WorldWideScience

Sample records for plastic accommodation processes

  1. The interactive processes of accommodation and vergence.

    Science.gov (United States)

    Semmlow, J L; Bérard, P V; Vercher, J L; Putteman, A; Gauthier, G M

    1994-01-01

    A near target generates two different, though related stimuli: image disparity and image blur. Fixation of that near target evokes three motor responses: the so-called oculomotor "near triad". It has long been known that both disparity and blur stimuli are each capable of independently generating all three responses, and a recent theory of near triad control (the Dual Interactive Theory) describes how these stimulus components normally work together in the aid of near vision. However, this theory also indicates that when the system becomes unbalanced, as in high AC/A ratios of some accommodative esotropes, the two components will become antagonistic. In this situation, the interaction between the blur and disparity driven components exaggerates the imbalance created in the vergence motor output. Conversely, there is enhanced restoration when the AC/A ratio is effectively reduced surgically.

  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. Process for remediation of plastic waste

    Science.gov (United States)

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

    2012-04-10

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

  5. Finite element evaluation of elasto-plastic accommodation energies during solid state transformations: Coherent, spherical precipitate in finite matrix

    International Nuclear Information System (INIS)

    Sen, S.; Balasubramaniam, R.; Sethuraman, R.

    1996-01-01

    The molar volume difference between the matrix and the precipitate phases in the case of solid state phase transformations results in the creation of stain energy in the system due to the misfit strains. A finite element model based on the initial strain approach is proposed to evaluate elasto-plastic accommodation energies during solid state transformation. The three-dimensional axisymmetric model has been used to evaluate energies as a function of transformation for α-β hydrogen transformations in the Nb-H system. The transformation has been analyzed for the cases of transformation progressing both from the center to surface and from the surface to center of the system. The effect of plastic deformation has been introduced to make the model realistic, specifically to the Nb-NbH phase transformation which involves a 4% linear misfit strain. It has been observed that plastic deformation reduces the strain energies compared to the linear elastic analysis

  6. Is There a Downside of Job Accommodations? An Employee Perspective on Individual Change Processes

    Directory of Open Access Journals (Sweden)

    Julia M. Kensbock

    2017-09-01

    Full Text Available By modifying the work environments, work routines, and work tasks of employees with health restrictions, organizations can effectively help them continue to perform their jobs successfully. As such, job accommodations are an effective tool to secure the continued employment of aging workers who develop disabilities across their life span. However, while accommodations tackle health-related performance problems, they might create new challenges on the part of the affected employee. Building on the organizational change and accommodations literatures, we propose a theoretical framework of negative experiences during accommodation processes and apply it to qualitative data from group interviews with 73 manufacturing workers at a German industrial company who were part of the company's job accommodation program. Although problems associated with health-related impairments were mostly solved by accommodation, affected employees with disabilities reported about interpersonal problems and conflicts similar to those that typically occur during organizational change. Lack of social support as well as poor communication and information were raised as criticisms. Furthermore, our findings indicate that discrimination, bullying, and maltreatment appear to be common during accommodation processes. To make accommodation processes more successful, we derive recommendations from the organizational change literature and apply it to the accommodation context. We also emphasize unique characteristics of the accommodation setting and translate these into practical implications.

  7. Is There a Downside of Job Accommodations? An Employee Perspective on Individual Change Processes

    Science.gov (United States)

    Kensbock, Julia M.; Boehm, Stephan A.; Bourovoi, Kirill

    2017-01-01

    By modifying the work environments, work routines, and work tasks of employees with health restrictions, organizations can effectively help them continue to perform their jobs successfully. As such, job accommodations are an effective tool to secure the continued employment of aging workers who develop disabilities across their life span. However, while accommodations tackle health-related performance problems, they might create new challenges on the part of the affected employee. Building on the organizational change and accommodations literatures, we propose a theoretical framework of negative experiences during accommodation processes and apply it to qualitative data from group interviews with 73 manufacturing workers at a German industrial company who were part of the company's job accommodation program. Although problems associated with health-related impairments were mostly solved by accommodation, affected employees with disabilities reported about interpersonal problems and conflicts similar to those that typically occur during organizational change. Lack of social support as well as poor communication and information were raised as criticisms. Furthermore, our findings indicate that discrimination, bullying, and maltreatment appear to be common during accommodation processes. To make accommodation processes more successful, we derive recommendations from the organizational change literature and apply it to the accommodation context. We also emphasize unique characteristics of the accommodation setting and translate these into practical implications. PMID:28979218

  8. Mechanisms of strain accommodation in plastically-deformed zircon under simple shear deformation conditions during amphibolite-facies metamorphism

    Science.gov (United States)

    Kovaleva, Elizaveta; Klötzli, Urs; Wheeler, John; Habler, Gerlinde

    2018-02-01

    This study documents the strain accommodation mechanisms in zircon under amphibolite-facies metamorphic conditions in simple shear. Microstructural data from undeformed, fractured and crystal-plastically deformed zircon crystals are described in the context of the host shear zone, and evaluated in the light of zircon elastic anisotropy. Our work challenges the existing model of zircon evolution and shows previously undescribed rheological characteristics for this important accessory mineral. Crystal-plastically deformed zircon grains have axis oriented parallel to the foliation plane, with the majority of deformed grains having axis parallel to the lineation. Zircon accommodates strain by a network of stepped low-angle boundaries, formed by switching between tilt dislocations with the slip systems {010} and {110} and rotation axis [001], twist dislocations with the rotation axis [001], and tilt dislocations with the slip system {001} and rotation axis [010]. The slip system {110} is newly described for zircon. Most misorientation axes in plastically-deformed zircon grains are parallel to the XY plane of the sample and have [001] crystallographic direction. Such behaviour of strained zircon lattice is caused by elastic anisotropy that has a direct geometric control on the rheology, deformation mechanisms and dominant slip systems in zircon. Young's modulus and P wave velocity have highest values parallel to zircon [001] axis, indicating that zircon is elastically strong along this direction. Poisson ratio and Shear modulus demonstrate that zircon is also most resistant to shearing along [001]. Thus, [001] axis is the most common rotation axis in zircon. The described zircon behaviour is important to take into account during structural and geochronological investigations of (poly)metamorphic terrains. Geometry of dislocations in zircon may help reconstructing the geometry of the host shear zone(s), large-scale stresses in the crust, and, possibly, the timing of

  9. 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.)

  10. Radiation processing of plastics for decorative purposes

    International Nuclear Information System (INIS)

    Knizhnik, R.I.; Onisko, A.D.

    1982-01-01

    Methods are reviewed for the radiation processing of polymeric films, sheets, plates and panels to form patterns, drawings, images and decorative finishing which have been recently developed in various countries. Methods of beam and radiation processing of transparent plastics are described for making a decorative article with a pattern inside the volume; advantages and shortcomings of the methods are shown. The method of radiation processing of transparent dielectric plastics by electron beam of a Microtron is considered in detail. It provides an economical method of fabrication of large-size highly artistic decorative articles with an original pattern inside the volume. Radiation processing operations are presented which are aimed at creation and visualization of regions of extended thermalized electron space charges stored by irradiation of dielectric. Examples are presented of large-size highly artistic decorative articles of polymethylmethacrylate which were used in interior of buildings and demonstrated at home and international exhibitions. (author)

  11. Radiation processing in the plastics industry

    International Nuclear Information System (INIS)

    Saunders, C.B.

    1988-01-01

    The interaction of ionizing radiation with organic substrates to produce useful physical and chemical changes is the basis of the radiation processing industry for plastics. Electron beam (EB) accelerators dominate the industry; however, there are a few small applications that use gamma radiation. The five general product categories that account for over 95% of the worldwide EB capacity used for plastics production are the following: wire and cable insulation; heat-shrinkable film, tubes and pipes; radiation-curable coatings; rubber products; and polyolefin foam. A total of 6.1% of the yearly production of these products in the United States is EB treated. The United States accounts for 59% of the total worldwide EB capacity of 20.5 MW (1984), followed by Europe (16%) and Japan (15%). There are 469 to 479 individual EB units worldwide used for the production of plastics and rubber. The average annual rate of growth (AARG) for the EB processing of plastics in Japan, from 1977 to 1987, was 13.3%. The AARG for Japan has decreased from 20% for 1977 to 198, to 6.4% for 1984 to 1987. Radiation cross-linking, of power cable insulation (cable rating ≥75 kV), thick polyolefin and rubber sheet (≥15 mm), and thick-walled tubing is one fo the potential applications for a 5- to 10-MeV EB system. Other products such as coatings, films and wire insulation may be economically EB-treated using a 5 to 10 MeV accelerator, if several layers of the product could be irradiated simultaneously. Two general product categories that require more study to determine the potential of high-energy EB processing are moulded plastics and composite materials. 32 refs

  12. Well-being, the Decision making process in residential care facilities and accommodation in Denmark

    DEFF Research Database (Denmark)

    Knudstrup, Mary-Ann; Harder, Henrik

    process. 3. Alternatives to "the living environments”. In general a discussion about “the living environments” as the only and right solution for organising the residential care facilities and accommodation in Denmark is recommended. Maybe there should be a possibility given to create more private...... for assisted living residential care facilities and accommodation for senior citizens selected from different parts of Denmark. The case study will provide important knowledge on municipal activities in the area of residential care facilities, as well as discuss the different actors’ roles in the decision......-based knowledge is needed: There is a need for research-based knowledge manuals among the actors involved in the planning and project design process which describe systematically the importance of working with the different aspects on well-being in residential care facilities and accommodation in Denmark. 2. More...

  13. Students' Thinking Process in Solving Combination Problems Considered from Assimilation and Accommodation Framework

    Science.gov (United States)

    Jalan, Sukoriyanto; Nusantara, Toto; Subanji, Subanji; Chandra, Tjang Daniel

    2016-01-01

    This study aims to explain the thinking process of students in solving combination problems considered from assimilation and accommodation frameworks. This research used a case study approach by classifying students into three categories of capabilities namely high, medium and low capabilities. From each of the ability categories, one student was…

  14. Flash Cracking Reactor for Waste Plastic Processing

    Science.gov (United States)

    Timko, Michael T.; Wong, Hsi-Wu; Gonzalez, Lino A.; Broadbelt, Linda; Raviknishan, Vinu

    2013-01-01

    Conversion of waste plastic to energy is a growing problem that is especially acute in space exploration applications. Moreover, utilization of heavy hydrocarbon resources (wastes, waxes, etc.) as fuels and chemicals will be a growing need in the future. Existing technologies require a trade-off between product selectivity and feedstock conversion. The objective of this work was to maintain high plastic-to-fuel conversion without sacrificing the liquid yield. The developed technology accomplishes this goal with a combined understanding of thermodynamics, reaction rates, and mass transport to achieve high feed conversion without sacrificing product selectivity. The innovation requires a reaction vessel, hydrocarbon feed, gas feed, and pressure and temperature control equipment. Depending on the feedstock and desired product distribution, catalyst can be added. The reactor is heated to the desired tempera ture, pressurized to the desired pressure, and subject to a sweep flow at the optimized superficial velocity. Software developed under this project can be used to determine optimal values for these parameters. Product is vaporized, transferred to a receiver, and cooled to a liquid - a form suitable for long-term storage as a fuel or chemical. An important NASA application is the use of solar energy to convert waste plastic into a form that can be utilized during periods of low solar energy flux. Unlike previous work in this field, this innovation uses thermodynamic, mass transport, and reaction parameters to tune product distribution of pyrolysis cracking. Previous work in this field has used some of these variables, but never all in conjunction for process optimization. This method is useful for municipal waste incinerator operators and gas-to-liquids companies.

  15. Advances in modeling plastic waste pyrolysis processes

    Energy Technology Data Exchange (ETDEWEB)

    Safadi, Y. [Department of Mechanical Engineering, American University of Beirut, PO Box 11-0236, Beirut (Lebanon); Zeaiter, J. [Chemical Engineering Program, American University of Beirut, PO Box 11-0236, Beirut (Lebanon)

    2013-07-01

    The tertiary recycling of plastics via pyrolysis is recently gaining momentum due to promising economic returns from the generated products that can be used as a chemical feedstock or fuel. The need for prediction models to simulate such processes is essential in understanding in depth the mechanisms that take place during the thermal or catalytic degradation of the waste polymer. This paper presents key different models used successfully in literature so far. Three modeling schemes are identified: Power-Law, Lumped-Empirical, and Population-Balance based equations. The categorization is based mainly on the level of detail and prediction capability from each modeling scheme. The data shows that the reliability of these modeling approaches vary with the degree of details the experimental work and product analysis are trying to achieve.

  16. Does ego development increase during midlife? The effects of openness and accommodative processing of difficult events.

    Science.gov (United States)

    Lilgendahl, Jennifer Pals; Helson, Ravenna; John, Oliver P

    2013-08-01

    Although Loevinger's model of ego development is a theory of personality growth, there are few studies that have examined age-related change in ego level over developmentally significant periods of adulthood. To address this gap in the literature, we examined mean-level change and individual differences in change in ego level over 18 years of midlife. In this longitudinal study, participants were 79 predominantly White, college-educated women who completed the Washington University Sentence Completion Test in early (age 43) and late (age 61) midlife as well as measures of the trait of Openness (ages 21, 43, 52, and 61) and accommodative processing (assessed from narratives of difficult life events at age 52). As hypothesized, the sample overall showed a mean-level increase in ego level from age 43 to age 61. Additionally, a regression analysis showed that both the trait of Openness at age 21 and accommodative processing of difficult events that occurred during (as opposed to prior to) midlife were each predictive of increasing ego level from age 43 to age 61. These findings counter prior claims that ego level remains stable during adulthood and contribute to our understanding of the underlying processes involved in personality growth in midlife. © 2012 Wiley Periodicals, Inc.

  17. 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.

  18. sampling plans for monitoring quality control process at a plastic

    African Journals Online (AJOL)

    Dr Obe

    AT A PLASTIC MANUFACTURING FIRM IN NIGERIA: A CASE STUDY. By. E.A. Onyeagoro ... manufacture similar products, so that each company ... monitoring of production to maintain process ... concept of designing quality into product, with.

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

    International Nuclear Information System (INIS)

    Grabco, D; Shikimaka, O; Harea, E

    2008-01-01

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

  20. Sampling Plans for Monitoring Quality Control Process at a Plastic ...

    African Journals Online (AJOL)

    This paper explores the problem of high quality cost at a medium –sized firm manufacturing various types and sizes of plastic container, using a real life data. In pursuance of their quality objectives, the company established a policy that dictates and expensive and time-consuming post-manufacturing process. While the ...

