. The judgment criterion of the crack initiation direction is presented and the corresponding crack initiation angle can be calculated by means of the displacement extrapolation method. The factual crack initiation angle of the metal bar has been measured by using the microscopic measurement system. The formula of the crack initiation life of V-shaped notch tip is built, which mainly includes the stress concentration factor of V-shaped notch, the tensile properties of metal material, and the cyclic loading conditions. The experimental results show that the obtained theoretical analyses about the crack initiation location, the crack initiation direction, and the crack initiation time in this paper are correct. It is also shown that the crack initiation time accounts for about 80% of the cropping time for every segment of the metal bar.

  13. Microstructural and geometric influences in the protective scales of Atractosteus spatula.

    Science.gov (United States)

    Sherman, Vincent R; Yaraghi, Nicholas A; Kisailus, David; Meyers, Marc A

    2016-12-01

    Atractosteus spatula has been described as a living fossil (having existed for 100 Myr), retaining morphological characteristics of early ancestors such as the ability to breathe air and survive above water for hours. Its highly effective armour consists of ganoid scales. We analyse the protective function of the scales and identify key features which lead to their resistance to failure. Microstructural features include: a twisted cross-plied mineral arrangement that inhibits crack propagation in the external ganoine layer, mineral crystals that deflect cracks in the bony region in order to activate the strength of mineralized collagen fibrils, and saw-tooth ridges along the interface between the two scale layers which direct cracks away from the intrinsically weak interface. The macroscale geometry is additionally evaluated and it is shown that the scales retain full coverage in spite of minimal overlap between adjacent scales while conforming to physiologically required strain and maintaining flexibility via a process in which adjacent rows of scales slide and concurrently reorient. © 2016 The Author(s).

  14. A comparative study of piscine defense: The scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula.

    Science.gov (United States)

    Sherman, Vincent R; Quan, Haocheng; Yang, Wen; Ritchie, Robert O; Meyers, Marc A

    2017-09-01

    We compare the characteristics of the armored scales of three large fish, namely the Arapaima gigas (arapaima), Latimeria chalumnae (coelacanth), and Atractosteus spatula (alligator gar), with specific focus on their unique structure-mechanical property relationships and their specialized ability to provide protection from predatory pressures, with the ultimate goal of providing bio-inspiration for manmade materials. The arapaima has flexible and overlapping cycloid scales which consist of a tough Bouligand-type arrangement of collagen layers in the base and a hard external mineralized surface, protecting it from piranha, a predator with extremely sharp teeth. The coelacanth has overlapping elasmoid scales that consist of adjacent Bouligand-type pairs, forming a double-twisted Bouligand-type structure. The collagenous layers are connected by collagen fibril struts which significantly contribute to the energy dissipation, so that the scales have the capability to defend from predators such as sharks. The alligator gar has inflexible articulating ganoid scales made of a hard and highly mineralized enamel-like outer surface and a tough dentine-like bony base, which resist powerful bite forces of self-predation and attack by alligators. The structural differences between the three scales correspond with the attack of their predators, and show refined mechanisms which may be imitated and incorporated into superior bioinspired and biomimetic designs that are specialized to resist specific modes of predation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Simulation of auroral current sheet equilibria and associated V-shaped potential structures

    International Nuclear Information System (INIS)

    Singh, N.; Thiemann, H.; Schunk, R.W.

    1983-01-01

    Results from numerical simulations of auroral current sheet equilibrium and associated V-shaped potential structures are presented. It is shown that with allowance for both hot magnetospheric ion and cold ionospheric ion populations, the perpendicular potential drop, assiciated with a non-neutral auroral current sheet is critically controlled by the temperature of the 'heated' ionospheric ions. The heating is caused by the wave turbulence excited by the auroral current sheet. In the presence of heated ionospheric ions, a relatively large variation in the temperature of the hot magnetospheric ion population causes a very small variation in the potential drop thetam. The perpendicular potential drop acts to produce a V-shaped double layer with multiple potential steps parallel to the magnetic field when a zero potential boundary condition is imposed at the ionospheric boundary. Outside the V-shaped potential structure, ionospheric return currents develop self-consistently

  16. Size-dependent modification of asteroid family Yarkovsky V-shapes

    Science.gov (United States)

    Bolin, B. T.; Morbidelli, A.; Walsh, K. J.

    2018-04-01

    Context. The thermal properties of the surfaces of asteroids determine the magnitude of the drift rate cause by the Yarkovsky force. In the general case of Main Belt asteroids, the Yarkovsky force is indirectly proportional to the thermal inertia, Γ. Aim. Following the proposed relationship between Γ and asteroid diameter D, we find that asteroids' Yarkovsky drift rates might have a more complex size dependence than previous thought, leading to a curved family V-shape boundary in semi-major axis, a, vs. 1/D space. This implies that asteroids are drifting faster at larger sizes than previously considered decreasing on average the known ages of asteroid families. Methods: The V-Shape curvature is determined for >25 families located throughout the Main Belt to quantify the Yarkovsky size-dependent drift rate. Results: We find that there is no correlation between family age and V-shape curvature. In addition, the V-shape curvature decreases for asteroid families with larger heliocentric distances suggesting that the relationship between Γ and D is weaker in the outer MB possibly due to homogenous surface roughness among family members.

  17. Isolation and characterization of microsatellite loci for alligator gar (Atractosteus spatula) and their variability in two other species (Lepisosteus oculatus and L. osseus) of Lepisosteidae

    Science.gov (United States)

    Moyer, G.R.; Sloss, Brian L.; Kreiser, B.R.; Feldheim, K.A.

    2009-01-01

    We report on the isolation of 17 polymorphic microsatellite loci from alligator gar (Atractosteus spatula), a large-bodied species that has experienced population declines across much of its range. These loci possessed 2-19 alleles and observed heterozygosities of 0-0.974. All loci conformed to Hardy-Weinberg equilibrium expectations, and none exhibited linkage disequilibrium. Nine and eight of these loci were found to be polymorphic in the related species Lepisosteus oculatus and L. osseus, respectively. These microsatellite loci should prove useful in conservation efforts of A. spatula through the study of population structure and hatchery broodstock management. ?? 2009 Blackwell Publishing Ltd.

  18. Broadband manipulation of refracted wavefronts by gradient acoustic metasurface with V-shape structure

    Science.gov (United States)

    Lan, Jun; Li, Yifeng; Liu, Xiaozhou

    2017-12-01

    We present a space folding acoustic metasurface with a V-shaped structure, which exhibits ultra-broadband and high efficiency transmission compared to previously investigated space folding metasurfaces. The proposal employs a gradient refractive index profile to redirect the refracted wave arbitrarily and an existence of air channels with direct sound propagation to improve impedance matching between the metasurface and the background medium. As expected from frequency-independent generalized Snell's law, the demonstrated acoustic metasurface can steer refracted wavefronts at will, including anomalous refraction, non-diffracting Bessel beam, sub-wavelength flat lens, and conversion of the propagating wave into the surface wave. The designed V-shape metasurface overcomes the limitation of narrowband, which may offer potential applications in medical ultrasound imaging and broadband acoustical devices.

  19. Optical second harmonic generation from V-shaped chromium nanohole arrays

    Science.gov (United States)

    Khoa Quang, Ngo; Miyauchi, Yoshihiro; Mizutani, Goro; Charlton, Martin D.; Chen, Ruiqi; Boden, Stuart; Rutt, Harvey

    2014-02-01

    We observed rotational anisotropy of optical second harmonic generation (SHG) from an array of V-shaped chromium nanoholes fabricated by electron beam lithography. Phenomenological analysis indicated that the effective nonlinear susceptibility element \\chi _{313}^{(2)} had a characteristic contribution to the observed anisotropic SHG intensity patterns. Here, coordinate 1 is in the direction of the tip of V shapes in the substrate plane, and 3 indicates the direction perpendicular to the sample surface. The SHG intensity for the S-polarized output light was very weak, probably owing to the cancellation effect of the image dipoles generated at the metal-air boundary. The possible origin of the observed nonlinearity is discussed in terms of the susceptibility elements obtained.

  20. Adaptive feature selection using v-shaped binary particle swarm optimization.

    Science.gov (United States)

    Teng, Xuyang; Dong, Hongbin; Zhou, Xiurong

    2017-01-01

    Feature selection is an important preprocessing method in machine learning and data mining. This process can be used not only to reduce the amount of data to be analyzed but also to build models with stronger interpretability based on fewer features. Traditional feature selection methods evaluate the dependency and redundancy of features separately, which leads to a lack of measurement of their combined effect. Moreover, a greedy search considers only the optimization of the current round and thus cannot be a global search. To evaluate the combined effect of different subsets in the entire feature space, an adaptive feature selection method based on V-shaped binary particle swarm optimization is proposed. In this method, the fitness function is constructed using the correlation information entropy. Feature subsets are regarded as individuals in a population, and the feature space is searched using V-shaped binary particle swarm optimization. The above procedure overcomes the hard constraint on the number of features, enables the combined evaluation of each subset as a whole, and improves the search ability of conventional binary particle swarm optimization. The proposed algorithm is an adaptive method with respect to the number of feature subsets. The experimental results show the advantages of optimizing the feature subsets using the V-shaped transfer function and confirm the effectiveness and efficiency of the feature subsets obtained under different classifiers.

  1. Yarkovsky effect and V-shapes: New method to compute family ages

    Science.gov (United States)

    Spoto, F.; Milani, A.; Cellino, A.; Knezevic, Z.; Novakovic, B.; Paolicchi, P.

    2014-07-01

    The computation of family ages is a high-priority goal. As a matter of principle, it can be achieved by using V-shape plots for the families old enough to have the Yarkovsky effect dominating the spread of the proper a and large enough for a statistically significant analysis of the shape. By performing an asteroid family classification with a very enlarged dataset, the results are not just ''more families'', but there are interesting qualitative changes. These are due to the large-number statistics, but also to the larger fraction of smaller objects contained in recently numbered asteroids. We are convinced that our method is effective in adding many smaller asteroids to the core families. As a result, we have a large number of families with very well defined V-shapes, thus with a good possibility of age estimation. We have developed our method to compute ages, which we believe is better than those used previously because it is more objective. Since there are no models for error in absolute magnitude H and for albedo, we have also developed a model of the error in the inverse of the diameter and then we have performed a weighted least-squares fit. We report at least 5/6 examples of dynamical families for which the computation of the V-shape is possible. These examples show the presence of different internal structure of the families, e.g., in the dynamical family of (4) Vesta, we have found two collisional families. The main problem in estimating the ages is the calibration. The difficulty in the Yarkovsky calibration, due to the need to extrapolate from near-Earth asteroids (NEAs) with measured da/dt to main-belt asteroids, is in most cases the main limitation to the accuracy of the age estimation. We obtain an age estimation by scaling the results for the NEA for which there is the best Yarkovsky effect determination, namely (101955) Bennu.

  2. A 'V' shaped superconducting levitation module for lift and guidance of a magnetic transportation system

    International Nuclear Information System (INIS)

    D'Ovidio, G.; Crisi, F.; Lanzara, G.

    2008-01-01

    A novel, YBCO based, magnetic transportation system (MagTranS) is presented and described. The feasibility of this system has been successfully tested and confirmed in a laboratory using a scaled demonstrator system. The MagTranS levitation system uses a stable, self-balancing 'V' shaped superconducting module for both lift and guidance of vehicles. The work concept of the MagTranS levitation module is described and differences with regards to the maglev current systems are highlighted. The results of levitation tests performed using a measurement set-up are presented and discussed. Lastly, levitation module performance studies are also carried out using numerical finite element analysis

  3. Enhance heat transfer in the channel with V-shaped wavy lower plate using liquid nanofluids

    Directory of Open Access Journals (Sweden)

    Azher M. Abed

    2015-03-01

    Full Text Available The heat transfer and flow characteristics in corrugated with V-shape lower plate using nanofluids are numerically studied. The computations are performed on uniform heat flux over a range of Reynolds number (Re 8000–20,000. The governing equations are numerically solved in the domain by a finite volume method (FVM using the k–ε standard turbulent model. Studies are carried out for different types of nanoparticles Al2O3,CuO, SiO2 and ZnO with different volume fractions in the range of 0–4%. Three different types of base fluid (water, glycerin, ethylene glycol are also examined. Results indicated that the average Nusselt number for nanofluids is greater than that of the base liquid. The SiO2 nanofluid yields the best heat transfer enhancement among all other type of nanofluids. Heat transfer enhancement increase with increases the volumetric concentration, but it is accompanied by increasing pressure drop values. Moreover, the average Nusselt number increases with an increase in Reynolds number and volume concentration. The SiO2–glycerin nanofluid has the highest Nusselt number compared with other base fluids. The present study shows that these V-shaped wavy channels have advantages by using nanofluids and thus serve as promising candidates for incorporation into efficient heat transfer devices.

  4. Kinetic mechanism of V-shaped twinning in 3C/4H-SiC heteroepitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Bin; Zhang, Yu-Ming; Jia, Ren-Xu, E-mail: rxjia@mail.xidian.edu.cn [School of Microelectronics, Xidian University, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xi' an 710071 (China); Wu, Hong-Ming [Graduate Institute of Electronics Engineering, National Taiwan University, 10617 Taipei, Taiwan (China); Feng, Zhe Chuan [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 10617 Taipei, Taiwan and Laboratory of Optoelectronic Materials and Detection Technology, Guangxi Key Laboratory for the Relativistic Astrophysics, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Lin, Hao-Hsiung [Graduate Institute of Electronics Engineering, National Taiwan University, 10617 Taipei, Taiwan and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 10617 Taipei, Taiwan (China)

    2016-05-15

    The authors investigated the kinetic mechanism of V-shaped twinning in 3C/4H-SiC heteroepitaxy. A fourfold V-shaped twinning complex was found, and its interface was measured with high-resolution transmission electron microscopy (HRTEM). Two linear coherent boundaries and a nonlinear incoherent boundary (also called the double-position boundary) were observed. On the basis of the HRTEM results, the authors proposed an adatom migration growth model, in which the activation barrier at the coherent boundary is much lower than that at the incoherent boundary. From a kinetic perspective, adatoms are prone to migrate to the side of the boundary with the lower potential energy if they have sufficient thermal energy to overcome the activation barrier. In the case of a coherent boundary, the growth rates of the domains either side of the boundary can be balanced through the intermigration of adatoms, leading to a linear boundary. Conversely, it is difficult for adatoms to migrate across an incoherent boundary, which results in asynchronous growth rates and a nonlinear boundary.

  5. Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

    Science.gov (United States)

    Lin, He; Brivio, Gian Paolo; Floreano, Luca; Fratesi, Guido

    2015-01-01

    Summary By first-principle simulations we study the effects of molecular deformation on the electronic and spectroscopic properties as it occurs for pentacene adsorbed on the most stable site of Al(001). The rationale for the particular V-shaped deformed structure is discussed and understood. The molecule–surface bond is made evident by mapping the charge redistribution. Upon X-ray photoelectron spectroscopy (XPS) from the molecule, the bond with the surface is destabilized by the electron density rearrangement to screen the core hole. This destabilization depends on the ionized carbon atom, inducing a narrowing of the XPS spectrum with respect to the molecules adsorbed hypothetically undistorted, in full agreement to experiments. When looking instead at the near-edge X-ray absorption fine structure (NEXAFS) spectra, individual contributions from the non-equivalent C atoms provide evidence of the molecular orbital filling, hybridization, and interchange induced by distortion. The alteration of the C–C bond lengths due to the V-shaped bending decreases by a factor of two the azimuthal dichroism of NEXAFS spectra, i.e., the energy splitting of the sigma resonances measured along the two in-plane molecular axes. PMID:26734516

  6. Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001

    Directory of Open Access Journals (Sweden)

    Anu Baby

    2015-11-01

    Full Text Available By first-principle simulations we study the effects of molecular deformation on the electronic and spectroscopic properties as it occurs for pentacene adsorbed on the most stable site of Al(001. The rationale for the particular V-shaped deformed structure is discussed and understood. The molecule–surface bond is made evident by mapping the charge redistribution. Upon X-ray photoelectron spectroscopy (XPS from the molecule, the bond with the surface is destabilized by the electron density rearrangement to screen the core hole. This destabilization depends on the ionized carbon atom, inducing a narrowing of the XPS spectrum with respect to the molecules adsorbed hypothetically undistorted, in full agreement to experiments. When looking instead at the near-edge X-ray absorption fine structure (NEXAFS spectra, individual contributions from the non-equivalent C atoms provide evidence of the molecular orbital filling, hybridization, and interchange induced by distortion. The alteration of the C–C bond lengths due to the V-shaped bending decreases by a factor of two the azimuthal dichroism of NEXAFS spectra, i.e., the energy splitting of the sigma resonances measured along the two in-plane molecular axes.

  7. A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint.

    Science.gov (United States)

    Li, Xiaoniu; Yao, Zhiyuan; Yang, Mojian

    2017-06-01

    A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint is proposed in this paper. The motor is comprised of a V-shaped transducer, a slider, a clamp, and a base. The V-shaped transducer consists of two piezoelectric beams connected through a flexible joint to form an appropriate coupling angle. The V-shaped motor is operated in the coupled longitudinal-bending mode. Longitudinal and bending movements are transferred by the flexible joint between the two beams. Compared with the coupled longitudinal-bending mode of the single piezoelectric beam or the symmetrical and asymmetrical modes of the previous V-shaped transducer, the coupled longitudinal-bending mode of the V-shaped transducer with a flexible joint provides higher vibration efficiency and more convenient mode conformance adjustment. A finite element model of the V-shaped transducer is created to numerically study the influence of geometrical parameters and to determine the final geometrical parameters. In this paper, three prototypes were then fabricated and experimentally investigated. The modal test results match well with the finite element analysis. The motor mechanical output characteristics of three different coupling angles θ indicate that V-90 (θ = 90°) is the optimal angle. The mechanical output experiments conducted using the V-90 prototype (Size: 59.4 mm × 30.7 mm × 4 mm) demonstrate that the maximum unloaded speed is 1.2 m/s under a voltage of 350 Vpp, and the maximum output force is 15 N under a voltage of 300 Vpp. The proposed novel V-shaped linear ultrasonic motor has a compact size and a simple structure with a large thrust-weight ratio (0.75 N/g) and high speed.

  8. Neural Models for the Broadside-Coupled V-Shaped Microshield Coplanar Waveguides

    Science.gov (United States)

    Guney, K.; Yildiz, C.; Kaya, S.; Turkmen, M.

    2006-09-01

    This article presents a new approach based on multilayered perceptron neural networks (MLPNNs) to calculate the odd-and even-mode characteristic impedances and effective permittivities of the broadside-coupled V-shaped microshield coplanar waveguides (BC-VSMCPWs). Six learning algorithms, bayesian regulation (BR), Levenberg-Marquardt (LM), quasi-Newton (QN), scaled conjugate gradient (SCG), resilient propagation (RP), and conjugate gradient of Fletcher-Powell (CGF), are used to train the MLPNNs. The neural results are in very good agreement with the results reported elsewhere. When the performances of neural models are compared with each other, the best and worst results are obtained from the MLPNNs trained by the BR and CGF algorithms, respectively.

  9. Controllable V-Shape Multi-Scroll Butterfly Attractor: System and Circuit Implementation

    KAUST Repository

    Zidan, Mohammed A.

    2012-07-23

    In this paper, a new controllable V-shape multiscroll attractor is presented, where a variety of symmetrical and unsymmetrical attractors with a variable number of scrolls can be controlled using new staircase nonlinear function and the parameters of the system. This attractor can be used to generate random signals with a variety of symbol distribution. Digital implementation of the proposed generator is also presented using a Xilinx Virtex® 4 Field Programmable Gate Array and experimental results are provided. The digital realization easily fits into a small area (<1.5% of the total area) and expresses a high throughput (4.3 Gbit/sec per state variable). © 2012 World Scientific Publishing Company.

  10. Controllable V-Shape Multi-Scroll Butterfly Attractor: System and Circuit Implementation

    KAUST Repository

    Zidan, Mohammed A.; Radwan, Ahmed G.; Salama, Khaled N.

    2012-01-01

    In this paper, a new controllable V-shape multiscroll attractor is presented, where a variety of symmetrical and unsymmetrical attractors with a variable number of scrolls can be controlled using new staircase nonlinear function and the parameters of the system. This attractor can be used to generate random signals with a variety of symbol distribution. Digital implementation of the proposed generator is also presented using a Xilinx Virtex® 4 Field Programmable Gate Array and experimental results are provided. The digital realization easily fits into a small area (<1.5% of the total area) and expresses a high throughput (4.3 Gbit/sec per state variable). © 2012 World Scientific Publishing Company.

  11. Nonorthogonality analysis of a thermoacoustic system with a premixed V-shaped flame

    International Nuclear Information System (INIS)

    Ji, Chenzhen; Zhao, Dan; Li, Xinyan; Li, Shihuai; Li, Junwei

    2014-01-01

    Highlights: • Nonorthogonality analysis of a choked thermoacoustic system is conducted. • A thermoacoustic model of a premixed V-shaped flame is developed. • Nonorthogonality is identified to arise from the boundary condition and the flame. • The contribution from the flame is shown to play a dominant role. • Eigenmodes nonorthogonality leads to transient growth of acoustic disturbances. - Abstract: Thermoacoustic instability occurs in many combustion systems, such as aero-engine afterburners, rocket motors, ramjets and gas turbines. It most often arises due to the coupling between unsteady heat release and acoustic waves. In this work, nonorthogonality analysis of a choked combustor with a gutter confined is conducted. Such configuration is used as a simplified model of the afterburner of an aero-engine. A thermoacoustic model is developed first to study the nonnormal interaction between acoustic disturbances and a premixed V-shaped flame anchored to the tip of the gutter. Eigenmode nonorthogonality analysis is then conducted. The thermoacoustic system is shown to be nonnormal and characterized by nonorthogonal eigenmodes. The nonorthogonality is identified to arise from both the complex boundary condition and the monopole-like flame. However, the contribution from the Robin-type boundary is approximately 1.5% of that from the flame. Thus the flame is identified to play a dominant role. One practical conclusions is that acoustic disturbances undergo transient growth in a combustion system with nonorthogonal eigenmodes. Such finite-time growth, which cannot be predicted by using classical linear theory might trigger high-amplitude self-sustained oscillations

  12. New 3-D coordination polymers based on semi-rigid V-shape tetracarboxylates

    International Nuclear Information System (INIS)

    Huang, Jing-Jing; Xu, Wei; Wang, Yan-Ning; Yu, Jie-Hui; Zhang, Ping; Xu, Ji-Qing

    2015-01-01

    Under the hydrothermal conditions, the reactions of transition-metal salts, tetracarboxylic acids and N,N′-donor ligands yielded three new coordination polymers as [Cu 4 (fph) 2 (bpe) 3 (H 2 O) 2 ]·2H 2 O (fph=4,4′-(hexafluoroisopropylidene)diphthalate, bpe=1,2-bis(pyridyl)ethylene) 1, [Co 2 (fph)(bpa) 2 (H 2 O) 2 ]·3H 2 O (bpa=1,2-bis(pyridyl)ethylane) 2, and [Ni(H 2 O)(H 2 oph)(bpa)] (oph=4,4′-oxydiphthalate) 3. X-ray single-crystal diffraction analysis revealed that the title three compounds all possess the three-dimensional (3-D) network structures. For compound 1, the fph molecules first link the Cu 2+ ions into a two-dimensional (2-D) wave-like layer with a (4,4) topology. The bpe molecules act as the second linkers, extending the 2-D layers into a 3-D network. For compound 2, the fph molecules still serve as the first connectors, linking the Co 2+ ions into a one-dimensional (1-D) tube-like chain. Then the bpa molecules propagate the chains into a 3-D (4,4,4)-connected network. In the formation of the 3-D network of compound 3, the oph molecule does not play a role. The bpa molecules as well as the water molecules act as a mixed bridge. Only a kind of 4-connected metal node is observed in compound 3. The magnetic properties of compounds 1–3 were investigated and all exhibit the predominant antiferromegnetic magnetic behaviors. - Graphical abstract: Structures of three semi-rigid V-shape tetracarboxylate-based coordination polymers were reported, and their magnetic properties were investigated. - Highlights: • Structures of three tetracarboxylate-based coordination polymers were reported. • Role of organic bases in metal–tetracarboxylate compounds was discussed. • Characters of V-shape and semi-rigidity for tetracarboxylate play a key role in crystal growth. • Their magnetic properties were investigated

  13. New 3-D coordination polymers based on semi-rigid V-shape tetracarboxylates

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jing-Jing; Xu, Wei; Wang, Yan-Ning [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023, Jilin (China); State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Qianjin Road 2699, Changchun 130012, Jilin (China); Yu, Jie-Hui, E-mail: jhyu@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023, Jilin (China); State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Qianjin Road 2699, Changchun 130012, Jilin (China); Zhang, Ping, E-mail: zhangping@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023, Jilin (China); Xu, Ji-Qing [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023, Jilin (China); State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Qianjin Road 2699, Changchun 130012, Jilin (China)

    2015-03-15

    Under the hydrothermal conditions, the reactions of transition-metal salts, tetracarboxylic acids and N,N′-donor ligands yielded three new coordination polymers as [Cu{sub 4}(fph){sub 2}(bpe){sub 3}(H{sub 2}O){sub 2}]·2H{sub 2}O (fph=4,4′-(hexafluoroisopropylidene)diphthalate, bpe=1,2-bis(pyridyl)ethylene) 1, [Co{sub 2}(fph)(bpa){sub 2}(H{sub 2}O){sub 2}]·3H{sub 2}O (bpa=1,2-bis(pyridyl)ethylane) 2, and [Ni(H{sub 2}O)(H{sub 2}oph)(bpa)] (oph=4,4′-oxydiphthalate) 3. X-ray single-crystal diffraction analysis revealed that the title three compounds all possess the three-dimensional (3-D) network structures. For compound 1, the fph molecules first link the Cu{sup 2+} ions into a two-dimensional (2-D) wave-like layer with a (4,4) topology. The bpe molecules act as the second linkers, extending the 2-D layers into a 3-D network. For compound 2, the fph molecules still serve as the first connectors, linking the Co{sup 2+} ions into a one-dimensional (1-D) tube-like chain. Then the bpa molecules propagate the chains into a 3-D (4,4,4)-connected network. In the formation of the 3-D network of compound 3, the oph molecule does not play a role. The bpa molecules as well as the water molecules act as a mixed bridge. Only a kind of 4-connected metal node is observed in compound 3. The magnetic properties of compounds 1–3 were investigated and all exhibit the predominant antiferromegnetic magnetic behaviors. - Graphical abstract: Structures of three semi-rigid V-shape tetracarboxylate-based coordination polymers were reported, and their magnetic properties were investigated. - Highlights: • Structures of three tetracarboxylate-based coordination polymers were reported. • Role of organic bases in metal–tetracarboxylate compounds was discussed. • Characters of V-shape and semi-rigidity for tetracarboxylate play a key role in crystal growth. • Their magnetic properties were investigated.

  14. Device Modeling of the Performance of Cu(In,GaSe2 Solar Cells with V-Shaped Bandgap Profiles

    Directory of Open Access Journals (Sweden)

    Shou-Yi Kuo

    2014-01-01

    Full Text Available The effect of Cu(In,GaSe2 (CIGS with V-shaped bandgap on device performance is investigated in detail. A series of Ga/(In+Ga ratio are set to study the influence of V-shaped bandgap profile on the electricity of CIGS thin film solar cells. The modeling of device current density-voltage (J-V curve and bandgap grading profile corresponded well to measurement results. Detailed characteristic and modeling results show that an increased gradient of bandgap from valley to the buffer layer CdS will result in a barrier and lead to an enhanced recombination in the valley. This phenomenon can be modified by the back electric field resulting from a gradient bandgap from valley (bandgap minimum to the Mo back contact. These results indicate CIGS-based solar cells can achieve higher performance by optimizing the V-shaped bandgap profile.

  15. Comparison of Different Turbulence Models for Numerical Simulation of Pressure Distribution in V-Shaped Stepped Spillway

    Directory of Open Access Journals (Sweden)

    Zhaoliang Bai

    2017-01-01

    Full Text Available V-shaped stepped spillway is a new shaped stepped spillway, and the pressure distribution is quite different from that of the traditional stepped spillway. In this paper, five turbulence models were used to simulate the pressure distribution in the skimming flow regimes. Through comparing with the physical value, the realizable k-ε model had better precision in simulating the pressure distribution. Then, the flow pattern of V-shaped and traditional stepped spillways was given to illustrate the unique pressure distribution using realizable k-ε turbulence model.

  16. Coherent addition of high power broad-area laser diodes with a compact VBG V-shaped external Talbot cavity

    Science.gov (United States)

    Liu, Bo; Braiman, Yehuda

    2018-05-01

    We introduced a compact V-shaped external Talbot cavity for phase locking of high power broad-area laser diodes. The length of compact cavity is ∼25 mm. Near diffraction-limit coherent addition of 10 broad-area laser diodes indicated that high quality phase locking was achieved. We measured the near-field emission mode of each individual broad-area laser diode with different feedback, such as a volume Bragg grating and a high reflection mirror. We found out that the best result of phase locking broad-area laser diodes was achieved by the compact V-shaped external Talbot cavity with volume Bragg grating feedback.

  17. Effects of Angle of Rotation on Pool Boiling Heat Transfer of V-shape Tube Bundle

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Myeong-Gie [Andong National University, Andong (Korea, Republic of)

    2016-10-15

    The most important facility for the systems is a passive heat exchanger that transfers core decay heat to the cold water in a water storage tank under atmospheric pressure. Since the space for the installation of the heat exchanger is usually limited, developing more efficient heat exchangers is important. In general, pool boiling is generated on the surface of the heat exchanging tube. The major design parameter of the heat exchanger is a tube arrangement. The upper tube is affected by the lower tube and the enhancement of the heat transfer on the upper tube is estimated by the bundle effect. Since heat transfer is related to the conditions of a tube surface, bundle geometries, and a liquid type, lots of studies have been carried out for the combinations of those parameters. An experimental study was performed to investigate the effects of the angle of rotation on pool boiling heat transfer of a V-shape tube bundle. For the test, two smooth stainless steel tubes of 19 mm outside diameter and the water at atmospheric pressure were used. The enhancement of the heat transfer is clearly observed when the angle becomes to 90° where the upper tube has the maximum region of influence by the lower tube. The convective flow and liquid agitation enhance heat transfer while the coalescence of the bubbles deteriorates heat transfer.

  18. Design of mulitlevel OLF approach ("V"-shaped decompressive laminoplasty) based on 3D printing technology.

    Science.gov (United States)

    Ling, Qinjie; He, Erxing; Ouyang, Hanbin; Guo, Jing; Yin, Zhixun; Huang, Wenhua

    2017-07-27

    To introduce a new surgical approach to the multilevel ossification of the ligamentum flavum (OLF) aided by three-dimensional (3D) printing technology. A multilevel OLF patient (male, 66 years) was scanned using computed tomography (CT). His saved DICOM format data were inputted to the Mimics14.0 3D reconstruction software (Materialise, Belgium). The resulting 3D model was used to observe the anatomical features of the multilevel OLF area and to design the surgical approach. At the base of the spinous process, two channels were created using an osteotomy bilaterally to create a "V" shape to remove the bone ligamentous complex (BLC). The decompressive laminoplasty using mini-plate fixation was simulated with the computer. The physical model was manufactured using 3D printing technology. The patient was subsequently treated using the designed surgery. The operation was completed successfully without any complications. The operative time was 90 min, and blood loss was 200 ml. One month after the operation, neurologic function was recovered well, and the JOA score was improved from 6 preoperatively to 10. Postoperative CT scanning showed that the OLF was totally removed, and the replanted BLC had not subsided. 3D printing technology is an effective, reliable, and minimally invasive method to design operations. The technique can be an option for multilevel OLF surgical treatment. This can provide sufficient decompression with minimum damage to the spine and other intact anatomical structures.

  19. The measurement of neutral beam thermal profiles on 'V'-shaped calorimeters

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Lagin, L.J.; Silber, K.

    1995-01-01

    It is customary in high power neutral beam systems to use a V-shaped calorimeter to stop and measure the beam. With proper instrumentation, it is possible to determine both the neutral beam power and divergence. By utilizing a near-grazing angle of incidence, the area over which the beam is in contact with the surface is increased, thereby decreasing the power density over the case of normal incidence. Thermocouples on the back of the calorimeter, in conjunction with real time fitting algorithms, are used to deduce the divergence from the thermal profile. This measurement implicitly assumes that the measured profile corresponds to that of the incident beam. It is shown that such is not the case. Energetic particle reflection at near-grazing angle causes the thermal profile on the calorimeter to be more peaked than the incident distribution. The implications of this on the non-linear multiple regression technique of determining the divergence are discussed. With the aid of a reflection model, developed and applied to the beam from a typical TFTR ion source, it is shown that a peaked power density can be modelled. Neural networks are being studied as a means of supplanting the older regression technique of measuring divergence. Y-direction divergences have been successfully derived using a one-dimensional neural network

  20. Feasibility study of a V-shaped pipe for passive aeration composting.

    Science.gov (United States)

    Ogunwande, Gbolabo A

    2011-03-01

    A V-shaped (Vs) pipe was improvised for composting of chicken litter in passive aeration piles. Three piles, equipped with horizontal (Ho), vertical (Ve) and Vs pipes were set up. The three treatments were replicated thrice. The effects of the aeration pipe on the physico-chemical properties of chicken litter and air distribution within the composting piles were investigated during composting. The properties monitored were temperature, pH, electrical conductivity, moisture content, total carbon, total nitrogen, total phosphorus and carbon-to-nitrogen ratio. Moisture level in the piles was replenished fortnightly to 60% during composting. The results of the study showed that all the piles attained the optimum temperature range (40-65°C) for effective composting and satisfied the requirements for sanitation. The non-significant (p > 0.05) temperature difference within the piles with Ve and Vs pipes indicated that these pipes were effective for uniform air distribution within the pile. The aeration pipe had significant (p ≤ 0.05) effect on pile temperature, pre-replenishment moisture content, pH and total phosphorus. In conclusion, the study showed that the Vs pipe is feasible and effective for passive aeration composting.

  1. Stability analysis of confined V-shaped flames in high-velocity streams.

    Science.gov (United States)

    El-Rabii, Hazem; Joulin, Guy; Kazakov, Kirill A

    2010-06-01

    The problem of linear stability of confined V-shaped flames with arbitrary gas expansion is addressed. Using the on-shell description of flame dynamics, a general equation governing propagation of disturbances of an anchored flame is obtained. This equation is solved analytically for V-flames anchored in high-velocity channel streams. It is demonstrated that dynamics of the flame disturbances in this case is controlled by the memory effects associated with vorticity generated by the perturbed flame. The perturbation growth rate spectrum is determined, and explicit analytical expressions for the eigenfunctions are given. It is found that the piecewise linear V structure is unstable for all values of the gas expansion coefficient. Despite the linearity of the basic pattern, however, evolutions of the V-flame disturbances are completely different from those found for freely propagating planar flames or open anchored flames. The obtained results reveal strong influence of the basic flow and the channel walls on the stability properties of confined V-flames.

  2. Experimental Investigation of Thermohydraulic Performance of a Rectangular Solar Air Heater Duct Equipped with V-Shaped Perforated Blocks

    Directory of Open Access Journals (Sweden)

    Tabish Alam

    2014-01-01

    Full Text Available This paper presents the thermohydraulic performance of rectangular solar air heater duct equipped with V-shaped rectangular perforated blocks attached to the heated surface. The V-shaped perforated blocks are tested for downstream (V-down to the air flow at Reynolds number from 2000 to 20000. The perforated blocks have relative pitch ratio (P/e from 4 to 12, relative blockage height ratio (e/H from 0.4 to 1.0, and open area ration from 5% to 25% at a fixed value of angle of attack of 60∘ in a rectangular duct having duct aspect ratio (W/H of 12. Thermohydraulic performance is compared at different geometrical parameters of V-shaped perforated blocks for equal pumping power which shows that maximum performance is observed at a relative pitch of 8, relative rib height of 0.8, and open area ration of 20%. It is also observed that the performance of V-shaped perforated blocks was better than transverse-perforated blocks.

  3. [EFFECTIVENESS OF ADVANCED SKIN FLAP AND V-SHAPED VENTRAL INCISION ALONG THE ROOT OF PENILE SHAFT FOR CONCEALED PENIS].

    Science.gov (United States)

    Lin, Junshan; Li, Dumiao; Zhang, Jianxing; Wu, Qiang; Xu, Yali; Lin, Li

    2015-09-01

    To investigate effectiveness of advanced skin flap and V-shaped ventral incision along the root of penile shaft for concealed penis in children. Between July 2007 and January 2015, 121 boys with concealed penis were treated with advanced skin flap and V-shaped ventral incision along the root of penile shaft. The age varied from 18 months to 13 years (mean, 7.2 years). Repair was based on a vertical incision in median raphe, complete degloving of penis and tacking its base to the dermis of the skin. Advanced skin flap and a V-shaped ventral incision along the root of penile shaft were used to cover the penile shaft. The operation time ranged from 60 to 100 minutes (mean, 75 minutes). Disruption of wound occurred in 1 case, and was cured after dressing change; and primary healing of incision was obtained in the others. The follow-up period ranged from 3 months to 7 years (median, 24 months). All patients achieved good to excellent cosmetic results with a low incidence of complications. The results were satisfactory in exposure of penis and prepuce appearance. No obvious scar was observed. The penis had similar appearance to that after prepuce circumcision. A combination of advanced skin flap and V-shaped ventral incision along the root of penile shaft is a simple, safe, and effective procedure for concealed penis with a similar appearance result to the prepuce circumcision.

  4. Ultrafast responses of dipolar and V-shaped dipicolinate derivatives with potential applications in the labeling of biomolecules

    Science.gov (United States)

    Wang, Yaochuan; Liu, Siyuan; Liu, Dajun; Wang, Guiqiu; Xiao, Haibo

    2016-02-01

    A dipolar dipicolinate derivative, trans-dimethyl-4-[4'-(N,N-diphenylamino)-styry1]-pyridin-2,6-dicarboxylate (P-1), and a P-1based V-shaped compound, {4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl) vinyl]}-N-phenyl-N-{4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl)vinylphenyl]}aniline (P-2), with intense two-photon fluorescence emission properties were systematically investigated by using steady-state absorption and fluorescence spectroscopy, open-aperture Z-scans, and two-photon excited fluorescence (TPF). The two-photon absorption cross-section of the V-shaped compound P-2 in tetrahydrofuran (THF) was determined to be 208 GM, which represents a 6.5-fold enhancement compared with its dipolar counterpart P-1 (32 GM). Extension of the intramolecular charge transfer (ICT) in the V-shaped dipicolinate derivative has been suggested as the mechanism of enhancement. The excited state dynamics from transient absorption spectroscopy were analyzed and discussed. The formation and relaxation lifetimes of the ICT state for these dipicolinate derivatives in THF solutions were found to be several picoseconds and several hundred picoseconds, respectively. The results show an increased ICT character of the V-shaped compound and a potential application for this compound in two-photon fluorescence imaging fields.

  5. Ultrafast responses of dipolar and V-shaped dipicolinate derivatives with potential applications in the labeling of biomolecules

    Directory of Open Access Journals (Sweden)

    Yaochuan Wang

    2016-02-01

    Full Text Available A dipolar dipicolinate derivative, trans-dimethyl-4-[4′-(N,N-diphenylamino-styry1]-pyridin-2,6-dicarboxylate (P-1, and a P-1based V-shaped compound, {4-[(E-2-(2,6-dimethoxycarbonylpyridin-4-yl vinyl]}-N-phenyl-N-{4-[(E-2-(2,6-dimethoxycarbonylpyridin-4-ylvinylphenyl]}aniline (P-2, with intense two-photon fluorescence emission properties were systematically investigated by using steady-state absorption and fluorescence spectroscopy, open-aperture Z-scans, and two-photon excited fluorescence (TPF. The two-photon absorption cross-section of the V-shaped compound P-2 in tetrahydrofuran (THF was determined to be 208 GM, which represents a 6.5-fold enhancement compared with its dipolar counterpart P-1 (32 GM. Extension of the intramolecular charge transfer (ICT in the V-shaped dipicolinate derivative has been suggested as the mechanism of enhancement. The excited state dynamics from transient absorption spectroscopy were analyzed and discussed. The formation and relaxation lifetimes of the ICT state for these dipicolinate derivatives in THF solutions were found to be several picoseconds and several hundred picoseconds, respectively. The results show an increased ICT character of the V-shaped compound and a potential application for this compound in two-photon fluorescence imaging fields.

  6. The multiple V-shaped double peeling of elastic thin films from elastic soft substrates

    Science.gov (United States)

    Menga, N.; Afferrante, L.; Pugno, N. M.; Carbone, G.

    2018-04-01

    In this paper, a periodic configuration of V-shaped double peeling process is investigated. Specifically, an elastic thin film is detached from a soft elastic material by applying multiple concentrated loads periodically distributed with spatial periodicity λ. The original Kendall's idea is extended to take into account the change in elastic energy occurring in the substrate when the detachment fronts propagate. The symmetric configuration typical of a V-peeling process causes the energy release rate to be sensitive to variations of the elastic energy stored in the soft substrate. This results in an enhancement of the adhesion strength because part of the external work required to trigger the peeling mechanism is converted in substrate elastic energy. A key role is played by both spatial periodicity λ and elasticity ratio E/Eh, between tape and substrate elastic moduli, in determining the conditions of stable adhesion. Indeed, the presence of multiple peeling fronts determines a modification of the mechanism of interaction, because deformations close to each peeling front are also affected by the stresses related to the other fronts. Results show that the energy release rate depends on the detached length of the tape so that conditions can be established which lead to an increase of the supported load compared to the classical peeling on rigid substrates. Finally, we also find that for any given value of the load per unit length, an optimum value of the wavelength λ exists that maximizes the tolerance of the system, before unstable propagation of the peeling front can occur.

  7. Parametric analysis of a solar still with inverted V-shaped glass condenser

    Directory of Open Access Journals (Sweden)

    Rubio Eduardo

    2015-01-01

    Full Text Available A parametric analysis of a solar still with an inverted V-shaped glass condenser is presented. Results are based on a new mathematical model obtained from a lumped-parameter analysis of the still, with an approach that makes each glass plate of the condensing system sensitive to orientation and depicts its thermal differences. Numerical computations are made to evaluate productivity and temperature differences between the condensing plates as a function of condenser orientation, extinction coefficient and thickness. From this study it was found a significant influence of incident solar radiation on the thermal performance of each condensing plate. Large extinction coefficients and thick glass plates increase absorption losses that result in an appreciable temperature difference. An extinction coefficient of 40 m-1 produces a temperature difference of 2.5°C between both condensers. A glass thickness of 10 mm may increase this temperature difference up to 3.5°C. With respect to the production, due to the still orientation, a difference of 8.7% was found for the condensing plates facing an east-west direction. The proposed model is able to reproduce the temperature and distillate production differences that arise between both condensers in good agreement with experimental data. The overall performance of the still, studied with this new approach, was also in accordance with the widely used traditional models for solar distillation. In addition, the condensing plates parameters of the still can be used to force a differential heating such that for the whole day the temperature of one condensing plate is always higher.

  8. Downstream Fining of Polydispersed Gravity Currents Along a V-Shaped Valley.

    Science.gov (United States)

    Besson, C. K.; Meriaux, C. A. M. D.

    2014-12-01

    Turbidity currents belong to the class of currents transporting sediments, whose deposits exhibit downstream grain size fining. In this study, the objective was to better understand the relationship between downstream fining and grain sizes at the source. To this end, we performed four lock-exchange experiments of polydispersed and turbulent gravity currents flowing along a 5-m long V-shaped valley. The particle volumetric concentrations were typically 3%. The four currents were made of 1) Silicon Carbide (SiC), 2) Glass Beads (GBs), 3) a combined poorly sorted SiC/GBs, and 4) a moderately sorted combined SiC/GBs. We used the Morphologi G3 tool developed by Malvern Instruments Corporate (Malvern Instruments Ltd, UK) for the grain size analyses. We first established a criterion for identifying the appropriate number of grain size classes nbclassfor characterizing the grain size distributions. We considered the four statistical indicators that are the arithmetic mean size dmean, the standard deviation σd, the skewness Skd, and the kurtosis Kd, and show that the four indicators for the initial grain size distributions reach plateaux when nb_class≥ 20. Hence we chose nbclass=20 as being our appropriate bin width. These four indicators were then calculated for samples taken along the deposits to establish the grain size distributions along the deposits. The subsequent profiles of dmean, σd, Skd, and Kd with distance from the lock show highly variable behaviours between the different initial distributions. In particular, the distance over which the loss of the largest grains of the initial distribution occurs [dmean> dmean(initial)], can cover up to half the runout length. Curiously, the different rates of fining estimated from the curves (dmean/ dmean(initial)) as a function of downstream distance (x/x_runout) do not appear to be well correlated with the sedimentation velocities based on dmean(initial). This is currently being investigated.

  9. Protocol for the trismus trial-therabite versus wooden spatula in the amelioration of trismus in patients with head and neck cancer: randomised pilot study.

    Science.gov (United States)

    Lee, Rana; Molassiotis, Alex; Rogers, Simon N; Edwards, Rhiannon Tudor; Ryder, David; Slevin, Nick

    2018-03-30

    Patients can develop trismus from their head and neck cancer or as a result of treatment. Trismus affects the jaw muscles and makes mouth opening difficult. To potentially combat trismus, patients could undertake proactive jaw stretching exercises prior to, during and after radiotherapy, although currently these are not the standard of care. This is a randomised, open-label, controlled, two-centre feasibility study, to assess the objective and subjective effectiveness and cost-effectiveness of therabite use compared with wooden spatula in ameliorating trismus in patients treated for stage 3 and 4 oral and oropharyngeal cancer, managed either by primary surgery followed by (chemo)radiotherapy or primary (chemo)radiotherapy. The principal objective assessment is measurement of maximum jaw opening. Assessments in all cases will be performed preradiotherapy and again at 3 and 6 months postintervention.Secondary aims of the study will be (1) to assess whether therabite or the wooden spatula intervention improves patients' quality of life, (2) reduce the level of post-treatment clinical management/healthcare use and (3) a nested qualitative study will explore the experience of the patient taking part in the intervention; data will be transcribed verbatim and analysis will be based on content analysis methods using the interview questions as the framework for examination. North West Greater Manchester granted ethical approval (REC Reference 11/NW/0744). Good Clinical Practice and the Declaration of Helsinki have been adhered to. The results will be presented internationally and submitted to a peer-reviewed journal. Head and neck cancer charities and information websites will also be approached. NCT01733797. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. Ultra-small v-shaped gold split ring resonators for biosensing using fundamental magnetic resonance in the visible spectrum

    Science.gov (United States)

    Mauluidy Soehartono, Alana; Mueller, Aaron David; Tobing, Landobasa Yosef Mario; Chan, Kok Ken; Zhang, Dao Hua; Yong, Ken-Tye

    2017-10-01

    Strong light localization within metal nanostructures occurs by collective oscillations of plasmons in the form of electric and magnetic resonances. This so-called localized surface plasmon resonance (LSPR) has gained much interest in the development of low-cost sensing platforms in the visible spectrum. However, demonstrations of LSPR-based sensing are mostly limited to electric resonances due to the technological limitations for achieving magnetic resonances in the visible spectrum. In this work, we report the first demonstration of LSPR sensing based on fundamental magnetic resonance in the visible spectrum using ultrasmall gold v-shaped split ring resonators. Specifically, we show the ability for detecting adsorption of bovine serum albumin and cytochrome c biomolecules at monolayer levels, and the selective binding of protein A/G to immunoglobulin G.

  11. Thermo-hydraulic performance of solar air heater having multiple v-shaped rib roughness on absorber plates

    Directory of Open Access Journals (Sweden)

    Dhananjay Kumar

    2018-03-01

    Full Text Available This paper presents the performance analysis of the effect of geometrical parameters having multiple v-shaped rib roughness on the airflow side of the absorber plates. Mathematical approach and solution procedure for the analysis of such a solar air heater has been developed theoretically and MATLAB code generated for the solution of the mathematical equations. The effect of parameters such as flow Reynolds number and Relative roughness height on the thermohydraulic performance have been examined and compared with the conventional flat plate solar air heater. A substantial improvement in thermal efficiency of roughened solar air heater as compared to smooth one due to appreciable enhancement in heat transfer coefficient. The enhancement in heat transfer coefficient is also accompanied by a considerable enhancement in pumping power requirement due to the increase in friction factor.

  12. 10th order laterally coupled GaN-based DFB laser diodes with V-shaped surface gratings

    Science.gov (United States)

    Kang, J. H.; Wenzel, H.; Hoffmann, V.; Freier, E.; Sulmoni, L.; Unger, R.-S.; Einfeldt, S.; Wernicke, T.; Kneissl, M.

    2018-02-01

    Single longitudinal mode operation of laterally coupled distributed feedback (DFB) laser diodes (LDs) based on GaN containing 10th-order surface Bragg gratings with V-shaped grooves is demonstrated using i-line stepper lithography and inductively coupled plasma etching. A threshold current of 82 mA, a slope efficiency of 1.7 W/A, a single peak emission at 404.5 nm with a full width at half maximum of 0.04 nm and a side mode suppression ratio of > 23 dB at an output power of about 46 mW were achieved under pulsed operation. The shift of the lasing wavelength of DFB LDs with temperature was around three times smaller than that of conventional ridge waveguide LDs.

  13. Zn(II) coordination polymers with flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lin [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Chong-Bo, E-mail: cbliu@nchu.edu.cn [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Yang, Gao-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Xiong, Zhi-Qiang [Center for Analysis and Testing, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Hong [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Wen, Hui-Liang [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China)

    2015-11-15

    Hydrothermal reactions of 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H{sub 2}L) and zinc ions in the presence of N-donor ancillary ligands afford four novel coordination polymers, namely, [Zn{sub 2}(μ{sub 2}-OH)(μ{sub 4}-O){sub 0.5}(L)]·0.5H{sub 2}O (1), [Zn(L)(2,2′-bipy)(H{sub 2}O)] (2), [Zn{sub 3}(L){sub 3}(phen){sub 2}]·H{sub 2}O (3) and [Zn{sub 2}(L){sub 2}(4,4′-bipy)] (4) (2,2′-bipy=2,2′-bipyridine; 4,4′-bipy=4,4′-bipyridine; phen=1,10-phenanthroline). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Complex 1 shows a 3-D clover framework consisting of [Zn{sub 4}(µ{sub 4}-O)(µ{sub 2}-OH){sub 2}]{sup 4+} clusters, and exhibits a novel (3,8)-connected topological net with the Schläfli symbol of {3·4·5}{sub 2}{3"4·4"4·5"2·6"6·7"1"0·8"2}, and contains double-stranded and two kinds of meso-helices. 2 displays a helical chain structure, which is further extended via hydrogen bonds into a 3-D supramolecular structure with meso-helix chains. 3 displays a 2-D {4"4·6"2} parallelogram structure, which is further extended via hydrogen bonds into a 3-D supramolecular structure with single-stranded helical chains. 4 shows a 2-D {4"4·6"2} square structure with left- and right-handed helical chains. Moreover, the luminescent properties of 1–4 have been investigated. - Graphical abstract: Four new Zn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent properties have been investigated. - Highlights: • Four novel Zn(II) coordination polymers with V-shaped ligand were characterized. • Complexes 1–4 show diverse intriguing helical characters. • Fluorescence properties of complexes 1–4 were investigated.

  14. Plastic Surgery

    Science.gov (United States)

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

  15. Kaftas prepared with V-shaped filleting chips of the Nile tilapia (Oreochromis niloticus exposed to smoking techniques

    Directory of Open Access Journals (Sweden)

    Maria Luiza Rodrigues de Souza

    2015-05-01

    Full Text Available Kaftas with V-shaped filleting chips of the Nile tilapia (Oreochromis niloticus were developed and the effects of the smoking technique on the characteristics of chemical composition, microbiological, sensory and benzo(apyrene were investigated. The filleting chips were ground and filleting included condiments and bacon. Kaftas were molded, frozen and distributed in a completely randomized design with three treatments (T 1 = baked in a grid; T 2 = smoked by friction and T 3 = smoked by liquid smoke with 10 replications. The kaftas subjected to hot smoke had lower moisture content (13.97%, whereas the no-smoking kaftas had the highest content (20.49%. Kaftas with liquid smoke had high crude protein content (48.06% and ash (9.49%, whereas the ash content was different only from no-smoking kaftas (8.79%. There was no significant difference in sensory parameters, except for flavor; smoked kaftas with liquid smoke were more accepted by the judges and the worst kaftas were no-smoked kaftas. Microbiological analysis showed that kaftas developed were appropriate to feed human beings within the required standards. Chips filleting is an alternative for the development of kaftas and those subjected to liquid smoke were considered the best.

  16. Thermoresponsive Supramolecular Chemotherapy by "V"-Shaped Armed β-Cyclodextrin Star Polymer to Overcome Drug Resistance.

    Science.gov (United States)

    Fan, Xiaoshan; Cheng, Hongwei; Wang, Xiaoyuan; Ye, Enyi; Loh, Xian Jun; Wu, Yun-Long; Li, Zibiao

    2018-04-01

    Pump mediated drug efflux is the key reason to result in the failure of chemotherapy. Herein, a novel star polymer β-CD-v-(PEG-β-PNIPAAm) 7 consisting of a β-CD core, grafted with thermo-responsive poly(N-isopropylacrylamide) (PNIPAAm) and biocompatible poly(ethylene glycol) (PEG) in the multiple "V"-shaped arms is designed and further fabricated into supramolecular nanocarriers for drug resistant cancer therapy. The star polymer could encapsulate chemotherapeutics between β-cyclodextrin and anti-cancer drug via inclusion complex (IC). Furthermore, the temperature induced chain association of PNIPAAm segments facilitated the IC to form supramolecular nanoparticles at 37 °C, whereas the presence of PEG impart great stability to the self-assemblies. When incubated with MDR-1 membrane pump regulated drug resistant tumor cells, much higher and faster cellular uptake of the supramolecular nanoparticles were detected, and the enhanced intracellular retention of drugs could lead to significant inhibition of cell growth. Further in vivo evaluation showed high therapeutic efficacy in suppressing drug resistant tumor growth without a significant impact on the normal functions of main organs. This work signifies thermo-responsive supramolecular chemotherapy is promising in combating pump mediated drug resistance in both in vitro and in vivo models, which may be encouraging for the advanced drug delivery platform design to overcome drug resistant cancer. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Response surface method optimization of V-shaped fin assisted latent heat thermal energy storage system during discharging process

    Directory of Open Access Journals (Sweden)

    Sina Lohrasbi

    2016-09-01

    Full Text Available Latent Heat Thermal Energy Storage Systems (LHTESS containing Phase Change Material (PCM are used to establish balance between energy supply and demand. PCMs have high latent heat but low thermal conductivity, which affects their heat transfer performance. In this paper, a novel fin array has been optimized by multi-objective Response Surface Method (RSM based on discharging process of PCM, and then this fin configuration is applied on LHTESS, and comparison between full discharging time by applying this fin array and LHTESS with other fin structures has been carried out. The employed numerical method in this paper is Standard Galerkin Finite Element Method. Adaptive grid refinement is used to solve the equations. Since the enhancement technique, which has been employed in the present study reduces the employed PCM mass, maximum energy storage capacity variations have been considered. Therefore phase change expedition and maximum energy storage capacity have been considered as the objectives of optimization and the importance of second objective is indicated which is proposed as the novelty here. Results indicate that considering maximum energy storage capacity as the objective of optimization procedure leads to efficient shape design of LHTESS. Also employing optimized V-shaped fin in LHTESS, expedites discharging process considerably in comparison with the LHTESS without fin.

  18. Sealing Failure Analysis on V-Shaped Sealing Rings of an Inserted Sealing Tool Used for Multistage Fracturing Processes

    Directory of Open Access Journals (Sweden)

    Gang Hu

    2018-06-01

    Full Text Available The inserted sealing tool is a critical downhole implement that is used to balance the downhole pressure in multistage fracturing operations and prevent fracturing fluid from overflow and/or backward flow. The sealing ring of an inserted sealing tool plays an important role in downhole sealing since a sealing failure would ail the fracturing operation. In order to improve the sealing performance and reduce the potential fracturing failures, this research aims to investigate the influence of V-shaped sealing ring geometries on sealing performance. Constitutive experiments of rubber materials were carried out and the parameters of the constitutive relationship of rubber materials were obtained. A two-dimensional axisymmetric model considering the sealing ring has been established and influences are investigated with considerations of various system parameters and operating conditions. It is found that the stresses concentrated at the shoulder and inner vertex of the sealing ring have direct impact on the damage of the sealing rings under operational conditions. Moreover, the sealing interference, among several other factors, greatly affects the life of the sealing ring. A new design of the sealing ring is suggested with optimized geometric parameters. Its geometric parameters are the edge height of 5 mm, the vertex angle of 90°–100°, and the interference of 0.1 mm, which show a better performance and prolonged operation life of the sealing ring.

  19. The influence of floodplain geomorphology and hydrologic connectivity on alligator gar (Atractosteus spatula) habitat along the embanked floodplain of the Lower Mississippi River

    Science.gov (United States)

    van der Most, Merel; Hudson, Paul F.

    2018-02-01

    The floodplain geomorphology of large lowland rivers is intricately related to aquatic ecosystems dependent upon flood pulse dynamics. The alligator gar (Atractosteus spatula) is native to the Lower Mississippi River and dependent upon floodplain backwater areas for spawning. In this study we utilize a geospatial approach to develop a habitat suitability index for alligator gar that explicitly considers hydrologic connectivity and the floodplain geomorphology along a frequently inundated segment of the Lower Mississippi River. The data sets include Landsat imagery, a high-resolution LiDAR digital elevation model (DEM), National Hydrography Dataset (NHD), and hydrologic and geomorphic data. A habitat suitability index is created based on the extent and frequency of inundation, water depth, temperature, and vegetation. A comparison between the remote sensing approach and the NHD revealed substantial differences in the area and location of water bodies available for alligator gar spawning. The final habitat suitability index indicates that a modest proportion (19%) of the overall embanked floodplain is available for alligator gar spawning. Opportunities exist for management efforts to utilize engineered and natural geomorphic features to facilitate hydrologic connectivity at flow levels below flood stage that would expand the habitat of alligator gar across the floodplain. The study results have direct implications regarding environmental restoration of the Lower Mississippi, an iconic example of an embanked meandering river floodplain.

  20. 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

  1. [Austin's horizontal V-shaped sliding osteotomy of the metatarsal head [Chevron-osteotomy) in the treatment of hallux valgus].

    Science.gov (United States)

    Steinböck, G

    1996-08-01

    From 1983 to 1995, 1587 patients suffering from hallux abductovalgus were treated with the Austin bunionectomy. The operation consists of a medial exostosis removal, a V-shaped laterally directed displacement osteotomy of the metatarsal head, lateral release and medial reefing of the capsulo-ligamentous structures. Lateral transposition is facilitated by performing a sufficient lateral release consisting of dissection of the lateral metatarsophalangeal ligament and separation of the adductor tendon from the base of the phalanx and the lateral sesamoid. In the case of intermetatarsal angles greater than 15 degrees, the metatarsal-sesamoid ligament is also severed just above the lateral sesamoid. The periosteum is stripped in a limited fashion dorsally and toward the plantar, leaving its insertion at the metatarsal head intact. After this procedure, reposition of the metatarsal head onto the sesamoids is usually possible and is maintained by reconstruction of the medial metatarsal-sesamoid ligament. In the author's own research material, metatarsophalangeal angles larger than 50 degrees and intermetatarsal angles of over 20 degrees could be corrected. Pronation of the toe is usually corrected by tenotomy of the abductor tendon near the base of the phalanx. Avascular necrosis is extremely rare with a careful operative technique. In our extensive research material, four cases of AVN were recognized. Provided there is free motion of the joint (60-0-20), mild radiological signs of osteoarthritis are no contraindication for the operation. Even in the aged, good results can be achieved provided there are no trophic problems. The Austin bunionectomy has proved to be a versatile method for treating bunion problems. The possibility of transposing the metatarsal head laterally, toward the plantar, proximally and distally by altering the direction of the osteotomy, as well as tilting it medially or laterally, has made this osteotomy an invaluable tool for addressing various

  2. Nonlinear dynamic modeling of a V-shaped metal based thermally driven MEMS actuator for RF switches

    Science.gov (United States)

    Bakri-Kassem, Maher; Dhaouadi, Rached; Arabi, Mohamed; Estahbanati, Shahabeddin V.; Abdel-Rahman, Eihab

    2018-05-01

    In this paper, we propose a new dynamic model to describe the nonlinear characteristics of a V-shaped (chevron) metallic-based thermally driven MEMS actuator. We developed two models for the thermal actuator with two configurations. The first MEMS configuration has a small tip connected to the shuttle, while the second configuration has a folded spring and a wide beam attached to the shuttle. A detailed finite element model (FEM) and a lumped element model (LEM) are proposed for each configuration to completely characterize the electro-thermal and thermo-mechanical behaviors. The nonlinear resistivity of the polysilicon layer is extracted from the measured current-voltage (I-V) characteristics of the actuator and the simulated corresponding temperatures in the FEM model, knowing the resistivity of the polysilicon at room temperature from the manufacture’s handbook. Both developed models include the nonlinear temperature-dependent material properties. Numerical simulations in comparison with experimental data using a dedicated MEMS test apparatus verify the accuracy of the proposed LEM model to represent the complex dynamics of the thermal MEMS actuator. The LEM and FEM simulation results show an accuracy ranging from a maximum of 13% error down to a minimum of 1.4% error. The actuator with the lower thermal load to air that includes a folded spring (FS), also known as high surface area actuator is compared to the actuator without FS, also known as low surface area actuator, in terms of the I-V characteristics, power consumption, and experimental static and dynamic responses of the tip displacement.