  1. Recrystallization kinetics of nanostructured copper processed by dynamic plastic deformation

    DEFF Research Database (Denmark)

    Lin, Fengxiang; Zhang, Yubin; Pantleon, Wolfgang

    2012-01-01

    The recrystallization kinetics of nanostructured copper samples processed by dynamic plastic deformation was investigated by electron backscatter diffraction. It was found that the evolution of the recrystallized volume fraction as a function of annealing time has a very low slope (n=0.37) when...

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

    Science.gov (United States)

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

    2018-05-01

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

  3. Study of primary energy transfer process in ultrafast plastic scintillators

    International Nuclear Information System (INIS)

    Bengtson, B.; Moszynski, M.

    1978-01-01

    The study of the light-pulse shape, the initial delay of light pulses and the light yield of plastics prepared by a modification of the NE111 scintillator were performed. The NE111 scintillator doped with several quench agents, the plastics prepared as a solution of butyl PBD in PVT of different concentration and PVT alone were studied. The study confirmed that the light pulse shape from fast binary plastics is well described analytically by the convolution of the clipped Gaussian and exponential functions. The investigation of the PVT-butyl PBD plastics shows that even more than three times larger concentration of butyl PBD compared to that of PBD in the NE111 solution does not improve the rise of the light pulse. Thus the rise time seems to be not controlled by the intermolecular energy transfer process. Finally, the observed rise time of the light pulse from the PVT sample was also approximated well by the Gaussian function. Altogether it brought a strong support for the earlier hypothesis that the initial slow rise of light pulses from plastic scintillators may come from the deexcitation of several higher levels of the solvent molecules excited by nuclear particles. (Auth.)

  4. Emotion Processing by ERP Combined with Development and Plasticity

    Science.gov (United States)

    2017-01-01

    Emotions important for survival and social interaction have received wide and deep investigations. The application of the fMRI technique into emotion processing has obtained overwhelming achievements with respect to the localization of emotion processes. The ERP method, which possesses highly temporal resolution compared to fMRI, can be employed to investigate the time course of emotion processing. The emotional modulation of the ERP component has been verified across numerous researches. Emotions, described as dynamically developing along with the growing age, have the possibility to be enhanced through learning (or training) or to be damaged due to disturbances in growth, which is underlain by the neural plasticity of emotion-relevant nervous systems. And mood disorders with typical symptoms of emotion discordance probably have been caused by the dysfunctional neural plasticity. PMID:28831313

  5. The process of homelessness: an event history analysis of length of stay for the Groningen shelter accommodation

    OpenAIRE

    Fernee, H.; Oldersma, F.; Popping, R.

    2010-01-01

    This study explores the process of shelter exits for homeless individuals and for different shelter types in the public shelter system in the city of Groningen in the Netherlands. Individualised administrative data from the Groningen Homelessness Monitor (2003–2006) are used for estimating a Weibull hazard rate regression model. Results show that the different shelter types fit adequately with their policy purposes : lengths of stay in emergency shelter accommodation appear to be shorter than...

  6. Processing biobased polymers using plasticizers: Numerical simulations versus experiments

    Science.gov (United States)

    Desplentere, Frederik; Cardon, Ludwig; Six, Wim; Erkoç, Mustafa

    2016-03-01

    In polymer processing, the use of biobased products shows lots of possibilities. Considering biobased materials, biodegradability is in most cases the most important issue. Next to this, bio based materials aimed at durable applications, are gaining interest. Within this research, the influence of plasticizers on the processing of the bio based material is investigated. This work is done for an extrusion grade of PLA, Natureworks PLA 2003D. Extrusion through a slit die equipped with pressure sensors is used to compare the experimental pressure values to numerical simulation results. Additional experimental data (temperature and pressure data along the extrusion screw and die are recorded) is generated on a dr. Collin Lab extruder producing a 25mm diameter tube. All these experimental data is used to indicate the appropriate functioning of the numerical simulation tool Virtual Extrusion Laboratory 6.7 for the simulation of both the industrial available extrusion grade PLA and the compound in which 15% of plasticizer is added. Adding the applied plasticizer, resulted in a 40% lower pressure drop over the extrusion die. The combination of different experiments allowed to fit the numerical simulation results closely to the experimental values. Based on this experience, it is shown that numerical simulations also can be used for modified bio based materials if appropriate material and process data are taken into account.

  7. Die design and process optimization of plastic gear extrusion

    Science.gov (United States)

    Zhang, Lei; Fu, Zhihong; Yao, Chen; Zang, Gongzheng; Wan, Yue

    2018-01-01

    The flow velocity of the melt in the extruder was simulated by using software Polyflow, and the size of the die channel with the best flow uniformity was obtained. The die profile shape is obtained by reverse design. The length of the shaping section is determined by Ansys transient thermal analysis. According to the simulation results, the design and manufacture of extrusion die of plastic gear and vacuum cooling setting were obtained. The influence of the five process parameters on the precision of the plastic gear were studied by the single factor analysis method, such as the die temperature T, the screw speed R, the die spacing S, the vacuum degree M and the hauling speed V. The optimal combination of process parameters was obtained by using the neural network particle swarm optimization algorithm(T = 197.05 °C, R = 9.04rpm, S = 67mm, M = -0.0194MPa). The tooth profile deviation of the extruded plastic gear can reach 9 level of accuracy.

  8. Study of plastic solidification process on solid radioactive waste treatment

    International Nuclear Information System (INIS)

    Jing Weiguan; Zhang Yinsheng; Qian Wenju

    1994-01-01

    Comparisons between the plastic solidification conditions of incinerated ash and waste cation resin by using thermosetting plastic polyvinyl chloride (PVC), polystyrene (PS) and polyethylene (PE), and identified physico-chemical properties and irradiation resistance of solidified products were presented. These solidified products have passed through different tests as compression strength, leachability, durability, stability, permeability and irradiation resistance (10 6 Gy) etc. The result showed that the solidified products possessed stable properties and met the storage requirement. The waste tube of radioimmunoassay, being used as solidification medium to contain incinerated ash, had good mechanical properties and satisfactory volume reduction. This process may develop a new way for disposal solid radioactive waste by means of re-using waste

  9. New process of co-coking of waste plastics and blend coal

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Yu, G.; Zhao, P. (and others) [Shougang Technical Research Institute, Beijing (China)

    2006-07-01

    To recycle and reuse waste plastics, as well as to get a new resource of coking, co-coking process of waste plastics and blend coal has been developed by Nippon Steel. However, the ratio of waste plastics in blend coal should be limited in the range of 1% to maintain the coke strength. This paper suggested a new process of co-coking of waste plastics and blend coal. The new process can add the waste plastics ratio up to 2-4%; when the waste plastics ratio is 2%, the coke strength after reaction with CO{sub 2} (CSR) increased 8%. 8 refs., 2 figs., 3 tabs.

  10. Electron beam processed plasticized epoxy coatings for surface protection

    International Nuclear Information System (INIS)

    Ibrahim, Mervat S.; Mohamed, Heba A.; Kandile, Nadia G.; Said, Hossam M.; Mohamed, Issa M.

    2011-01-01

    Highlights: · Coating formulations with EA 70%, HD 20%, and castor oil 10% under 1 Mrad pass -1 irradiation dose showed the best adhesion and passed bending tests. · The prepared EP-SF-An adduct improve anti-corrosion properties of coatings without any significant effect on physical, mechanical and chemical properties of the cured film. The optimum amount of aniline adduct as corrosion inhibitor was found to be 0.4 g for 100 g of coating formulation. · The corrosion inhibition efficiency of the prepared adduct competed the commercial efficiency. - Abstract: Epoxy acrylate oligomer (EA) was plasticized by adding different plasticizers such as epoxidized soybean oil, glycerol and castor oil and cured by electron beam (EB). Different irradiation doses (1, 2.5 and 5 Mrad pass -1 ) were used in the curing process. The effect of both different irradiation doses and plasticizers on the end use performance properties of epoxy acrylate coating namely, pencil hardness, bending test, adhesion test, acid and alkali resistance test were studied. It was observed that incorporation of castor oil in epoxy acrylate diluted by 1,6-hexanediol diacrylate (HD) monomer with a ratio (EA 70%, HD 20%, castor oil 10%) under 1 Mrad pass -1 irradiation dose improved the physical, chemical and mechanical properties of cured films than the other plasticizer. Sunflower free fatty acid was epoxidized in situ under well established conditions. The epoxidized sunflower free fatty acids (ESFA) were subjected to react with aniline in sealed ampoules under inert atmosphere at 140 deg. C. The produced adducts were added at different concentrations to epoxy acrylate coatings under certain EB irradiation dose and then evaluated as corrosion inhibitors for carbon steel surfaces in terms of weight loss measurements and corrosion resistance tests. It was found that, addition of 0.4 g of aniline adduct to 100 g epoxy acrylate formula may give the best corrosion protection for carbon steel and compete the

  11. Grain refinement through severe plastic deformation (SPD) processing

    International Nuclear Information System (INIS)

    Izairi, N.; Vevecka - Priftaj, A.

    2012-01-01

    There is considerable current interest in processing metallic samples through procedures involving the imposition of severe plastic deformation (SPD). These procedures lead to very significant grain refinement to the submicrometer or even the nanometer level, resulting in advanced physical properties. Among various SPD processes, Equal Channel Angular Pressing, High pressure Torsion and Accumulated Roll Bonding have been widely used for many metals and alloys. In the present work, we present an overview of the most used methods of SPD for grain refinement and the production of bulk nano structured materials with enhancement in their mechanical and functional properties. In order to examine the potential for using ECAP to refine the grain size and improve the mechanical properties, two commercial 5754 Al alloy and AA 3004 , were selected for study. Processing by ECAP gives a reduction in the grain size and an increase in the microhardness. (Author)

  12. Radiation Processing of Starch Based Plastic Blends. Chapter 15

    International Nuclear Information System (INIS)

    Khandal, D.; Mikus, P.; Dole, P.; Baumberger, S.; Coqueret, X.

    2016-01-01

    There is an increasing interest in renewable and environmentally friendly polymers from biomass for substituting synthetic polymers in various sectors and for various applications, as well as in finding new applications. Basic and applied research aims particularly to develop bio-sourced polymers for materials (for example, materials for packaging, soil mulching and for manufacturing automobile interiors), specialty products (for example, adhesives, absorbents, humectants and surfactants) and high value added products (for example, cosmetics and pharmaceutical applications). Despite the promising growth and inherent potential of bio-based plastics, they still account for only 1% of the total polymer market. The total technical substitution potential of the bio-based market is considered to be almost 270 Mt, but market projections are always only a few Mt, simply because the major barriers hindering potential growth are the high production costs and technical challenges involved in scaling up the process from the laboratory to an industrial production scale.

  13. Higher harmonic imaging of tensile plastic deformation in loading and reloading processes by local resonance method

    International Nuclear Information System (INIS)

    Kawashima, Koichiro; Yasui, Hajime

    2015-01-01

    We have imaged plastically deformed region in a 5052 aluminum plate under tensile loading, unloading and reloading processes by using an immersion local resonance method. By transmitting large-amplitude burst wave of which frequency is a through-thickness resonant frequency of the plate, dislocation loops in plastic zone are forced to vibrate. The higher harmonic amplitude excited by the dislocation movement is mapped for the transducer position. The extension of plastic zone under monotonically increased loading, decrease in harmonic amplitude under unloading process and marked extension of plastic zone in reloading up to 0.4% plastic strain are clearly imaged. (author)

  14. PACT: Calculating nWOW accommodation that suits the organisations’ work processes

    OpenAIRE

    Evi De Bruyne

    2014-01-01

    Workplace change and New Ways of Working seem to have become a fixed value in FM practice in the Netherlands today. Stimulated by new technological possibilities and maybe even by the world-wide crisis, companies are rethinking their office environments. The possibility to work anytime and anywhere seems key. However this requires a different approach to quantify the needed space and determine the types of workplaces to fit an organisations’ processes.Since one employee is no longer automatic...

  15. The energy audit process for universities accommodation in Malaysia: a preliminary study

    Science.gov (United States)

    Dzulkefli Muhammad, Hilmi

    2017-05-01

    The increase of energy consumption in the Malaysian Universities has raised national concerns due to the fact that its consumption increase government fiscal budget and at the same time contributes negative impacts towards the environment. The purpose of this research is to focus on the process of energy audit conducted in the Malaysian universities and to identify the significant practice that can improve energy consumption of the selected universities. The significant criteria in energy audit may be found by comparing the energy implementation process of selected Malaysian universities through the investigation of energy consumption behavior and the number of electrical appliances, equipment, machinery and buildings activities that have an impact on energy consumption that can improve energy-efficiency in building. The Energy Efficiency Index (EEI) will be used as an indicator and combined with the suggested application of HOMER software to obtain solution and possible improvement of energy consumption during energy audit implementation. A document analysis approach will also be obtained in order to identify the best practice through the selected energy documentations. The result of this research may be used as a guideline for other universities that consume high energy in order to help improving the implementation of energy audit process in their universities.

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

    Directory of Open Access Journals (Sweden)

    Sugiono Sugiono

    2017-09-01

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

  17. Statistical reliability analyses of two wood plastic composite extrusion processes

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  18. Plastic creep flow processes in fracture at elevated temperatures

    International Nuclear Information System (INIS)

    Rice, J.R.

    1979-01-01

    Recent theoretical developments on fracture at elevated temperature in the presence of overall plastic (dislocation) creep are discussed. Two topics are considered: stress fields at tips of macroscopic cracks in creeping solids; and diffusive growth of microscopic grain boundary cavities in creeping solids

  19. Development of mathematical models for automation of strength calculation during plastic deformation processing

    Science.gov (United States)

    Steposhina, S. V.; Fedonin, O. N.

    2018-03-01

    Dependencies that make it possible to automate the force calculation during surface plastic deformation (SPD) processing and, thus, to shorten the time for technological preparation of production have been developed.

  20. Plastic limit analysis with non linear kinematic strain hardening for metalworking processes applications

    International Nuclear Information System (INIS)

    Chaaba, Ali; Aboussaleh, Mohamed; Bousshine, Lahbib; Boudaia, El Hassan

    2011-01-01

    Limit analysis approaches are widely used to deal with metalworking processes analysis; however, they are applied only for perfectly plastic materials and recently for isotropic hardening ones excluding any kind of kinematic hardening. In the present work, using Implicit Standard Materials concept, sequential limit analysis approach and the finite element method, our objective consists in extending the limit analysis application for including linear and non linear kinematic strain hardenings. Because this plastic flow rule is non associative, the Implicit Standard Materials concept is adopted as a framework of non standard plasticity modeling. The sequential limit analysis procedure which considers the plastic behavior with non linear kinematic strain hardening as a succession of perfectly plastic behavior with yielding surfaces updated after each sequence of limit analysis and geometry updating is applied. Standard kinematic finite element method together with a regularization approach is used for performing two large compression cases (cold forging) in plane strain and axisymmetric conditions

  1. Adaptability : How to accommodate changing user preferences

    NARCIS (Netherlands)

    Remoy, H.T.; van der Voordt, D.J.M.

    2013-01-01

    Purpose: When current accommodation is unsatisfactorily, office organisations consider relocating to new accommodation that optimally facilitate their main processes, supporting image and financial yield. However, due to high vacancy levels, public opinion and governmental awareness oppose new

  2. Improving the circular economy via hydrothermal processing of high-density waste plastics.

    Science.gov (United States)

    Helmer Pedersen, Thomas; Conti, Federica

    2017-10-01

    Rising environmental concerns on climate changes are causing an increasing attention on circular economies. The plastic economy, in particular, is in focus due to the accelerating consumption of plastics, mainly derived from virgin feedstock, combined with the lack of plastic recycling strategies. This work presents a novel outlook on the potential of using supercritical hydrothermal processing of waste plastic fractions for tertiary recycling. The study investigates hydrothermal processing of nine different, high-density types of plastics into original resin monomers and other value-added chemical compounds. The outlook presents conversion yields, carbon balances, and chemical details on the products obtained. It is found that all the investigated resins are prone to hydrothermal treatment, and that high yields of monomers and high value compounds (up to nearly 100%), suitable for chemicals and fuels applications, can be obtained. For instance, for polycarbonate, styrene-butadiene, poly(lactic acid), poly(ethylene terephthalate), and poly(butylene terephthalate), original monomeric compounds can be reclaimed for manufacturing new resins. The promising results presented demonstrate that hydrothermal processing of high-density plastics is a prospective technology for increasing the circularity of the plastic economy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The teaching-learning process of plastic expression in students with Down syndrome

    Directory of Open Access Journals (Sweden)

    Julio Antonio Conill Armenteros

    2018-03-01

    Full Text Available The drawing constitutes a means through which the child expresses the level of physical, mental, emotional and creative development achieved and plays an important role in the plastic expression. The study took into account the identification of needs in the teaching - learning process of plastic expression in students with Down syndrome, for which a didactic strategy was designed that contains actions of a teaching nature and establishes interdisciplinary links between the different subjects of the curriculum. The investigative process was conducted on a dialectical-materialist basis and methods were used at the theoretical, empirical and statistical-mathematical levels, such as: documentary analysis, interview, drawing technique, among others. Five students with Down syndrome participated in the study of the special school "28 de Enero" of Pinar del Río and the instructor who directs the workshops of creation of Plastic Arts. The investigations allowed to determine the regularities that distinguish the process of teaching - learning of the plastic expression in these students, as well as the needs of the Plastic Arts instructor for the conduction of said process. The didactic strategy allowed the process of teaching - learning of the plastic expression to encourage creativity and the development of motor skills, from the projection of actions that contribute to the diagnosis and treatment of this process in order to achieve the maximum integral development possible and the preparation for the independent adult life of the school student with Down syndrome.

  4. Reversal of long-term potentiation-like plasticity processes after motor learning disrupts skill retention.

    Science.gov (United States)

    Cantarero, Gabriela; Lloyd, Ashley; Celnik, Pablo

    2013-07-31

    Plasticity of synaptic connections in the primary motor cortex (M1) is thought to play an essential role in learning and memory. Human and animal studies have shown that motor learning results in long-term potentiation (LTP)-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. Moreover, biochemical processes essential for LTP are also crucial for certain types of motor learning and memory. Thus, it has been speculated that the occlusion of LTP-like plasticity after learning, indicative of how much LTP was used to learn, is essential for retention. Here we provide supporting evidence of it in humans. Induction of LTP-like plasticity can be abolished using a depotentiation protocol (DePo) consisting of brief continuous theta burst stimulation. We used transcranial magnetic stimulation to assess whether application of DePo over M1 after motor learning affected (1) occlusion of LTP-like plasticity and (2) retention of motor skill learning. We found that the magnitude of motor memory retention is proportional to the magnitude of occlusion of LTP-like plasticity. Moreover, DePo stimulation over M1, but not over a control site, reversed the occlusion of LTP-like plasticity induced by motor learning and disrupted skill retention relative to control subjects. Altogether, these results provide evidence of a link between occlusion of LTP-like plasticity and retention and that this measure could be used as a biomarker to predict retention. Importantly, attempts to reverse the occlusion of LTP-like plasticity after motor learning comes with the cost of reducing retention of motor learning.

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

    Science.gov (United States)

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

    2013-04-01

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

  6. The crystallography of carbide-free bainites in thermo-mechanically processed low Si transformation-induced plasticity steels

    Energy Technology Data Exchange (ETDEWEB)

    Pereloma, Elena V. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Electron Microscopy Centre, University of Wollongong, New South Wales 2500 (Australia); Al-Harbi, Fayez [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Gazder, Azdiar A., E-mail: azdiar@uow.edu.au [Electron Microscopy Centre, University of Wollongong, New South Wales 2500 (Australia)

    2014-12-05

    Highlights: • First EBSD study comparing ferrite in granular bainite and bainitic laths in two TRIP steels. • Both TRIP steels (base and with Nb–Ti additions) subjected to the same TMP schedule. • Crystallography of the ferrite in the 2 bainites studied using the K–S orientation relationship. • Variants in GB associated with self-accommodation. • BF variant selection linked to RA plastic accommodation and limited volume. - Abstract: Carbide-free bainites are important microstructural constituents in bainitic, nanobainitic and transformation-induced plasticity (TRIP) steels. A comparison of the crystallography of ferrite in granular bainite and bainitic ferrite lath morphologies, both of which were simultaneously present in a base and a Nb–Ti containing TRIP steel, has been carried out using electron back-scattering diffraction. Ferrite in granular bainite was characterised by the realisation of nearly all 24 variants of the Kurdjumov–Sachs orientation relationship; which in turn was associated with the self-accommodation of the transformation strain. On the other hand, bainitic ferrite comprised a mostly parallel lath structure between thick interlayers of retained austenite and exhibited variant selection such that one or more crystallographic packets are not realised and sometimes only 1–2 variants formed in a crystallographic packet. The variant selection in bainitic ferrite laths was associated with: (i) the plastic accommodation of transformation strain by retained austenite and, (ii) the limited available volume for its formation.

  7. The crystallography of carbide-free bainites in thermo-mechanically processed low Si transformation-induced plasticity steels

    International Nuclear Information System (INIS)

    Pereloma, Elena V.; Al-Harbi, Fayez; Gazder, Azdiar A.

    2014-01-01

    Highlights: • First EBSD study comparing ferrite in granular bainite and bainitic laths in two TRIP steels. • Both TRIP steels (base and with Nb–Ti additions) subjected to the same TMP schedule. • Crystallography of the ferrite in the 2 bainites studied using the K–S orientation relationship. • Variants in GB associated with self-accommodation. • BF variant selection linked to RA plastic accommodation and limited volume. - Abstract: Carbide-free bainites are important microstructural constituents in bainitic, nanobainitic and transformation-induced plasticity (TRIP) steels. A comparison of the crystallography of ferrite in granular bainite and bainitic ferrite lath morphologies, both of which were simultaneously present in a base and a Nb–Ti containing TRIP steel, has been carried out using electron back-scattering diffraction. Ferrite in granular bainite was characterised by the realisation of nearly all 24 variants of the Kurdjumov–Sachs orientation relationship; which in turn was associated with the self-accommodation of the transformation strain. On the other hand, bainitic ferrite comprised a mostly parallel lath structure between thick interlayers of retained austenite and exhibited variant selection such that one or more crystallographic packets are not realised and sometimes only 1–2 variants formed in a crystallographic packet. The variant selection in bainitic ferrite laths was associated with: (i) the plastic accommodation of transformation strain by retained austenite and, (ii) the limited available volume for its formation

  8. Study and understanding of n/γ discrimination processes in organic plastic scintillators

    International Nuclear Information System (INIS)

    Hamel, Matthieu; Blanc, Pauline; Rocha, Licinio; Normand, Stephane; Pansu, Robert

    2013-01-01

    For 50 years, it was assumed that unlike liquid scintillators or organic crystals, plastic scintillators were not able to discriminate fast neutrons from gamma. In this work, we will demonstrate that triplet-triplet annihilations (which are responsible of n/γ discrimination) can occur even in plastic scintillators, following certain conditions. Thus, the presentation will deal with the chemical preparation, the characterization and the comparison of n/γ pulse shape discrimination of various plastic scintillators. To this aim, scale-up of the process allowed us to prepare a O 100 mm x*110 mm thick. (authors)

  9. INVESTIGATION OF MATERIAL RESISTANCE TO PLASTIC DEFORMATION AT PROCESSING METALS BY PRESSURE WITH IMPOSING ULTRASONIC OSCILLATIONS

    Directory of Open Access Journals (Sweden)

    V. V. Klubovich

    2007-01-01

    Full Text Available The paper contains substantiation for application of experimental technique in order to investigate material resistance to plastic deformation at processing metals by pressure with imposing ultrasonic oscillations while proceeding from laws of similarity. It is shown that at modeling any metal processing by pressure with imposing ultrasonic oscillations it is possible to consider that actual elastic and plastic metal properties remain constant during processing under ultrasound action. The second aspect that requires a special attention at modeling is pulse or vibration-shock deformation at processing metals by pressure with imposing ultrasonic oscillations.

  10. Learning-induced neural plasticity of speech processing before birth.

    Science.gov (United States)

    Partanen, Eino; Kujala, Teija; Näätänen, Risto; Liitola, Auli; Sambeth, Anke; Huotilainen, Minna

    2013-09-10

    Learning, the foundation of adaptive and intelligent behavior, is based on plastic changes in neural assemblies, reflected by the modulation of electric brain responses. In infancy, auditory learning implicates the formation and strengthening of neural long-term memory traces, improving discrimination skills, in particular those forming the prerequisites for speech perception and understanding. Although previous behavioral observations show that newborns react differentially to unfamiliar sounds vs. familiar sound material that they were exposed to as fetuses, the neural basis of fetal learning has not thus far been investigated. Here we demonstrate direct neural correlates of human fetal learning of speech-like auditory stimuli. We presented variants of words to fetuses; unlike infants with no exposure to these stimuli, the exposed fetuses showed enhanced brain activity (mismatch responses) in response to pitch changes for the trained variants after birth. Furthermore, a significant correlation existed between the amount of prenatal exposure and brain activity, with greater activity being associated with a higher amount of prenatal speech exposure. Moreover, the learning effect was generalized to other types of similar speech sounds not included in the training material. Consequently, our results indicate neural commitment specifically tuned to the speech features heard before birth and their memory representations.

  11. Some features of radiation processing in the plastics industry

    International Nuclear Information System (INIS)

    Dobo, J.

    1985-01-01

    In the last few years, the production of free radicals by radiation became competitive with chemical initiators. Nevertheless radiation processing got only a firm footing, where distinct advantages could be demonstrated as compared with conventional processes, either in the technology or the product quality. This paper is intended to direct attention to some of the special features of radiation processing. (author)

  12. Some features of radiation processing in the plastics industry

    Science.gov (United States)

    D´, J.

    In the last few years, the production of free radicals by radiation became competitive with chemical initiators. Nevertheless, radiation processing got only a firm footing, where distinct advantages could be demonstrated as compared with conventional processes, either in the technology or the product quality. This paper is intended to direct attention to some of the special features of radiation processing.

  13. Process combinations for the manufacturing of metal-plastic hybrid parts

    International Nuclear Information System (INIS)

    Drossel, W-G; Lies, C; Albert, A; Haase, R; Müller, R; Scholz, P

    2016-01-01

    The usage of innovative lightweight materials and processing technologies gains importance in manifold industrial scopes. Especially for moving parts and mobility products the weight is decisively. The aerospace and automotive industries use light and high-strength materials to reduce weight and energy consumption and thereby improve the performance of their products. Composites with reinforced plastics are of particular importance. They offer a low density in combination with high specific stiffness and strength. A pure material substitution through reinforced plastics is still not economical. The approach of using hybrid metal-plastic structures with the principle of “using the right material at the right place” is a promising solution for the economical realization of lightweight structures with a high achievement potential. The article shows four innovative manufacturing possibilities for the realization of metal-plastic-hybrid parts. (paper)

  14. Waste plastics as supplemental fuel in the blast furnace process: improving combustion efficiencies.

    Science.gov (United States)

    Kim, Dongsu; Shin, Sunghye; Sohn, Seungman; Choi, Jinshik; Ban, Bongchan

    2002-10-14

    The possibility of using waste plastics as a source of secondary fuel in a blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. For instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in a blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with a decrease in particle size, the combustibility of waste polyethylene could be improved at a given distance from the tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at a longer distance from the tuyere.

  15. INVESTIGATION ON UTILITY OF PLASTIC WASTE AS AN ADDITIVE FOR BITUMINOUS CONCRETE USING WET PROCESS OF MIXING

    Directory of Open Access Journals (Sweden)

    Anurag Virendra Tiwari

    2017-12-01

    Full Text Available Purpose. Plastic waste has become a major environmental issue of concern due to its exponential growth due to rapid urbanization. The paper investigates utility of plastic waste as an additive for bituminous concrete using wet process of mixing. Methodology. The methodology for the present paper has been designed with complex research consisting of Marshall mix design of the bituminous mix added with plastic waste for modifying bitumen using wet process of mixing, performing the tests on the samples and analyzing the results in the form of table and figures. In the present paper LDPE and HDPE type of plastic waste are used to modify the bitumen. Finding. The results show that addition of 6 percent of bitumen improves the Marshall properties of the mix. Use of plastic to modify the bitumen not only makes the road surface more durable but also it is an eco-friendly way of proper disposal of plastic waste. Originality. The processes used for mixing the plastic waste to the bitumen are dry process and wet process. Dry process of mixing the plastic waste to the bituminous mix is most common and lot of study is carried out on its application. In the present paper wet process of mixing has not yet been studied much. Practical Value. The practical application of utilizing the plastic waste to modify bitumen in the bituminous mix improves the stability values resulting in the more durable road surface. Also the method ensures the proper disposal of plastic waste in eco-friendly way.