  3. Global financial crisis making a V-shaped fluctuation in NO2 pollution over the Yangtze River Delta

    Science.gov (United States)

    Du, Yin; Xie, Zhiqing

    2017-04-01

    The Yangtze River Delta (YRD), China's main cultural and economic center, has become one of the most seriously polluted areas in the world with respect to nitrogen oxides (NOx), owing to its rapid industrialization and urbanization, as well as substantial coal consumption. On the basis of nitrogen dioxide (NO2) density data from ozone monitoring instrument (OMI) and ground-based observations, the effects of industrial fluctuations due to the financial crisis on local NO2 pollution were quantitatively assessed. The results were as follows. (1) A distinct V-shaped fluctuation of major industrial products, thermal generating capacity, electricity consumption, and tropospheric NO2 densities was associated with the global financial crisis from May 2007 to December 2009, with the largest anomalies 1.5 times more than standard deviations at the height of the crisis period from November 2008 to February 2009. (2) Among all industrial sectors, thermal power plants were mainly responsible for fluctuations in local NO2 pollution during the crisis period. Thermal generating capacity had its greatest decrease of 12.10% at the height of the crisis compared with that during November 2007-February 2008, leading to local tropospheric NO2 density decreasing by 16.97%. As the crisis appeased, thermal generating capacity increased by 29.63% from November 2009 to February 2010, and tropospheric NO2 densities correspondingly increased by 30.07%. (3) Among all industrial sectors in the YRD, the thermal power sector has the greatest coal consumption of about 65.96%. A decline in thermal power of about 10% can induce a decrease of about 30% in NOx emissions and NO2 densities, meaning that a relative small fluctuation in industrial production can lead to a large decrease in tropospheric NO2 densities over industrially developed areas like the YRD region. Since electricity is mainly obtained from local coal-burning thermal plants without NOx-processing equipment, installing NOx

  4. Effects of annealing and deforming temperature on microstructure and deformation characteristics of Ti-Ni-V shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    He Zhirong, E-mail: hezhirong01@163.com [School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723003 (China); Liu Manqian [School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723003 (China)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer The deformation behaviors of annealed Ti-50.8Ni-0.5V shape memory alloy (SMA) were given. Black-Right-Pointing-Pointer The effect of annealing temperature on microstructure and deformation characteristics of Ti-50.8Ni-0.5V SMA was shown. Black-Right-Pointing-Pointer The effect of deforming temperature on deformation characteristics of Ti-50.8Ni-0.5V SMA was given. - Abstract: Effects of annealing temperature T{sub an} and deforming temperature T{sub d} on microstructure and deformation characteristics of Ti-50.8Ni-0.5V (atomic fraction, %) shape memory alloy were investigated by means of optical microscopy and tensile test. With increasing T{sub an}, the microstructure of Ti-50.8Ni-0.5V alloy wire changes from fiber style to equiaxed grain, and the recrystallization temperature of the alloy is about 580 Degree-Sign C; the critical stress for stress-induced martensite {sigma}{sub M} of the alloy decreases first and then increases, and the minimum value 382 MPa is got at T{sub an} = 450 Degree-Sign C; the residual strain {epsilon}{sub R} first increases, then decreases, and then increases, and its maximum value 2.5% is reached at T{sub an} = 450 Degree-Sign C. With increasing T{sub d}, a transformation from shape memory effect (SME) to superelasticity (SE) occurs in the alloy annealed at different temperatures, and the SME {yields} SE transformation temperature was affected by T{sub an}; the {sigma}{sub M} of the alloy increases linearly; the {epsilon}{sub R} of the alloy annealed at 350-600 Degree-Sign C decreases first and then tends to constant, while that of the alloy annealed at 650 Degree-Sign C and 700 Degree-Sign C decreases first and then increases. To get an excellent SE at room temperature for Ti-50.8Ni-0.5V alloy, T{sub an} should be 500-600 Degree-Sign C.

  5. Sliding and pressure evaluation on conventional and V-shaped seats of reclining wheelchairs for stroke patients with flaccid hemiplegia: a crossover trial

    Directory of Open Access Journals (Sweden)

    Chen Chi-Myn

    2011-07-01

    Full Text Available Abstract Background Reclining wheelchairs are commonly used to transport elderly stroke patients in Taiwan. However, there is concern that the patient's body in the wheelchair often slides forward when they return to a seated position, increasing the sitting pressure. Therefore, a novel reclining wheelchair with an ergonomic "V-Seat" was designed to prevent forward sliding and pressure sores. The use of these reclining chairs by stroke patients has not yet been studied. Thus, we investigated the effects of V-shaped and conventional seats in reclining wheelchairs on the extent of forward sliding and on the sitting pressure of stroke patients with flaccid hemiplegia and of able-bodied elders. Methods We recruited 13 able-bodied elders and 11 stroke patients with flaccid hemiplegia and performed 5 reclining cycles in both types of wheelchair. The amount of sliding along the backrest (BS plane and the seat (SS plane, the mean sitting pressure (MP, and the sacral peak pressure (SPP of the subjects were recorded. We used the Wilcoxon signed-rank test to compare the BS, SS, MP, and SPP in wheelchairs with conventional and V-shaped seats, and we used the Wilcoxon rank sum test to compare the differences in BS and SS between stroke patients and able-bodied elders in both types of reclining wheelchair. Results The BS, SS, and SPP of stroke patients were significantly lower in the wheelchairs with V-shaped seats than in conventional wheelchairs in most comparisons; however, the BS of able-bodied elders was higher in V-shaped seats than in conventional seats. The SS and SPP of stroke patients were significantly higher than those of able-bodied elders in both types of reclining wheelchair, and the BS of stroke patients was significantly higher than that of able-bodied elders only in conventional reclining wheelchairs. Conclusions The use of V-shaped seats in reclining wheelchairs can help reduce the forward sliding and sacral peak pressure of stroke patients

  6. Effects of the number of wells on the performance of green InGaN/GaN LEDs with V-shape pits grown on Si substrates

    Science.gov (United States)

    Wu, Qingfeng; Zhang, Jianli; Mo, Chunlan; Wang, Xiaolan; Quan, Zhijue; Wu, Xiaoming; Pan, Shuan; Wang, Guangxu; Liu, Junlin; Jiang, Fengyi

    2018-02-01

    The effect of the number of wells on quantum efficiency and forward voltage of vertical green InGaN/GaN multiple quantum wells (MQWs) light-emitting diodes (LEDs) grown on Si substrate has been experimentally investigated. We have prepared three LED samples with 3, 5 and 7 wells. Electroluminescence measurement shows that the LED with 5 wells has the highest external quantum efficiency (EQE) and the lowest forward voltage. It is observed that V-shaped pits grow up in size and density with an increase in quantum well number by means of scan electron microscope. Due to more hole injection via V-shaped pits, a larger area ratio of pits as a result of more number of wells would bring a lower forward voltage and a higher EQE. However, besides the increasing series resistance would bring a higher forward voltage, the interface of MQWs would become rougher and deteriorate the emission efficiency when increasing the wells number.

  7. Effects of V-shaped edge defect and H-saturation on spin-dependent electronic transport of zigzag MoS2 nanoribbons

    International Nuclear Information System (INIS)

    Li, Xin-Mei; Long, Meng-Qiu; Cui, Li-Ling; Xiao, Jin; Zhang, Xiao-Jiao; Zhang, Dan; Xu, Hui

    2014-01-01

    Based on nonequilibrium Green's function in combination with density functional theory calculations, the spin-dependent electronic transport properties of one-dimensional zigzag molybdenum disulfide (MoS 2 ) nanoribbons with V-shaped defect and H-saturation on the edges have been studied. Our results show that the spin-polarized transport properties can be found in all the considered zigzag MoS 2 nanoribbons systems. The edge defects, especially the V-shaped defect on the Mo edge, and H-saturation on the edges can suppress the electronic transport of the systems. Also, the spin-filtering and negative differential resistance behaviors can be observed obviously. The mechanisms are proposed for these phenomena. - Highlights: • The spin-dependent electronic transport of zigzag MoS 2 nanoribbons. • The effects of V-shaped edge defect and H-saturation. • The effects of spin-filter and negative differential resistance can be observed

  8. Structure and thermal behavior of a nickel complex based on a V-shaped bis(4-(1H-imidazol-1-yl)phenyl)amine ligand

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Yan, E-mail: felixjiao@163.com; Wang, Zhe; Qiu, Yu; He, Jing-Man; Chen, Min-dong [Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Innovative Research Laboratory of Energy & Environmental Catalysis, School of Environmental Science and Engineering (China)

    2015-12-15

    A new coordination polymer ([Ni(BIPA)(bpdc)(H{sub 2}O){sub 2}]){sub n} has been prepared based on a new V-shaped bis(4-(1H-imidazol-1-yl)phenyl)amine (BIPA) ligand. Complex was characterized by elemental analysis, IR spectra, X-ray powder diffraction, thermal analysis and single crystal X-ray analysis. Complex exhibits a 1D → 3D structure. Hydrogen bonds play an important role in the formation of supramolecular network structure. Thermal analysis indicates that complex exhibits a high thermal stability.

  9. Diagnostic value of an abnormal smear in non-pregnant women. Evaluation of positive smear from the surface of the portio obtained by the cottonswab method or by the dry wooden Ayre spatula and the relevance of positive smear from the endocervix and/or from the surface of the portio

    DEFF Research Database (Denmark)

    Lundvall, L; Højgaard, L L; Højgaard, K

    1990-01-01

    During a 3-4 year period, 324 women with a positive smear were registered consecutively and prospectively and divided into two groups according to the design of the investigation. In one group the smear was taken with an Ayre spatula and in the other group with a cotton swab. The purpose of this ...

  10. Plastic dosimeter

    International Nuclear Information System (INIS)

    Nagai, Shiro; Matsuda, Kohji.

    1988-01-01

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

  11. PLASTIC SURGERY

    African Journals Online (AJOL)

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

  12. 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.

  13. Technical pitfalls in a porcine brain retraction model. The impact of brain spatula on the retracted brain tissue in a porcine model: a feasibility study and its technical pitfalls

    Energy Technology Data Exchange (ETDEWEB)

    Thiex, R.; Hans, F.J.; Gilsbach, J.M. [Aachen University, Department of Neurosurgery, Aachen (Germany); Krings, T. [Aachen University, Department of Neuroradiology, Aachen (Germany); Sellhaus, B. [Aachen University, Department of Neuropathology, Aachen (Germany)

    2005-10-01

    We describe technical pitfalls of a porcine brain injury model for identifying primary and secondary pathological sequelae following brain retraction by brain spatula. In 16 anaesthetised male pigs, the right frontal brain was retracted in the interhemispheric fissure by a brain spatulum with varying pressures applied by the gravitational force of weights from 10 to 70 g for a duration of 30 min. The retracted brain tissue was monitored for changes in intracranial pressure and perfusion of the cortex using a Laser Doppler Perfusion Imager (MoorLDI). To evaluate the extent of oedema and cortical contusions, MRI was performed 30 min and 72 h after brain retraction. Following the MR scan, the retracted brain areas were histopathologically assessed using H and E and Fluoro-Jade B staining for neuronal damage. Sinus occlusion occurred in four animals, resulting in bilateral cortical contusions and extensive brain oedema. Retracting the brain with weights of 70 g (n=4) caused extensive oedema on FLAIR images that correlated clinically with a hemiparesis in three animals. Morphologically, an increased number of Fluoro-Jade B-positive neurons were found. A sequential decrease in weights prevented functional deficits in animals. A retraction pressure applied by 10-g weights (n=7) caused a mean rise in intracranial pressure to 4.0{+-}3.1 mm Hg, and a decrement in mean cortical perfusion from 740.8{+-}41.5 to 693.8{+-}72.4 PU/cm2, (P<0.24). A meticulous dissection of the interhemispheric fissure and a reduction of weights to 10 g were found to be mandatory to study the cortical impact caused by brain spatula reproducibly. (orig.)

  14. Technical pitfalls in a porcine brain retraction model. The impact of brain spatula on the retracted brain tissue in a porcine model: a feasibility study and its technical pitfalls

    International Nuclear Information System (INIS)

    Thiex, R.; Hans, F.J.; Gilsbach, J.M.; Krings, T.; Sellhaus, B.

    2005-01-01

    We describe technical pitfalls of a porcine brain injury model for identifying primary and secondary pathological sequelae following brain retraction by brain spatula. In 16 anaesthetised male pigs, the right frontal brain was retracted in the interhemispheric fissure by a brain spatulum with varying pressures applied by the gravitational force of weights from 10 to 70 g for a duration of 30 min. The retracted brain tissue was monitored for changes in intracranial pressure and perfusion of the cortex using a Laser Doppler Perfusion Imager (MoorLDI). To evaluate the extent of oedema and cortical contusions, MRI was performed 30 min and 72 h after brain retraction. Following the MR scan, the retracted brain areas were histopathologically assessed using H and E and Fluoro-Jade B staining for neuronal damage. Sinus occlusion occurred in four animals, resulting in bilateral cortical contusions and extensive brain oedema. Retracting the brain with weights of 70 g (n=4) caused extensive oedema on FLAIR images that correlated clinically with a hemiparesis in three animals. Morphologically, an increased number of Fluoro-Jade B-positive neurons were found. A sequential decrease in weights prevented functional deficits in animals. A retraction pressure applied by 10-g weights (n=7) caused a mean rise in intracranial pressure to 4.0±3.1 mm Hg, and a decrement in mean cortical perfusion from 740.8±41.5 to 693.8±72.4 PU/cm2, (P<0.24). A meticulous dissection of the interhemispheric fissure and a reduction of weights to 10 g were found to be mandatory to study the cortical impact caused by brain spatula reproducibly. (orig.)

  15. Variations of structures and solid-state conductivity of isomeric silver(I) coordination polymers having linear and V-shaped thiophene-centered ditriazole ligands

    International Nuclear Information System (INIS)

    Hu, Bin; Geng, Jiao; Zhang, Lie; Huang, Wei

    2014-01-01

    A pair of new linear and V-shaped acceptor–donor–acceptor (A−D−A) thiophene-centered ditriazole structural isomers, i.e., 2,5-di(1H-1,2,4-triazol-1-yl)thiophene (L 1 ) and 3,4-di(1H-1,2,4-triazol-1-yl)thiophene (L 2 ), has been synthesized and characterized. They are used as μ 2 -bridging ligands to prepare a pair of silver(I) coordination polymers formulated as [Ag(L 1 )(NO 3 )] n (1) and [Ag(L 2 )(NO 3 )] n (2), which are also structural isomers at the supramolecular level. X-ray single-crystal diffraction analyses for 1 and 2 reveal that they exhibit the same one-dimensional (1D) coordination polymers but different structural architectures because of the distinguishable shape and configuration of isomeric ligands (L 1 and L 2 ) and the alterations of the coordination numbers. More interestingly, compared with the free ligands, 1D silver(I) polymeric isomers 1 and 2 show significant enhancement of solid-state conductivity to different extents (1.42×10 4 and 2.17×10 3 times), where 6.96 times' enhancement of solid-state conductivity from 1 to 2 has been observed. The formation of Ag–N coordinative bonds and the configurational discrepancy of L 1 and L 2 are believed to play important roles in facilitating the electron transport between molecules, which can also be supported by Density Function Theory calculations of their band gaps. - Graphical abstract: A pair of linear and V-shaped isomeric thiophene-centered ditriazole ligands (L 1 ) and L 2 are used to prepare a pair of silver(I) polymeric isomers (1 and 2), where significant enhancement of solid-state conductivity to different extents are observed originating from the distinguishable shape and configuration of isomeric ligands. - Highlights: • A pair of linear and V-shaped thiophene-centered ditriazole structural isomers is prepared. • They are used as µ 2 -bridging ligands to prepare a pair of silver(I) polymeric isomers. • Significant enhancement of solid-state conductivity is observed

  16. 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...

  17. 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

  18. Magical Engineering Plastic

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwang Ung

    1988-01-15

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

  19. Magical Engineering Plastic

    International Nuclear Information System (INIS)

    Kim, Gwang Ung

    1988-01-01

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

  20. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

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

  1. Pervasive plastic

    Science.gov (United States)

    2018-05-01

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

  2. Plastic 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...

  3. Plastic deformation

    NARCIS (Netherlands)

    Sitter, de L.U.

    1937-01-01

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

  4. Arthroscopically assisted stabilization of acute high-grade acromioclavicular joint separations in a coracoclavicular Double-TightRope technique: V-shaped versus parallel drill hole orientation.

    Science.gov (United States)

    Kraus, Natascha; Haas, Norbert P; Scheibel, Markus; Gerhardt, Christian

    2013-10-01

    The arthroscopically assisted Double-TightRope technique has recently been reported to yield good to excellent clinical results in the treatment of acute, high-grade acromioclavicular dislocation. However, the orientation of the transclavicular-transcoracoidal drill holes remains a matter of debate. A V-shaped drill hole orientation leads to better clinical and radiologic results and provides a higher vertical and horizontal stability compared to parallel drill hole placement. This was a cohort study; level of evidence, 2b. Two groups of patients with acute high-grade acromioclavicular joint instability (Rockwood type V) were included in this prospective, non-randomized cohort study. 15 patients (1 female/14 male) with a mean age of 37.7 (18-66) years were treated with a Double-TightRope technique using a V-shaped orientation of the drill holes (group 1). 13 patients (1 female/12 male) with a mean age of 40.9 (21-59) years were treated with a Double-TightRope technique with a parallel drill hole placement (group 2). After 2 years, the final evaluation consisted of a complete physical examination of both shoulders, evaluation of the Subjective Shoulder Value (SSV), Constant Score (CS), Taft Score (TF) and Acromioclavicular Joint Instability Score (ACJI) as well as a radiologic examination including bilateral anteroposterior stress views and bilateral Alexander views. After a mean follow-up of 2 years, all patients were free of shoulder pain at rest and during daily activities. Range of motion did not differ significantly between both groups (p > 0.05). Patients in group 1 reached on average 92.4 points in the CS, 96.2 % in the SSV, 10.5 points in the TF and 75.9 points in the ACJI. Patients in group 2 scored 90.5 points in the CS, 93.9 % in the SSV, 10.5 points in the TF and 84.5 points in the ACJI (p > 0.05). Radiographically, the coracoclavicular distance was found to be 13.9 mm (group 1) and 13.4 mm (group 2) on the affected side and 9.3 mm (group 1

  5. plastic waste recycling

    African Journals Online (AJOL)

    Dr Ahmed

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

  6. Syntheses, structures, and magnetic properties of cobalt(II) and nickel(II) coordination polymers based on a V-shaped ligand

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Shuang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China); Yi, Fei-Yan [The School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211 (China); Li, Guanghua [State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China); Yu, Yang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China); Wang, Jing-yuan, E-mail: jywang@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190 (China); Liu, Dan, E-mail: liudan2007@ciac.ac.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China); Song, Shu-Yan [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China)

    2017-06-15

    Two coordination polymers [Co{sub 2}(TA)(4,4′-bipy){sub 2}(H{sub 2}O){sub 2}]·H{sub 2}O (1) and [Ni{sub 2}(TA)(4,4′-bipy){sub 2}(H{sub 2}O){sub 4}]·3H{sub 2}O (2) were prepared by hydrothermal reactions of MCl{sub 2}·6H{sub 2}O (M = Co, Ni) with a V-shaped ligand TDPA (3,3′,4,4′-thiodiphthalic anhydride) and a I-shaped N-donor co-ligand (4,4′-bipy). They were characterized by elemental analyses, thermogravinetric analyses, and magnetic behavior. As is expected, TDPA hydrolyzes into the corresponding tetra-carboxylate acid H{sub 4}TA (3,3′,4,4′-thiodiphthalic acid) during the reactions. Co{sub 2} dimer and Ni mononuclear center are connected into two-dimensional (2D) layers by H{sub 4}TA and 4,4′-bipy bridge in 1 and 2, respectively. The most amazing feature is that 1 and 2 exhibit interesting spin-canting metamagnetism and weak ferromagnetic behavior, respectively, with the critical Néel temperature of T{sub N} =4 K for 1 and T{sub N} =13 K for 2, based on variable temperature magnetic susceptibility measurements. In low mono- or dinuclear metal system, such magnetic behaviors have rare been observed. Furthermore, complex 1 will be a potential metamagnet material. - Graphical abstract: Two Co(II) and Ni(II) coordination polymers were synthesized by hydrothermal reactions from a V-shape ligand (3,3′,4,4′-thiodiphthalic anhydride) and a I-shape ligand (4,4′-bipy), which were characterized by single crystal X-ray diffraction, elemental analyses, thermogravinetric analyses, and magnetic behavior, and exhibit interesting spin-canting metamagnetism and weak ferromagnetic behavior, respectively. - Highlights: • Two Co(II) and Ni(II) coordination polymers were successfully synthesized. • Co(II) coordination polymer shows an interesting spin-canting metamagnetism. • Ni(II) coordination polymer exhibits a weak ferromagnetic behavior.

  7. An investigation of heat transfer augmentation and friction characteristics in solar air heater duct with V-shaped wire as artificial roughness on absorber plate

    Energy Technology Data Exchange (ETDEWEB)

    Madhukeshwara, N. [Department of Mechanical Engineering, B.I.E.T, Davanagere, Karnataka (India); Prakash, E.S. [Department of Studies in Mechanical Engineering, U.B.D.T.C.E, Davanagere, Karnataka (India)

    2013-07-01

    An experimental investigation of heat transfer augmentation and friction characteristics of fully developed turbulent flow in a rectangular duct of solar air heater with absorber plate having V-shaped wire ribs as artificial roughness on its underside is carried out. The investigation covers wide range of different parameters of wire ribbed roughness: relative roughness pitch (p/e) from 10 to 40, relative roughness height (e/Dh) from 0.01 to 0.04 and angle of attack of flow from 20° to 90°. Duct aspect ratio (W/B) is kept 5 and Reynolds number (Re) is varied from 2,500 to 8,500. The heat transfer and friction factor values obtained are compared with those of smooth duct under similar flow conditions. Expressions are developed for Nusselt number and friction factor for the roughness geometry. Enhancement of Nusselt number and friction factor for roughened duct are 1.5 and 2.7 times of smooth duct respectively.

  8. Plastic scintillator

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  9. Toxicological Threats of Plastic

    Science.gov (United States)

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

  10. Rational assembly of Pb(II)/Cd(II)/Mn(II) coordination polymers based on flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Gao-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Chong-Bo, E-mail: cbliu@nchu.edu.cn [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Liu, Hong [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Robbins, Julianne; Zhang, Z. John [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Yin, Hong-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Wen, Hui-Liang [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Wang, Yu-Hua [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China)

    2015-05-15

    Six new coordination polymers, namely, [Pb(L)(H{sub 2}O)] (1), [Pb(L)(phen)] (2), [Pb{sub 2}(L){sub 2}(4,4′-bipy){sub 0.5}] (3), [Cd(L)(phen)] (4), [Cd(L)(4,4′-bipy)]·H{sub 2}O (5) and [Mn(L)(4,4′-bipy)]·H{sub 2}O (6) have been synthesized by the hydrothermal reaction of 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H{sub 2}L) with Pb(II)/Cd(II)/Mn(II) in the presence of ancillary ligands 4,4′-bipyridine (4,4′-bipy) or 1,10-phenanthroline (phen). Complexes 1 and 4–6 exhibit 2-D structures, and complexes 2–3 display 3-D frameworks, of which L{sup 2−} ligands join metal ions to single-stranded helical chains of 1, 3–6 and double-stranded helical chains of 2. Complexes 2 and 3 also contain double-stranded Metal–O helices. Topology analysis reveals that complexes 1 and 4 both represent 4-connected sql net, 2 represents 6-connected pcu net, 3 exhibits a novel (3,12)-connected net, while 5 and 6 display (3,5)-connected gek1 net. The six complexes exhibit two kinds of inorganic–organic connectivities: I{sup 0}O{sup 2} for 1, 4–6, and I{sup 1}O{sup 2} for 2–3. The photoluminescent properties of 4–5 and the magnetic properties of 6 have been investigated. - Graphical abstract: Six new Pb(II)/Cd(II)/Mn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent and magnetic properties have been investigated. - Highlights: • Six novel M(II) coordination polymers with 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid and N-donor ligands. • Complexes 1–6 show diverse intriguing helical characters. • The luminescent properties of complexes 1–5 were investigated. • Complex 6 shows antiferromagnetic coupling.

  11. Influence of surface geometry on the culture of human cell lines: A comparative study using flat, round-bottom and v-shaped 96 well plates.

    Directory of Open Access Journals (Sweden)

    Sara Shafaie

    Full Text Available In vitro cell based models have been invaluable tools for studying cell behaviour and for investigating drug disposition, toxicity and potential adverse effects of administered drugs. Within this drug discovery pipeline, the ability to assess and prioritise candidate compounds as soon as possible offers a distinct advantage. However, the ability to apply this approach to a cell culture study is limited by the need to provide an accurate, in vitro-like, microenvironment in conjunction with a low cost and high-throughput screening (HTS methodology. Although the geometry and/or alignment of cells has been reported to have a profound influence on cell growth and differentiation, only a handful of studies have directly compared the growth of a single cell line on different shaped multiwell plates the most commonly used substrate for HTS, in vitro, studies. Herein, the impact of various surface geometries (flat, round and v-shaped 96 well plates, as well as fixed volume growth media and fixed growth surface area have been investigated on the characteristics of three commonly used human cell lines in biopharmaceutical research and development, namely ARPE-19 (retinal epithelial, A549 (alveolar epithelial and Malme-3M (dermal fibroblastic cells. The effect of the surface curvature on cells was characterised using a combination of a metabolic activity assay (CellTiter AQ/MTS, LDH release profiles (CytoTox ONE and absolute cell counts (Guava ViaCount, respectively. In addition, cell differentiation and expression of specific marker proteins were determined using flow cytometry. These in vitro results confirmed that surface topography had a significant effect (p < 0.05 on cell activity and morphology. However, although specific marker proteins were expressed on day 1 and 5 of the experiment, no significant differences were seen between the different plate geometries (p < 0.05 at the later time point. Accordingly, these results highlight the impact of

  12. 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...