  16. Magical Engineering Plastic

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwang Ung

    1988-01-15

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

  17. Magical Engineering Plastic

    International Nuclear Information System (INIS)

    Kim, Gwang Ung

    1988-01-01

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

  18. Deformation Behavior during Processing in Carbon Fiber Reinforced Plastics

    Science.gov (United States)

    Ogihara, Shinji; Kobayashi, Satoshi

    In this study, we manufacture the device for measuring the friction between the prepreg curing process and subjected to pull-out tests with it The prepreg used in this study is a unidirectional carbon/epoxy, produced by TORAY designation of T700SC/2592.When creating specimens 4-ply prepregs are prepared and laminated. The 2-ply prepregs in the middle are shifted 50mm. In order to measure the friction between the prepreg during the cure process, we simulate the environment in the autoclave in the device, and we experiment in pull-out test. Test environment simulating temperature and pressure. The speed of displacement should be calculated by coefficient of thermal expansions (CTE). By calculation, 0.05mm/min gives the order of magnitude of displacement speed. In this study, 3 pull-out speeds are used: 0.01, 0.05 and 0.1mm/min. The specimen was heated by a couple of heaters, and we controlled the heaters with a temperature controller along the curing conditions of the prepreg. We put pressure using 4 bolts. Two strain gages were put on the bolt. We can understand the load applied to the specimen from the strain of the bolt. Pressure was adjusted the tightness of the bolt according to curing conditions. By using such a device, the pull-out test performed by tensile testing machine while adding temperature and pressure. During the 5 hours, we perform experiments while recording the load and stroke. The shear stress determined from the load and the stroke, and evaluated.

  19. Supramodal processing optimizes visual perceptual learning and plasticity.

    Science.gov (United States)

    Zilber, Nicolas; Ciuciu, Philippe; Gramfort, Alexandre; Azizi, Leila; van Wassenhove, Virginie

    2014-06-01

    Multisensory interactions are ubiquitous in cortex and it has been suggested that sensory cortices may be supramodal i.e. capable of functional selectivity irrespective of the sensory modality of inputs (Pascual-Leone and Hamilton, 2001; Renier et al., 2013; Ricciardi and Pietrini, 2011; Voss and Zatorre, 2012). Here, we asked whether learning to discriminate visual coherence could benefit from supramodal processing. To this end, three groups of participants were briefly trained to discriminate which of a red or green intermixed population of random-dot-kinematograms (RDKs) was most coherent in a visual display while being recorded with magnetoencephalography (MEG). During training, participants heard no sound (V), congruent acoustic textures (AV) or auditory noise (AVn); importantly, congruent acoustic textures shared the temporal statistics - i.e. coherence - of visual RDKs. After training, the AV group significantly outperformed participants trained in V and AVn although they were not aware of their progress. In pre- and post-training blocks, all participants were tested without sound and with the same set of RDKs. When contrasting MEG data collected in these experimental blocks, selective differences were observed in the dynamic pattern and the cortical loci responsive to visual RDKs. First and common to all three groups, vlPFC showed selectivity to the learned coherence levels whereas selectivity in visual motion area hMT+ was only seen for the AV group. Second and solely for the AV group, activity in multisensory cortices (mSTS, pSTS) correlated with post-training performances; additionally, the latencies of these effects suggested feedback from vlPFC to hMT+ possibly mediated by temporal cortices in AV and AVn groups. Altogether, we interpret our results in the context of the Reverse Hierarchy Theory of learning (Ahissar and Hochstein, 2004) in which supramodal processing optimizes visual perceptual learning by capitalizing on sensory

  20. DMS cyclone separation processes for optimization of plastic wastes recycling and their implications.

    Science.gov (United States)

    Gent, Malcolm Richard; Menendez, Mario; Toraño, Javier; Torno, Susana

    2011-06-01

    It is demonstrated that substantial reductions in plastics presently disposed of in landfills can be achieved by cyclone density media separation (DMS). In comparison with the size fraction of plastics presently processed by industrial density separations (generally 6.4 to 9.5 mm), cyclone DMS methods are demonstrated to effectively process a substantially greater range of particle sizes (from 0.5 up to 120 mm). The purities of plastic products and recoveries obtained with a single stage separation using a cylindrical cyclone are shown to attain virtually 100% purity and recoveries >99% for high-density fractions and >98% purity and recoveries were obtained for low-density products. Four alternative schemas of multi-stage separations are presented and analyzed as proposed methods to obtain total low- and high-density plastics fraction recoveries while maintaining near 100% purities. The results of preliminary tests of two of these show that the potential for processing product purities and recoveries >99.98% of both density fractions are indicated. A preliminary economic comparison of capital costs of DMS systems suggests cyclone DMS methods to be comparable with other DMS processes even if the high volume capacity for recycling operations of these is not optimized.

  1. Evaluating exposures to complex mixtures of chemicals during a new production process in the plastics industry

    NARCIS (Netherlands)

    Meijster, T.; Burstyn, I.; Wendel de Joode, B. van; Posthumus, M.A.; Kromhout, H.

    2004-01-01

    The goal of this study was to monitor emission of chemicals at a factory where plastics products were fabricated by a new robotic (impregnated tape winding) production process. Stationary and personal air measurements were taken to determine which chemicals were released and at what concentrations.

  2. Techno-economic evaluation of high temperature pyrolysis processes for mixed plastic waste.

    NARCIS (Netherlands)

    Westerhout, R.W.J.; Westerhout, R.W.J.; van Koningsbruggen, M.P.; van der Ham, Aloysius G.J.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    1998-01-01

    Three pyrolysis processes for Mixed Plastic Waste (MPW) with different reactors (Bubbling Fluidized Bed, Circulating Fluidized Bed and Rotating Cone Reactor, respectively BFB, CFB and RCR) were designed and evaluated. The estimated fixed capital investment for a 50 kton/year MPW pyrolysis plant

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

    NARCIS (Netherlands)

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

    2005-01-01

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

  4. Criteria for prediction of plastic instabilities for hot working processes. (Part I: Theoretical review)

    International Nuclear Information System (INIS)

    Al Omar, A.; Prado, J. M.

    2010-01-01

    Hot working processes often induce high levels of deformation at high strain rates, and impose very complex multiaxial modes of solicitation. These processes are essentially limited by apparition and development of plastic instabilities. These may be the direct cause of rapid crack propagation, which lead to a possible final rupture. The complexity of deformation modes and the simultaneous intervention of several parameters have led many researchers to develop various criteria, with different approaches, to predict the occurrence of defects and to optimize process control parameters. The aim of the present paper is to summarize the general characteristics of some instability criteria, widely used in the literature, for the prediction of plastic instabilities during hot working. It was considered appropriate to divide the work into two parts: part I presents the phenomenological criteria for the prediction of plastic instabilities, based on descriptive observation of microscopic phenomena of the deformation (strain hardening and strain rate sensitivity), and discusses the continuum criteria based on the principle of maximum rate of entropy production of irreversible thermodynamics applied to continuum mechanics of large plastic flow. Also, this part provides a bibliographical discussion among several authors with regard to the physical foundations of dynamic materials model. In part II, of the work, a comparative study has been carried out to characterize the flow instability during a hot working process of a medium carbon microalloyed using phenomenological and continuum criteria. (Author) 83 refs.

  5. Evaluating Exposures to Complex Mixtures of Chemicals During a New Production Process in the Plastics Industry

    NARCIS (Netherlands)

    Meijster, T.; Burstyn, I.; Wendel de Joode, van B.; Posthumus, M.A.; Kromhout, H.

    2004-01-01

    The goal of this study was to monitor emission of chemicals at a factory where plastics products were fabricated by a new robotic (impregnated tape winding) production process. Stationary and personal air measurements were taken to determine which chemicals were released and at what concentrations.

  6. Characteristics of process oils from HTI coal/plastics co-liquefaction runs

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, G.A.; Brandes, S.D.; Winschel, R.A. [and others

    1995-12-31

    The objective of this project is to provide timely analytical support to DOE`s liquefaction development effort. Specific objectives of the work reported here are presented. During a few operating periods of Run POC-2, HTI co-liquefied mixed plastics with coal, and tire rubber with coal. Although steady-state operation was not achieved during these brief tests periods, the results indicated that a liquefaction plant could operate with these waste materials as feedstocks. CONSOL analyzed 65 process stream samples from coal-only and coal/waste portions of the run. Some results obtained from characterization of samples from Run POC-2 coal/plastics operation are presented.

  7. Device and process for binding toxic or radioactive wastes in plastic

    International Nuclear Information System (INIS)

    Metscher, K.

    1978-01-01

    The first section of the process is provided with supply devices for the plastic and a heater to melt it. The second section contains devices for injecting waste and means for compressing the plastic melt and for dispersing the waste to be bound in the plastic melt. The third section is heated and is provided with outgoing pipes for volatile and/or evaporated liquids at normal pressure or sub-pressure. A further section can follow for homogenizing the mixture directly. A condenser for liquefaction is included in the outgoing pipes for the volatile components. A thermoplastic, preferably low molecule polystyrol in granulate form is used, which melts at temperatures above 130 0 C. (PW) [de

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

    Science.gov (United States)

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

    2017-11-01

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

  9. Study of Reactive Melt Processing Behavior of Externally Plasticized Cellulose Acetate in Presence of Isocyanate

    Directory of Open Access Journals (Sweden)

    Rafael Erdmann

    2014-12-01

    Full Text Available Two types of externally plasticized cellulose acetate (CA were chemically modified using 4,4'-methylene diphenyl diisocyanate (MDI as crosslinking agent. Crosslinking was performed in the molten state by means of melt mixing in an internal mixer. The viscoelastic properties of the non-crosslinked, externally plasticized CA show typical temperature dependence, similar to conventional thermoplastics. A strong increase in storage modulus is observed with increasing crosslink density indicating that the crosslinked compounds exhibit predominately elastic response. The complex viscosity also increases considerably with increasing crosslink density and does not reach the typical Newtonian plateau at low radial frequencies any more. The viscoelastic properties correlate well with the data recorded online during reactive melt processing in the internal mixer. In comparison to the non-crosslinked CA, the crosslinked compounds show higher glass transition temperature, higher VICAT softening temperatures, improved thermal stability and lower plasticizer evaporation at evaluated temperatures.

  10. Processing and properties of a solid energy fuel from municipal solid waste (MSW) and recycled plastics.

    Science.gov (United States)

    Gug, JeongIn; Cacciola, David; Sobkowicz, Margaret J

    2015-01-01

    Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in higher heating value. Analysis of the post-processing water uptake and compressive strength showed a correlation between density and stability to both mechanical stress and humid environment. Proximate analysis indicated heating values comparable to coal. The results showed that mechanical and moisture uptake stability were improved when the moisture and air contents were optimized. Moreover, the briquette

  11. Processing and properties of a solid energy fuel from municipal solid waste (MSW) and recycled plastics

    International Nuclear Information System (INIS)

    Gug, JeongIn; Cacciola, David; Sobkowicz, Margaret J.

    2015-01-01

    Highlights: • Briquetting was used to produce solid fuels from municipal solid waste and recycled plastics. • Optimal drying, processing temperature and pressure were found to produce stable briquettes. • Addition of waste plastics yielded heating values comparable with typical coal feedstocks. • This processing method improves utilization of paper and plastic diverted from landfills. - Abstract: Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in

  12. Processing and properties of a solid energy fuel from municipal solid waste (MSW) and recycled plastics

    Energy Technology Data Exchange (ETDEWEB)

    Gug, JeongIn, E-mail: Jeongin_gug@student.uml.edu; Cacciola, David, E-mail: david_cacciola@student.uml.edu; Sobkowicz, Margaret J., E-mail: Margaret_sobkowiczkline@uml.edu

    2015-01-15

    Highlights: • Briquetting was used to produce solid fuels from municipal solid waste and recycled plastics. • Optimal drying, processing temperature and pressure were found to produce stable briquettes. • Addition of waste plastics yielded heating values comparable with typical coal feedstocks. • This processing method improves utilization of paper and plastic diverted from landfills. - Abstract: Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in

  13. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Ch., E-mail: kerschbaum@ikv.rwth-aachen.de; Kerschbaum, M., E-mail: kerschbaum@ikv.rwth-aachen.de; Küsters, K., E-mail: kerschbaum@ikv.rwth-aachen.de [Institute of Plastics Processing at RWTH Aachen University (IKV), Pontstrasse 49, 52064 Aachen (Germany)

    2014-05-15

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.

  14. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    International Nuclear Information System (INIS)

    Hopmann, Ch.; Kerschbaum, M.; Küsters, K.

    2014-01-01

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization

  15. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    Science.gov (United States)

    Hopmann, Ch.; Kerschbaum, M.; Küsters, K.

    2014-05-01

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.

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

    Science.gov (United States)

    Babaie, Hassan; Davarpanah, Armita

    2016-04-01

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

  17. A method of increasing the depth of the plastically deformed layer in the roller burnishing process

    Science.gov (United States)

    Kowalik, Marek; Trzepiecinski, Tomasz

    2018-05-01

    The subject of this paper is an analysis of the determination of the depth of the plastically deformed layer in the process of roller burnishing a shaft using a newly developed method in which a braking moment is applied to the roller. It is possible to increase the depth of the plastically deformed layer by applying the braking moment to the roller during the burnishing process. The theoretical considerations presented are based on the Hertz-Bielayev and Huber-Mises theories and permit the calculation of the depth of plastic deformation of the top layer of the burnished shaft. The theoretical analysis has been verified experimentally and using numerical calculations based on the finite element method using the Msc.MARC program. Experimental tests were carried out on ring-shaped samples made of C45 carbon steel. The samples were burnished at different values of roller force and different values of braking moment. A significant increase was found in the depth of the plastically deformed surface layer of roller burnished shafts. Usage of the phenomenon of strain hardening of steel allows the technology presented here to increase the fatigue life of the shafts.

  18. Dimensional accuracy optimization of the micro-plastic injection molding process using the Taguchi design method

    Directory of Open Access Journals (Sweden)

    Chil-Chyuan KUO KUO

    2015-06-01

    Full Text Available Plastic injection molding is an important field in manufacturing industry because there are many plastic products that produced by injection molding. However, the time and cost required for producing a precision mold are the most troublesome problems that limit the application at the development stage of a new product in precision machinery industry. This study presents an approach of manufacturing a hard mold with microfeatures for micro-plastic injection molding. This study also focuses on Taguchi design method for investigating the effect of injection parameters on the dimensional accuracy of Fresnel lens during plastic injection molding. It was found that the dominant factor affecting the microgroove depth of Fresnel lens is packing pressure. The optimum processing parameters are packing pressure of 80 MPa, melt temperature of 240 °C, mold temperature of 90 °C and injection speed of 50 m/s. The dimensional accuracy of Fresnel lens can be controlled within ±3 µm using the optimum level of process parameters through the confirmation test. The research results of this study have industrial application values because electro-optical industries are able to significantly reduce a new optical element development cycle time.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.5864

  19. Intelligent methods for the process parameter determination of plastic injection molding

    Science.gov (United States)

    Gao, Huang; Zhang, Yun; Zhou, Xundao; Li, Dequn

    2018-03-01

    Injection molding is one of the most widely used material processing methods in producing plastic products with complex geometries and high precision. The determination of process parameters is important in obtaining qualified products and maintaining product quality. This article reviews the recent studies and developments of the intelligent methods applied in the process parameter determination of injection molding. These intelligent methods are classified into three categories: Case-based reasoning methods, expert system- based methods, and data fitting and optimization methods. A framework of process parameter determination is proposed after comprehensive discussions. Finally, the conclusions and future research topics are discussed.

  20. Anti-Hebbian Spike Timing Dependent Plasticity and Adaptive Sensory Processing

    Directory of Open Access Journals (Sweden)

    Patrick D Roberts

    2010-12-01

    Full Text Available Adaptive processing influences the central nervous system's interpretation of incoming sensory information. One of the functions of this adaptative sensory processing is to allow the nervous system to ignore predictable sensory information so that it may focus on important new information needed to improve performance of specific tasks. The mechanism of spike timing-dependent plasticity (STDP has proven to be intriguing in this context because of its dual role in long-term memory and ongoing adaptation to maintain optimal tuning of neural responses. Some of the clearest links between STDP and adaptive sensory processing have come from in vitro, in vivo, and modeling studies of the electrosensory systems of fish. Plasticity in such systems is anti-Hebbian, i.e. presynaptic inputs that repeatedly precede and hence could contribute to a postsynaptic neuron’s firing are weakened. The learning dynamics of anti-Hebbian STDP learning rules are stable if the timing relations obey strict constraints. The stability of these learning rules leads to clear predictions of how functional consequences can arise from the detailed structure of the plasticity. Here we review the connection between theoretical predictions and functional consequences of anti-Hebbian STDP, focusing on adaptive processing in the electrosensory system of weakly electric fish. After introducing electrosensory adaptive processing and the dynamics of anti-Hebbian STDP learning rules, we address issues of predictive sensory cancellation and novelty detection, descending control of plasticity, synaptic scaling, and optimal sensory tuning. We conclude with examples in other systems where these principles may apply.

  1. Anti-hebbian spike-timing-dependent plasticity and adaptive sensory processing.

    Science.gov (United States)

    Roberts, Patrick D; Leen, Todd K

    2010-01-01

    Adaptive sensory processing influences the central nervous system's interpretation of incoming sensory information. One of the functions of this adaptive sensory processing is to allow the nervous system to ignore predictable sensory information so that it may focus on important novel information needed to improve performance of specific tasks. The mechanism of spike-timing-dependent plasticity (STDP) has proven to be intriguing in this context because of its dual role in long-term memory and ongoing adaptation to maintain optimal tuning of neural responses. Some of the clearest links between STDP and adaptive sensory processing have come from in vitro, in vivo, and modeling studies of the electrosensory systems of weakly electric fish. Plasticity in these systems is anti-Hebbian, so that presynaptic inputs that repeatedly precede, and possibly could contribute to, a postsynaptic neuron's firing are weakened. The learning dynamics of anti-Hebbian STDP learning rules are stable if the timing relations obey strict constraints. The stability of these learning rules leads to clear predictions of how functional consequences can arise from the detailed structure of the plasticity. Here we review the connection between theoretical predictions and functional consequences of anti-Hebbian STDP, focusing on adaptive processing in the electrosensory system of weakly electric fish. After introducing electrosensory adaptive processing and the dynamics of anti-Hebbian STDP learning rules, we address issues of predictive sensory cancelation and novelty detection, descending control of plasticity, synaptic scaling, and optimal sensory tuning. We conclude with examples in other systems where these principles may apply.

  2. Coupled THM processes in EDZ of crystalline rocks using an elasto-plastic cellular automaton

    Science.gov (United States)

    Pan, Peng-Zhi; Feng, Xia-Ting; Huang, Xiao-Hua; Cui, Qiang; Zhou, Hui

    2009-05-01

    This paper aims at a numerical study of coupled thermal, hydrological and mechanical processes in the excavation disturbed zones (EDZ) around nuclear waste emplacement drifts in fractured crystalline rocks. The study was conducted for two model domains close to an emplacement tunnel; (1) a near-field domain and (2) a smaller wall-block domain. Goodman element and weak element were used to represent the fractures in the rock mass and the rock matrix was represented as elasto-visco-plastic material. Mohr-Coulomb criterion and a non-associated plastic flow rule were adopted to consider the viscoplastic deformation in the EDZ. A relation between volumetric strain and permeability was established. Using a self-developed EPCA2D code, the elastic, elasto-plastic and creep analyses to study the evolution of stress and deformations, as well as failure and permeability evolution in the EDZ were conducted. Results indicate a strong impact of fractures, plastic deformation and time effects on the behavior of EDZ especially the evolution of permeability around the drift.

  3. Kinetic modeling of solid-state partitioning phase transformation with simultaneous misfit accommodation

    International Nuclear Information System (INIS)

    Song, Shaojie; Liu, Feng

    2016-01-01

    Considering a spherical misfitting precipitate growing into a finite elastic-perfectly plastic supersaturated matrix, a kinetic modeling for such solid-state partitioning phase transformation is presented, where the interactions of interface migration, solute diffusion and misfit accommodation are analyzed. The linkage between interface migration and solute diffusion proceeds through interfacial composition and interface velocity; their effects on misfit accommodation are mainly manifested in an effective transformation strain, which depends on instantaneous composition field and precipitate size. Taking γ to α transformation of a binary Fe-0.5 at.% C alloy under both isothermal and continuous cooling conditions as examples, the effects of misfit accommodation on the coupling interface migration and solute diffusion are well evaluated and discussed. For the isothermal transformation, a counterbalancing influence between mechanical and chemical driving forces is found so that the mixed-mode transformation kinetics is not sensitive with respect to the elastic–plastic accommodation of the effective misfit strain. Different from the isothermal process, during the continuous cooling condition, the effects of misfit accommodation on the kinetics of solid-state partitioning phase transformation are mainly manifested in the great decrease of the transformation starting temperature and the thermodynamic equilibrium composition. The present kinetic modeling was applied to predict the experimentally measured γ/α transformation of Fe-0.47 at.% C alloy conducted with a cooling rate of 10 K min −1 and a good agreement was achieved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Forbit, George Teke

    2012-04-04

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

  5. Process combinations for the manufacturing of metal-plastic hybrid parts

    OpenAIRE

    Drossel, Welf-Guntram; Lies, Carsten; Albert, André; Haase, Rico; Müller, Roland; Scholz, Peter

    2016-01-01

    The usage of innovative lightweight materials and processing technologies gains importance in manifold industrial scopes. Especially for moving parts and mobility products the weight is decisively. The aerospace and automotive industries use light and high-strength materials to reduce weight and energy consumption and thereby improve the performance of their products. Composites with reinforced plastics are of particular importance. They offer a low density in combination with high specific s...

  6. The process of homelessness : an event history analysis of length of stay for the Groningen shelter accommodation

    NARCIS (Netherlands)

    Fernee, H.; Oldersma, F.; Popping, R.

    2010-01-01

    This study explores the process of shelter exits for homeless individuals and for different shelter types in the public shelter system in the city of Groningen in the Netherlands. Individualised administrative data from the Groningen Homelessness Monitor (2003–2006) are used for estimating a Weibull

  7. Interactions between Depression and Facilitation within Neural Networks: Updating the Dual-Process Theory of Plasticity

    Science.gov (United States)

    Prescott, Steven A.

    1998-01-01

    Repetitive stimulation often results in habituation of the elicited response. However, if the stimulus is sufficiently strong, habituation may be preceded by transient sensitization or even replaced by enduring sensitization. In 1970, Groves and Thompson formulated the dual-process theory of plasticity to explain these characteristic behavioral changes on the basis of competition between decremental plasticity (depression) and incremental plasticity (facilitation) occurring within the neural network. Data from both vertebrate and invertebrate systems are reviewed and indicate that the effects of depression and facilitation are not exclusively additive but, rather, that those processes interact in a complex manner. Serial ordering of induction of learning, in which a depressing locus precedes the modulatory system responsible for inducing facilitation, causes the facilitation to wane. The parallel and/or serial expression of depression and waning facilitation within the stimulus–response pathway culminates in the behavioral changes that characterize dual-process learning. A mathematical model is presented to formally express and extend understanding of the interactions between depression and facilitation. PMID:10489261

  8. Effect of Sorbitol Plasticizer on the Structure and Properties of Melt Processed Polyvinyl Alcohol Films.

    Science.gov (United States)

    Tian, Huafeng; Liu, Di; Yao, Yuanyuan; Ma, Songbai; Zhang, Xing; Xiang, Aimin

    2017-12-01

    Poly (vinyl alcohol) (PVA) possesses wide applications as food packaging materials, but is difficult to melt process for its strong inter/intra hydrogen bonding. In this work, flexible PVA films with different content of sorbitol plasticizers were prepared by melt processing with the assistance of water. And the influence of sorbitol plasticizer content on the crystallinity, optical transparency, water-retaining capability, mechanical properties, thermal stability and oxygen and water permeability were investigated. The results indicated that sorbitol dramatically improved the melt processing ability of PVA. Sorbitol could interact with PVA to form strong hydrogen bonding interactions, which would decrease the original hydrogen bonding of the matrix, resulting in the decrease of crystallinity degrees. The glass transition, melting and crystallization peak temperatures decreased with the increase of sorbitol. All the films exhibited fine optical transparency. The water retaining capability were improved with the increase of sorbitol. Especially, an increase in elongation at break and decrease in Young's modulus and tensile strength were observed indicating good plasticizing effect of sorbitol on PVA films. In addition, the PVA films prepared in this work exhibited fine barrier properties against oxygen and water, suggesting wide application potential as packaging materials. © 2017 Institute of Food Technologists®.

  9. Modelling accumulation of marine plastics in the coastal zone; what are the dominant physical processes?

    Science.gov (United States)

    Critchell, Kay; Lambrechts, Jonathan

    2016-03-01

    Anthropogenic marine debris, mainly of plastic origin, is accumulating in estuarine and coastal environments around the world causing damage to fauna, flora and habitats. Plastics also have the potential to accumulate in the food web, as well as causing economic losses to tourism and sea-going industries. If we are to manage this increasing threat, we must first understand where debris is accumulating and why these locations are different to others that do not accumulate large amounts of marine debris. This paper demonstrates an advection-diffusion model that includes beaching, settling, resuspension/re-floating, degradation and topographic effects on the wind in nearshore waters to quantify the relative importance of these physical processes governing plastic debris accumulation. The aim of this paper is to prioritise research that will improve modelling outputs in the future. We have found that the physical characteristic of the source location has by far the largest effect on the fate of the debris. The diffusivity, used to parameterise the sub-grid scale movements, and the relationship between debris resuspension/re-floating from beaches and the wind shadow created by high islands also has a dramatic impact on the modelling results. The rate of degradation of macroplastics into microplastics also have a large influence in the result of the modelling. The other processes presented (settling, wind drift velocity) also help determine the fate of debris, but to a lesser degree. These findings may help prioritise research on physical processes that affect plastic accumulation, leading to more accurate modelling, and subsequently management in the future.

  10. Optimization of injection molding process parameters for a plastic cell phone housing component

    Science.gov (United States)

    Rajalingam, Sokkalingam; Vasant, Pandian; Khe, Cheng Seong; Merican, Zulkifli; Oo, Zeya

    2016-11-01

    To produce thin-walled plastic items, injection molding process is one of the most widely used application tools. However, to set optimal process parameters is difficult as it may cause to produce faulty items on injected mold like shrinkage. This study aims at to determine such an optimum injection molding process parameters which can reduce the fault of shrinkage on a plastic cell phone cover items. Currently used setting of machines process produced shrinkage and mis-specified length and with dimensions below the limit. Thus, for identification of optimum process parameters, maintaining closer targeted length and width setting magnitudes with minimal variations, more experiments are needed. The mold temperature, injection pressure and screw rotation speed are used as process parameters in this research. For optimal molding process parameters the Response Surface Methods (RSM) is applied. The major contributing factors influencing the responses were identified from analysis of variance (ANOVA) technique. Through verification runs it was found that the shrinkage defect can be minimized with the optimal setting found by RSM.

  11. Processing and characterization of plasticized PLA/PHB blends for biodegradable multiphase systems

    Directory of Open Access Journals (Sweden)

    I. Armentano

    2015-07-01

    Full Text Available Blends of poly(lactic acid (PLA and poly(3-hydroxybutyrate (PHB plasticized with a lactic acid oligomer (OLA added at three different concentrations (15, 20 and 30 wt% by weight, were prepared by an optimized extrusion process to improve the processability and mechanical properties of these biopolymers for flexible film manufacturing. Morphological, chemical, thermal, mechanical, barrier and migration properties were investigated and formulations with desired performance in eco-friendly films were selected. The efficiency of OLA as plasticizer for PLA_PHB blends was demonstrated by the significant decrease of their glass transition temperatures and a considerable improvement of their ductile properties. The measured improvements in the barrier properties are related to the higher crystallinity of the plasticized PLA_PHB blends, while the overall migration test underlined that all the proposed formulations maintained migration levels below admitted levels. The PLA_PHB blend with 30 wt% OLA was selected as the optimum formulation for food packaging, since it offered the best compromise between ductility and oxygen and water vapor barrier properties with practically no migration.

  12. Development of crayfish bio-based plastic materials processed by small-scale injection moulding.

    Science.gov (United States)

    Felix, Manuel; Romero, Alberto; Cordobes, Felipe; Guerrero, Antonio

    2015-03-15

    Protein has been investigated as a source for biodegradable polymeric materials. This work evaluates the development of plastic materials based on crayfish and glycerol blends, processed by injection moulding, as a fully biodegradable alternative to conventional polymer-based plastics. The effect of different additives, namely sodium sulfite or bisulfite as reducing agents, urea as denaturing agent and L-cysteine as cross-linking agent, is also analysed. The incorporation of any additive always yields an increase in energy efficiency at the mixing stage, but its effect on the mechanical properties of the bioplastics is not so clear, and even dampened. The additive developing a greater effect is L-cysteine, showing higher Young's modulus values and exhibiting a remnant thermosetting potential. Thus, processing at higher temperature yields a remarkable increase in extensibility. This work illustrates the feasibility of crayfish-based green biodegradable plastics, thereby contributing to the search for potential value-added applications for this by-product. © 2014 Society of Chemical Industry.