  13. A family of entangled coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and auxiliary N-donor ligands: Luminescent sensing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Bai, Chao [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); Yuan, Fei; Xue, Gang-Lin [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China)

    2017-05-15

    Eight Zn(II)-based coordination polymers, namely, [Zn{sub 2}L{sub 2}(2,2’-bipy)]{sub n}·nH{sub 2}O (1), [Zn{sub 2}L{sub 2}(phen)]{sub n}·nH{sub 2}O (2), [ZnL(phen)(H{sub 2}O)]{sub n} (3), [Zn{sub 3}L{sub 3}(4,4’-bipy)]{sub n} (4), [Zn{sub 2}L{sub 2}(4,4’-bipy){sub 2}]{sub n} [Zn{sub 2}L{sub 2}(H{sub 2}O){sub 2}]{sub n}·2nH{sub 2}O (5), [Zn{sub 4}L{sub 4}(bpp){sub 2}]{sub n} (6), [ZnL(bbi){sub 0.5}]{sub n} (7), [ZnL(bpz)]{sub n} (8) (H{sub 2}L=4,4’-([1,2-phenylenebis-(methylene)]bis(oxy))dibenzoic acid, 2,2’-bipy =2,2’-bipyridine, phen =1,10-phenanthroline, 4,4’-bpy=4,4’-bipyridine, bpp =1,3-bis(4-pyridyl)propane, bbi=1,4-bis(imidazol-1-yl)butane, bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), have been hydrothermally synthesized and structurally characterized. 1–8 display various coordination motifs with different entangled forms and conformations due to the effect of the assistant N-donor ligands. The photoluminescent properties of compounds 1–8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2+} cations and CrO{sub 4}{sup 2-} anions, as well as detection ability for the different organic solvents and nitro explosives. These results indicated that it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multi-photofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials. - Graphical abstract: Eight new Zn(II)-based coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and different N-donor ligands have been hydrothermally synthesized through fixing the metal salts and the solvent systems. The photoluminescent properties of complexes 1−8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2

  14. A family of entangled coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and auxiliary N-donor ligands: Luminescent sensing

    International Nuclear Information System (INIS)

    Wang, Jun; Bai, Chao; Hu, Huai-Ming; Yuan, Fei; Xue, Gang-Lin

    2017-01-01

    Eight Zn(II)-based coordination polymers, namely, [Zn 2 L 2 (2,2’-bipy)] n ·nH 2 O (1), [Zn 2 L 2 (phen)] n ·nH 2 O (2), [ZnL(phen)(H 2 O)] n (3), [Zn 3 L 3 (4,4’-bipy)] n (4), [Zn 2 L 2 (4,4’-bipy) 2 ] n [Zn 2 L 2 (H 2 O) 2 ] n ·2nH 2 O (5), [Zn 4 L 4 (bpp) 2 ] n (6), [ZnL(bbi) 0.5 ] n (7), [ZnL(bpz)] n (8) (H 2 L=4,4’-([1,2-phenylenebis-(methylene)]bis(oxy))dibenzoic acid, 2,2’-bipy =2,2’-bipyridine, phen =1,10-phenanthroline, 4,4’-bpy=4,4’-bipyridine, bpp =1,3-bis(4-pyridyl)propane, bbi=1,4-bis(imidazol-1-yl)butane, bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), have been hydrothermally synthesized and structurally characterized. 1–8 display various coordination motifs with different entangled forms and conformations due to the effect of the assistant N-donor ligands. The photoluminescent properties of compounds 1–8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu 2+ cations and CrO 4 2- anions, as well as detection ability for the different organic solvents and nitro explosives. These results indicated that it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multi-photofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials. - Graphical abstract: Eight new Zn(II)-based coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and different N-donor ligands have been hydrothermally synthesized through fixing the metal salts and the solvent systems. The photoluminescent properties of complexes 1−8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu 2+ cations and CrO 4 2- anions, as well as detection ability for the different organic solvents and nitro explosives, in which indicates it could be

  15. Engineered SOI slot waveguide ring resonator V-shape resonance combs for refraction index sensing up to 1300nm/RIU (Conference Presentation)

    Science.gov (United States)

    Zhang, Weiwei; Serna, Samuel; Le Roux, Xavier; Vivien, Laurent; Cassan, Eric

    2016-05-01

    breakthrough of the performance of slot ring resonator sensing ability. Different from the normal sensing regime by monitoring one specific resonance (λres) peak shift, the proposed approach stems from the sensitivity of the RR critical coupling. The critical coupling peak is auto-selected out by matching the following condition: the ring resonator's round trip attenuation coefficient a(λ) being equal to the coupler self-coupling coefficient k(λ), thus resulting in the deepest extinction ratio (ER) among the spectrum RR comb. The obtained sensing comb, based on a V-shape spectrum envelop, is engineered by controlling a(λ) and k(λ) with opposite monotonicities. Both a(λ)and k(λ) are tuned to have a large dispersion along the wavelength, which means that |a(λ)-k(λ)| keeps rapidly increasing as λres is far away from λc, eliminating the resonance ER quickly down to 0. Experimentally, slot waveguide ring resonators with a radius of 50µm have been fabricated on a standard silicon platform with a Si thickness of 220nm, loaded by racetrack couplers with a straight coupling length of 20µm. Sensing experiments have been carried out by changing the top cladding material from a series of Cargille optical liquids with refraction index values ranging from 1.3 to 1.5. The Q factors of critical coupling resonances was monitored from 2,000 to 6,000, and measured wavelength shifts of this peak are from 1.41µm to 1.56µm. The maximum sensitivity of 1300nm/RIU is observed in the cladding index range 1.30-1.35. To conclude, a new sensing regime by tracking the critical coupling resonance λc of slot waveguide ring resonators is demonstrated. The reported sensitivity is up 1300nm/RIU around the water RI of 1.33, and the monitored sensing FOM is about 2300, which is very close to the FOM values achieved from nanobeam cavities. This work can thus contribute to future integrated optical sensing schemes based on slot RRs.

  16. Wood-plastic combination

    International Nuclear Information System (INIS)

    Schaudy, R.

    1978-02-01

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

  17. 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 ...

  18. 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....

  19. 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.

  20. 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.

  1. 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...

  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 plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve...

  3. Our plastic age.

    Science.gov (United States)

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

    2009-07-27

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

  4. Our plastic age

    Science.gov (United States)

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

    2009-01-01

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

  5. 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.

  6. ENVIRONMENTAL ISSUE-PLASTIC

    OpenAIRE

    Sunita Shakle

    2017-01-01

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

  7. Our plastic age

    OpenAIRE

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

    2009-01-01

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

  8. Plasticity: modeling & computation

    National Research Council Canada - National Science Library

    Borja, Ronaldo Israel

    2013-01-01

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

  9. 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.

  10. 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.

  11. Internally cooled V-shape inclined monochromator

    Czech Academy of Sciences Publication Activity Database

    Oberta, Peter; Áč, V.; Hrdý, Jaromír

    2008-01-01

    Roč. 15, - (2008), 8-11 ISSN 0909-0495 R&D Projects: GA AV ČR IAA100100716 Grant - others:VEGA(SK) 1/4134/07 Institutional research plan: CEZ:AV0Z10100522 Keywords : inclined monochromator * heat load * internal cooling Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.333, year: 2008

  12. Stem cell plasticity.

    Science.gov (United States)

    Lakshmipathy, Uma; Verfaillie, Catherine

    2005-01-01

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

  13. Plastics and environment

    International Nuclear Information System (INIS)

    Avenas, P.

    1996-01-01

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

  14. Plastics: Friend or foe?

    Directory of Open Access Journals (Sweden)

    O P Gupta

    2018-01-01

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

  15. Recycling of plastics

    Energy Technology Data Exchange (ETDEWEB)

    Kaminsky, W; Menzel, J; Sinn, H

    1976-01-01

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

  16. 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.)

  17. Art and Plastic Surgery.

    Science.gov (United States)

    Fernandes, Julio Wilson; Metka, Susanne

    2016-04-01

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

  18. DEVELOPMENT OF PLASTIC SURGERY.

    Science.gov (United States)

    Pećanac, Marija Đ

    2015-01-01

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

  19. Recycling of packing plastics

    International Nuclear Information System (INIS)

    Gintenreiter-Koegl, S.

    2001-05-01

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

  20. A Conservative Formulation for Plasticity

    Science.gov (United States)

    1992-01-01

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

  1. The plasticity of clays

    Science.gov (United States)

    Group, F.F.

    1905-01-01

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

  2. Plastics control paraffin buildup

    Energy Technology Data Exchange (ETDEWEB)

    1965-06-01

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

  3. Investigation into Plastic Cards

    Directory of Open Access Journals (Sweden)

    Neringa Stašelytė

    2015-03-01

    Full Text Available The article examines the strength of laminating plastic cards at different lamination temperatures. For investigation purposes, two types of plastic substrate and films have been used. Laminate strength has been tested (CMYK to establish the impact of colours on the strength of laminate. The paper compares inks supplied by two different producers. The colour characteristics of CIE L*a*b* space before and after the lamination process have been found. According to lamination strength and characteristics of the colours, the most suitable inks, temperature and films have been chosen.

  4. Joining by plastic deformation

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  5. Elastic plastic fracture mechanics

    International Nuclear Information System (INIS)

    Simpson, L.A.

    1978-07-01

    The application of linear elastic fracture mechanics (LEFM) to crack stability in brittle structures is now well understood and widely applied. However, in many structural materials, crack propagation is accompanied by considerable crack-tip plasticity which invalidates the use of LEFM. Thus, present day research in fracture mechanics is aimed at developing parameters for predicting crack propagation under elastic-plastic conditions. These include critical crack-opening-displacement methods, the J integral and R-curve techniques. This report provides an introduction to these concepts and gives some examples of their applications. (author)

  6. Emissies uit een vleesvarkensstal voorzien van een V-vormige mestband voor het gescheiden afvoeren van mest en urine = Emissions from a housing system for fattening pigs with a V-shaped manure belt for separated removal of faeces and urine

    NARCIS (Netherlands)

    Ellen, H.H.; Hol, J.M.G.; Mosquera, J.; Aarnink, A.J.A.

    2013-01-01

    This study reports the emissions of ammonia, odour, fine dust (PM10 and PM2.5), methane and nitrous oxide from an animal house for fattening pigs provided with V-shaped manure belts for separated removal of faeces and urine (the Kempfarm system).

  7. Plastic flashtube chambers

    International Nuclear Information System (INIS)

    Frisken, W.R.

    1977-01-01

    A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

  8. Plastic Surgery: Tackling Misconceptions

    African Journals Online (AJOL)

    will succeed. First impressions tend to last, and if young people's first impression of plastic surgeons is that they spend much of their time doing cosmetic surgery then this is a first impression that might be long ... Res 2014;4 Suppl S3:169‑70. Access this article online. Quick Response Code: Website: www.amhsr.org. DOI:.

  9. Biobased Plastics 2012

    NARCIS (Netherlands)

    Bolck, C.H.; Ravenstijn, J.; Molenveld, K.; Harmsen, P.F.H.

    2011-01-01

    Dit boek geeft inzicht in de huidige op de markt verkrijgbare biobased plastics en de te verwachten ontwikkelingen. Er wordt gekeken naar zowel thermoplastische als thermohardende materialen. Het boek biedt inzicht in de productie, verwerking en eigenschappen van de verschillende types. Daarnaast

  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. Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    1989-01-01

    In the paper it is shown how upper and lower bounds for the reliability of plastic slabs can be determined. For the fundamental case it is shown that optimal bounds of a deterministic and a stochastic analysis are obtained on the basis of the same failure mechanisms and the same stress fields....

  12. Individual differences in behavioural plasticities.

    Science.gov (United States)

    Stamps, Judy A

    2016-05-01

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

  13. Plasticity characteristic obtained by indentation

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  14. Plastic pollutants in water environment

    OpenAIRE

    Mrowiec Bożena

    2017-01-01

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

  15. Introduction to Computational Plasticity

    International Nuclear Information System (INIS)

    Hartley, P

    2006-01-01

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

  16. 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.

  17. Sub-nanosecond plastic scintillators

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  18. Sub-nanosecond plastic scintillators

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  19. Compensatory plasticity: time matters

    Directory of Open Access Journals (Sweden)

    Latifa eLazzouni

    2014-06-01

    Full Text Available Plasticity in the human and animal brain is the rule, the base for development, and the way to deal effectively with the environment for making the most efficient use of all the senses. When the brain is deprived of one sensory modality, plasticity becomes compensatory: the exception that invalidates the general loss hypothesis giving the opportunity of effective change. Sensory deprivation comes with massive alterations in brain structure and function, behavioural outcomes, and neural interactions. Blind individuals do as good as the sighted and even more, show superior abilities in auditory, tactile and olfactory processing. This behavioural enhancement is accompanied with changes in occipital cortex function, where visual areas at different levels become responsive to non-visual information. The intact senses are in general used more efficiently in the blind but are also used more exclusively. New findings are disentangling these two aspects of compensatory plasticity. What is due to visual deprivation and what is dependent on the extended use of spared modalities? The latter seems to contribute highly to compensatory changes in the congenitally blind. Short term deprivation through the use of blindfolds shows that cortical excitability of the visual cortex is likely to show rapid modulatory changes after few minutes of light deprivation and therefore changes are possible in adulthood. However, reorganization remains more pronounced in the congenitally blind. Cortico-cortical pathways between visual areas and the areas of preserved sensory modalities are inhibited in the presence of vision, but are unmasked after loss of vision or blindfolding as a mechanism likely to drive cross-modal information to the deafferented visual cortex. Plasticity in the blind is also accompanied with neurochemical and morphological changes; both intrinsic connectivity and functional coupling at rest are altered but are likewise dependent on different sensory

  20. Mesocycles in conserving plastics

    DEFF Research Database (Denmark)

    Shashoua, Yvonne

    2016-01-01

    driven by the need to balance the requirements for reversibility in conservation practices with the artist’s intent and significance. Developments within each of the three mesocycles from the 1990s to date are discussed in this article. Environmental science and toxicology of waste plastics offer a novel...... source of information about real time degradation in terrestrial and marine microenvironments that seems likely to contribute to the conservation of similar materials in contemporary artworks....

  1. Plastic footwear for leprosy.

    Science.gov (United States)

    Antia, N H

    1990-03-01

    The anaesthetic foot in leprosy poses the most major problem in the rehabilitation of its patients. Various attempts have been made to produce protective footwear such as the microcellular rubber-car-tyre sandals. Unfortunately these attempts have had little success on a large scale because of the inability to produce them in large numbers and the stigma attached to such unusual footwear. While such footwear may be superior to the 'tennis' shoe in protecting the foot from injury by the penetration of sharp objects, it fails to distribute the weight-bearing forces which is the major cause of plantar damage and ulceration in the anaesthetic foot. This can be achieved by providing rigidity to the sole, as demonstrated by the healing of ulcers in plaster of paris casts or the rigid wooden clog. A new type of moulded plastic footwear has been evolved in conjunction with the plastic footwear industry which provides footwear that can be mass produced at a low price and which overcomes the stigma of leprosy. Controlled rigidity is provided by the incorporation of a spring steel shank between the sponge insole and the hard wearing plastic sole. Trials have demonstrated both the acceptability of the footwear and its protective effects as well as its hard wearing properties.

  2. Plastic waste disposal apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Kito, S

    1972-05-01

    A test plant plastic incinerator was constructed by the Takuma Boiler Manufacturing Co. for Sekisui Chemical Industries, and the use of a continuous feed spreader was found to be most effective for prevention of black smoke, and the use of a venturi scrubber proved to be effective for elimination of hydrogen chloride gas. The incinerator was designed for combustion of polyvinyl chloride exclusively, but it is also applicable for combustion of other plastics. When burning polyethylene, polypropylene, or polystyrene, (those plastics which do not produce toxic gases), the incinerator requires no scrubber for the combustion gas. The system may or may not have a pretreatment apparatus. For an incinerator with a pretreatment system, the flow chart comprises a pit, a supply crane, a vibration feeder, a metal eliminator, a rotation shredder, a continuous screw feeder with a quantitative supply hopper, a pretreatment chamber (300 C dry distillation), a quantitative supply hopper, and the incinerator. The incinerator is a flat non-grid type combustion chamber with an oil burner and many air nozzles. From the incinerator, ashes are sent by an ash conveyor to an ash bunker. The combustion gas goes to the boiler, and the water supplied the boiler water pump creates steam. The heat from the gas is sent back to the pretreatment system through a heat exchanger. The gas then goes to a venturi scrubber and goes out from a stack.

  3. 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.

  4. Performance of molded plastic scintillators

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  5. Plastics in the Marine Environment.

    Science.gov (United States)

    Law, Kara Lavender

    2017-01-03

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

  6. Plastics in the Marine Environment

    Science.gov (United States)

    Law, Kara Lavender

    2017-01-01

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

  7. Abiotic degradation of plastic films

    Science.gov (United States)

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

    2017-01-01

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

  8. EXPLOITING THE TOOTHPICK EFFECT OF THE CYTOBRUSH BY PLASTIC EMBEDDING OF CERVICAL SAMPLES

    NARCIS (Netherlands)

    BOON, ME; ZEPPA, P; OUWERKERKNOORDAM, E; KOK, LP

    1991-01-01

    The introduction of the combined spatula-Cytobrush sampling method has increased the diagnostic accuracy of cervical cytology. However, the smears from a small number of cases contained epithelial fragments dislodged by the "toothpick effect" of the Cytobrush. Due to their thickness, these

  9. 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.

  10. Plastics pipe couplings

    International Nuclear Information System (INIS)

    Glover, J.B.

    1980-07-01

    A method is described of making a pipe coupling of the type comprising a plastics socket and a resilient annular sealing member secured in the mouth thereof, in which the material of at least one component of the coupling is subjected to irradiation with high energy radiation whereby the material is caused to undergo cross-linking. As examples, the coupling may comprise a polyethylene or plasticised PVC socket the material of which is subjected to irradiation, and the sealing member may be moulded from a thermoplastic elastomer which is subjected to irradiation. (U.K.)

  11. Plastic pollutants in water environment

    Directory of Open Access Journals (Sweden)

    Mrowiec Bożena

    2017-12-01

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

  12. 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

  13. New polyvinylchloride plasticizers

    Directory of Open Access Journals (Sweden)

    MAZITOVA Aliya Karamovna

    2017-11-01

    Full Text Available One of the main large-capacity polymers of modern chemical industry is polyvinylchloride (PVC. Polyvinylchloride is characterized by many useful engineering properties – chemical firmness in different environments, good electric properties, etc. It explains immensely various use of materials on the basis of PVC in different engineering industries. It is cable, building, light industries, mechanical engineering and automotive industry where PVC is widely applied. One of the reasons why PVC production is dramatically growing is that there is no yet other polymer which could be subjected to such various modifying as it is done with PVC. However under normal temperature this polymer is fragile and isn't elastic that limits the field of its application. Rapid growth of production of polyvinylchloride is explained by its ability to modify properties, due to introduction of special additives when processing. Introduction of plasticizers – mostlly esters of organic and inorganic acids – into PVC allows significant changing properties of polymer. Plasticizers facilitate process of receiving polymeric composition, increase flexibility and elasticity of the final polymeric product due to internal modification of polymeric molecule.

  14. Americium behaviour in plastic vessels

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  15. 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.

  16. Americium behaviour in plastic vessels.

    Science.gov (United States)

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

    2010-01-01

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

  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. 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

  20. 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.

  1. Nigerian Journal of Plastic Surgery

    African Journals Online (AJOL)

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

  2. 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,

  3. 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.

  4. 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...

  5. Computational strain gradient crystal plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2014-01-01

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

  6. Grain Interactions in Crystal Plasticity

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  7. 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.

  8. 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.

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

    Science.gov (United States)

    Xanthos, Dirk; Walker, Tony R

    2017-05-15

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

  10. Water Vapor Permeation in Plastics

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-01

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

  11. Extruding plastic scintillator at Fermilab

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  12. Space Plastic Recycling System, Phase I

    Data.gov (United States)

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

  13. Durability of wood plastic composites manufactured from recycled plastic

    Directory of Open Access Journals (Sweden)

    Irina Turku

    2018-03-01

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

  14. 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...

  15. Developmental plasticity: Friend or foe?

    Science.gov (United States)

    Michels, Karin B

    2017-01-01

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

  16. Radiation damage in plastic scintillators

    International Nuclear Information System (INIS)

    Majewski, S.

    1990-01-01

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

  17. 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...

  18. 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.

  19. Wood plastic combination

    International Nuclear Information System (INIS)

    Cunanan, S.A.; Bonoan, L.S.; Verceluz, F.P.; Azucena, E.A.

    1976-03-01

    The purpose of this study is to improve the physical and mechaniproperties of local inferior quality wood species by radiation-induced graft polymerization with plastic monomers. The process involves the following: 1) Preparation of sample; 2) Impregnation of sample with the monomers; 3) Irradiation of the impregnated sample with the use of 20,000 curie Co-60 as gamma-source; 4) Drying of irradiated sample to remove the unpolymerized monomer. Experimentation on different wood species were undertaken and the results given. From the results obtained, it can be concluded that the monomers systems MMA, MMA-USP, and styrene-USP are suitable for graft polymerization with the wood species almon, apitong, bagtikan, mayapis, red lauan, and tanguile. This is shown by their maximum conversion value which range from 86% to 96% with the optimum dose range of 1 to 2 Mrads. However, in the application of WPC process, properties that are required in a given wood product must be considered, thus aid in the selection of the monomer system to be used with a particular wood species. Some promising applications of WPC is in the manufacture of picker sticks, shuttles, and bobbins for the textile industry. However, there is a need for a pilot plant scale study so that an economic assessment of the commercial feasibility of this process can be made

  20. Helene: A Plastic Model

    Science.gov (United States)

    Umurhan, O. M.; Moore, J. M.; Howard, A. D.; Schenk, P.; White, O. L.

    2014-12-01

    Helene, the Saturnian L4 Trojan satellite co-orbiting Dionne and sitting within the E-ring, possesses an unusual morphology characteristic of broad km-scale basins and depressions and a generally smooth surface patterned with streaks and grooves which are indicative of non-typical mass transport. Elevation angles do not appear to exceed 10o at most. The nature and origin of the surface materials forming these grooved patterns is unknown. Given the low surface gravity (plastic-like flow like a Bingham fluid, we setup and test a number of likely scenarios to explain the observations. The numerical results qualitatively indicate that treating the mass-wasting materials as a Bingham material reproduces many of the qualitative features observed. We also find that in those simulations in which accretion is concomitant with Bingham mass-wasting, the long time-evolution of the surface flow shows intermittency in the total surface activity (defined as total surface integral of the absolute magnitude of the mass-flux). Detailed analyses identify the locations where this activity is most pronounced and we will discuss these and its implications in further detail.

  1. Energy recovery from plastic wastes

    Energy Technology Data Exchange (ETDEWEB)

    Baur, A; Atzger, J

    1983-07-01

    The conversion of plastic wastes to energy is suggested as a practicable and advantageous alternative to recycling. A two-stage pilot gasification plant for the pyrolysis of wastes is described and the utilization of the resulting fuel gas discussed.

  2. 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.

  3. Neuromodulation, development and synaptic plasticity.

    Science.gov (United States)

    Foehring, R C; Lorenzon, N M

    1999-03-01

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

  4. WEATHERABILITY OF ENHANCED DEGRADABLE PLASTICS

    Science.gov (United States)

    The main objective of this study was to assess the performance and the asociated variability of several selected enhanced degradable plastic materials under a variety of different exposure conditions. Other objectives were to identify the major products formed during degradation ...

  5. 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....

  6. Biocide Usage in Plastic Products

    OpenAIRE

    Kavak, Nergizhan; Çakır, Ayşegül; Koltuk, Fatmagül; Uzun, Utku

    2015-01-01

    People’s demand of improving their life quality caused to the term of hygiene become popular and increased the tendency to use more reliable and healthy products. This tendency makes the continuous developments in the properties of the materials used in manufactured goods compulsory. It is possible to create anti-bacterial plastic products by adding biocidal additives to plastic materials which have a wide-range of application in the areas such as health (medicine), food and many other indust...

  7. Interhemispheric plasticity in humans.

    Science.gov (United States)

    Hortobágyi, Tibor; Richardson, Sarah Pirio; Lomarev, Mikhael; Shamim, Ejaz; Meunier, Sabine; Russman, Heike; Dang, Nguyet; Hallett, Mark

    2011-07-01

    Chronic unimanual motor practice increases the motor output not only in the trained but also in the nonexercised homologous muscle in the opposite limb. We examined the hypothesis that adaptations in motor cortical excitability of the nontrained primary motor cortex (iM1) and in interhemispheric inhibition from the trained to the nontrained M1 mediate this interlimb cross education. Healthy, young volunteers (n=12) performed 1000 submaximal voluntary contractions (MVC) of the right first dorsal interosseus (FDI) at 80% MVC during 20 sessions. Trained FDI's MVC increased 49.9%, and the untrained FDI's MVC increased 28.1%. Although corticospinal excitability in iM1, measured with transcranial magnetic stimulation (TMS) before and after every fifth session, increased 6% at rest, these changes, as those in intracortical inhibition and facilitation, did not correlate with cross education. When weak and strong TMS of iM1 were delivered on a background of a weak and strong muscle contraction, respectively, of the right FDI, excitability of iM1 increased dramatically after 20 sessions. Interhemispheric inhibition decreased 8.9% acutely within sessions and 30.9% chronically during 20 sessions and these chronic reductions progressively became more strongly associated with cross education. There were no changes in force or TMS measures in the trained group's left abductor minimi digiti and there were no changes in the nonexercising control group (n=8). The findings provide the first evidence for plasticity of interhemispheric connections to mediate cross education produced by a simple motor task.

  8. 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.

  9. 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...

  10. 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...

  11. Plastic zonder olie : lesmodule voor nieuwe scheikunde

    OpenAIRE

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

    2013-01-01

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

  12. Elimination of Plastic Polymers in Natural Environments

    OpenAIRE

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

    2017-01-01

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

  13. Avalanches and plastic flow in crystal plasticity: an overview

    Science.gov (United States)

    Papanikolaou, Stefanos; Cui, Yinan; Ghoniem, Nasr

    2018-01-01

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

  14. Plasticity characteristic obtained by indentation

    International Nuclear Information System (INIS)

    Milman, Yu V

    2008-01-01

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

  15. Mechanisms of GABAergic Homeostatic Plasticity

    Directory of Open Access Journals (Sweden)

    Peter Wenner

    2011-01-01

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

  16. Neurogenomic mechanisms of social plasticity.

    Science.gov (United States)

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

    2015-01-01

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

  17. Smartphones and the plastic surgeon.

    Science.gov (United States)

    Al-Hadithy, Nada; Ghosh, Sudip

    2013-06-01

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

  18. Exercise and plasticize the brain

    DEFF Research Database (Denmark)

    Mala, Hana; Wilms, Inge

    Neuroscientific studies continue to shed light on brain’s plasticity and its innate mechanisms to recover. The recovery process includes re-wiring of the existing circuitry, establishment of new connections, and recruitment of peri-lesional and homologous areas in the opposite hemisphere....... The plasticity of the brain can be stimulated and enhanced through training, which serves as a fundamental element of neurorehabilitative strategies. For instance, intensive cognitive and physical training promote the activation of processes that may help the brain to adapt to new conditions and needs. However...... neurorehabilitation is to understand and define how to stimulate the injured brain to elicit the desired adaptation. Research focuses on uncovering specific elements relevant for training planning and execution in order to create an environment that stimulates and maximizes the exploitation of the brain’s plastic...

  19. Surface properties of beached plastics.

    Science.gov (United States)

    Fotopoulou, Kalliopi N; Karapanagioti, Hrissi K

    2015-07-01

    Studying plastic characteristics in the marine environment is important to better understand interaction between plastics and the environment. In the present study, high-density polyethylene (HDPE), polyethylene terephalate (PET), and polyvinyl chloride (PVC) samples were collected from the coastal environment in order to study their surface properties. Surface properties such as surface functional groups, surface topography, point of zero charge, and color change are important factors that change during degradation. Eroded HDPE demonstrated an altered surface topography and color and new functional groups. Eroded PET surface was uneven, yellow, and occasionally, colonized by microbes. A decrease in Fourier transform infrared (FTIR) peaks was observed for eroded PET suggesting that degradation had occurred. For eroded PVC, its surface became more lamellar and a new FTIR peak was observed. These surface properties were obtained due to degradation and could be used to explain the interaction between plastics, microbes, and pollutants.

  20. The Prism Plastic Calorimeter (PPC)

    CERN Multimedia

    2002-01-01

    This proposal supports two goals: \\\\ \\\\ First goal:~~Demonstrate that current, widely used plastic technologies allow to design Prism Plastic Calorimeter~(PPC) towers with a new ``liquid crystal'' type plastic called Vectra. It will be shown that this technique meets the requirements for a LHC calorimeter with warm liquids: safety, hermeticity, hadronic compensation, resolution and time response. \\\\ \\\\ Second goal:~~Describe how one can design a warm liquid calorimeter integrated into a LHC detector and to list the advantages of the PPC: low price, minimum of mechanical structures, minimum of dead space, easiness of mechanical assembly, accessibility to the electronics, possibility to recirculate the liquid. The absorber and the electronic being outside of the liquid and easily accessible, one has maximum flexibility to define them. \\\\ \\\\ The R&D program, we define here aims at showing the feasibility of these new ideas by building nine towers of twenty gaps and exposing them to electron and hadron beams.

  1. Plastic solidification of radioactive wastes

    International Nuclear Information System (INIS)

    Moriyama, Noboru

    1981-01-01

    Over 20 years have elapsed after the start of nuclear power development, and the nuclear power generation in Japan now exceeds the level of 10,000 MW. In order to meet the energy demands, the problem of the treatment and disposal of radioactive wastes produced in nuclear power stations must be solved. The purpose of the plastic solidification of such wastes is to immobilize the contained radionuclides, same as other solidification methods, to provide the first barrier against their move into the environment. The following matters are described: the nuclear power generation in Japan, the radioactive wastes from LWR plants, the position of plastic solidification, the status of plastic solidification in overseas countries and in Japan, the solidification process for radioactive wastes with polyethylene, and the properties of solidified products, and the leachability of radionuclides in asphalt solids. (J.P.N.)

  2. Constraints on the evolution of phenotypic plasticity

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  3. Plasticity Theory of Fillet Welds

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    a safe and statically admissible stress distribution is established. The plasticity solutions are compared with tests carried out at the Engineering Academy of Denmark, Lyngby, in the early nineties, and old fillet weld tests. The new failure conditions are in very good agreement with the yield load......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...... tests, but not so good agreement with the old failure load tests....

  4. The Plastic Tension Field Method

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper describes a calculation method for steel plate girders with transverse web stiffeners subjected to shear. It may be used for predicting the failure load or, as a design method, to determine the optimal amount of internal web stiffeners. The new method is called the plastic tension field...... method. The method is based on the theory of plasticity and is analogous to the so-called diagonal compression field method developed for reinforced concrete beams with transverse stirrups, which is adopted in the common European concrete code (Eurocode 2). Many other theories have been developed...

  5. Preparation of coloured wood plastics

    International Nuclear Information System (INIS)

    Lebedev, V.T.; Filippova, T.G.; Rajchuk, F.Z.

    1977-01-01

    A study has been made into the possibility of using fat, as well as alcohol- and water-soluble dyes for radiation-chemical dying of polymers and plastics filled with wood. The use of fat-soluble azo and anthraquinone dyes permits obtaining intensely colored wood-plastic materials based on methyl methacrylate by way of gamma radiation with doses of up to 3 Mrad. At a dose above 5 Mrad, a marked tarnishing of the dye or a change in color and stains are observed. Dyes in styrene withstand higher radiation doses without any significant destruction

  6. A work criterion for plastic collapse

    International Nuclear Information System (INIS)

    Muscat, Martin; Mackenzie, Donald; Hamilton, Robert

    2003-01-01

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

  7. Body dysmorphia and plastic surgery.

    Science.gov (United States)

    Kyle, Allison

    2012-01-01

    Body dysmorphic disorder is a mental disorder characterized by a preoccupation with some aspect of one's appearance. In cosmetic surgery, this preoccupation can be overlooked by practitioners resulting in a discrepancy between expected and realistic outcome. Identifying the characteristics of this disorder may be crucial to the practitioner-patient relationship in the plastic surgery setting.

  8. Ways of Viewing Pictorial Plasticity

    NARCIS (Netherlands)

    Wijntjes, M.W.A.

    2017-01-01

    The plastic effect is historically used to denote various forms of stereopsis. The vivid impression of depth often associated with binocular stereopsis can also be achieved in other ways, for example, using a synopter. Accounts of this go back over a hundred years. These ways of viewing all aim

  9. Ways of Viewing Pictorial Plasticity

    Directory of Open Access Journals (Sweden)

    Maarten W. A. Wijntjes

    2017-03-01

    Full Text Available The plastic effect is historically used to denote various forms of stereopsis. The vivid impression of depth often associated with binocular stereopsis can also be achieved in other ways, for example, using a synopter. Accounts of this go back over a hundred years. These ways of viewing all aim to diminish sensorial evidence that the picture is physically flat. Although various viewing modes have been proposed in the literature, their effects have never been compared. In the current study, we compared three viewing modes: monocular blur, synoptic viewing, and free viewing (using a placebo synopter. By designing a physical embodiment that was indistinguishable for the three experimental conditions, we kept observers naïve with respect to the differences between them; 197 observers participated in an experiment where the three viewing modes were compared by performing a rating task. Results indicate that synoptic viewing causes the largest plastic effect. Monocular blur scores lower than synoptic viewing but is still rated significantly higher than the baseline conditions. The results strengthen the idea that synoptic viewing is not due to a placebo effect. Furthermore, monocular blur has been verified for the first time as a way of experiencing the plastic effect, although the effect is smaller than synoptic viewing. We discuss the results with respect to the theoretical basis for the plastic effect. We show that current theories are not described with sufficient details to explain the differences we found.

  10. Ways of Viewing Pictorial Plasticity.

    Science.gov (United States)

    Wijntjes, Maarten W A

    2017-01-01

    The plastic effect is historically used to denote various forms of stereopsis. The vivid impression of depth often associated with binocular stereopsis can also be achieved in other ways, for example, using a synopter. Accounts of this go back over a hundred years. These ways of viewing all aim to diminish sensorial evidence that the picture is physically flat. Although various viewing modes have been proposed in the literature, their effects have never been compared. In the current study, we compared three viewing modes: monocular blur, synoptic viewing, and free viewing (using a placebo synopter). By designing a physical embodiment that was indistinguishable for the three experimental conditions, we kept observers naïve with respect to the differences between them; 197 observers participated in an experiment where the three viewing modes were compared by performing a rating task. Results indicate that synoptic viewing causes the largest plastic effect. Monocular blur scores lower than synoptic viewing but is still rated significantly higher than the baseline conditions. The results strengthen the idea that synoptic viewing is not due to a placebo effect. Furthermore, monocular blur has been verified for the first time as a way of experiencing the plastic effect, although the effect is smaller than synoptic viewing. We discuss the results with respect to the theoretical basis for the plastic effect. We show that current theories are not described with sufficient details to explain the differences we found.

  11. Electron beam micromachining of plastics

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor

    2014-01-01

    Roč. 49, 5-6 (2014), s. 310-314 ISSN 0861-4717 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA MŠk EE.2.3.20.0103 Institutional support: RVO:68081731 Keywords : micromachining of plastics * Electron beam Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  12. Field based plastic contamination sensing

    Science.gov (United States)

    The United States has a long-held reputation of being a dependable source of high quality, contaminant-free cotton. Recently, increased incidence of plastic contamination from sources such as shopping bags, vegetable mulch, surface irrigation tubing, and module covers has threatened the reputation o...

  13. Recycling of plastics in Germany

    International Nuclear Information System (INIS)

    Thienen, N. von; Patel, M.

    1999-01-01

    This article deals with the waste management of post-consumer plastics in Germany and its potential to save fossil fuels and reduce CO 2 emissions. Since most experience is available for packaging, the paper first gives an overview of the legislative background and the material flows for this sector. Then recycling and recovery processes for plastics waste from all sectors are assessed in terms of their contribution to energy saving and CO 2 abatement. Practically all the options studied show a better performance than waste treatment in an average incinerator which has been chosen as the reference case. High ecological benefits can be achieved by mechanical recycling if virgin polymers are substituted. The paper then presents different scenarios for managing plastic waste in Germany in 1995: considerable savings can be made by strongly enhancing the efficiency of waste incinerators. Under these conditions the distribution of plastics waste among mechanical recycling, feedstock recycling and energy recovery has a comparatively mall impact on the overall results. The maximum savings amount to 74 PJ of energy, i.e, 9% of the chemical sector energy demand in 1995 and 7.0 Mt CO 2 , representing 13% of the sector's emissions. The assessment does not support a general recommendation of energy recovery due to the large difference between the German average and the best available municipal waste-to-energy facilities and also due to new technological developments in the field of mechanical recycling

  14. Transformation plasticity and hot pressing

    International Nuclear Information System (INIS)

    Chaklader, A.C.D.

    1975-01-01

    The transformation plasticity during the phase transition of quartz to cristobalite, monoclinic reversible tetragonal of zirconia, metakaolin to a spinel phase, and brucite to periclase was investigated by studying their compaction characteristics. Viscous flow was found to be the predominant mechanism of mass transport (after an initial particle rearrangement stage) in the case of quartz to cristobalite phase change where the transformation was associated with the formation of an intermediate amorphous silica phase. The results on the monoclinic reversible tetragonal transformation of zirconia indicated that it is most likely controlled by internal strain induced by the stress associated with the volume change (ΔV/V) and the flow stress of the weaker phase. Particle movement and deformation of the weaker phase (possibly tetragonal) may be the manifestation of this plasticity. The plasticity in the case of metakaolin to a spinel phase appeared to start before the exothermic reaction (generally encountered in a dta plot) and may be diffusion controlled. The plasticity encountered during brucite to periclase transformation may be the combined effect of disintegration of precursor particles, vapor-phase lubrication and some deformability of freshly formed very fine MgO particles

  15. Plastics and beaches: A degrading relationship

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  16. Toward Modeling Limited Plasticity in Ceramic Materials

    National Research Council Canada - National Science Library

    Grinfeld, Michael; Schoenfeld, Scott E; Wright, Tim W

    2008-01-01

    The characteristic features of many armor-related ceramic materials are the anisotropy on the micro-scale level and the very limited, though non-vanishing, plasticity due to limited number of the planes for plastic slip...

  17. Antireflection coatings on plastics deposited by plasma ...

    Indian Academy of Sciences (India)

    In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses ... Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. ... Bulletin of Materials Science | News.

  18. Mechanical behaviour of nanoparticles: Elasticity and plastic ...

    Indian Academy of Sciences (India)

    2015-06-03

    Jun 3, 2015 ... Mechanical behaviour of nanoparticles: Elasticity and plastic deformation mechanisms ... The main results in terms of elasticity and plastic deformation mechanisms are then reported ... Pramana – Journal of Physics | News.

  19. Recycling plastic bottles in a creative way

    OpenAIRE

    Pavlin, Suzana

    2016-01-01

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

  20. Plastic Accumulation in the Mediterranean Sea

    OpenAIRE

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

    2015-01-01

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

  1. 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.

  2. PLASTIC ANALYSIS OF STEEL FRAME STRUCTURE

    Directory of Open Access Journals (Sweden)

    M. Rogac

    2013-05-01

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

  3. 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...

  4. 7 CFR 58.326 - Plastic cream.

    Science.gov (United States)

    2010-01-01

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

  5. Use of Plastic Mulch for Vegetable Production

    OpenAIRE

    Maughan, Tiffany; Drost, Dan

    2016-01-01

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

  6. The evolution of age-dependent plasticity

    NARCIS (Netherlands)

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

    2014-01-01

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

  7. Plastic Debris Is a Human Health Issue

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    NARCIS (Netherlands)

    Jamari, Jamari; Schipper, Dirk J.

    2007-01-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    OpenAIRE

    Pasqual i Camprubí, Gemma

    2010-01-01

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

  11. Plasticity Approach to Shear Design

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1998-01-01

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

  12. 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....

  13. Alternative Diesel from Waste Plastics

    Directory of Open Access Journals (Sweden)

    Stella Bezergianni

    2017-10-01

    Full Text Available The long term ambition of energy security and solidarity, coupled with the environmental concerns of problematic waste accumulation, is addressed via the proposed waste-to-fuel technology. Plastic waste is converted into automotive diesel fuel via a two-step thermochemical process based on pyrolysis and hydrotreatment. Plastic waste was pyrolyzed in a South East Asia plant rendering pyrolysis oil, which mostly consisted of middle-distillate (naphtha and diesel hydrocarbons. The diesel fraction (170–370 °C was fractionated, and its further upgrade was assessed in a hydroprocessing pilot plant at the Centre for Research and Technology Hellas (CERTH in Greece. The final fuel was evaluated with respect to the diesel fuel quality specifications EN 590, which characterized it as a promising alternative diesel pool component with excellent ignition quality characteristics and low back end volatility.

  14. Polishing compound for plastic surfaces

    Science.gov (United States)

    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. Temperature dependence of plastic scintillators

    Science.gov (United States)

    Peralta, L.

    2018-03-01

    Plastic scintillator detectors have been studied as dosimeters, since they provide a cost-effective alternative to conventional ionization chambers. Several articles have reported undesired response dependencies on beam energy and temperature, which provides the motivation to determine appropriate correction factors. In this work, we studied the light yield temperature dependency of four plastic scintillators, BCF-10, BCF-60, BC-404, RP-200A and two clear fibers, BCF-98 and SK-80. Measurements were made using a 50 kVp X-ray beam to produce the scintillation and/or radioluminescence signal. The 0 to 40 °C temperature range was scanned for each scintillator, and temperature coefficients were obtained.

  16. Vascular plasticity in cerebrovascular disorders

    DEFF Research Database (Denmark)

    Edvinsson, Lars I H; Povlsen, Gro Klitgaard

    2011-01-01

    Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries and micr......Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries...... therapeutic target for prevention of vasoconstrictor receptor upregulation after stroke. Together, those findings provide new perspectives on the pathophysiology of ischemic stroke and point toward a novel way of reducing vasoconstriction, neuronal cell death, and thus neurologic deficits after stroke....

  17. Process for remediation of plastic waste

    Science.gov (United States)

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

    2012-04-10

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

  18. Learning and plasticity in adolescence

    OpenAIRE

    Fuhrmann, Delia Ute Dorothea

    2017-01-01

    Adolescence is the period of life between puberty and relative independence. It is a time during which the human brain undergoes protracted changes - particularly in the frontal, parietal and temporal cortices. These changes have been linked to improvements in cognitive performance; and are thought to render adolescence a period of relatively high levels of plasticity, during which the environment has a heightened impact on brain development and behaviour. This thesis investigates learning an...

  19. Studies of novel plastic scintillators

    International Nuclear Information System (INIS)

    McInally, I.D.

    1979-08-01

    The general aim of this study was to synthesize fluorescent compounds which are capable of polymerisation, to prepare polymers and co-polymers from these compounds and to study the photophysical properties of these materials. In this way it is hoped to produce plastic scintillators exhibiting improved energy transfer efficiency. Materials studied included POS(2-phenyl-5-(p vinyl) phenyloxazole) vinyl naphthalene, methyl anthracene terminated poly vinyl toluene) and derivatives of BuPBD. (author)

  20. Ways of Viewing Pictorial Plasticity

    OpenAIRE

    Maarten W. A. Wijntjes

    2017-01-01

    The plastic effect is historically used to denote various forms of stereopsis. The vivid impression of depth often associated with binocular stereopsis can also be achieved in other ways, for example, using a synopter. Accounts of this go back over a hundred years. These ways of viewing all aim to diminish sensorial evidence that the picture is physically flat. Although various viewing modes have been proposed in the literature, their effects have never been compared. In the current study, we...

  1. The Plastic Surgery Hand Curriculum.

    Science.gov (United States)

    Silvestre, Jason; Levin, L Scott; Serletti, Joseph M; Chang, Benjamin

    2015-12-01

    Designing an effective hand rotation for plastic surgery residents is difficult. The authors address this limitation by elucidating the critical components of the hand curriculum during plastic surgery residency. Hand questions on the Plastic Surgery In-Service Training Exam for six consecutive years (2008 to 2013) were characterized by presence of imaging, vignette setting, question taxonomy, answer domain, anatomy, and topic. Answer references were quantified by source and year of publication. Two hundred sixty-six questions were related to hand surgery (22.7 percent of all questions; 44.3 per year) and 61 were accompanied by an image (22.9 percent). Vignettes tended to be clinic- (50.0 percent) and emergency room-based (35.3 percent) (p < 0.001). Questions required decision-making (60.5 percent) over interpretation (25.9 percent) and recall skills (13.5 percent) (p < 0.001). Answers focused on interventions (57.5 percent) over anatomy/pathology (25.2 percent) and diagnoses (17.3 percent) (p < 0.001). Nearly half of the questions focused on the digits. The highest yield topics were trauma (35.3 percent), reconstruction (24.4 percent), and aesthetic and functional problems (14.2 percent). The Journal of Hand Surgery (American volume) (20.5 percent) and Plastic and Reconstructive Surgery (18.0 percent) were the most-cited journals, and the median publication lag was 7 years. Green's Operative Hand Surgery was the most-referenced textbook (41.8 percent). These results will enable trainees to study hand surgery topics with greater efficiency. Faculty can use these results to ensure that tested topics are covered during residency training. Thus, a benchmark is established to improve didactic, clinical, and operative experiences in hand surgery.

  2. Processing of plastic track detectors

    International Nuclear Information System (INIS)

    Somogyi, G.

    1977-01-01

    A survey of some actual problems of the track processing methods available at this time for plastics is presented. In the case of the conventional chemical track-etching technique, mainly the etching situations related to detector geometry, and the relationship between registration sensitivity and the etching parameters are considered. Special attention is paid to the behaviour of track-revealing by means of electrochemical etching. Finally, some properties of a promising new track processing method based on graft polymerization are discussed. (author)

  3. Processing of plastic track detectors

    International Nuclear Information System (INIS)

    Somogyi, G.

    1976-01-01

    A survey of some actual problems of the track processing methods available at this time for plastics is presented. In the case of the conventional chemical track etching technique mainly the etching situations related to detector geometry and the relationship of registration sensitivity and the etching parameters are considered. A special attention is paid to the behaviour of track revealing by means of electrochemical etching. Finally, some properties of a promising new track processing method based on graft polymerization is discussed. (orig.) [de

  4. Elastic-plastic fracture mechanics of compact bone

    Science.gov (United States)

    Yan, Jiahau

    Bone is a composite composed mainly of organics, minerals and water. Most studies on the fracture toughness of bone have been conducted at room temperature. Considering that the body temperature of animals is higher than room temperature, and that bone has a high volumetric percentage of organics (generally, 35--50%), the effect of temperature on fracture toughness of bone should be studied. Single-edged V-shaped notched (SEVN) specimens were prepared to measure the fracture toughness of bovine femur and manatee rib in water at 0, 10, 23, 37 and 50°C. The fracture toughness of bovine femur and manatee rib were found to decrease from 7.0 to 4.3 MPa·m1/2 and from 5.5 to 4.1 MPa·m1/2, respectively, over a temperature range of 50°C. The decreases were attributed to inability of the organics to sustain greater stresses at higher temperatures. We studied the effects of water and organics on fracture toughness of bone using water-free and organics-free SEVN specimens at 23°C. Water-free and organics-free specimens were obtained by placing fresh bone specimen in a furnace at different temperatures. Water and organics significantly affected the fracture toughness of bone. Fracture toughness of the water-free specimens was 44.7% (bovine femur) and 32.4% (manatee rib) less than that of fresh-bone specimens. Fracture toughness of the organics-free specimens was 92.7% (bovine femur) and 91.5% (manatee rib) less than that of fresh bone specimens. Linear Elastic Fracture Mechanics (LEFM) is widely used to study bone. However, bone often has small to moderate scale yielding during testing. We used J integral, an elastic-plastic fracture-mechanics parameter, to study the fracture process of bone. The J integral of bovine femur increased from 6.3 KJ/mm2 at 23°C to 6.7 KJ/mm2 at 37°C. Although the fracture toughness of bovine bone decreases as the temperature increases, the J integral results show a contrary trend. The energy spent in advancing the crack beyond the linear

  5. Vocal plasticity in a reptile.

    Science.gov (United States)

    Brumm, Henrik; Zollinger, Sue Anne

    2017-05-31

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

  6. Plastic buckling of cylindrical shells

    International Nuclear Information System (INIS)

    Bandyopadhyay, K.; Xu, J.; Shteyngart, S.; Eckert, H.

    1994-01-01

    Cylindrical shells exhibit buckling under axial loads at stresses much less than the respective theoretical critical stresses. This is due primarily to the presence of geometrical imperfections even though such imperfections could be very small (e.g., comparable to thickness). Under internal pressure, the shell regains some of its buckling strength. For a relatively large radius-to-thickness ratio and low internal pressure, the effect can be reasonably estimated by an elastic analysis. However, for low radius-to-thickness ratios and greater pressures, the elastic-plastic collapse controls the failure load. in order to quantify the elastic-plastic buckling capacity of cylindrical shells, an analysis program was carried out by use of the computer code BOSOR5 developed by Bushnell of Lockheed Missiles and Space Company. The analysis was performed for various radius-to-thickness ratios and imperfection amplitudes. The purpose of the analytical program was to compute the buckling strength of underground cylindrical tanks, that are used for storage of nuclear wastes, for realistic geometric imperfections and internal pressure loads. This paper presents the results of the elastic-plastic analyses and compares them with other available information for various pressure loads

  7. Plastic solid waste utilization technologies: A Review

    Science.gov (United States)

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

    2017-11-01

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

  8. 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.

  9. Is the holy grail plastic? Radiation identification from plastic scintillators

    International Nuclear Information System (INIS)

    Butchins, L. J. C.; Gosling, J. M.; Hogbin, M. R. W.; Jones, D. C.; Lacey, R. J.; Stearn, J. G.

    2009-01-01

    Thousands of shipping containers containing Naturally Occurring Radioactive Materials (NORM) made from ceramics, stoneware and other natural products are transported worldwide on a daily basis. Some of these NORM loads are sufficiently radioactive to trigger alarms from plastic scintillator detectors which have limited ability to also identify the radionuclides present thus necessitating secondary inspection which increases the operational overhead. Previous studies have been carried out to ascertain if radionuclide discrimination using plastic scintillators is possible with a variety of approaches including deconvolution and computer learning. In this paper, a two stage algorithm is described. An example implementation of the algorithm is presented, applied to operational data, and has been installed in real time operation on a polyvinyl-toluene (PVT) detector. The approach requires the collection of a large library of spectra using examples of the detectors to be deployed. In this study, data from both actual freight loads passing through a port and predefined freight containing various radionuclides were collected. The library represents freight loads that may contain industrial, medical, nuclear, and NORM radionuclides. The radionuclides in the predefined freight were placed in various orientations and in various amounts of shielding to mimic many different scenarios. Preliminary results on an initial subset of data containing industrial and NORM sources show the number of mis-classifications to be less than 1% of the total test data. Good initial results were obtained even for low energy radionuclides such as 241 Am. Where discrimination is not possible, and principle components overlap, this region or 'cloud' of the n-dimensional plot can be put aside. Those spectra that fall in the 'cloud' can be regarded as suspect and in these cases, some secondary screening will still be necessary. It is predicted that the algorithm will enable recognition of NORM loads

  10. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  12. 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.

  13. "Oriental anthropometry" in plastic surgery

    Directory of Open Access Journals (Sweden)

    Senna-Fernandes Vasco

    2008-01-01

    Full Text Available Background : According to Chinese medicine, the acupuncture-points′ (acupoints locations are proportionally and symmetrically distributed in well-defined compartment zones on the human body surface Oriental Anthropometry" (OA. Acupoints, if considered as aesthetic-loci, might be useful as reference guides in plastic surgery (PS. Aim: This study aimed to use aesthetic-loci as anatomical reference in surgical marking of Aesthetic Plastic Surgery. Method: This was an observational study based on aesthetic surgeries performed in private clinic. This study was based on 106 cases, comprising of 102 women and 4 men, with ages varying from 07 to 73 years, and with heights of between 1.34 m and 1.80 m. Patients were submitted to aesthetic surgical planning by relating aesthetic-loci to conventional surgical marking, including breast surgeries, abdominoplasty, rhytidoplasty, blepharoplasty, and hair implant. The aesthetic-surgical-outcome (ASO of the patients was assessed by a team of plastic surgeons (who were not involved in the surgical procedures over a follow-up period of one year by using a numeric-rating-scale in percentage (% terms. A four-point-verbal-rating-scale was used to record the patients′ opinion of therapeutic-satisfaction (TS. Results: ASO was 75.3 ± 9.4% and TS indicated that most patients (58.5% obtained "good" results. Of the remainder, 38.7% found the results "excellent", and 2.8% found them "fair". Discussion and Conclusion : The data suggested that the use of aesthetic-loci may be a useful tool for PS as an anatomical reference for surgical marking. However, further investigation is required to assess the efficacy of the OA by providing the patients more reliable balance and harmony in facial and body contours surgeries.

  14. Dislocation Dynamics During Plastic Deformation

    CERN Document Server

    Messerschmidt, Ulrich

    2010-01-01

    The book gives an overview of the dynamic behavior of dislocations and its relation to plastic deformation. It introduces the general properties of dislocations and treats the dislocation dynamics in some detail. Finally, examples are described of the processes in different classes of materials, i.e. semiconductors, ceramics, metals, intermetallic materials, and quasicrystals. The processes are illustrated by many electron micrographs of dislocations under stress and by video clips taken during in situ straining experiments in a high-voltage electron microscope showing moving dislocations. Thus, the users of the book also obtain an immediate impression and understanding of dislocation dynamics.

  15. A miniaturized plastic dilution refrigerator

    International Nuclear Information System (INIS)

    Bindilatti, V.; Oliveira, N.F.Jr.; Martin, R.V.; Frossati, G.

    1996-01-01

    We have built and tested a miniaturized dilution refrigerator, completely contained (still, heat exchanger and mixing chamber) inside a plastic (PVC) tube of 10 mm diameter and 170 mm length. With a 25 cm 2 CuNi heat exchanger, it reached temperatures below 50 mK, for circulation rates below 70 μmol/s. The cooling power at 100 mK and 63 μmol/s was 45 μW. The experimental space could accommodate samples up to 6 mm in diameter. (author)

  16. Synaptic plasticity in drug reward circuitry.

    Science.gov (United States)

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

    2002-11-01

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

  17. River plastic emissions to the world's oceans

    Science.gov (United States)

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

    2017-06-01

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

  18. Biodegradability of Plastics: Challenges and Misconceptions.

    Science.gov (United States)

    Kubowicz, Stephan; Booth, Andy M

    2017-11-07

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

  19. Phyllosphere yeasts rapidly break down biodegradable plastics

    OpenAIRE

    Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

    2011-01-01

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily ...

  20. Plastic Recycling Experiments in Materials Education

    Science.gov (United States)

    Liu, Ping; Waskom, Tommy L.

    1996-01-01

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

  1. Radiation resistance of plastic solid

    International Nuclear Information System (INIS)

    Moriyama, Noboru; Dojiri, Shigeru; Wadachi, Yoshiki

    1985-01-01

    The radiation from nucleides contained in solidified wates have some effects on the degradation of the solidification materials. This report deals with effects of such radiation on the mechanical strength of waste-plastics composites and on the generation of gasses. It is shown that the mechanical strength of polyethylene and polyester solids will not decrease at a total absorbed dose of 10 6 rad, a dose which a low-level waste composite is expected to receive during an infinite period of time. Rather, it increases in the case of polyethylene. The amount of gas generated from degraded polyethylene is about three times as large as that from polyester, namely, about 6 l per 200 l drum can at 10 6 rad. Hydrogen accounts for about 80 % of the total gas generated from polyethylene. On the other hand, the gas from polyester solid mainly contains hydrogen, carbon dioxide, carbon monoxide and methane, with a composition greatly dependent on the type of the waste contained. It is concluded from these results that plastic materials can serve satisfactorily as for as the effects of radiation on their mechanical strength and gas generation are concerned. A more important problem still remaining to be solved is the effects of radiation on the leaching of radioactive nuclides. (Nogami, K.)

  2. Waste product profile: Plastic film and bags

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  3. Extruded plastic scintillator for MINERvA

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  4. Leaching of plastic additives to marine organisms

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  5. Environment friendly solutions of plastics waste management

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  6. Neuronal cytoskeleton in synaptic plasticity and regeneration.

    Science.gov (United States)

    Gordon-Weeks, Phillip R; Fournier, Alyson E

    2014-04-01

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

  7. 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.

  8. Some Limitations in the Use of Plastic and Dyed Plastic Dosimeters

    DEFF Research Database (Denmark)

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

    1975-01-01

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

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

    OpenAIRE

    Zhou, Feng; Cheng, Guangxu

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

  11. Views of college students on plastic surgery.

    Science.gov (United States)

    Ahmad, Muhammad; Mohmand, Humayun; Ahmad, Nabila

    2013-06-01

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

  12. 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.

  13. Properties of plastic filtration material

    Energy Technology Data Exchange (ETDEWEB)

    Paluch, W.

    1988-01-01

    Discusses properties of filters made of thermoplastic granulated material. The granulated plastic has a specific density of 10.3-10.6 kN/m/sup 3/ and a bulk density of about 6 kN/m/sup 3/. Its chemical resistance to acids, bases and salts is high but is it soluble in organic solvents. Filters made of this material are characterized by a porosity coefficient of 36.5% and a bulk density of 5.7-6.8 kN/m/sup 3/. Physical and mechanical properties of filter samples made of thermoplastic granulated material (50x50x50 mm) were investigated under laboratory conditions. Compression strength and influencing factors were analyzed (ambient temperature, manufacturing technology). Tests show that this filtration material developed by Poltegor is superior to other filtration materials used in Poland.

  14. ECM remodeling and its plasticity

    Science.gov (United States)

    Feng, Jingchen; Jones, Christopher A. R.; Cibula, Matthew; Mao, Xiaoming; Sander, Leonard M.; Levine, Herbert; Sun, Bo

    The mechanical interactions between cells and Extracellular Matrix (ECM) are of great importance in many cellular processes. These interactions are reciprocal, i.e. contracting cells pull and reorganize the surrounding matrix, while the remodeled matrix feeds back to regulate cell activities. Recent experiments show in collagen gels with densely distributed cells, aligned fiber bundles are formed in the direction between neighboring cells. Fibers flow into the center region between contracting cell pairs in this process, which causes the concentration of fibers in the fiber bundles to become significantly enhanced. Using an extended lattice-based model, we show that viscoelasticity plays an essential role in ECM remodeling and contributes to the enhanced concentration in fiber bundles. We further characterize ECM plasticity within our model and verify our results with rheometer experiments.

  15. Circuit design on plastic foils

    CERN Document Server

    Raiteri, Daniele; Roermund, Arthur H M

    2015-01-01

    This book illustrates a variety of circuit designs on plastic foils and provides all the information needed to undertake successful designs in large-area electronics.  The authors demonstrate architectural, circuit, layout, and device solutions and explain the reasons and the creative process behind each. Readers will learn how to keep under control large-area technologies and achieve robust, reliable circuit designs that can face the challenges imposed by low-cost low-temperature high-throughput manufacturing.   • Discusses implications of problems associated with large-area electronics and compares them to standard silicon; • Provides the basis for understanding physics and modeling of disordered material; • Includes guidelines to quickly setup the basic CAD tools enabling efficient and reliable designs; • Illustrates practical solutions to cope with hard/soft faults, variability, mismatch, aging and bias stress at architecture, circuit, layout, and device levels.

  16. Vascular plasticity in cerebrovascular disorders

    DEFF Research Database (Denmark)

    Edvinsson, Lars I H; Povlsen, Gro Klitgaard

    2011-01-01

    and microvessels that takes place after different types of stroke. Receptors like the endothelin type B, angiotensin type 1, and 5-hydroxytryptamine type 1B/1D receptors are upregulated in the smooth muscle layer of cerebral arteries after different types of ischemic stroke as well as after subarachnoid hemorrhage......Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries...... therapeutic target for prevention of vasoconstrictor receptor upregulation after stroke. Together, those findings provide new perspectives on the pathophysiology of ischemic stroke and point toward a novel way of reducing vasoconstriction, neuronal cell death, and thus neurologic deficits after stroke....

  17. AUGMENTATION-RELATED BRAIN PLASTICITY

    Directory of Open Access Journals (Sweden)

    Giovanni eDi Pino

    2014-06-01

    Full Text Available Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyzes the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain.Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools.Augmentation modifies function and structure of a number of areas, i.e. primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the

  18. Cyclic Plastic Deformation and Welding Simulation

    NARCIS (Netherlands)

    Ten Horn, C.H.L.J.

    2003-01-01

    One of the concerns of a fitness for purpose analysis is the quantification of the relevant material properties. It is known from experiments that the mechanical properties of a material can change due to a monotonic plastic deformation or a cyclic plastic deformation. For a fitness for purpose

  19. Nano-plastics in the aquatic environment.

    Science.gov (United States)

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

    2015-10-01

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

  20. Plastic Accumulation in the Mediterranean Sea

    KAUST Repository

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

    2015-01-01

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

  1. Mixed gas plasticization phenomena in asymmetric membranes

    NARCIS (Netherlands)

    Visser, Tymen

    2006-01-01

    This thesis describes the thorough investigation of mixed gas transport behavior of asymmetric membranes in the separation of feed streams containing plasticizing gases in order to gain more insights into the complicated behavior of plasticization. To successfully employ gas separation membranes in

  2. Candidate genes in ocular dominance plasticity

    NARCIS (Netherlands)

    Rietman, M.L.; Sommeijer, J.-P.; Levelt, C.N.; Heimel, J.A.; Brussaard, A.B.; Borst, J.G.G.; Elgersma, Y.; Galjart, N.; van der Horst, G.T.; Pennartz, C.M.; Smit, A.B.; Spruijt, B.M.; Verhage, M.; de Zeeuw, C.I.

    2012-01-01

    Many studies have been devoted to the identification of genes involved in experience-dependent plasticity in the visual cortex. To discover new candidate genes, we have reexamined data from one such study on ocular dominance (OD) plasticity in recombinant inbred BXD mouse strains. We have correlated

  3. Plastic accumulation in the Mediterranean sea.

    Directory of Open Access Journals (Sweden)

    Andrés Cózar

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

  4. Residual stresses in plastic random systems

    NARCIS (Netherlands)

    Alava, M.J.; Karttunen, M.E.J.; Niskanen, K.J.

    1995-01-01

    We show that yielding in elastic plastic materials creates residual stresses when local disorder is present. The intensity of these stresses grows with the external stress and degree of initial disorder. The one-dimensional model we employ also yields a discontinuous transition to perfect plasticity

  5. Plastic biliary stents for malignant biliary diseases

    NARCIS (Netherlands)

    Huibregtse, Inge; Fockens, Paul

    2011-01-01

    Plastic biliary endoprostheses have not changed much since their introduction more than 3 decades ago. Although their use has been challenged by the introduction of metal stents, plastic stents still remain commonly used. Much work has been done to improve the problem of stent obstruction but

  6. Plastic soep komt op ons bord

    NARCIS (Netherlands)

    Franeker, van J.A.