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

    Science.gov (United States)

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

    2017-10-01

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

  14. Formation Process of Triangular Morphology of Self-Accommodation Martensite in Ti-Nb-Al Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Kamioka Nozomi

    2015-01-01

    Full Text Available The formation process of a habit plane variant (HPV cluster with triangular morphology (T-cluster in Ti- Nb-Al shape memory alloy was investigated by in-situ optical microscopy. Upon cooling the specimen, martensitic transformation occurred and two types of V-shaped clusters and the T-clusters were observed. Two types of V-shaped cluster were the cluster connected by the {111} type I twin (VI and the cluster connected by the type II twin (VII. The T-cluster is formed by the connection of three HPVs by {111} type I twin. The T-cluster is formed by the growth of the third HPV that is nucleated at the tip of a HPV in a VI-cluster and exhibits inward growth. It is suggested that the T-cluster is a derivative of the VI-cluster. This growth behaviour is discussed based on the incompatibility of the clusters.

  15. Synaptic plasticity, neural circuits, and the emerging role of altered short-term information processing in schizophrenia

    Science.gov (United States)

    Crabtree, Gregg W.; Gogos, Joseph A.

    2014-01-01

    Synaptic plasticity alters the strength of information flow between presynaptic and postsynaptic neurons and thus modifies the likelihood that action potentials in a presynaptic neuron will lead to an action potential in a postsynaptic neuron. As such, synaptic plasticity and pathological changes in synaptic plasticity impact the synaptic computation which controls the information flow through the neural microcircuits responsible for the complex information processing necessary to drive adaptive behaviors. As current theories of neuropsychiatric disease suggest that distinct dysfunctions in neural circuit performance may critically underlie the unique symptoms of these diseases, pathological alterations in synaptic plasticity mechanisms may be fundamental to the disease process. Here we consider mechanisms of both short-term and long-term plasticity of synaptic transmission and their possible roles in information processing by neural microcircuits in both health and disease. As paradigms of neuropsychiatric diseases with strongly implicated risk genes, we discuss the findings in schizophrenia and autism and consider the alterations in synaptic plasticity and network function observed in both human studies and genetic mouse models of these diseases. Together these studies have begun to point toward a likely dominant role of short-term synaptic plasticity alterations in schizophrenia while dysfunction in autism spectrum disorders (ASDs) may be due to a combination of both short-term and long-term synaptic plasticity alterations. PMID:25505409

  16. Accumulation of organic compounds leached from plastic materials used in biopharmaceutical process containers.

    Science.gov (United States)

    Jenke, Dennis R; Zietlow, David; Garber, Mary Jo; Sadain, Salma; Reiber, Duane; Terbush, William

    2007-01-01

    Plastic materials are widely used in medical items, such as solution containers, transfusion sets, transfer tubing, and devices. An emerging trend in the biotechnology industry is the utilization of plastic containers to prepare, transport, and store an assortment of solutions including buffers, media, and in-process and finished product. The direct contact of such containers with the product at one or more points in its lifetime raises the possibility that container leachables may accumulate in the finished product. The interaction between several commercially available container materials and numerous model test solutions (representative of buffers and media used in biopharmaceutical applications) was investigated. This paper summarizes the identification of leachables associated with the container materials and documents the levels to which targeted leachables accumulate in the test solutions under defined storage conditions.

  17. Experimental Investigation of the Productivity of a Wet Separation Process of Traditional and Bio-Plastics

    Directory of Open Access Journals (Sweden)

    Monica Moroni

    2018-05-01

    Full Text Available The separation process within a mechanical recycling plant plays a major role in the context of the production of high-quality secondary raw materials and the reduction of extensive waste disposal in landfills. Traditional plants for plastic separation employ dry or wet processes that rely on the different physical properties among the polymers. The hydraulic separator is a device employing a wet technology for particle separation. It allows the separation of two-polymer mixtures into two products, one collected within the instrument and the other one expelled through its outlet ducts. Apparatus performance were analyzed as a function of fluid and solid flow rates, flow patterns developing within the apparatus, in addition to the density, shape, and size of the polymers. For the hydraulic configurations tested, a two-way coupling takes place where the fluid exerts an influence on the plastic particles and the opposite occurs too. The interaction between the solid and liquid phases determines whether a certain polymer settles within the device or is expelled from the apparatus. Tests carried out with samples of increasing volumes of solid particles demonstrate that there are no significant differences in the apparatus effectiveness as far as a two-way interaction takes place. Almost pure concentrates of Polyethylene Terephthalate (PET, Polyvinyl Chloride (PVC, and Polycarbonate (PC can be obtained from a mixture of traditional polymers. Tests conducted on Polylactic Acid (PLA and Mater-Bi® samples showed that the hydraulic separator can be effectively employed to separate bio-plastics from conventional plastics with remarkable grade and recovery.

  18. Stress evolution in elastic-plastic electrodes during electrochemical processes: A numerical method and its applications

    Science.gov (United States)

    Wen, Jici; Wei, Yujie; Cheng, Yang-Tse

    2018-07-01

    Monitoring in real time the stress state in high capacity electrodes during charge-discharge processes is pivotal to the performance assessment and structural optimization of advanced batteries. The wafer curvature measurement technique broadly employed in thin-film industry, together with stress analysis using the Stoney equation, has been successfully adopted to measure in situ the stress in thin film electrodes. How large plastic deformation or interfacial delamination during electrochemical cycles in such electrodes affects the applicability of Stoney equation remains unclear. Here we develop a robust electrochemical-mechanical coupled numerical procedure to investigate the influence of large plastic deformation and interfacial failure on the measured stress in thin film electrodes. We identify how the constitutive behavior of electrode materials and film-substrate interfacial properties affect the measured stress-capacity curves of electrodes, and hence establish the relationship of electrode material parameters with the characteristics of stress-capacity curves. Using Li-ions batteries as examples, we show that plastic deformation and interfacial delamination account for the asymmetric stress-capacity loops seen in in situ stress measurements. The methods used here, along with the finite-element code in the supplementary material, may be used to model the electrode behavior as a function of the state of charge.

  19. Laser Cutting of Carbon Fiber Reinforced Plastics - Investigation of Hazardous Process Emissions

    Science.gov (United States)

    Walter, Juergen; Hustedt, Michael; Staehr, Richard; Kaierle, Stefan; Jaeschke, Peter; Suttmann, Oliver; Overmeyer, Ludger

    Carbon fiber reinforced plastics (CFRP) show high potential for use in lightweight applications not only in aircraft design, but also in the automotive or wind energy industry. However, processing of CFRP is complex and expensive due to their outstanding mechanical properties. One possibility to manufacture CFRP structures flexibly at acceptable process speeds is high-power laser cutting. Though showing various advantages such as contactless energy transfer, this process is connected to potentially hazardous emission of respirable dust and organic gases. Moreover, the emitted particles may be fibrous, thus requiring particular attention. Here, a systematic analysis of the hazardous substances emitted during laser cutting of CFRP with thermoplastic and thermosetting matrix is presented. The objective is to evaluate emission rates for the total particulate and gaseous fractions as well as for different organic key components. Furthermore, the influence of the laser process conditions shall be assessed, and first proposals to handle the emissions adequately are made.

  20. Comparison of plastic strains on AA5052 by single point incremental forming process using digital image processing

    Energy Technology Data Exchange (ETDEWEB)

    Mugendiran, V.; Gnanavelbabu, A. [Anna University, Chennai, Tamilnadu (India)

    2017-06-15

    In this study, a surface based strain measurement was used to determine the formability of the sheet metal. A strain measurement may employ manual calculation of plastic strains based on the reference circle and the deformed circle. The manual calculation method has a greater margin of error in the practical applications. In this paper, an attempt has been made to compare the formability by implementing three different theoretical approaches: Namely conventional method, least square method and digital based strain measurements. As the sheet metal was formed by a single point incremental process the etched circles get deformed into elliptical shapes approximately, image acquisition has been done before and after forming. The plastic strains of the deformed circle grids are calculated based on the non- deformed reference. The coordinates of the deformed circles are measured by various image processing steps. Finally the strains obtained from the deformed circle are used to plot the forming limit diagram. To evaluate the accuracy of the system, the conventional, least square and digital based method of prediction of the forming limit diagram was compared. Conventional method and least square method have marginal error when compared with digital based processing method. Measurement of strain based on image processing agrees well and can be used to improve the accuracy and to reduce the measurement error in prediction of forming limit diagram.

  1. Comparison of plastic strains on AA5052 by single point incremental forming process using digital image processing

    International Nuclear Information System (INIS)

    Mugendiran, V.; Gnanavelbabu, A.

    2017-01-01

    In this study, a surface based strain measurement was used to determine the formability of the sheet metal. A strain measurement may employ manual calculation of plastic strains based on the reference circle and the deformed circle. The manual calculation method has a greater margin of error in the practical applications. In this paper, an attempt has been made to compare the formability by implementing three different theoretical approaches: Namely conventional method, least square method and digital based strain measurements. As the sheet metal was formed by a single point incremental process the etched circles get deformed into elliptical shapes approximately, image acquisition has been done before and after forming. The plastic strains of the deformed circle grids are calculated based on the non- deformed reference. The coordinates of the deformed circles are measured by various image processing steps. Finally the strains obtained from the deformed circle are used to plot the forming limit diagram. To evaluate the accuracy of the system, the conventional, least square and digital based method of prediction of the forming limit diagram was compared. Conventional method and least square method have marginal error when compared with digital based processing method. Measurement of strain based on image processing agrees well and can be used to improve the accuracy and to reduce the measurement error in prediction of forming limit diagram.

  2. Reasonable Accommodation Information Tracking System

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Reasonable Accommodation Information Tracking System (RAITS) is a case management system that allows the National Reasonable Accommodation Coordinator (NRAC) and...

  3. Utility accommodation and conflict tracker (UACT) installation and configuration manual.

    Science.gov (United States)

    2009-02-01

    Project 0-5475 performed a comprehensive analysis of utility conflict data/information flows between utility : accommodation stakeholders in the Texas Department of Transportation project development process, : developed data models to accommodate wo...

  4. Manufacturability of Wood Plastic Composite Sheets on the Basis of the Post-Processing Cooling Curve

    Directory of Open Access Journals (Sweden)

    Sami Matthews

    2015-10-01

    Full Text Available Extruded wood-plastic composites (WPCs are increasingly regarded as promising materials for future manufacturing industries. It is necessary to select and tune the post-processing methods to be able to utilize these materials fully. In this development, temperature-related material properties and the cooling rate are important indicators. This paper presents the results of natural cooling in a factory environment fit into a cooling curve function with temperature zones for forming, cutting, and packaging overlaid using a WPC material. This information is then used in the evaluation of manufacturability and productivity in terms of cost effectiveness and technical quality by comparing the curve to actual production time data derived from a prototype post-process forming line. Based on this information, speed limits for extrusion are presented. This paper also briefly analyzes techniques for controlling material cooling to counter the heat loss before post-processing.

  5. Plastic deformation of solids viewed as a self-excited wave process

    International Nuclear Information System (INIS)

    Zuev, L.B.; Danilov, V.I.

    1998-01-01

    A self-excited wave model of plastic flow in crystalline solids is proposed. Experimental data on plastic flow in single crystals and polycrystalline solids involving different mechanisms have been correlated. The main types of strain localization in the materials investigated have been established and correlated with the respective stages of plastic flow curves. The best observing conditions have been defined for the major types of autowaves emerging by plastic deformation. The synergetic concepts of self-organization are shown to apply to description of plastic deformation. Suggested is a self-excited wave model of plastic flow in materials with different mechanisms of deformation. (orig.)

  6. Characterization of microcrystalline I-layer for solar cells prepared in low temperature - plastic compatible process

    KAUST Repository

    Sliz, Rafal

    2012-06-01

    Microcrystalline silicon (mc-Si) lms deposited using a Plasma Enhanced Chemical Vapour Deposition (PECVD) process constitute an important material for manufacturing low-cost, large-area thin-lm devices, such as solar cells or thin-lm transistors. Although the deposition of electronic-grade mc-Si using the PECVD process is now well established, the high substrate temperature required (~400°C) does not lend itself to electronic devices with exible form factors fabricated on low-cost plastic substrates. In this study, we rst investigated an intrinsic mc-Si layer deposited at plastic-compatible substrate temperatures (~150°C) by characterising the properties of the lm and then evaluated its applicability to p-i-n solar cells though device characterisation. When the performance of the solar cell was correlated with lm properties, it was found that, although it compared unfavourably with mc-Si deposited at higher temperatures, it remained a very promising option. Nonetheless, further development is required to increase the overall eciency of mc-Si exible solar cells.

  7. Analysis of metal forming processes by using physical modeling and new plastic similarity condition

    International Nuclear Information System (INIS)

    Gronostajski, Z.; Hawryluk, M.

    2007-01-01

    In recent years many advances have been made in numerical methods, for linear and non-linear problems. However the success of them depends very much on the correctness of the problem formulation and the availability of the input data. Validity of the theoretical results can be verified by an experiment using the real or soft materials. An essential reduction of time and costs of the experiment can be obtained by using soft materials, which behaves in a way analogous to that of real metal during deformation. The advantages of using of the soft materials are closely connected with flow stress 500 to 1000 times lower than real materials. The accuracy of physical modeling depend on the similarity conditions between physical model and real process. The most important similarity conditions are materials similarity in the range of plastic and elastic deformation, geometrical, frictional and thermal similarities. New original plastic similarity condition for physical modeling of metal forming processes is proposed in the paper. It bases on the mathematical description of similarity of the flow stress curves of soft materials and real ones

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

    Energy Technology Data Exchange (ETDEWEB)

    Forbit, George Teke

    2012-04-04

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

  9. Improving the circular economy via hydrothermal processing of high-density waste plastics

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Conti, Federica

    2017-01-01

    Rising environmental concerns on climate changes are causing an increasing attention on circular economies. The plastic economy, in particular, is in focus due to the accelerating consumption of plastics, mainly derived from virgin feedstock, combined with the lack of plastic recycling strategies...