    2011-01-01

    De wereldwijd verspreide 'soep' van kleine plastic deeltjes in zeeën en oceanen vormt een omvangrijk mondiaal milieuprobleem. Niet alleen leidt het plastic tot verstrikking en verstopping bij vogels en vissen, ook brengt de giftigheid van de materie de voedselketen in gevaar. Om te voorkomen dat die

  7. Undergraduate Plastic Surgery Education: Problems, Challenges ...

    African Journals Online (AJOL)

    based on principles rather than limited procedures, with surgical interventions ranging from complex microsurgery-based reconstructions to aesthetic procedures. However, medical students' perceptions of the field of plastic surgery are limited and underestimate the versatility of services offered by plastic surgeons.[1,2] In ...

  8. Plastic collapse load of corroded steel plates

    Indian Academy of Sciences (India)

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

  9. Liquid crystal displays with plastic substrates

    Science.gov (United States)

    Lueder, Ernst H.

    1998-04-01

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

  10. COMPOSITES FROM RECYCLED WOOD AND PLASTICS

    Science.gov (United States)

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

  11. Biological degradation of plastics: a comprehensive review.

    Science.gov (United States)

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

    2008-01-01

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

  12. Marine Debris and Plastic Source Reduction Toolkit

    Science.gov (United States)

    Many plastic food service ware items originate on college and university campuses—in cafeterias, snack rooms, cafés, and eateries with take-out dining options. This Campus Toolkit is a detailed “how to” guide for reducing plastic waste on college campuses.

  13. Studies of elastic-plastic instabilities

    DEFF Research Database (Denmark)

    Tvergaard, Viggo

    1999-01-01

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

  14. 49 CFR 192.59 - Plastic pipe.

    Science.gov (United States)

    2010-10-01

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

  15. Do dwarf chameleons ( Bradypodion ) show developmental plasticity?

    African Journals Online (AJOL)

    It has been hypothesized that B. melanocephalum and B. thamnobates may be phenotypically plastic populations of the same species, since environmental conditions, the driving force behind developmental plasticity, varies between the distributions of these two allopatric taxa.We raised juveniles of both species under ...

  16. Plastic zonder olie : lesmodule voor nieuwe scheikunde

    NARCIS (Netherlands)

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

    2013-01-01

    Lesmodule voor nieuwe scheikunde voor leerlingen uit 5 en 6 vwo. Bioplastics worden gemaakt uit natuurlijke grondstoffen. Als ze de synthetische plastics vervangen kan de voorraad aardolie ontzien worden. Omdat veel bioplastics afbreekbaar zijn, kan ook de berg plastic afval krimpen. Maar zijn

  17. 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).

  18. Robust Return Algorithm for Anisotropic Plasticity Models

    DEFF Research Database (Denmark)

    Tidemann, L.; Krenk, Steen

    2017-01-01

    Plasticity models can be defined by an energy potential, a plastic flow potential and a yield surface. The energy potential defines the relation between the observable elastic strains ϒe and the energy conjugate stresses Τe and between the non-observable internal strains i and the energy conjugat...

  19. Demonstrating Fluorescence with Neon Paper and Plastic

    Science.gov (United States)

    Birriel, Jennifer J.; Roe, Clarissa

    2015-01-01

    Several papers in this journal have dealt with the fluorescence in orange neon plastic, olive oil, and soda. In each case, the fluorescent emission was excited by either green or violet-blue laser light. In this paper, we examine the fluorescent emission spectra of so-called neon colored papers and plastic clipboards available in department and…

  20. 7 CFR 58.348 - Plastic cream.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Plastic cream. 58.348 Section 58.348 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Products Bearing Usda Official Identification § 58.348 Plastic cream. The flavor shall be sweet, pleasing...

  1. What is behind the plastic strain rate?

    NARCIS (Netherlands)

    Hütter, M.; Grmela, M.; Öttinger, H.C.

    2009-01-01

    The plastic strain rate plays a central role in macroscopic models on elasto-viscoplasticity. In order to discuss the concept behind this quantity, we propose, first, a kinetic toy model to describe the dynamics of sliding layers representative of plastic deformation of single crystalline metals.

  2. Plastic Accumulation in the Mediterranean Sea

    Science.gov (United States)

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

    2015-01-01

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

  3. Plastic Accumulation in the Mediterranean Sea

    KAUST Repository

    Cózar, Andrés

    2015-04-01

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

  4. Allergic contact dermatitis to plastic banknotes.

    Science.gov (United States)

    Mohamed, M; Delaney, T A; Horton, J J

    1999-08-01

    Allergic contact dermatitis to ultraviolet (UV) cured acrylates occurs predominantly in occupationally exposed workers. Two men presented with dermatitis coinciding with the location of banknotes in their pockets. Patch testing confirmed allergic contact dermatitis to multiple acrylates and Australian plastic banknotes. This is the first report of contact allergy to acrylates present in Australian plastic banknotes.

  5. Industrial plastics waste: Identification and segregation

    Science.gov (United States)

    Widener, Edward L.

    1990-01-01

    Throwaway plastic products, mainly packaging, are inundating our landfills and incinerators. Most are ethenic thermoplastics, which can be recycled as new products or fossil-fuels. Lab experiments are described, involving destructive and non-destructive tests for identifying and using plastics. The burn-test, with simple apparatus and familiar samples, is recommended as quick, cheap and effective.

  6. Plastic accumulation in the Mediterranean sea.

    Science.gov (United States)

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

    2015-01-01

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

  7. Tiny plastic lung mimics human pulmonary function

    Science.gov (United States)

    Careers Inclusion & Diversity Work-Life Balance Career Resources Apply for a Job Postdocs Students Goals Recycling Green Purchasing Pollution Prevention Reusing Water Resources Environmental Management Releases - 2016 » April » Tiny plastic lung mimics human pulmonary function Tiny plastic lung mimics

  8. Plastic crystal phases of simple water models

    International Nuclear Information System (INIS)

    Aragones, J. L.; Vega, C.

    2009-01-01

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

  9. Bibliometric trend analyses of plastic surgery research

    NARCIS (Netherlands)

    Loonen, M.P.J.

    2007-01-01

    The present thesis was designed to evaluate the qualitative and quantitative aspects of plastic surgery research by means of a bibliometric citation analysis of plastic surgical presentations and publications. Citations to such published work provides an indication of the impact and the relevance of

  10. A linear model of ductile plastic damage

    International Nuclear Information System (INIS)

    Lemaitre, J.

    1983-01-01

    A three-dimensional model of isotropic ductile plastic damage based on a continuum damage variable on the effective stress concept and on thermodynamics is derived. As shown by experiments on several metals and alloys, the model, integrated in the case of proportional loading, is linear with respect to the accumulated plastic strain and shows a large influence of stress triaxiality [fr

  11. Reliability of Elasto-Plastic Structural Systems

    DEFF Research Database (Denmark)

    Delmar, M. V.; Sørensen, John Dalsgaard

    1990-01-01

    This paper proposes a method for generating safety margins and failure mode equations for elasto-plastic structures where interaction of load effects is taken into account. Structural failure is defined by large nodal displacements or plastic collapse. A branch-and-bound technique is used...

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

    DEFF Research Database (Denmark)

    Tarp-Johansen, Niels Jacob; Ditlevsen, Ove Dalager

    2001-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Steigmann David J.

    2011-01-01

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

  14. [Survey of plasticizers in polyvinyl chloride toys].

    Science.gov (United States)

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

    2012-01-01

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

  15. Phyllosphere yeasts rapidly break down biodegradable plastics.

    Science.gov (United States)

    Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-Hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

    2011-11-29

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands.

  16. Plasticity of pressure-sensitive materials

    CERN Document Server

    Ochsner, Andreas

    2014-01-01

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

  17. Nanoparticles from Degradation of Biodegradable Plastic Mulch

    Science.gov (United States)

    Flury, Markus; Sintim, Henry; Bary, Andy; English, Marie; Schaefer, Sean

    2017-04-01

    Plastic mulch films are commonly used in crop production. They provide multiple benefits, including control of weeds and insects, increase of soil and air temperature, reduction of evaporation, and prevention of soil erosion. The use of plastic mulch film in agriculture has great potential to increase food production and security. Plastic mulch films must be retrieved and disposed after usage. Biodegradable plastic mulch films, who can be tilled into the soil after usage offer great benefits as alternative to conventional polyethylene plastic. However, it has to be shown that the degradation of these mulches is complete and no micro- and nanoparticles are released during degradation. We conducted a field experiment with biodegradable mulches and tested mulch degradation. Mulch was removed from the field after the growing season and composted to facilitate degradation. We found that micro- and nanoparticles were released during degradation of the mulch films in compost. This raises concerns about degradation in soils as well.

  18. Energy recycling of plastic and rubber wastes

    International Nuclear Information System (INIS)

    Hussain, R.

    2003-01-01

    Major areas for applications of plastics and rubbers are building and construction, packaging, transportation, automobiles, furniture, house wares, appliances, electrical and electronics. Approximately 20% of all the plastics produced are utilized by the building and construction industry/sup (1-3)/. Categories of polymers mostly used in the above industries include poly (vinyl chloride), polypropylene, polyethylene, polystyrene phenolics, acrylics and urethanes. Tyres and tubes are almost exclusively made up of rubbers. One third of total consumption of plastics finds applications, like films, bottles and packaging, in food-products that have a maximum life-span of two years, after which these find way to waste dumps. As the polymer industry in Pakistan is set to grow very rapidly in the near future the increase in utilization of plastic products in synchronous with the advent of computers and information technology. About 0.60 Kg per capita of waste generated daily in Lahore /(7.14)/ contains considerable quantity of plastics. (AB)

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  20. Plastics and environmental health: the road ahead.

    Science.gov (United States)

    North, Emily J; Halden, Rolf U

    2013-01-01

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

  1. Plastics and Environmental Health: The Road Ahead

    Science.gov (United States)

    North, Emily J.; Halden, Rolf U.

    2013-01-01

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

  2. A strain gradient plasticity theory with application to wire torsion

    KAUST Repository

    Liu, J. X.; El Sayed, Tamer S.

    2014-01-01

    Based on the framework of the existing strain gradient plasticity theories, we have examined three kinds of relations for the plastic strain dependence of the material intrinsic length scale, and thus developed updated strain gradient plasticity

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

    Science.gov (United States)

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

    2016-08-01

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

  4. Plastic debris in the open ocean

    KAUST Repository

    Cozar, Andres

    2014-06-30

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

  5. Plastic debris in the open ocean.

    Science.gov (United States)

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

    2014-07-15

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

  6. The future of A-150 TE plastic

    International Nuclear Information System (INIS)

    Goodman, L.J.

    1985-01-01

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

  7. Modeling plasticity by non-continuous deformation

    Science.gov (United States)

    Ben-Shmuel, Yaron; Altus, Eli

    2017-10-01

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

  8. Smart film actuators using biomass plastic

    International Nuclear Information System (INIS)

    Yoneyama, Satoshi; Tanaka, Nobuo

    2011-01-01

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

  9. Plastic debris in the open ocean

    Science.gov (United States)

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

    2014-01-01

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

  10. Aktau Plastics Plant Explosives Material Report

    Energy Technology Data Exchange (ETDEWEB)

    CASE JR.,ROGER S.

    1999-12-01

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

  11. Microbial Enzymatic Degradation of Biodegradable Plastics.

    Science.gov (United States)

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

    2017-01-01

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

  12. Methodology for plastic fracture - a progress report

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  13. Pregnancy and the Plastic Surgery Resident.

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-06-25

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

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

    Science.gov (United States)

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

    2018-01-01

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

  16. Recrystallization induced plasticity in austenite and ferrite

    International Nuclear Information System (INIS)

    Huang Mingxin; Pineau, André; Bouaziz, Olivier; Vu, Trong-Dai

    2012-01-01

    Highlights: ► Plasticity can be induced by recrystallization in austenite and ferrite. ► Strain rate is proportional to recrystallization kinetics. ► Overall atomic flux selects a preferential direction may be the origin. - Abstract: New experimental evidences are provided to demonstrate that plastic strain can be induced by recrystallization in austenite and ferrite under an applied stress much smaller than their yield stresses. Such Recrystallization Induced Plasticity (RIP) phenomenon occurs because the overall atomic flux during recrystallization follows a preferential direction imposed by the applied stress.

  17. New plastic plane stress model for concrete

    International Nuclear Information System (INIS)

    Winnicki, A.; Cichon, Cz.

    1993-01-01

    In the paper a description of concrete behaviour in the plane stress case is given on the basis of the modified bounding surface plasticity theory. Three independent plastic mechanisms have been introduced describing axiatoric and deviatoric plastic strains and their coupling. All the new analytical formulae for material functions being in agreement with experiments and loading/unloading criteria have been proposed. In addition, for the proper description of concrete behaviour in tension a new, separate function of bounding surface shrinkage has been introduced. (author)

  18. Plastic deformation of 2D crumpled wires

    International Nuclear Information System (INIS)

    Gomes, M A F; Donato, C C; Brito, V P; Coelho, A S O

    2008-01-01

    When a single long piece of elastic wire is injected through channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper this packing process is investigated but using plastic wires which give rise to completely irreversible structures of different morphology. In particular, the plastic deformation from circular to oblate configurations of crumpled wires is experimentally studied, obtained by the application of an axial strain. Among other things, it is shown that in spite of plasticity, irreversibility and very large deformations, scaling is still observed.

  19. Estimation of the Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Pirzada, G. B. : Ph.D.

    In this thesis, work related to fundamental conditions has been extended to non-fundamental or the general case of probabilistic analysis. Finally, using the ss-unzipping technique a door has been opened to system reliability analysis of plastic slabs. An attempt has been made in this thesis...... to give a probabilistic treatment of plastic slabs which is parallel to the deterministic and systematic treatment of plastic slabs by Nielsen (3). The fundamental reason is that in Nielsen (3) the treatment is based on a deterministic modelling of the basic material properties for the reinforced...

  20. SLEEP AND OLFACTORY CORTICAL PLASTICITY

    Directory of Open Access Journals (Sweden)

    Dylan eBarnes

    2014-04-01

    Full Text Available In many systems, sleep plays a vital role in memory consolidation and synaptic homeostasis. These processes together help store information of biological significance and reset synaptic circuits to facilitate acquisition of information in the future. In this review, we describe recent evidence of sleep-dependent changes in olfactory system structure and function which contribute to odor memory and perception. During slow-wave sleep, the piriform cortex becomes hypo-responsive to odor stimulation and instead displays sharp-wave activity similar to that observed within the hippocampal formation. Furthermore, the functional connectivity between the piriform cortex and other cortical and limbic regions is enhanced during slow-wave sleep compared to waking. This combination of conditions may allow odor memory consolidation to occur during a state of reduced external interference and facilitate association of odor memories with stored hedonic and contextual cues. Evidence consistent with sleep-dependent odor replay within olfactory cortical circuits is presented. These data suggest that both the strength and precision of odor memories is sleep-dependent. The work further emphasizes the critical role of synaptic plasticity and memory in not only odor memory but also basic odor perception. The work also suggests a possible link between sleep disturbances that are frequently co-morbid with a wide range of pathologies including Alzheimer’s disease, schizophrenia and depression and the known olfactory impairments associated with those disorders.

  1. Plastic deformation of indium nanostructures

    International Nuclear Information System (INIS)

    Lee, Gyuhyon; Kim, Ju-Young; Burek, Michael J.; Greer, Julia R.; Tsui, Ting Y.

    2011-01-01

    Highlights: → Indium nanopillars display two different deformation mechanisms. → ∼80% exhibited low flow stresses near that of bulk indium. → Low strength nanopillars have strain rate sensitivity similar to bulk indium. → ∼20% of compressed indium nanopillars deformed at nearly theoretical strengths. → Low-strength samples do not exhibit strength size effects. - Abstract: Mechanical properties and morphology of cylindrical indium nanopillars, fabricated by electron beam lithography and electroplating, are characterized in uniaxial compression. Time-dependent deformation and influence of size on nanoscale indium mechanical properties were investigated. The results show two fundamentally different deformation mechanisms which govern plasticity in these indium nanostructures. We observed that the majority of indium nanopillars deform at engineering stresses near the bulk values (Type I), with a small fraction sustaining flow stresses approaching the theoretical limit for indium (Type II). The results also show the strain rate sensitivity and flow stresses in Type I indium nanopillars are similar to bulk indium with no apparent size effects.

  2. Plasticity of spermatogonial stem cells

    Directory of Open Access Journals (Sweden)

    Paul S Cooke

    2015-06-01

    Full Text Available There have been significant breakthroughs over the past decade in the development and use of pluripotent stem cells as a potential source of cells for applications in regenerative medicine. It is likely that this methodology will begin to play an important role in human clinical medicine in the years to come. This review describes the plasticity of one type of pluripotent cell, spermatogonial stem cells (SSCs, and their potential therapeutic applications in regenerative medicine and male infertility. Normally, SSCs give rise to sperm when in the testis. However, both human and murine SSCs can give rise to cells with embryonic stem (ES cell-like characteristics that can be directed to differentiate into tissues of all three embryonic germ layers when placed in an appropriate inductive microenvironment, which is in contrast to other postnatal stem cells. Previous studies have reported that SSCs expressed an intermediate pluripotent phenotype before differentiating into a specific cell type and that extended culture was necessary for this to occur. However, recent studies from our group using a tissue recombination model demonstrated that SSCs differentiated rapidly into another tissue, in this case, prostatic epithelium, without expression of pluripotent ES cell markers before differentiation. These results suggest that SSCs are capable of directly differentiating into other cell types without going through an intermediate ES cell-like stage. Because SSCs do not require reprogramming to achieve a pluripotent state, they are an attractive source of pluripotent cells for use in regenerative medicine.

  3. A Plastic Bottle in Rectosigmoid

    Directory of Open Access Journals (Sweden)

    A. Derakhshanfar

    2007-07-01

    Full Text Available Introduction: Evaluation and treatment of foreign bodies in rectum involves careful history and physical examination. The cases of forced introduction of the objects most commonly are , sexual assault , self – introduced for anal eroticism and accidental insertion.Case Report: We describe a case of a patient with rectal impaction following self administration of a plastic bottle for anal sexual gratification. A 49 years old man was admitted in the emergency department with the history of self introduced a bottle into his rectum physical examination and abdominal X-Ray diagnosed the case as impacted foreign body in rectosigmoid. An attempt was made to deliver the bottle through the rectum but because of high lying big bottle in the sigmoid laporotomy was performed and the bottle was removed though a longitudinal incision on sigmoid colon.Conclusion: Retained rectosigmoid foreign bodies have been encountered more frequently and present a dilemma for management and rarely laporotomy for extraction of foreign bodies was performed.

  4. Measures for recycling plastic wastes in France

    Energy Technology Data Exchange (ETDEWEB)

    Cossais, J C [Ministere de l' Industrie et de la Recherche, 75 - Paris (France). Delegation aux Economies de Matieres Premieres

    1978-05-01

    Raw materials crisis and environmental awareness have lead to the question of intensively dealing with the recycling of plastics. Although plastic wastes (residues) industrially occuring have been recycled for a long time, this is certainly not always the case in the subsequent stages. One must particularly give thought to the considerable quantities of agricultural and municipal wastes. Besides the problem of collecting the waste which can only be satisfactorily solved by separate collection or setting up sorting places, it is necessary for the recycling plastic wastes on a large scale to find or develop sellable products. The product for sale is limited by economical aspects and prejudices against recycled materials. The public have taken to a series of measures in France to simplify recycling plastic wastes. Private industry is also beginning to take interest in this new sources of raw materials.

  5. Fundamentals of the theory of plasticity

    CERN Document Server

    Kachanov, L M

    2004-01-01

    Intended for use by advanced engineering students and professionals, this volume focuses on plastic deformation of metals at normal temperatures, as applied to strength of machines and structures. 1971 edition.

  6. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  7. Thermoset plastics for the nuclear track detection

    International Nuclear Information System (INIS)

    Fujii, M.

    1984-01-01

    Characteristics of thermoset plastics for the nuclear track detection have been studied. Some of the samples show good etching properties and will be useful for observations of super heavy primaries. (author)

  8. Plasticity of cortical excitatory-inhibitory balance.

    Science.gov (United States)

    Froemke, Robert C

    2015-07-08

    Synapses are highly plastic and are modified by changes in patterns of neural activity or sensory experience. Plasticity of cortical excitatory synapses is thought to be important for learning and memory, leading to alterations in sensory representations and cognitive maps. However, these changes must be coordinated across other synapses within local circuits to preserve neural coding schemes and the organization of excitatory and inhibitory inputs, i.e., excitatory-inhibitory balance. Recent studies indicate that inhibitory synapses are also plastic and are controlled directly by a large number of neuromodulators, particularly during episodes of learning. Many modulators transiently alter excitatory-inhibitory balance by decreasing inhibition, and thus disinhibition has emerged as a major mechanism by which neuromodulation might enable long-term synaptic modifications naturally. This review examines the relationships between neuromodulation and synaptic plasticity, focusing on the induction of long-term changes that collectively enhance cortical excitatory-inhibitory balance for improving perception and behavior.

  9. 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....... The study confirmed the difficulty to clearly identify an optimal strategy for plastic waste management. In fact none of the examined scenarios emerged univocally as the best option for all impact categories. When moving from the P0 treatment strategy to the other scenarios, substantial improvements can...... 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...

  10. Venous thromboembolism prophylaxis in plastic surgery

    DEFF Research Database (Denmark)

    Nielsen, Lea Juul; Matzen, Steen H

    2017-01-01

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

  11. Linking Scales in Plastic Deformation and Fracture

    DEFF Research Database (Denmark)

    Martinez-Paneda, Emilio; Niordson, Christian Frithiof; S. Deshpande, Vikram

    2017-01-01

    We investigate crack growth initiation and subsequent resistance in metallic materials by means of an implicit multi-scale approach. Strain gradient plasticity is employed to model the mechanical response of the solid so as to incorporate the role of geometrically necessary dislocations (GNDs......) and accurately capture plasticity at the small scales involved in crack tip deformation. The response ahead of the crack is described by means of a traction-separation law, which is characterized by the cohesive strength and the fracture energy. Results reveal that large gradients of plastic strain accumulatein...... the vicinity of the crack, elevating the dislocation density and the local stress. This stress elevation enhances crack propagation and significantly lowers the steady state fracture toughness with respect to conventional plasticity. Important insight is gained into fracture phenomena that cannot be explained...

  12. Sol-gel antireflective coating on plastics

    Science.gov (United States)

    Ashley, Carol S.; Reed, Scott T.

    1990-01-01

    An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

  13. Construction loads experienced by plastic composite ties.

    Science.gov (United States)

    2014-07-01

    Damage to plastic composite ties during handling and track installation has been reported by a number of railroads. Results from : a survey conducted to identify specific handling issues were used to develop field and laboratory tests to measure the ...

  14. Leaching behavior of solidified plastics radioactive wastes

    International Nuclear Information System (INIS)

    Yook, Chong Chul; Lee, Byung Hun; Jae, Won Mok; Kim, Kyung Eung

    1986-01-01

    It is highly needed to develope the solidification process to dispose safely the radioactive wastes increasing with the growth of the nuclear industry. The leaching mechanisms of the solidified plastic wastes were investigated and the leaching rates of the plastic wastes were also measured among the many solidification processes. In addition, the transport equation based on the diffusion or the diffusion-dissolution was compared with the empirical equation derived from the experimental data by graphical method. Consequently, leaching process of the solidified plastic wastes is quite well agreed with the mass transport theory, but it may be difficult to simulate leaching process by diffusion dissolution mechanism. But the theoretical equation could be applicable to the cumulative amount of radionuclides leached form the plastic wastes disposed into the environment. (Author)

  15. Core Characteristics Deterioration due to Plastic Deformation

    Science.gov (United States)

    Kaido, Chikara; Arai, Satoshi

    This paper discusses the effect of plastic deformation at core manufacturing on the characteristics of cores where non-oriented electrical steel sheets are used as core material. Exciting field and iron loss increase proportionally to plastic deformation in the case of rPeddy currents increase because plastic deformations of crystalline grains are distributed and then the flux distribution is induced. In the case of rP>20, the deterioration tend to saturate, and the increases in magnetic field and iron loss are 1000 to 1500A/m and 2 to 4W/kg. They are related to grain size, and high grade with larger grain may have lager field increase and smaller iron loss increase. Anomalous eddy current losses scarcely increase in this region. In actual motors, the plastic deformation affects iron loss increase although exciting current increases a little.

  16. Pathological Plasticity in Fragile X Syndrome

    Directory of Open Access Journals (Sweden)

    Brandon S. Martin

    2012-01-01

    Full Text Available Deficits in neuronal plasticity are common hallmarks of many neurodevelopmental disorders. In the case of fragile-X syndrome (FXS, disruption in the function of a single gene, FMR1, results in a variety of neurological consequences directly related to problems with the development, maintenance, and capacity of plastic neuronal networks. In this paper, we discuss current research illustrating the mechanisms underlying plasticity deficits in FXS. These processes include synaptic, cell intrinsic, and homeostatic mechanisms both dependent on and independent of abnormal metabotropic glutamate receptor transmission. We place particular emphasis on how identified deficits may play a role in developmental critical periods to produce neuronal networks with permanently decreased capacity to dynamically respond to changes in activity central to learning, memory, and cognition in patients with FXS. Characterizing early developmental deficits in plasticity is fundamental to develop therapies that not only treat symptoms but also minimize the developmental pathology of the disease.

  17. Plastic debris in the open ocean

    OpenAIRE

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

    2014-01-01

    There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. Howeve...

  18. Development of a Plastic Recycling Machine

    OpenAIRE

    I. A. Daniyan,

    2017-01-01

    Plastics are not degradable materials, therefore improper disposal after use constitute environmental problem. The developed plastic recycler was fabricated using 1.5 mm mild metal sheet punched and rolled into cylindrical form. The outer peeling drum was punched inward and fixed to the machine frame while the inner peeling drum was punched outward. The inner drum was constructed using 1.5 mm galvanized metal sheet while the die was constructed using carbon steel. It has an outer diameter of ...

  19. Molding apparatus. [for thermosetting plastic compositions

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

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

  20. Laser direct joining of metal and plastic

    International Nuclear Information System (INIS)

    Katayama, Seiji; Kawahito, Yousuke

    2008-01-01

    We have developed an innovative rapid laser direct joining process of metal and plastic lap plates without adhesives or glues. The joints made between a Type 304 stainless steel plate and a polyethylene terephthalate (PET) plastic sheet of 30 mm width possessed tensile shear loads of about 3000 N. Transmission electron microscope photographs of the joint demonstrated that Type 304 and the PET were bonded on the atomic, molecular or nanostructural level through a Cr oxide film

  1. Plastic for indicating a radiation dose

    International Nuclear Information System (INIS)

    Hori, Y.; Yoshikawa, N.; Ohmori, S.

    1975-01-01

    A plastic film suitable for indicating radiation dose contains a chlorine polymer, at least one acid sensitive coloring agent and a plasticizer. The film undergoes a distinct change of color in response to a given radiation dose, the degree of change proportional to the total change. These films may be stored for a long period without loss of sensitivity, and have good color stability after irradiation. (auth)

  2. Banana peels based bio-plastic

    OpenAIRE

    Taodharos, Shady

    2018-01-01

    Every developed country depends on the industry as the main factor of its economy. Lack of exports, depression in both the general economy and the value of the currency are consequences of neglecting the industry. All countries work on increasing the efficiency of their industries by whether working on the input, the output, the cost or the time of the process. Plastic industry is considered one of the most important industries because plastic is an important factor in the making of many usef...

  3. Neuron-glia metabolic coupling and plasticity

    OpenAIRE

    Magistretti PJ

    2011-01-01

    Abstract The focus of the current research projects in my laboratory revolves around the question of metabolic plasticity of neuron glia coupling. Our hypothesis is that behavioural conditions such as for example learning or the sleep wake cycle in which synaptic plasticity is well documented or during specific pathological conditions are accompanied by changes in the regulation of energy metabolism of astrocytes. We have indeed observed that the 'metabolic profile' of astrocytes is modified...

  4. Plastic bowing of the ribs in children

    Energy Technology Data Exchange (ETDEWEB)

    Caro, P.A.; Borden, S. IV

    1988-06-01

    Four cases of plastic bowing of the ribs are presented. In three patients with Werdnig-Hoffman disease, plastic curvatures were associated with chronic pneumonia and atelectasis. We postulate that intrapulmonary retractive forces can deform ribs thinned by muscular atrophy. In turn, thoracic collapse can perpetuate lobar and segmental atelectasis. In one case of osteogenesis imperfecta without pneumonia, we believe normal muscle forces bent ribs weakened by deficiency of normal cortical architecture.

  5. Plastic bowing of the ribs in children

    International Nuclear Information System (INIS)

    Caro, P.A.; Borden, S. IV

    1988-01-01

    Four cases of plastic bowing of the ribs are presented. In three patients with Werdnig-Hoffman disease, plastic curvatures were associated with chronic pneumonia and atelectasis. We postulate that intrapulmonary retractive forces can deform ribs thinned by muscular atrophy. In turn, thoracic collapse can perpetuate lobar and segmental atelectasis. In one case of osteogenesis imperfecta without pneumonia, we believe normal muscle forces bent ribs weakened by deficiency of normal cortical architecture. (orig.)

  6. Treatment of contaminated waste plastics material

    International Nuclear Information System (INIS)

    Sims, J.; Hitchcock, J.W.

    1984-01-01

    Radioactive contaminated plastics material is treated by reducing it to uniform-sized debris and extruding it from a heated extruder into a sealed container in monolithic block form or as an in-fill matrix for other contaminated waste articles to create a substantially void-free sealed mass for disposal. Density adjusting fillers may be included. Extrusion may alternatively take place into a clean sealable plastics tube. (author)

  7. Soil plasticity with a different porosity

    Directory of Open Access Journals (Sweden)

    Klovanych Sergii

    2017-01-01

    Full Text Available The model of soils with different porosity in the framework of the associated theory of plasticity is presented The single analytical function describes the loading surface in the stress space. The deformational hardening/softening and the phenomenon of dilatancy during plastic flow are incorporated in the model. The triaxial compression tests are simulated and compared with the experimental results for different values of the void ratio and initial hydrostatic stresses.

  8. Plastic, Fantastic? What We Make. Science and Technology Education in Philippine Society.

    Science.gov (United States)

    Philippines Univ., Quezon City. Inst. for Science and Mathematics Education Development.

    This module provides information about plastics, focusing on the uses of plastic bags in particular. Topic areas considered include: (1) making plastic bags; (2) transparency of plastic bags; (3) plastic bags and food odors; (4) food containers (before and since plastics); and (5) disposing of plastic bags and other plastic products. The text is…

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

    International Nuclear Information System (INIS)

    Betten, J.; Frosch, H.G.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Kumasaki, H.; Shinozaki, Y.

    1979-01-01

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

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

    Science.gov (United States)

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

    2018-06-01

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

  12. Changing trends in plastic surgery training

    Directory of Open Access Journals (Sweden)

    Ramesh Kumar Sharma

    2014-01-01

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

  13. Changing trends in plastic surgery training.

    Science.gov (United States)

    Sharma, Ramesh Kumar

    2014-05-01

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

  14. 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.

  15. Plastic photochromic eyewear: a status report

    Science.gov (United States)

    Crano, John C.; Elias, Richard C.

    1991-12-01

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

  16. Discoloration of plasticized PVC upon irradiation

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  17. 49 CFR 192.193 - Valve installation in plastic pipe.

    Science.gov (United States)

    2010-10-01

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

  18. 49 CFR 178.517 - Standards for plastic boxes.

    Science.gov (United States)

    2010-10-01

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

  19. 49 CFR 192.321 - Installation of plastic pipe.

    Science.gov (United States)

    2010-10-01

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

  20. 49 CFR 178.519 - Standards for plastic film bags.

    Science.gov (United States)

    2010-10-01

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

  1. 33 CFR 183.552 - Plastic encased fuel tanks: Installation.

    Science.gov (United States)

    2010-07-01

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

  2. DMPD: Developmental plasticity of lymphocytes. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18472258 Developmental plasticity of lymphocytes. Cobaleda C, Busslinger M. Curr Op...in Immunol. 2008 Apr;20(2):139-48. Epub 2008 May 9. (.png) (.svg) (.html) (.csml) Show Developmental plastic...ity of lymphocytes. PubmedID 18472258 Title Developmental plasticity of lymphocytes. Authors Cobaleda C, Bus

  3. 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 plastic...

  4. 49 CFR 192.191 - Design pressure of plastic fittings.

    Science.gov (United States)

    2010-10-01

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

  5. Consumer Exposure to Bisphenol A from Plastic Bottles

    Science.gov (United States)

    Bidabadi, Fatemeh

    2013-01-01

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

  6. 21 CFR 872.5470 - Orthodontic plastic bracket.

    Science.gov (United States)

    2010-04-01

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

  7. Scenarios study on post-consumer plastic packaging waste recycling

    NARCIS (Netherlands)

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

    2013-01-01

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

  8. Plasticity: A New Materialist Approach to Policy and Methodology

    Science.gov (United States)

    Ulmer, Jasmine B.

    2015-01-01

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

  9. Finite element analysis of a finite-strain plasticity problem

    International Nuclear Information System (INIS)

    Crose, J.G.; Fong, H.H.

    1984-01-01

    A finite-strain plasticity analysis was performed of an engraving process in a plastic rotating band during the firing of a gun projectile. The aim was to verify a nonlinear feature of the NIFDI/RB code: plastic large deformation analysis of nearly incompressible materials using a deformation theory of plasticity approach and a total Lagrangian scheme. (orig.)

  10. 21 CFR 878.3925 - Plastic surgery kit and accessories.

    Science.gov (United States)

    2010-04-01

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

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

    Science.gov (United States)

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

    2018-04-01

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

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

    Science.gov (United States)

    Syaubari; Safwani, S.; Riza, M.

    2018-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Stoeckhert, K [ed.

    1981-01-01

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

  14. Monitoring the abundance of plastic debris in the marine environment

    OpenAIRE

    Ryan, Peter G.; Moore, Charles J.; van Franeker, Jan A.; Moloney, Coleen L.

    2009-01-01

    Plastic debris has significant environmental and economic impacts in marine systems. Monitoring is crucial to assess the efficacy of measures implemented to reduce the abundance of plastic debris, but it is complicated by large spatial and temporal heterogeneity in the amounts of plastic debris and by our limited understanding of the pathways followed by plastic debris and its long-term fate. To date, most monitoring has focused on beach surveys of stranded plastics and other litter. Infreque...

  15. Behavioral Response to Plastic Bag Legislation in Botswana

    OpenAIRE

    Dikgang, Johane; Visser, Martine

    2010-01-01

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

  16. Are consumers concerned about plastic water bottles environmental impact?

    OpenAIRE

    Caroline Orset; Nicolas Barret; Aurélien Lemaire

    2015-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

  18. Recent advancements and prospects of plastic surgery

    Directory of Open Access Journals (Sweden)

    Xin XING

    2011-09-01

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

  19. Social Media and the Plastic Surgery Patient.

    Science.gov (United States)

    Sorice, Sarah C; Li, Alexander Y; Gilstrap, Jarom; Canales, Francisco L; Furnas, Heather J

    2017-11-01

    Many plastic surgeons use social media as a marketing tool to attract and retain patients, but information about how patients use social media and their preferred types of plastic surgery posts have been lacking. To investigate patients' preferred social media networks and the type of posts they wished to see, a cross-sectional study was conducted in a single aesthetic practice of two plastic surgeons by surveying 100 consecutive patients. The age of the patients averaged 44.4 years (range, 17 to 78 years). Facebook had the greatest patient use and engagement, with YouTube second in use, and Instagram second in number of engaged users. Over half used Pinterest, but with little daily engagement. Only one-fourth used Snapchat, but the percentage of users who were highly engaged was second only to Facebook. The least popular network was Twitter, with the fewest patient users and least engagement. Social media played a minor role compared with the practice's Web site in both influencing patients to choose the practice and providing information on the day of the appointment. Patients most wanted to see posts on a plastic surgeon's social media platform related to practice information, before-and-after photographs, and contests. Articles about plastic surgery held the least interest. Among five types of Web site content, patients expressed most interest in before-and-after photographs. This study is the first to articulate the plastic surgery patient perspective regarding social media. The findings aim to help plastic surgeons maximize their influence on their target audience.

  20. [The role of balneology in plastic surgery].

    Science.gov (United States)

    Correia, N; Binet, A; Caliot, J; Poli Merol, M-L; Bodin, F; François-Fiquet, C

    2016-02-01

    Balneology can be part of the plastic surgery care sector. The objectives of this study were firstly to the state of knowledge about the hydrotherapy and specify the place reserved for hydrotherapy by surgeons as an adjunct in plastic and reconstructive surgery (adult and child). Multicentric national study by poll (Google Drive®) focused at plastic and/or pediatric surgeons. The following information was analyzed: frequency, timing of prescription, indications, the surgeon's feelings towards hydrotherapy and the differences between adult's and children's prescriptions. Fifty-four teams were contacted: 22 responses were received (15 "adult" plastic surgeons, 9 "pediatric" plastic surgeons, 6 pediatric surgeons, with 12 out of 22 working with burnt patients). Eighteen out of 22 prescribed hydrotherapy. Twenty out of 22 thought that hydrotherapy had a role as adjuvant therapy in plastic surgery. The indications were: burns (11/20), skin-graft hypertrophy (10/20), inflammatory and pruritic scar and cutaneous trophic disorders (9/20), psychological (3/20), retractions (2/20), weight loss and smoking (1/20). The timing of the prescription was: 6 months and 1 year (8/20) after surgery/trauma. Twenty out of 22 found a beneficial effect: physical (19/20): reduction of inflammatory signs, pruritus and pain, scar maturation, skin thinning improvement; psychological (14/20): positive for patient/family. Five out of 17 made the difference between child/adult, 10/17 made no difference but only treated adults or children. The respondents in the study are probably more sensitive to the effects of hydrotherapy that non-respondents. It is difficult to assess the real impact of hydrotherapy in plastic surgery because distinguishing spontaneous favorable evolution of a scar from one only due to the hydrotherapy or multidisciplinary management is difficult. However, hydrotherapy seems to have its role among multidisciplinary management. Copyright © 2015 Elsevier Masson SAS. All

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

  3. 75 FR 34170 - Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium Automotive Exteriors, LLC...

    Science.gov (United States)

    2010-06-16

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

  4. Practical solution of plastic deformation problems in elastic-plastic range

    Science.gov (United States)

    Mendelson, A; Manson, S

    1957-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  6. Impact of Bio-Based Plastics on Current Recycling of Plastics

    Directory of Open Access Journals (Sweden)

    Luc Alaerts

    2018-05-01

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

  7. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Science.gov (United States)

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

    2013-01-01

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

  8. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Directory of Open Access Journals (Sweden)

    José Maria Rodrigues da Luz

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

  9. Degradation of plastic carrier bags in the marine environment

    International Nuclear Information System (INIS)

    O'Brine, Tim; Thompson, Richard C.

    2010-01-01

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

  10. Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

    Science.gov (United States)

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

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    Li Boyang

    2008-01-01

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

  12. Plastic Surgery Response in Natural Disasters.

    Science.gov (United States)

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

    2015-06-01

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

  13. Plasticity - a limiting case of creep

    International Nuclear Information System (INIS)

    Cords, H.; Kleist, G.; Zimmermann, R.

    1986-11-01

    The present work is an attempt to develop further the so-called unified theory for viscoplastic constitutive equations as used for metals or metal alloys. Typically, in similar approaches creep strains and plastic strains are derived from one common stress-strain relationship for inelastic strain rates employing an internal stress function as a back stress. Some novel concepts concerning the definition of the internal stress, plastic yielding and material hardening have been introduced, formulated mathematically and tested for correspondence with a standard type of materials behaviour. As a result of the investigations a system of simultaneous differential equations is defined which has been used to elaborate a common view on a number of different material effects observed in creep and plasticity i.e. normal and inverted primary creep, recoverable creep, incubation time and anelasticity in stress reduction, negative stress relaxation, plastic yielding, perfect plasticity, negative strain rate sensitivity, serrated flow, strain hardening in monotonic and cyclic loading. The theoretical approach is mainly based on a lateral contraction movement not following rigidly the longitudinal extension of the material specimen by a prescribed constant value of Poisson's ratio as usual, but following the axial extension in a process of drag which allows for retardation and which simultaneously impedes the longitudinal straining. (orig.) [de

  14. Neuron-glia metabolic coupling and plasticity.

    Science.gov (United States)

    Magistretti, Pierre J

    2006-06-01

    The coupling between synaptic activity and glucose utilization (neurometabolic coupling) is a central physiological principle of brain function that has provided the basis for 2-deoxyglucose-based functional imaging with positron emission tomography (PET). Astrocytes play a central role in neurometabolic coupling, and the basic mechanism involves glutamate-stimulated aerobic glycolysis; the sodium-coupled reuptake of glutamate by astrocytes and the ensuing activation of the Na-K-ATPase triggers glucose uptake and processing via glycolysis, resulting in the release of lactate from astrocytes. Lactate can then contribute to the activity-dependent fuelling of the neuronal energy demands associated with synaptic transmission. An operational model, the 'astrocyte-neuron lactate shuttle', is supported experimentally by a large body of evidence, which provides a molecular and cellular basis for interpreting data obtained from functional brain imaging studies. In addition, this neuron-glia metabolic coupling undergoes plastic adaptations in parallel with adaptive mechanisms that characterize synaptic plasticity. Thus, distinct subregions of the hippocampus are metabolically active at different time points during spatial learning tasks, suggesting that a type of metabolic plasticity, involving by definition neuron-glia coupling, occurs during learning. In addition, marked variations in the expression of genes involved in glial glycogen metabolism are observed during the sleep-wake cycle, with in particular a marked induction of expression of the gene encoding for protein targeting to glycogen (PTG) following sleep deprivation. These data suggest that glial metabolic plasticity is likely to be concomitant with synaptic plasticity.

  15. Radiation crosslinking of highly plasticized PVC

    Science.gov (United States)

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

    1996-02-01

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

  16. Radiation crosslinking of highly plasticized PVC

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  17. The neurophysiologist perspective into MS plasticity

    Directory of Open Access Journals (Sweden)

    Elise eHoudayer

    2015-09-01

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

  18. The Neurophysiologist Perspective into MS Plasticity.

    Science.gov (United States)

    Houdayer, Elise; Comi, Giancarlo; Leocani, Letizia

    2015-01-01

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

  19. Phyllosphere yeasts rapidly break down biodegradable plastics

    Science.gov (United States)

    2011-01-01

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands. PMID:22126328

  20. Role of Plastics on Human Health.

    Science.gov (United States)

    Kumar, Pramod

    2018-05-01

    Plastics, currently the universal workhorse materials of modern economy, because of their low cost and varied functional properties are posing serious threat to environment and consumer's health in many direct and indirect ways. Rising concern about the impact of plastics on environment and human health, has forced the industry to look for alternatives. This review studies current understanding of benefits and concerns surrounding use of plastics, reviews literature about health effects in humans and discusses the current state of evidence, as well as future research trends. There is increasing concern regarding additives in plastics to which most people are exposed, such as phthalates, bisphenol A or polybrominated diphenyl ethers (PBDE), and their detection in humans, leading to harmful impact on health. The studies are divided, among many other issues on the fact of considering these additives as carcinogens or toxicants, but there is a consensus that these chemicals have the ability to alter the endocrine system. Human data are limited compared to large body of experimental evidence documenting reproductive or developmental toxicity in relation to these compounds in animals. The concentrations of these additives in young children, a segment particularly sensitive to exogenous insults, are typically higher, indicating the need to decrease exposure to these compounds. The rapid increase in usage of plastics and increased awareness about its health hazard has lent urgency to the whole issue.

  1. Epigenetic Basis of Neuronal and Synaptic Plasticity.

    Science.gov (United States)

    Karpova, Nina N; Sales, Amanda J; Joca, Samia R

    2017-01-01

    Neuronal network and plasticity change as a function of experience. Altered neural connectivity leads to distinct transcriptional programs of neuronal plasticity-related genes. The environmental challenges throughout life may promote long-lasting reprogramming of gene expression and the development of brain disorders. The modifications in neuronal epigenome mediate gene-environmental interactions and are required for activity-dependent regulation of neuronal differentiation, maturation and plasticity. Here, we highlight the latest advances in understanding the role of the main players of epigenetic machinery (DNA methylation and demethylation, histone modifications, chromatin-remodeling enzymes, transposons, and non-coding RNAs) in activity-dependent and long- term neural and synaptic plasticity. The review focuses on both the transcriptional and post-transcriptional regulation of gene expression levels, including the processes of promoter activation, alternative splicing, regulation of stability of gene transcripts by natural antisense RNAs, and alternative polyadenylation. Further, we discuss the epigenetic aspects of impaired neuronal plasticity and the pathogenesis of neurodevelopmental (Rett syndrome, Fragile X Syndrome, genomic imprinting disorders, schizophrenia, and others), stressrelated (mood disorders) and neurodegenerative Alzheimer's, Parkinson's and Huntington's disorders. The review also highlights the pharmacological compounds that modulate epigenetic programming of gene expression, the potential treatment strategies of discussed brain disorders, and the questions that should be addressed during the development of effective and safe approaches for the treatment of brain disorders.

  2. Optical absorption in recycled waste plastic polyethylene

    Science.gov (United States)

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

    2018-03-01

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

  3. Color change, phenotypic plasticity, and camouflage

    Directory of Open Access Journals (Sweden)

    Martin eStevens

    2016-05-01

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

  4. Neural plasticity of development and learning.

    Science.gov (United States)

    Galván, Adriana

    2010-06-01

    Development and learning are powerful agents of change across the lifespan that induce robust structural and functional plasticity in neural systems. An unresolved question in developmental cognitive neuroscience is whether development and learning share the same neural mechanisms associated with experience-related neural plasticity. In this article, I outline the conceptual and practical challenges of this question, review insights gleaned from adult studies, and describe recent strides toward examining this topic across development using neuroimaging methods. I suggest that development and learning are not two completely separate constructs and instead, that they exist on a continuum. While progressive and regressive changes are central to both, the behavioral consequences associated with these changes are closely tied to the existing neural architecture of maturity of the system. Eventually, a deeper, more mechanistic understanding of neural plasticity will shed light on behavioral changes across development and, more broadly, about the underlying neural basis of cognition. (c) 2010 Wiley-Liss, Inc.

  5. Plasticity size effects in voided crystals

    DEFF Research Database (Denmark)

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

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

  6. Plasticity size effects in voided crystals

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  7. Method of solidifying radioactive waste by plastics

    International Nuclear Information System (INIS)

    Yasumura, Keijiro; Tomita, Toshihide.

    1976-01-01

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

  8. 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.

  9. On fracture in finite strain gradient plasticity

    DEFF Research Database (Denmark)

    Martínez Pañeda, Emilio; Niordson, Christian Frithiof

    2016-01-01

    In this work a general framework for damage and fracture assessment including the effect of strain gradients is provided. Both mechanism-based and phenomenological strain gradient plasticity (SGP) theories are implemented numerically using finite deformation theory and crack tip fields are invest......In this work a general framework for damage and fracture assessment including the effect of strain gradients is provided. Both mechanism-based and phenomenological strain gradient plasticity (SGP) theories are implemented numerically using finite deformation theory and crack tip fields...... are investigated. Differences and similarities between the two approaches within continuum SGP modeling are highlighted and discussed. Local strain hardening promoted by geometrically necessary dislocations (GNDs) in the vicinity of the crack leads to much higher stresses, relative to classical plasticity...... in the multiple parameter version of the phenomenological SGP theory. Since this also dominates the mechanics of indentation testing, results suggest that length parameters characteristic of mode I fracture should be inferred from nanoindentation....

  10. The Corticohippocampal Circuit, Synaptic Plasticity, and Memory

    Science.gov (United States)

    Basu, Jayeeta; Siegelbaum, Steven A.

    2015-01-01

    Synaptic plasticity serves as a cellular substrate for information storage in the central nervous system. The entorhinal cortex (EC) and hippocampus are interconnected brain areas supporting basic cognitive functions important for the formation and retrieval of declarative memories. Here, we discuss how information flow in the EC–hippocampal loop is organized through circuit design. We highlight recently identified corticohippocampal and intrahippocampal connections and how these long-range and local microcircuits contribute to learning. This review also describes various forms of activity-dependent mechanisms that change the strength of corticohippocampal synaptic transmission. A key point to emerge from these studies is that patterned activity and interaction of coincident inputs gives rise to associational plasticity and long-term regulation of information flow. Finally, we offer insights about how learning-related synaptic plasticity within the corticohippocampal circuit during sensory experiences may enable adaptive behaviors for encoding spatial, episodic, social, and contextual memories. PMID:26525152

  11. The unaccountability case of plastic pellet pollution.

    Science.gov (United States)

    Karlsson, Therese M; Arneborg, Lars; Broström, Göran; Almroth, Bethanie Carney; Gipperth, Lena; Hassellöv, Martin

    2018-04-01

    Plastic preproduction pellets are found in environmental samples all over the world and their presence is often linked to spills during production and transportation. To better understand how these pellets end up in the environment we assessed the release of plastic pellets from a polyethylene production site in a case study area on the Swedish west coast. The case study encompasses; field measurements to evaluate the level of pollution and pathways, models and drifters to investigate the potential spread and a revision of the legal framework and the company permits. This case study show that millions of pellets are released from the production site annually but also that there are national and international legal frameworks that if implemented could help prevent these spills. Bearing in mind the negative effects observed by plastic pollution there is an urgent need to increase the responsibility and accountability of these spills. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  12. BC-454 boron-loaded plastic scintillator

    International Nuclear Information System (INIS)

    Bellian, J.G.

    1984-01-01

    Prototype samples of plastic scintillators containing up to 10% by weight of natural boron have been produced. The maximum size scintillators made to date are 28 mm dia. x 100 mm long. Rods containing up to 2% boron are now made routinely and work is progressing on higher concentrations. The plastics are clear and emit the same blue fluorescence as other common plastic scintillators. It is expected that rods up to 3'' dia. containing 5% boron will be produced during the next few months. BC-454 is particularly useful in neutron research, materials studies, some types of neutron dosimetry, and monitoring of medium to high energy neutrons in the presence of other types radiation. It combines attractive features that enhance its usefulness to the physics community

  13. Modelling of elasto-plastic material behaviour

    International Nuclear Information System (INIS)

    Halleux, J.P.

    1981-01-01

    The present report describes time-independent elasto-plastic material behaviour modelling techniques useful for implementation in fast structural dynamics computer programs. Elasto-plastic behaviour is characteristic for metallic materials such as steel and is thus of particular importance in the study of reactor safety-related problems. The classical time-independent elasto-plastic flow theory is recalled and the fundamental incremental stress-strain relationships are established for strain rate independent material behaviour. Some particular expressions useful in practice and including reversed loading are derived and suitable computational schemes are shwon. Modelling of strain rate effects is then taken into account, according to experimental data obtained from uniaxial tension tests. Finally qualitative strain rate history effects are considered. Applications are presented and illustrate both static and dynamic material behaviour

  14. MAGNETAR FIELD EVOLUTION AND CRUSTAL PLASTICITY

    International Nuclear Information System (INIS)

    Lander, S. K.

    2016-01-01

    The activity of magnetars is believed to be powered by colossal magnetic energy reservoirs. We sketch an evolutionary picture in which internal field evolution in magnetars generates a twisted corona, from which energy may be released suddenly in a single giant flare, or more gradually through smaller outbursts and persistent emission. Given the ages of magnetars and the energy of their giant flares, we suggest that their evolution is driven by a novel mechanism: magnetic flux transport/decay due to persistent plastic flow in the crust, which would invalidate the common assumption that the crustal lattice is static and evolves only under Hall drift and Ohmic decay. We estimate the field strength required to induce plastic flow as a function of crustal depth, and the viscosity of the plastic phase. The star’s superconducting core may also play a role in magnetar field evolution, depending on the star’s spindown history and how rotational vortices and magnetic fluxtubes interact.

  15. Towards the effective plastic waste management in Bangladesh: a review.

    Science.gov (United States)

    Mourshed, Monjur; Masud, Mahadi Hasan; Rashid, Fazlur; Joardder, Mohammad Uzzal Hossain

    2017-12-01

    The plastic-derived product, nowadays, becomes an indispensable commodity for different purposes. A huge amount of used plastic causes environmental hazards that turn in danger for marine life, reduces the fertility of soil, and contamination of ground water. Management of this enormous plastic waste is challenging in particular for developing countries like Bangladesh. Lack of facilities, infrastructure development, and insufficient budget for waste management are some of the prime causes of improper plastic management in Bangladesh. In this study, the route of plastic waste production and current plastic waste management system in Bangladesh have been reviewed extensively. It emerges that no technical and improved methods are adapted in the plastic management system. A set of the sustainable plastic management system has been proposed along with the challenges that would emerge during the implementation these strategies. Successful execution of the proposed systems would enhance the quality of plastic waste management in Bangladesh and offers enormous energy from waste.

  16. Benthic plastic debris in marine and fresh water environments.

    Science.gov (United States)

    Corcoran, Patricia L

    2015-08-01

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

  17. Seabirds, gyres and global trends in plastic pollution

    International Nuclear Information System (INIS)

    Franeker, Jan A. van; Law, Kara Lavender

    2015-01-01

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

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

    Science.gov (United States)

    Gu, Lei; Ozbakkaloglu, Togay

    2016-05-01

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

  19. Thermodynamic theory of dislocation-enabled plasticity

    International Nuclear Information System (INIS)

    Langer, J. S.

    2017-01-01

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

  20. Plastic solidification system for radioactive waste

    International Nuclear Information System (INIS)

    Kani, Jiro; Irie, Hiromitsu; Obu, Etsuji; Nakayama, Yasuyuki; Matsuura, Hiroyuki.

    1979-01-01

    The establishment of a new solidification system is an important theme for recent radioactive-waste disposal systems. The conditions required of new systems are: (1) the volume of the solidified product to be reduced, and (2) the property of the solidified product to be superior to the conventional ones. In the plastic solidification system developed by Toshiba, the waste is first dried and then solidified with thermosetting resin. It has been confirmed that the property of the plastic solidified product is superior to that of the cement-or bitumen-solidified product. Investigation from various phases is being carried on for the application of this method to commercial plants. (author)

  1. LPG based all plastic pressure sensor

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Lwin, R.; Leon-Saval, S.

    2015-01-01

    A prototype all-plastic pressure sensor is presented and characterized for potential use as an endoscope. The sensor is based on Long Period Gratings (LPG) inscribed with a CO2 laser in 6-ring microstructured PMMA fiber. Through a latex coated, plastic 3D-printed transducer pod, external pressure...... is converted to longitudinal elongation of the pod and therefore of the fiber containing the LPG. The sensor has been characterised for pressures of up to 160 mBar in an in-house built pressure chamber. Furthermore, the influence of the fiber prestrain, fiber thickness and the effect of different glues...

  2. PET scanning in plastic and reconstructive surgery.

    Science.gov (United States)

    Liodaki, Eirini; Eirini, Liodaki; Liodakis, Emmanouil; Emmanouil, Liodakis; Papadopoulos, Othonas; Othonas, Papadopoulos; Machens, Hans-Günther; Hans-Günther, Machens; Papadopulos, Nikolaos A; Nikolaos, Papadopulos A

    2012-02-01

    In this report we highlight the use of PET scan in plastic and reconstructive surgery. PET scanning is a very important tool in plastic surgery oncology (melanoma, soft-tissue sarcomas and bone sarcomas, head and neck cancer, peripheral nerve sheath tumors of the extremities and breast cancer after breast esthetic surgery), as diagnosis, staging, treatment planning and follow-up of cancer patients is based on imaging. PET scanning seems also to be useful as a flap monitoring system as well as an infection's imaging tool, for example in the management of diabetic foot ulcer. PET also contributes to the understanding of pathophysiology of keloids which remain a therapeutic challenge.

  3. Permanent and plastic epigenesis in neuroendocrine systems.

    Science.gov (United States)

    Auger, Catherine J; Auger, Anthony P

    2013-08-01

    The emerging area of neuroepigenetics has been linked to numerous mental health illnesses. Importantly, a large portion of what we know about early gene×environment interactions comes from examining epigenetic modifications of neuroendocrine systems. This review will highlight how neuroepigenetic mechanisms during brain development program lasting differences in neuroendocrine systems and how other neuroepigenetic processes remain plastic, even within the adult brain. As epigenetic mechanisms can either be stable or plastic, elucidating the mechanisms involved in reversing these processes could aid in understanding how to reverse pathological epigenetic programming. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Cosmic ray spectroscopy using plastic scintillator detector

    International Nuclear Information System (INIS)

    Rudra, Sharmili; Nandan, Akhilesh P.; Neog, Himangshu; Biswas, S.; Mohanty, B.; Mahapatra, S.; Samal, P.K.

    2014-01-01

    A simple and new technique has been developed using plastic scintillator detectors for cosmic ray spectroscopy without single channel analyzer (SCA) or multichannel analyzer (MCA). In this technique only a leading edge discriminator (LED) and a NIM scaler have been used. Plastic scintillator detectors has been used to measure the velocity of cosmic ray muons. Here the time difference has been measured from the Tektronix DPO 5054 digital phosphor oscilloscope with 500 MHz and 5 GS/s. The details of experimental technique, analysis procedure and experimental results are presented

  5. Transgenerational plasticity is adaptive in the wild.

    Science.gov (United States)

    Galloway, Laura F; Etterson, Julie R

    2007-11-16

    Plants exhibit adaptive responses to light, but it is not known whether parental plants transmit environmental cues that elicit adaptive responses in offspring. We show that offspring life history (annual versus biennial) is influenced by the maternal light environment (understory versus light gap). This transgenerational plasticity is adaptive when offspring are grown in their maternal light environment, where seeds typically disperse. Projections of population growth show that plants that are appropriately cued for their light environment through maternal effects have 3.4 times greater fitness than otherwise. Transgenerational plasticity has evolved in response to natural variation in light and provides a flexible mechanism by which sedentary organisms cope with heterogeneous environments.

  6. Rational interpretation of the postulates in plasticity

    Directory of Open Access Journals (Sweden)

    Bohua Sun

    2014-01-01

    Full Text Available This article is mainly focussed on revisited of the two well-known postulates of plasticity, i.e., the Drucker and the Il’iushin postulate, and it describes their rational interpretation within the framework of irreversible thermodynamics and using exterior calculus. It shows that the Il’iushin and the Drucker postulate is the integral form and local form of the irreversible thermodynamics of plastic deformation, respectively. The Drucker and Il’iushin postulate is equivalent for both soft and hardening materials.

  7. External insulation with cellular plastic materials

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2014-01-01

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

  8. Waste Plastic Converting into Hydrocarbon Fuel Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin; Mamunor Rashid, Mohammad; Molla, Mohammad

    2010-09-15

    The increased demand and high prices for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. (NSR) has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel (patent pending). The method and principle of the production / process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

  9. Numerical simulation of large deformation polycrystalline plasticity

    International Nuclear Information System (INIS)

    Inal, K.; Neale, K.W.; Wu, P.D.; MacEwen, S.R.

    2000-01-01

    A finite element model based on crystal plasticity has been developed to simulate the stress-strain response of sheet metal specimens in uniaxial tension. Each material point in the sheet is considered to be a polycrystalline aggregate of FCC grains. The Taylor theory of crystal plasticity is assumed. The numerical analysis incorporates parallel computing features enabling simulations of realistic models with large number of grains. Simulations have been carried out for the AA3004-H19 aluminium alloy and the results are compared with experimental data. (author)

  10. KVP meter errors induced by plastic wrap

    International Nuclear Information System (INIS)

    Jefferies, D.; Morris, J.W.; White, V.P.