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

    Directory of Open Access Journals (Sweden)

    Dyi-Cheng Chen

    2014-04-01

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

  11. Accommodating Picky Palates

    Science.gov (United States)

    Lum, Lydia

    2007-01-01

    Healthy gourmet offerings are fast becoming the norm at college dining halls around the country. At a time when the children of Baby Boomers are hitting higher education in record numbers, college officials have scrambled to accommodate their picky palates and their insistence for healthier meals than were served to past generations. At the same…

  12. Fluoxetine requires the endfeet protein aquaporin-4 to enhance plasticity of astrocyte processes

    Directory of Open Access Journals (Sweden)

    Barbara eDi Benedetto

    2016-02-01

    Full Text Available Morphological alterations in astrocytes are characteristic for post mortem brains of patients affected by major depressive disorder (MDD. Recently, a significant reduction in the coverage of blood vessels (BVs by aquaporin-4 (AQP-4-positive astrocyte endfeet has been shown in the prefrontal cortex (PFC of MDD patients, suggesting that either alterations in the morphology of endfeet or in AQP-4 distribution might be responsible for the disease phenotype or constitute a consequence of its progress. Antidepressant drugs (ADs regulate the expression of several proteins, including astrocyte-specific ones. Thus, they may target AQP-4 to induce morphological changes in astrocytes and restore their proper shape or relocate AQP-4 to endfeet. Using an animal model of depression, rats selectively bred for high anxiety-like behavior (HAB, we confirmed a reduced coverage of BVs in the adult PFC by AQP-4-immunoreactive (AQP-4-IR astrocyte processes with respect to nonselected Wistar rats (NAB, thereby validating it for our study. A further evaluation of the morphology of astrocyte in brain slices (ex vivo and in vitro using an antibody against the astrocyte-specific cytoskeletal protein glial fibrillary acidic protein (GFAP revealed that HAB astrocytes extended less processes than NAB cells. Furthermore, short-term drug treatment in vitro with the AD fluoxetine (FLX was sufficient to increase the plasticity of astrocyte processes, enhancing their number in NAB-derived cells and recovering their basal number in HAB-derived cells. This enhanced FLX-dependent plasticity occurred, however, only in the presence of intact AQP-4, as demonstrated by the lack of effect after the downregulation of AQP-4 with RNAi in both NAB and HAB cells. Nonetheless, a similar short-term treatment did neither modulate the coverage of BVs with AQP-4-positive astrocyte endfeet in NAB nor in HAB rats, although dosage and time of treatment were sufficient to fully recover GFAP expression

  13. Cycle time improvement for plastic injection moulding process by sub groove modification in conformal cooling channel

    Science.gov (United States)

    Kamarudin, K.; Wahab, M. S.; Batcha, M. F. M.; Shayfull, Z.; Raus, A. A.; Ahmed, Aqeel

    2017-09-01

    Mould designers have been struggling for the improvement of the cooling system performance, despite the fact that the cooling system complexity is physically limited by the fabrication capability of the conventional tooling methods. However, the growth of Solid Free Form Technology (SFF) allow the mould designer to develop more than just a regular conformal cooling channel. Numerous researchers demonstrate that conformal cooling channel was tremendously given significant result in the improvement of productivity and quality in the plastic injection moulding process. This paper presents the research work that applies the passive enhancement method in square shape cooling channel to enhance the efficiency of cooling performance by adding the sub groove to the cooling channel itself. Previous design that uses square shape cooling channel was improved by adding various numbers of sub groove to meet the best sub groove design that able reduced the cooling time. The effect of sub groove design on cooling time was investigated by Autodesk Modlflow Insight software. The simulation results showed that the various sub groove designs give different values to ejection time. The Design 7 showed the lowest value of ejection time with 24.3% increment. The addition of sub groove significantly increased a coolant velocity and a rate of heat transfer from molten plastic to coolant.

  14. Research of Tool Durability in Surface Plastic Deformation Processing by Burnishing of Steel Without Metalworking Fluids

    Science.gov (United States)

    Grigoriev, S. N.; Bobrovskij, N. M.; Melnikov, P. A.; Bobrovskij, I. N.

    2017-05-01

    Modern vector of development of machining technologies aimed at the transition to environmentally safe technologies - “green” technologies. The concept of “green technology” includes a set of signs of knowledge intended for practical use (“technology”). One of the ways to improve the quality of production is the use of surface plastic deformation (SPD) processing methods. The advantage of the SPD is a capability to combine effects of finishing and strengthening treatment. The SPD processing can replace operations: fine turning, grinding or polishing. The SPD is a forceful contact impact of indentor on workpiece’s surface in condition of their relative motion. It is difficult to implement the core technology of the SPD (burnishing, roller burnishing, etc.) while maintaining core technological advantages without the use of lubricating and cooling technology (metalworking fluids, MWF). The “green” SPD technology was developed by the authors for dry processing and has not such shortcomings. When processing with SPD without use of MWF requirements for tool’s durability is most significant, especially in the conditions of mass production. It is important to determine the period of durability of tool at the design stage of the technological process with the purpose of wastage preventing. This paper represents the results of durability research of natural and synthetic diamonds (polycrystalline diamond - ASPK) as well as precision of polycrystalline superabrasive tools made of dense boron nitride (DBN) during SPD processing without application of MWF.

  15. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation.

    Science.gov (United States)

    Li, Jia; Wu, Guiqing; Xu, Zhenming

    2015-01-01

    Plastic products can be found everywhere in people's daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (-)-PE-PS-PC-PVC-ABS-PP-(+), while the triboelectric series obtained by cyclone was (-)-PE-PS-PC-PVC-ABS-PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Effects of mechanical and chemical processes on the degradation of plastic beach debris on the island of Kauai, Hawaii

    International Nuclear Information System (INIS)

    Cooper, David A; Corcoran, Patricia L

    2010-01-01

    Plastic debris is accumulating on the beaches of Kauai at an alarming rate, averaging 484 pieces/day in one locality. Particles sampled were analyzed to determine the effects of mechanical and chemical processes on the breakdown of polymers in a subtropical setting. Scanning electron microscopy (SEM) indicates that plastic surfaces contain fractures, horizontal notches, flakes, pits, grooves, and vermiculate textures. The mechanically produced textures provide ideal loci for chemical weathering to occur which further weakens the polymer surface leading to embrittlement. Fourier transform infrared spectroscopy (FTIR) results show that some particles have highly oxidized surfaces as indicated by intense peaks in the lower wavenumber region of the spectra. Our textural analyses suggest that polyethylene has the potential to degrade more readily than polypropylene. Further evaluation of plastic degradation in the natural environment may lead to a shift away from the production and use of plastic materials with longer residence times.

  17. Investigate earing of TWIP steel sheet during deep-drawing process by using crystal plasticity constitutive model

    Directory of Open Access Journals (Sweden)

    Yang J.

    2015-01-01

    Full Text Available By combining the nonlinear finite element analysis techniques and crystal plasticity theory, the macroscopic mechanical behaviour of crystalline material, the texture evolution and earing-type characteristics are simulated accurately. In this work, a crystal plasticity model exhibiting deformation twinning is introduced based on crystal plasticity theory and saturation-type hardening laws for FCC metal Fe-22Mn-0.6C TWIP steel. Based on the CPFE model and parameters which have been determined for TWIP steel, a simplified finite element model for deep drawing is promoted by using crystal plasticity constitutive model. The earing characteristics in typical deep-drawing process are simulated well. Further, the drawing forces are calculated and compared to the experimental results from reference. Meanwhile, the impacts of drawing coefficient and initial texture on the earing characteristics are investigated for controlling the earing.

  18. Polycarbonate as an Elasto-Plastic Material Model for Simulation of the Microstructure Hot Imprint Process

    Directory of Open Access Journals (Sweden)

    Rokas Šakalys

    2013-08-01

    Full Text Available The thermal imprint process of polymer micro-patterning is widely applied in areas such as manufacturing of optical parts, solar energy, bio-mechanical devices and chemical chips. Polycarbonate (PC, as an amorphous polymer, is often used in thermoforming processes because of its good replication characteristics. In order to obtain replicas of the best quality, the imprint parameters (e.g., pressure, temperature, time, etc. must be determined. Therefore finite element model of the hot imprint process of lamellar periodical microstructure into PC has been created using COMSOL Multiphysics. The mathematical model of the hot imprint process includes three steps: heating, imprinting and demolding. The material properties of amorphous PC strongly depend on the imprint temperature and loading pressure. Polycarbonate was modelled as an elasto-plastic material, since it was analyzed below the glass transition temperature. The hot imprint model was solved using the heat transfer and the solid stress-strain application modes with thermal contact problem between the mold and polycarbonate. It was used for the evaluation of temperature and stress distributions in the polycarbonate during the hot imprint process. The quality of the replica, by means of lands filling ratio, was determined as well.

  19. Grain-size dependent accommodation due to intragranular distributions of dislocation loops

    International Nuclear Information System (INIS)

    Richeton, T.; Berbenni, S.; Berveiller, M.

    2009-01-01

    A grain-size dependent accommodation law for polycrystals is deduced from an inclusion/matrix problem (i.e., each grain is seen as embedded in a homogeneous equivalent medium) where plastic strain inside the inclusion is given as a discrete distribution of circular coaxial glide dislocation loops. The loops are assumed constrained at spherical grain boundaries. From thermodynamic considerations specific to a process of identical plastification in all the loops (considered as 'super-dislocations'), an average back-stress over the grain is derived. In order to compute the very early stages of plastic deformation in a face-centred cubic polycrystal, this back-stress is incorporated into a diluted model in terms of concentration of plastic grains. Contrary to conventional mean-field approaches, a grain-size effect is obtained for the initial overall strain-hardening behaviour. This size effect results from an intrinsic contribution of intragranular slip heterogeneities on the kinematical hardening

  20. Harmonic reduction by using single-tuned passive filter in plastic processing industry

    Science.gov (United States)

    Fahmi, M. I.; Baafai, U.; Hazmi, A.; Nasution, T. H.

    2018-02-01

    The using of non-linear loads generated by industrial machines may result inconsistent harmonics that do not reach the IEEE 519 - 1992 standards. This study discusses the use of single-tuned passive filters in reducing harmonics in the plastics processing industry. The system modeling using matlab / simulink simulation resulted in total harmonic distortion (THD) of 15.55%, can be reduced to 4.77% harmonics in accordance with IEEE 519 - 1992 standards. From the simulation results also seen that single-tuned passive filter can reduce the harmonics of the current 82.23% harmonic that wants to be reduced and also can reduce other orders harmonics between 7% to 8%.

  1. Structural synaptic plasticity in the hippocampus induced by spatial experience and its implications in information processing.

    Science.gov (United States)

    Carasatorre, M; Ramírez-Amaya, V; Díaz Cintra, S

    2016-10-01

    Long-lasting memory formation requires that groups of neurons processing new information develop the ability to reproduce the patterns of neural activity acquired by experience. Changes in synaptic efficiency let neurons organise to form ensembles that repeat certain activity patterns again and again. Among other changes in synaptic plasticity, structural modifications tend to be long-lasting which suggests that they underlie long-term memory. There is a large body of evidence supporting that experience promotes changes in the synaptic structure, particularly in the hippocampus. Structural changes to the hippocampus may be functionally implicated in stabilising acquired memories and encoding new information. Copyright © 2012 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Co-processing of lignite-plastic mixtures into liquid distillate fractions in the presence of iron catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, B.N.; Sharypov, V.I.; Beregovtsova, N.G.; Baryshnikov, S.V.; Doroginskaya, A.N. [Russian Academy of Sciences, Krasnoyarsk (Russian Federation). Inst. of Chemistry of Natural Organic Materials Sibirian Branch

    1997-12-31

    Some features of co-processing of Kansk-Achinsk lignite with plastics into hydrocarbon mixtures in the presence of activated iron-containing minerals (hematite, magnetite, pyrrhotite) were investigated under various operating parameters. The following catalytic processes were studied: pyrolysis in an inert atmosphere, hydropyrolysis and water-steam cracking. (orig.)

  3. X-ray imager using solution processed organic transistor arrays and bulk heterojunction photodiodes on thin, flexible plastic substrate

    NARCIS (Netherlands)

    Gelinck, G.H.; Kumar, A.; Moet, D.; Steen, J.L. van der; Shafique, U.; Malinowski, P.E.; Myny, K.; Rand, B.P.; Simon, M.; Rütten, W.; Douglas, A.; Jorritsma, J.; Heremans, P.L.; Andriessen, H.A.J.M.

    2013-01-01

    We describe the fabrication and characterization of large-area active-matrix X-ray/photodetector array of high quality using organic photodiodes and organic transistors. All layers with the exception of the electrodes are solution processed. Because it is processed on a very thin plastic substrate

  4. Accommodating Different Learning Styles

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2014-01-01

    Design engineering educations often struggle to accommodate a highly diverse group of students as it combines an equally diverse range of topics in one education. This paper investigates how a specific course, Mathematics and Form, integrates two distinct areas into one course with the aim of fac...... shapes and form, whereas other types of students do not. The results thereby underpin that learning is typically based on individual preferences and that cross-disciplinary educational programmes have to accommodate this....... of facilitating learning across this diverse group of students. The paper is based on a survey with 99 former participants of the course as respondents. The results of the survey imply that certain types of students benefit from the combination of mathematical theory and practical exercises related to basic...

  5. Ecotourism and Ecolodge Accommodation

    Directory of Open Access Journals (Sweden)

    Dragan Bulatović

    2017-12-01

    Full Text Available In ecotourism, as a specific form of tourism, conscientious individuals and groups participate, who by its influence on nature are trying to reduce effects produced by so called mass tourism. Ecotourism product should be developed on the contemporary tourism trends, with full respect of local specificity which represent commitment in regard to competitive destinations. Existence of receptive factors, such as facilities for accommodation, nutrition, entertainment and recreation, represent one of the basic prerequisites for the development of any ecotourism destination. Ecotourists seek accommodation which is ecologically acceptable, modest but cozy at the same time and provides unique experience in natural surroundings. In accordance with these demands protected areas all around the world offer its visitors high quality Ecolodge facilities, which are fully submerged into nature. During their construction and management strict criteria of protection of the environment are followed with optimal waste and energy management. Montenegro has enviable spacious potential for this kind of accommodation in protected areas, especially in its five national parks, so this form of accommodation has to find its place in the future development of tourism. Designing and construction of ecotourism facilities has to be strategically planned and the fact, that it is not enough just to have attractive location but also specific content it has to offer, has to be respected. Ecolodge facilities should be designed and built in accordance with traditional architecture and surrounding materials, to influence as little as possible on the environment and to use alternative energy sources. In other words, it is necessary to provide sustainability of these facilities.

  6. Accommodative loss after retinal cryotherapy.

    Science.gov (United States)

    Uno, Tsuyoshi; Okuyama, Michiko; Tanabe, Tatsuro; Kawamura, Ryosuke; Ideta, Hidenao

    2009-01-01

    To investigate the effects of peripheral retinal cryotherapy on accommodative amplitude in patients with retinal lattice degeneration. Prospective, observational case series. We studied 92 eyes in 69 patients (age range, 13 to 79 years) treated with cryotherapy for lattice degeneration between December 2001 and September 2004. Pretreatment and posttreatment accommodative amplitudes were measured. Acute accommodative loss was calculated from the difference between accommodative amplitudes before treatment and one week after treatment. We investigated the time course of accommodative amplitudes, acute accommodative loss in different age groups and in pretreatment accommodative amplitude groups, the influence of cryotherapy numbers on accommodative amplitude, and the influence of cryotherapy sites on accommodative amplitude. No significant difference was noted between pretreatment and posttreatment accommodative amplitudes in the overall subject cohort. Dividing subjects by age revealed significant decreases in accommodative amplitude only among patients in their 10s and 20s at one and three weeks after treatment. Accommodative amplitude was lowest among those in their 10s, followed by that among those in their 20s (P < .01). Accommodative amplitudes recovered to pretreatment level by six weeks. Acute accommodative loss was greatest in those in their 10s compared with other age groups (P < .01). A significant correlation was observed between acute accommodative loss and cryotherapy numbers (P = .03; r = 0.41). The decrease in accommodative amplitude was greatest at one week after treatment and recovered to pretreatment levels after six weeks. Accommodative amplitude showed the greatest decrease after cryotherapy among patients in their 10s and 20s. A decrease in accommodative amplitude was observed with increased numbers of cryotherapy spots administered.