    1991-01-01

    The purpose of this study was to determine whether erroneous kVp meter readings, induced by plastic wrap, affected the actual kVp (output) of a dental X-ray machine. To evaluate the effect of plastic wrap on dental X-ray machine kVp meters, a radiation output device was used to measure output in mR/ma.s. An intraoral dental X-ray unit (S.S. White Model number-sign 90W) was used to make the exposures. First, the kVp meter was not covered with plastic wrap and output readings were recorded at various kVp settings with the milliamperage and time held constant. Secondly, the same kVp settings were selected before the plastic wrap was placed. Milliamperage and time were again held to the same constant. The X-ray console was then covered with plastic wrap prior to measuring the output for each kVp. The wrap possessed a static charge. This charge induced erroneous kVp meter readings. Out-put readings at the various induced kVp settings were then recorded. A kVp of 50 with no wrap present resulted in the same output as a kVp of 50 induced to read 40 or 60 kVp by the presence of wrap. Similar results were obtained at other kVp settings. This indicates that the plastic wrap influences only the kVp meter needle and not the actual kilovoltage of the X-ray machine. Dental X-ray machine operators should select kVp meter readings prior to placing plastic wrap and should not adjust initial settings if the meter is deflected later by the presence of wrap. The use of such a procedure will result in proper exposures, fewer retakes, and less patient radiation. If plastic wrap leads to consistent exposure errors, clinicians may wish to use a 0.5% sodium hypochlorite disinfectant as an alternative to the barrier technique

  11. Elastic-plastic-creep analysis of shells

    International Nuclear Information System (INIS)

    Pai, D.H.

    1979-01-01

    This paper presents the recent experience of a designer/fabricator of nuclear heat transport components in the area of elastic-plastic-creep analysis of shell-like structures. A brief historical perspective is first given to highlight the evolution leading to the present industry practice. The ASME elevated temperature design criteria will be discussed followed by examples of actual computations performed to support the design/analysis and fabrication of a breeder reactor component in which a substantial amount of elastic-plastic-creep analysis was performed. Mathematical challenges encountered by the design analyst in these problems will be highlighted. Developmental needs and future trends will then be given

  12. TEDEL programme, notice of the plasticity section

    International Nuclear Information System (INIS)

    Hoffmann, Alain.

    1975-05-01

    A plasticity model was introduced and is now operational in the TEDEL programme (piping and framework). At the moment it allows for either regular loading or cyclic loading under isotropic hardening conditions. The dynamic module allows the study of dynamic-plastic problems (such as accidents on a piping system). It can accept several types of material characterized by traction curves which may be of any form. Instructions are also given for the use of a new option (variable) by which the displacement values laid down for different load situations may be modified [fr

  13. Antifriction basalt-plastics based on polypropylene

    Science.gov (United States)

    Bashtannik, P. I.; Ovcharenko, V. G.

    1997-05-01

    A study is made of the dependence of the mechanical and friction-engineering properties of polypropylene reinforced with basalt fibers on the viscosity of the polymer matrix. It is established that the main factors that determine the mechanical properties of the plastics are the quality of impregnation of the fibers by the binder and the residual length of the reinforcing filler in the composite after extrusion and injection molding. The material that was developed has a low friction coefficient and low rate of wear within a relatively brood range of friction conditions. The basalt-plastics can be used in the rubbing parts of machines and mechanisms subjected to dry friction.

  14. 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.

  15. Flotation separation of waste plastics for recycling-A review.

    Science.gov (United States)

    Wang, Chong-qing; Wang, Hui; Fu, Jian-gang; Liu, You-nian

    2015-07-01

    The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2013-04-15

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

  17. Correlations of plasticity in sheared glasses

    NARCIS (Netherlands)

    Varnik, F.; Mandal, S.; Chikkadi, V.; Denisov, D.; Olsson, P.; Vågberg, D.; Raabe, D.; Schall, P.

    2014-01-01

    n a recent paper [Mandal et al., Phys. Rev. E 88, 022129 (2013)], the nature of spatial correlations of plasticity in hard-sphere glasses was addressed both via computer simulations and in experiments. It was found that the experimentally obtained correlations obey a power law, whereas the

  18. Bacterial production of the biodegradable plastics polyhydroxyalkanoates.

    Science.gov (United States)

    Urtuvia, Viviana; Villegas, Pamela; González, Myriam; Seeger, Michael

    2014-09-01

    Petroleum-based plastics constitute a major environmental problem due to their low biodegradability and accumulation in various environments. Therefore, searching for novel biodegradable plastics is of increasing interest. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are biodegradable plastics. Life cycle assessment indicates that PHB is more beneficial than petroleum-based plastics. In this report, bacterial production of PHAs and their industrial applications are reviewed and the synthesis of PHAs in Burkholderia xenovorans LB400 is described. PHAs are synthesized by a large number of microorganisms during unbalanced nutritional conditions. These polymers are accumulated as carbon and energy reserve in discrete granules in the bacterial cytoplasm. 3-hydroxybutyrate and 3-hydroxyvalerate are two main PHA units among 150 monomers that have been reported. B. xenovorans LB400 is a model bacterium for the degradation of polychlorobiphenyls and a wide range of aromatic compounds. A bioinformatic analysis of LB400 genome indicated the presence of pha genes encoding enzymes of pathways for PHA synthesis. This study showed that B. xenovorans LB400 synthesize PHAs under nutrient limitation. Staining with Sudan Black B indicated the production of PHAs by B. xenovorans LB400 colonies. The PHAs produced were characterized by GC-MS. Diverse substrates for the production of PHAs in strain LB400 were analyzed. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Mechanisms for pituitary tumorigenesis: the plastic pituitary

    OpenAIRE

    Melmed, Shlomo

    2003-01-01

    The anterior pituitary gland integrates the repertoire of hormonal signals controlling thyroid, adrenal, reproductive, and growth functions. The gland responds to complex central and peripheral signals by trophic hormone secretion and by undergoing reversible plastic changes in cell growth leading to hyperplasia, involution, or benign adenomas arising from functional pituitary cells. Discussed herein are the mechanisms underlying hereditary pituitary hypoplasia, reversible pituitary hyperplas...

  20. 4 π physics with the plastic ball

    International Nuclear Information System (INIS)

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

    1982-10-01

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

  1. Crack Tip Mechanics in Distortion Gradient Plasticity

    DEFF Research Database (Denmark)

    Fuentes-Alonso, Sandra; Martínez Pañeda, Emilio

    2017-01-01

    Gradient Plasticity (DGP), the influence on crack tip mechanics of DGP's distinguishing features that entail superior modelling capabilities has not been investigated yet. In this work crack tip fields are thoroughly examined by implementing the higher order theory of DGP in an implicit finite element...

  2. Production of grids in plastic detectors

    CERN Document Server

    Birabeau, J P; Brun, R; Cordaillat, A; Mendola, Onofrio

    1972-01-01

    In order to facilitate the locating of tracks of charged particles in cellulose nitrate and polycarbonate (makrofol, lexan) foils, a method has been developed for the photo-deposition of translucent coordinate grids on this materials. The grids are resistant to the strongly caustic solutions used in developing tracks in plastic foils. (9 refs) .

  3. Deposition of grids on plastic detectors

    CERN Document Server

    Birabeau, J P; Mendola, Onofrio

    1972-01-01

    In order to facilitate the locating of tracks of charged particles in cellulose-nitrate and polycarbonate (Makrofol, Lexan) foils, a method has been developed for the photo-deposition of translucent coordinate grids on these materials. The grids are resistant to the strongly caustic solutions used in developing tracks in plastic foils. (9 refs) .

  4. On lower order strain gradient plasticity theories

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Hutchinson, J. W.

    2002-01-01

    By way of numerical examples, this paper explores the nature of solutions to a class of strain gradient plasticity theories that employ conventional stresses, equilibrium equations and boundary conditions. Strain gradients come into play in these modified conventional theories only to alter...

  5. Fullerenes and nanostructured plastic solar cells

    NARCIS (Netherlands)

    Knol, Joop; Hummelen, Jan C.; Kuzmany, H; Fink, J; Mehring, M; Roth, S

    1998-01-01

    We report on the present on the present status of the plastic solar cell and on the design of fullerene derivatives and pi-conjugated donor molecules that can function as acceptor-donor pairs and (supra-) molecular building blocks in organized, nanostructured interpenetrating networks, forming a

  6. 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

  7. P2X Receptors and Synaptic Plasticity

    Czech Academy of Sciences Publication Activity Database

    Pankratov, Y.; Lalo, U.; Krishtal, A.; Verkhratsky, Alexei

    2009-01-01

    Roč. 158, č. 1 (2009), s. 137-148 ISSN 0306-4522 Institutional research plan: CEZ:AV0Z50390512 Keywords : ATP * P2X receptors * synaptic plasticity Subject RIV: FH - Neurology Impact factor: 3.292, year: 2009

  8. [Application of thermosetting plastics to eliminate undercuts].

    Science.gov (United States)

    Bielawski, T

    1989-01-01

    The author proposes to utilize the properties of thermosetting plastics used in other fields to use them in prosthetics in order to eliminate undercuts. Application of extra equipment in claspograph in the form of studs of three dimension makes formation of undercuts' blockade easier improving the result of work at the same time.

  9. Earthquake excited elasto-plastic structures

    DEFF Research Database (Denmark)

    Randrup-thomsen, Søren; Heuer, R.

    1996-01-01

    Studies of the single degree of freedom elasto-plastic oscillator is well-known in the literature. Some of these works use an associated linear system to describe special features in non-linear domains. One very successful work of this kind uses the socalled Slepian model process related to the a...

  10. Cladding failure by local plastic instability

    International Nuclear Information System (INIS)

    Kramer, J.M.; Deitrich, L.W.

    1977-01-01

    Cladding failure is one of the major considerations in analysis of fast-reactor fuel pin behavior during hypothetical accident transients since time, location and nature of failure govern the early post-failure material motion and reactivity feedback. Out-of-Pile transient burst tests of both irradiated and unirradiated fast-reactor cladding show that local plastic instability, or bulging, often precedes rupture. To investigate the details of cladding bulging, a perturbation analysis of the equations governing the large deformation of a cylindrical shell has been developed. The overall deformation history is assumed to consist of a small perturbation epsilon of the radial displacement superimposed on large axisymmetric displacements. Computations have been carried out using high temperature properties of stainless steel in conjunction with various constitutive theories, including a generalization of the Endochronic Theory of Plasticity in which both time-independent and time-dependent plastic strains are modeled. Although the results of the calculations are all qualitatively similar, it appears that modeling of both time-independent and time-dependent plastic strains is necessary to interpret the transient burst test results. Sources for bulge formation that have been considered include initial geometric imperfections and thermal perturbations due to either eccentric fuel pellets or non-symmetric cooling. (Auth.)

  11. Recombination rate plasticity: revealing mechanisms by design

    Science.gov (United States)

    Sefick, Stephen; Rushton, Chase

    2017-01-01

    For over a century, scientists have known that meiotic recombination rates can vary considerably among individuals, and that environmental conditions can modify recombination rates relative to the background. A variety of external and intrinsic factors such as temperature, age, sex and starvation can elicit ‘plastic’ responses in recombination rate. The influence of recombination rate plasticity on genetic diversity of the next generation has interesting and important implications for how populations evolve. Further, many questions remain regarding the mechanisms and molecular processes that contribute to recombination rate plasticity. Here, we review 100 years of experimental work on recombination rate plasticity conducted in Drosophila melanogaster. We categorize this work into four major classes of experimental designs, which we describe via classic studies in D. melanogaster. Based on these studies, we highlight molecular mechanisms that are supported by experimental results and relate these findings to studies in other systems. We synthesize lessons learned from this model system into experimental guidelines for using recent advances in genotyping technologies, to study recombination rate plasticity in non-model organisms. Specifically, we recommend (1) using fine-scale genome-wide markers, (2) collecting time-course data, (3) including crossover distribution measurements, and (4) using mixed effects models to analyse results. To illustrate this approach, we present an application adhering to these guidelines from empirical work we conducted in Drosophila pseudoobscura. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109222

  12. Amphibious fishes: evolution and phenotypic plasticity.

    Science.gov (United States)

    Wright, Patricia A; Turko, Andy J

    2016-08-01

    Amphibious fishes spend part of their life in terrestrial habitats. The ability to tolerate life on land has evolved independently many times, with more than 200 extant species of amphibious fishes spanning 17 orders now reported. Many adaptations for life out of water have been described in the literature, and adaptive phenotypic plasticity may play an equally important role in promoting favourable matches between the terrestrial habitat and behavioural, physiological, biochemical and morphological characteristics. Amphibious fishes living at the interface of two very different environments must respond to issues relating to buoyancy/gravity, hydration/desiccation, low/high O2 availability, low/high CO2 accumulation and high/low NH3 solubility each time they traverse the air-water interface. Here, we review the literature for examples of plastic traits associated with the response to each of these challenges. Because there is evidence that phenotypic plasticity can facilitate the evolution of fixed traits in general, we summarize the types of investigations needed to more fully determine whether plasticity in extant amphibious fishes can provide indications of the strategies used during the evolution of terrestriality in tetrapods. © 2016. Published by The Company of Biologists Ltd.

  13. Telemedicine and Plastic Surgery: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Denis Souto Valente

    2015-01-01

    Full Text Available Background. Telemedicine can be defined as the use of electronic media for transmission of information and medical data from one site to another. The objective of this study is to demonstrate an experience of telemedicine in plastic surgery. Methods. 32 plastic surgeons received a link with password for real-time streaming of a surgery. At the end of the procedure, the surgeons attending the procedure by the Internet answered five questions. The results were analyzed with descriptive statistics. Results. 27 plastic surgeons attended the online procedure in real-time. 96.3% considered the access to the website as good or excellent and 3.7% considered it bad. 14.8% reported that the transmission was bad and 85.2% considered the quality of transmission as good or excellent. 96.3% classified the live broadcasting as a good or excellent learning experience and 3.7% considered it a bad experience. 92.6% reported feeling able to perform this surgery after watching the demo and 7.4% did not feel able. 100% of participants said they would like to participate in other surgical demonstrations over the Internet. Conclusion. We conclude that the use of telemedicine can provide more access to education and medical research, for plastic surgeons looking for medical education from distant regions.

  14. Design principles of electrical synaptic plasticity.

    Science.gov (United States)

    O'Brien, John

    2017-09-08

    Essentially all animals with nervous systems utilize electrical synapses as a core element of communication. Electrical synapses, formed by gap junctions between neurons, provide rapid, bidirectional communication that accomplishes tasks distinct from and complementary to chemical synapses. These include coordination of neuron activity, suppression of voltage noise, establishment of electrical pathways that define circuits, and modulation of high order network behavior. In keeping with the omnipresent demand to alter neural network function in order to respond to environmental cues and perform tasks, electrical synapses exhibit extensive plasticity. In some networks, this plasticity can have dramatic effects that completely remodel circuits or remove the influence of certain cell types from networks. Electrical synaptic plasticity occurs on three distinct time scales, ranging from milliseconds to days, with different mechanisms accounting for each. This essay highlights principles that dictate the properties of electrical coupling within networks and the plasticity of the electrical synapses, drawing examples extensively from retinal networks. Copyright © 2017 The Author. Published by Elsevier B.V. All rights reserved.

  15. Adaptive tuning of elasto-plastic damper

    DEFF Research Database (Denmark)

    Høgsberg, Jan Riess; Krenk, Steen

    2007-01-01

    the damper parameter(s) with respect to the magnitude of the damper motion. The procedure is demonstrated in terms of the bilinear elasto-plastic damper model, and optimality corresponds to maximum modal damping. A parametric solution for the damping ratio is obtained by a two-component system reduction...

  16. Fluorescent compounds for plastic scintillation applications

    International Nuclear Information System (INIS)

    Pla-Dalmau, A.; Bross, A.D.

    1994-04-01

    Several 2-(2'-hydroxyphenyl)benzothiazole, -benzoxazole, and -benzimidazole derivatives have been prepared. Transmittance, fluorescence, light yield, and decay time characteristics of these compounds have been studied in a polystyrene matrix and evaluated for use in plastic scintillation detectors. Radiation damage studies utilizing a 60 C source have also been performed

  17. A large area plastic Cherenkov detector

    International Nuclear Information System (INIS)

    Bernabei, R.; Bidoli, V.; Zorzi, G. de; Biagio, A. di

    1978-01-01

    A large area Cherenkov counter has been built up using as a radiator a sheet of Pilot 425 plastic, (180x20)cm 2 x2.5 cm. Experimental tests performed with a pion beam in order to measure the average number of photoelectrons collected by photomultipliers and the scintillation to Cherenkov light ratio. (Auth.)

  18. Light pulse shapes from plastic scintillators

    International Nuclear Information System (INIS)

    Moszynski, M.; Bengtson, B.

    1977-01-01

    A detailed study of the light pulse shape from the binary NE 111 and the ternary Pilot U, Naton 136, KL 236, NE 102A, NE 104 and NE 110 plastic scintillators was performed by the single photon method using XP 1021 and C 31024 photomultipliers. The analysis of the shape of the light pulses determined experimentally for several samples of different dimensions gave the following conclusions. The original light pulse shape from the binary NE 111 scintillator, as measured with a 5 mm thick polished sample is described analytically by the convolution integral of a Gaussian and an exponential function. The Gaussian function may reflect a deexcitation of several higher levels of the solvent molecules excited by nuclear particles preceding an intermolecular energy transfer in the scintillator. It may introduce a rather important limitation of the speed of plastic scintillators as the standard deviation of the Gaussian function is equal to 0.2 ns. The light pulse shape from the ternary plastics is described by the convolution integral of a Gaussian and two exponential functions. The Gaussian function presents the rate of energy transfer from nuclear particles to the primary solute as in the binary plastics. The exponential functions describe the energy transfer from the primary solute to the wavelength shifter and the final emission of the light. (Auth.)

  19. Plastic Deformation of Pressured Metallic Glass

    Directory of Open Access Journals (Sweden)

    Yun Cheng

    2017-11-01

    Full Text Available Although pressured metallic glass (MG has been reported in the literature; there are few studies focusing on pressure effects on the structure; dynamics and its plastic deformation. In this paper; we report on and characterize; via molecular dynamics simulation, the structure and dynamics heterogeneity of pressured MGs, and explore a causal link between local structures and plastic deformation mechanism of pressured glass. The results exhibit that the dynamical heterogeneity of metallic liquid is more pronounced at high pressure, while the MGs were less fragile after the release of external pressure, reflected by the non-Gaussian parameter (NGP. High pressure glass shows better plastic deformation; and the local strain zone distributed more uniformly than of in normal glass. Further research indicates that although the number of icosahedrons in pressured glass was much larger than that in normal glass, while the interpenetrating connections of icosahedra (ICOI exhibited spatial correlations were rather poor; In addition, the number of ‘fast’ atoms indexed by the atoms’ moving distance is larger than that in normal glass; leading to the sharp decreasing in number of icosahedrons during deformation. An uniform distribution of ‘fast’ atoms also contributed to better plastic deformation ability in the pressured glass. These findings may suggest a link between the deformation and destruction of icosahedra with short-range order.

  20. Plastic Tubing and Maple Syrup Quality

    Science.gov (United States)

    Russell S. Walters; Harry W. Yawney

    1978-01-01

    Maple syrup made from sap collected using improperly or carelessly installed plastic pipelines varied more in color from day to day, and was more often darker in color, than sap collected from either the property installed pipeline or clean, frequently emptied galvanized buckets. Use of both properly installed tubing and buckets, following recommended procedures,...

  1. Elastic plastic buckling of elliptical vessel heads

    International Nuclear Information System (INIS)

    Alix, M.; Roche, R.L.

    1981-08-01

    The risks of buckling of dished vessel head increase when the vessel is thin walled. This paper gives the last results on experimental tests of 3 elliptical heads and compares all the results with some empirical formula dealing with elastic and plastic buckling

  2. Remeshing in analysis of large plastic deformations

    DEFF Research Database (Denmark)

    Pedersen, Thomas Ø

    1998-01-01

    Very distorted elements in a finite element computation will affect the results in a negative way. In applications where large plastic deformations are present, the mesh often deteriorates so badly, that remeshing is the only option to avoid a breakdown in the numerical computations. In the present...

  3. Monopole track characteristics in plastic detectors

    Science.gov (United States)

    Ahlen, S. P.

    1975-01-01

    Total and restricted energy loss rates were calculated for magnetic monopoles of charge g = 137 e in Lexan polycarbonate. Range-energy curves are also presented. The restricted energy loss model is used to estimate the appearance of a monopole track in plastic detectors. These results should be useful for the design and analysis of monopole experiments.

  4. Plastic debris in the open ocean

    KAUST Repository

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

    2014-01-01

    of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet

  5. Ageing and recycling of plastic crates

    NARCIS (Netherlands)

    Vink, P.; Rotteveel, R.T.; Wisse, J.D.M.

    1985-01-01

    Plastic crates will deteriorate and ultimately fail due to brittle fracture if, either during use or storage, they are exposed to sunlight. The time to failure depends on the UV stability of the polymer used, but in particular also on the conditions of use, such as time of exposure, height of the

  6. Development, maternal effects, and behavioral plasticity.

    Science.gov (United States)

    Mateo, Jill M

    2014-11-01

    Behavioral, hormonal, and genetic processes interact reciprocally, and differentially affect behavior depending on ecological and social contexts. When individual differences are favored either between or within environments, developmental plasticity would be expected. Parental effects provide a rich source for phenotypic plasticity, including anatomical, physiological, and behavioral traits, because parents respond to dynamic cues in their environment and can, in turn, influence offspring accordingly. Because these inter-generational changes are plastic, parents can respond rapidly to changing environments and produce offspring whose phenotypes are well suited for current conditions more quickly than occurs with changes based on evolution through natural selection. I review studies on developmental plasticity and resulting phenotypes in Belding's ground squirrels (Urocitellus beldingi), an ideal species, given the competing demands to avoid predation while gaining sufficient weight to survive an upcoming hibernation, and the need for young to learn their survival behaviors. I will show how local environments and perceived risk of predation influence not only foraging, vigilance, and anti-predator behaviors, but also adrenal functioning, which may be especially important for obligate hibernators that face competing demands on the storage and mobilization of glucose. Mammalian behavioral development is sensitive to the social and physical environments provided by mothers during gestation and lactation. Therefore, maternal effects on offspring's phenotypes, both positive and negative, can be particularly strong. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  7. Plastic Brains and the Dialectics of Dialectics

    Science.gov (United States)

    Loxley, Andrew; Murphy, Colette; Seery, Aidan

    2014-01-01

    This article advances the thinking of Lima, Ostermann and Rezende's "Marxism in Vygotskian approaches to cultural studies of science education" and Mark Zuss' response to their paper. Firstly, it introduces Catherine Malabou's concept of plasticity, from which Hegel's dialectic can be re-read as historical materialist…

  8. Data-driven in computational plasticity

    Science.gov (United States)

    Ibáñez, R.; Abisset-Chavanne, E.; Cueto, E.; Chinesta, F.

    2018-05-01

    Computational mechanics is taking an enormous importance in industry nowadays. On one hand, numerical simulations can be seen as a tool that allows the industry to perform fewer experiments, reducing costs. On the other hand, the physical processes that are intended to be simulated are becoming more complex, requiring new constitutive relationships to capture such behaviors. Therefore, when a new material is intended to be classified, an open question still remains: which constitutive equation should be calibrated. In the present work, the use of model order reduction techniques are exploited to identify the plastic behavior of a material, opening an alternative route with respect to traditional calibration methods. Indeed, the main objective is to provide a plastic yield function such that the mismatch between experiments and simulations is minimized. Therefore, once the experimental results just like the parameterization of the plastic yield function are provided, finding the optimal plastic yield function can be seen either as a traditional optimization or interpolation problem. It is important to highlight that the dimensionality of the problem is equal to the number of dimensions related to the parameterization of the yield function. Thus, the use of sparse interpolation techniques seems almost compulsory.

  9. Small scale plasticity - an ad hoc review

    International Nuclear Information System (INIS)

    Ng, K S; Ngan, A H W

    2009-01-01

    Recent uniaxial compression experiments on FCC metallic micro-crystals revealed their unique deformation behaviour as compared to the bulk situation. The distinctive behaviour includes size-dependent proof strength, intermittent plasticity during loading and creep, low steady-state creep rate, heterogeneous slip, limited dislocation accumulation, etc. This paper reviews the key experimental observations as well as modelling efforts for the underlying mechanisms.

  10. Synaptic plasticity and the warburg effect

    KAUST Repository

    Magistretti, Pierre J.

    2014-01-01

    Functional brain imaging studies show that in certain brain regions glucose utilization exceeds oxygen consumption, indicating the predominance of aerobic glycolysis. In this issue, Goyal et al. (2014) report that this metabolic profile is associated with an enrichment in the expression of genes involved in synaptic plasticity and remodeling processes. © 2014 Elsevier Inc.

  11. Human Maternal Brain Plasticity: Adaptation to Parenting

    Science.gov (United States)

    Kim, Pilyoung

    2016-01-01

    New mothers undergo dynamic neural changes that support positive adaptation to parenting and the development of mother-infant relationships. In this article, I review important psychological adaptations that mothers experience during pregnancy and the early postpartum period. I then review evidence of structural and functional plasticity in human…

  12. Optimization of wood plastic composite decks

    Science.gov (United States)

    Ravivarman, S.; Venkatesh, G. S.; Karmarkar, A.; Shivkumar N., D.; Abhilash R., M.

    2018-04-01

    Wood Plastic Composite (WPC) is a new class of natural fibre based composite material that contains plastic matrix reinforced with wood fibres or wood flour. In the present work, Wood Plastic Composite was prepared with 70-wt% of wood flour reinforced in polypropylene matrix. Mechanical characterization of the composite was done by carrying out laboratory tests such as tensile test and flexural test as per the American Society for Testing and Materials (ASTM) standards. Computer Aided Design (CAD) model of the laboratory test specimen (tensile test) was created and explicit finite element analysis was carried out on the finite element model in non-linear Explicit FE code LS - DYNA. The piecewise linear plasticity (MAT 24) material model was identified as a suitable model in LS-DYNA material library, describing the material behavior of the developed composite. The composite structures for decking application in construction industry were then optimized for cross sectional area and distance between two successive supports (span length) by carrying out various numerical experiments in LS-DYNA. The optimized WPC deck (Elliptical channel-2 E10) has 45% reduced weight than the baseline model (solid cross-section) considered in this study with the load carrying capacity meeting acceptance criterion (allowable deflection & stress) for outdoor decking application.

  13. Ocean acidification challenges copepod phenotypic plasticity

    Directory of Open Access Journals (Sweden)

    A. Vehmaa

    2016-11-01

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

  14. Ocean acidification challenges copepod reproductive plasticity

    Science.gov (United States)

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

    2015-11-01

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

  15. 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.

  16. A mobile antineutrino detector with plastic scintillators

    International Nuclear Information System (INIS)

    Kuroda, Y.; Oguri, S.; Kato, Y.; Nakata, R.; Inoue, Y.; Ito, C.; Minowa, M.

    2012-01-01

    We propose a new type segmented antineutrino detector made of plastic scintillators for the nuclear safeguard application. A small prototype was built and tested to measure background events. A satisfactory unmanned field operation of the detector system was demonstrated. Besides, a detailed Monte Carlo simulation code was developed to estimate the antineutrino detection efficiency of the detector.

  17. Durability of wood-plastic composite lumber

    Science.gov (United States)

    Rebecca E. Ibach

    2010-01-01

    Wood-plastic composite (WPC) lumber has been marketed as a low-maintenance, high-durability product. Retail sales in the United States were slightly less than $1 billion in 2008. Applications include docking, railing, windows, doors, fencing, siding, moldings, landscape timbers, car interior parts, and furniture. The majority of these products are used outdoors and...

  18. Attitudes of Consumers Towards the Green Plastic

    Directory of Open Access Journals (Sweden)

    Gabriela Elnecave Kruter

    2012-06-01

    Full Text Available The demands regarding sustainable production and consumption are growing increasingly, the market is opening doors for companies to innovate in products and processes that present themselves as a solution to social and environmental problems facing society today. To this end, in 2010, a Brazilian company began producing the "green" polyethylene, or green plastic, which differs from conventional polyethylene because it is produced from the ethanol from cane sugar and not from naphtha oil. Because it is a new product on the market and little known, this study aims to understand consumer attitudes towards green plastic. Environmental concerns, ecologically conscious consumer behavior, purchase intention and previous knowledge of green plastic were also assessed. Were conducted initially in-depth interviews, which helped quantitative stage, an online survey, applied to a sample of 300 individuals. Results indicate that surveyed consumers have positive attitudes towards green plastic and intention to purchase products made ​​with this material. Despite exhibiting a high degree of environmental awareness, they show only moderate attitudes in relation to sustainable consumption in practice. We can conclude that there is still much to be done by companies and society so that a greater degree of maturity and respect for the environment can be achieved.

  19. Catalytic Pyrolysis of Waste Plastic Mixture

    Science.gov (United States)

    Sembiring, Ferdianta; Wahyu Purnomo, Chandra; Purwono, Suryo

    2018-03-01

    Inorganic waste especially plastics still become a major problem in many places. Low biodegradability of this materials causes the effort in recycling become very difficult. Most of the municipal solid waste (MSW) recycling facilities in developing country only use composting method to recover the organic fraction of the waste, while the inorganic fraction is still untreated. By pyrolysis, plastic waste can be treated to produce liquid fuels, flammable gas and chars. Reduction in volume and utilization of the liquid and gas as fuel are the major benefits of the process. By heat integration actually this process can become a self-sufficient system in terms of energy demand. However, the drawback of this process is usually due to the diverse type of plastic in the MSW creating low grade of liquid fuel and harmful gases. In this study, the mixture of plastics i.e. polypropylene (PP) and polyethylene terephthalate (PET) is treated using pyrolysis with catalyst in several operating temperature. PET is problematic to be treated using pyrolysis due to wax-like byproduct in liquid which may cause pipe clogging. The catalyst is the mixture of natural zeolite and bentonite which is able to handle PP and PET mixture feed to produce high grade liquid fuels in terms of calorific value and other fuel properties.

  20. Radiation processing of wood-plastic composites

    International Nuclear Information System (INIS)

    Czvikovszky, T.

    1992-01-01

    There are three main types of radiation-processed composite material derived from plastics and fibrous natural polymers. The first are the monomer-impregnated, radiation-treated wood-plastic composites (WPC). They became a commercial success in the early 1970s. More recently, work has focused on improving the WPCs by creating in them interpenetrating network (IPN) systems by the use of appropriate multifunctional oligomers and monomers. The main kinetic features of radiation-initiated chain polymerization remain applicable even in impregnated wood. The second type are the plastics filled or reinforced with dispersed wood fiber or other cellulosics (WFRP). In their case, radiation processing offers a new opportunity to apply radiation-reactive adhesion promoters between wood or cellulosic fibers and the thermoplastic matrices. The third type are the laminar composites made by electron beam coating of wood-based agglomerate sheets and boards. This chapter reviews the industrial applications and the radiation processing of the three types of the wood-plastic composites and indicates future trends. (orig.)