  7. Grafting of Maleic Anhydride onto Polyethylene by Blend Process forEnvironmentally Friendly Plastics

    International Nuclear Information System (INIS)

    Hendrana, Sunit; Retno-Yusiasih; Sudirman; Ipit-Karyaningsih; Djimat-Lisnawati

    2000-01-01

    Grafting maleic anhydride (MAH) onto polyethylene is one of the route tomake plastics which can be consumed by microbe in the soil. High temperaturesolution process is one of the method to perform grafting. This method is notreally handy since it involves many steps. Therefore, in this work a simplemethod is performed to graft MAH onto polyethylene, i.e., blending process.As the process occurs in melt, the reaction is more likely to be diffusioncontrol rather than chemical control. Therefore, there are many parameterscan affect the grafting such as temperature of the blending, speed of therotation, concentration of MAH and concentration of dicumyl peroxide (DCP).Preliminary work in our laboratorium found an optimum condition for the firsttwo parameters. Thus, in this work the effect of concentration of MAH and DCPis studied into the effectiveness of grafting process. One of the indicationof unexpected reaction is formation of gel, or in other words the formationof X-link among polyethylene molecules. The grafted polyethylene ischaracterized by calculation of gel content, thermal properties by TG/DTA andFourier Transform Infrared (FTIR). The results show the concentration of MAHand DCP play roles. However, initiator DCP has more significance effect thanthe MAH. (author)

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

    Science.gov (United States)

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

    2018-02-01

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

  9. Employment Accommodations for People with Disabilities: Does Gender Really Matter?

    Directory of Open Access Journals (Sweden)

    Helen P Hartnett

    2014-06-01

    Full Text Available AbstractThe Americans with Disabilities Act (ADA requires employersto provide reasonable accommodations for any qualified individual with adisability. By examining the ongoing evaluation data from the Job AccommodationNetwork (JAN, this study seeks to investigate whether or not genderdifferences are present in the reasonable accommodation process. Open andclosed-ended data are collected using a 20-minute structured telephoneinterview of JAN customers (n= 1,247; 44% response rate. The results show veryfew differences between men’s and women’s accommodation request types, whetheror not accommodations were granted, the costs of requested accommodations, andsatisfaction with JAN. A significant difference, however, was found by genderon the effectiveness of the accommodation.  Key Words: Accommodations, Disabilities, Gender, Employment, Social Work Practice

  10. Finite element modelling of shot peening process: Prediction of the compressive residual stresses, the plastic deformations and the surface integrity

    International Nuclear Information System (INIS)

    Frija, M.; Hassine, T.; Fathallah, R.; Bouraoui, C.; Dogui, A.

    2006-01-01

    This paper presents a numerical simulation of the shot peening process using finite element method. The majority of the controlling parameters of the process have been taken into account. The shot peening loading has been characterised by using energy equivalence between the dynamic impact and a static indentation of a peening shot in the treated surface. The behaviour of the subjected material is supposed to be elastic plastic with damage. An integrated law of the damage proposed by Lemaitre and Chaboche has been used. The proposed model leads to obtain the residual stress, the plastic deformation profiles and the surface damage. An application on a shot peened Ni-based super alloy Waspaloy has been carried out. The comparison of the residual stresses, obtained by X-ray diffraction method and by finite element calculation, shows a good correlation. The in-depth profile of the plastic deformations and the superficial damage values are in good agreement with the experimental observations

  11. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jia, E-mail: weee@sjtu.edu.cn; Wu, Guiqing; Xu, Zhenming

    2015-01-15

    Highlights: • The cyclone charging was more effective and stable than vibrating charging. • The small particle size was better changed than large ones and was more suitable recycled by TES. • The drying pretreatment is good for improving the short-term charging effect. - Abstract: Plastic products can be found everywhere in people’s daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (−)-PE–PS–PC–PVC–ABS–PP-(+), while the triboelectric series obtained by cyclone was (−)-PE–PS–PC–PVC–ABS–PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator.

  12. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation

    International Nuclear Information System (INIS)

    Li, Jia; Wu, Guiqing; Xu, Zhenming

    2015-01-01

    Highlights: • The cyclone charging was more effective and stable than vibrating charging. • The small particle size was better changed than large ones and was more suitable recycled by TES. • The drying pretreatment is good for improving the short-term charging effect. - Abstract: Plastic products can be found everywhere in people’s daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (−)-PE–PS–PC–PVC–ABS–PP-(+), while the triboelectric series obtained by cyclone was (−)-PE–PS–PC–PVC–ABS–PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator

  13. Nonverbal Accommodation in Healthcare Communication

    OpenAIRE

    D’Agostino, Thomas A.; Bylund, Carma L.

    2013-01-01

    This exploratory study examined patterns of nonverbal accommodation within healthcare interactions and investigated the impact of communication skills training and gender concordance on nonverbal accommodation behavior. The Nonverbal Accommodation Analysis System (NAAS) was used to code the nonverbal behavior of physicians and patients within 45 oncology consultations. Cases were then placed in one of seven categories based on patterns of accommodation observed across the interaction. Results...

  14. Co-processing of agricultural plastic waste and switchgrass via tail gas reactive pyrolysis

    Science.gov (United States)

    Mixtures of agricultural plastic waste in the form of polyethylene hay bale covers (PE) (4-37%) and switchgrass were investigated using the US Department of Agriculture’s tail gas reactive pyrolysis (TGRP) at different temperatures (400-570 deg C). TGRP of switchgrass and plastic mixtures significan...

  15. From perceptual to lexico-semantic analysis--cortical plasticity enabling new levels of processing.

    Science.gov (United States)

    Schlaffke, Lara; Rüther, Naima N; Heba, Stefanie; Haag, Lauren M; Schultz, Thomas; Rosengarth, Katharina; Tegenthoff, Martin; Bellebaum, Christian; Schmidt-Wilcke, Tobias

    2015-11-01

    Certain kinds of stimuli can be processed on multiple levels. While the neural correlates of different levels of processing (LOPs) have been investigated to some extent, most of the studies involve skills and/or knowledge already present when performing the task. In this study we specifically sought to identify neural correlates of an evolving skill that allows the transition from perceptual to a lexico-semantic stimulus analysis. Eighteen participants were trained to decode 12 letters of Morse code that were presented acoustically inside and outside of the scanner environment. Morse code was presented in trains of three letters while brain activity was assessed with fMRI. Participants either attended to the stimulus length (perceptual analysis), or evaluated its meaning distinguishing words from nonwords (lexico-semantic analysis). Perceptual and lexico-semantic analyses shared a mutual network comprising the left premotor cortex, the supplementary motor area (SMA) and the inferior parietal lobule (IPL). Perceptual analysis was associated with a strong brain activation in the SMA and the superior temporal gyrus bilaterally (STG), which remained unaltered from pre and post training. In the lexico-semantic analysis post learning, study participants showed additional activation in the left inferior frontal cortex (IFC) and in the left occipitotemporal cortex (OTC), regions known to be critically involved in lexical processing. Our data provide evidence for cortical plasticity evolving with a learning process enabling the transition from perceptual to lexico-semantic stimulus analysis. Importantly, the activation pattern remains task-related LOP and is thus the result of a decision process as to which LOP to engage in. © 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.

  16. Accommodating ‘design’

    DEFF Research Database (Denmark)

    Karpova, Yulia

    2013-01-01

    This article investigates the background of Soviet industrial design in Soviet art theory. Instead of considering design's interconnection with technology and science, or with consumption and everyday life, the author traces its conceptualisation as a new artistic phenomenon. Using archival records...... of professional discussions, polemical articles in the art press and design projects, the author looks at how industrial design was incorporated into the Soviet order of things. She concludes that accommodation of the Western model was the way to reform the system of socialism from inside, typical for the Soviet...

  17. [Spasm of accommodation].

    Science.gov (United States)

    Lindberg, Laura

    2014-01-01

    Spasm of accommodation refers to prolonged contraction of the ciliary muscle, most commonly causing pseudomyopia to varying degrees in both eyes by keeping the lens in a state of short sightedness. It may also be manifested as inability to allow the adaptation spasticity prevailing in the ciliary muscle relax without measurable myopia. As a rule, this is a functional ailment triggered by prolonged near work and stress. The most common symptoms include blurring of distance vision, varying visual acuity as well as pains in the orbital region and the head, progressing into a chronic state. Cycloplegic eye drops are used as the treatment.

  18. Texture Evolution in a Ti-Ta-Nb Alloy Processed by Severe Plastic Deformation

    Science.gov (United States)

    Cojocaru, Vasile-Danut; Raducanu, Doina; Gloriant, Thierry; Cinca, Ion

    2012-05-01

    Titanium alloys are extensively used in a variety of applications because of their good mechanical properties, high biocompatibility, and corrosion resistance. Recently, β-type Ti alloys containing Ta and Nb have received much attention because they feature not only high specific strength but also biocorrosion resistance, no allergic problems, and biocompatibility. A Ti-25Ta-25Nb β-type titanium alloy was subjected to severe plastic deformation (SPD) processing by accumulative roll bonding and investigated with the aim to observe the texture developed during SPD processing. Texture data expressed by pole figures, inverse pole figures, and orientation distribution functions for the (110), (200), and (211) β-Ti peaks were obtained by XRD investigations. The results showed that it is possible to obtain high-intensity share texture modes ({001}) and well-developed α and γ-fibers; the most important fiber is the α-fiber ({001} to {114} to {112} ). High-intensity texture along certain crystallographic directions represents a way to obtain materials with high anisotropic properties.

  19. Mechanisms of nanoclay-enhanced plastic foaming processes: effects of nanoclay intercalation and exfoliation

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Anson; Wijnands, Stephan F. L.; Kuboki, Takashi; Park, Chul B., E-mail: park@mie.utoronto.ca [University of Toronto, Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering (Canada)

    2013-08-15

    The foaming behaviors of high-density polypropylene-nanoclay composites with intercalated and exfoliated nanoclay particles blown with carbon dioxide were examined via in situ observation of the foaming processes in a high-temperature/high-pressure view-cell. The intercalated nanoclay particles were 300-600 nm in length and 50-200 nm in thickness, while the exfoliated nanoclay particles were 100-200 nm in length and 1 nm in thickness. Contrary to common belief, it was discovered that intercalated nanoclay yielded higher cell density than exfoliated nanoclay despite its lower particle density. This was attributed to the higher tensile stresses generated around the larger and stiffer intercalated nanoclay particles, which led to increase in supersaturation level for cell nucleation. Also, the coupling agent used to exfoliate nanoclay would increase the affinity between polymer and surface of nanoclay particles. Consequently, the critical work needed for cell nucleation would be increased; pre-existing microvoids, which could act as seeds for cell nucleation, were also less likely to exist. Meanwhile, exfoliated nanoclay had better cell stabilization ability to prevent cell coalescence and cell coarsening. This investigation clarifies the roles of nanoclay in plastic foaming processes and provides guidance for the advancement of polymer nanocomposite foaming technology.

  20. Dislocations and elementary processes of plasticity in FCC metals: atomic scale simulations

    International Nuclear Information System (INIS)

    Rodney, D.

    2000-01-01

    We present atomic-scale simulations of two elementary processes of FCC crystal plasticity. The first study consists in the simulation by molecular dynamics, in a nickel crystal, of the interactions between an edge dislocation and glissile interstitial loops of the type that form under irradiation in displacement cascades. The simulations show various atomic-scale interaction processes leading to the absorption and drag of the loops by the dislocation. These reactions certainly contribute to the formation of the 'clear bands' observed in deformed irradiated materials. The simulations also allow to study quantitatively the role of the glissile loops in irradiation hardening. In particular, dislocation unpinning stresses for certain pinning mechanisms are evaluated from the simulations. The second study consists first in the generalization in three dimensions of the quasi-continuum method (QCM), a multi-scale simulation method which couples atomistic techniques and the finite element method. In the QCM, regions close to dislocation cores are simulated at the atomic-scale while the rest of the crystal is simulated with a lower resolution by means of a discretization of the displacement fields using the finite element method. The QCM is then tested on the simulation of the formation and breaking of dislocation junctions in an aluminum crystal. Comparison of the simulations with an elastic model of dislocation junctions shows that the structure and strength of the junctions are dominated by elastic line tension effects, as is assumed in classical theories. (author)

  1. 2.45 GHz Microwave Processing and Its Influence on Glass Fiber Reinforced Plastics

    Science.gov (United States)

    Zaremba, Swen

    2018-01-01

    During the production of fiber-reinforced composite materials, liquid resin is introduced into the fiber material and cured, i.e., hardened. An elevated temperature is needed for this curing. Microwave curing of composites has been investigated for some time, but it has mostly been done using small domestic or laboratory equipment. However, no investigation has been carried out using an industrial-sized chamber-microwave for glass fiber-reinforced plastic (GFRP). Here, we show that microwave curing produces laminates of the same quality as oven-cured ones. The study shows that, if the process is done right, GFRP samples can be produced with an industrial scale microwave. Even if not fully cured, microwave samples show a glass transition temperature measured with DMA (Tg-DMA) that is comparable to the Tg-DMA according to the proposed cure cycle on the data sheet. Specific microwave-cured configurations show better inter-laminar shear strength than oven specimens. The results show that microwave-based heat introduction can be a beneficial curing method for GFRP laminates. A microwave-optimized process is faster and leads to better mechanical properties. PMID:29783684

  2. Development of Process for Disposal of Plastic Waste Using Plasma Pyrolysis Technology and Option for Energy Recovery

    Czech Academy of Sciences Publication Activity Database

    Punčochář, Miroslav; Ruj, B.; Chatterj, P.K.

    2012-01-01

    Roč. 42, SI (2012), s. 420-430 E-ISSN 1877-7058. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague, 25.08.2012-29.08.2012] Institutional support: RVO:67985858 Keywords : plastic waste * plasma pyrolysis * syngas Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  3. Sustainable Catalytic Process for Synthesis of Triethyl Citrate Plasticizer over Phosphonated USY Zeolite

    Directory of Open Access Journals (Sweden)

    Kakasaheb Y. Nandiwaleand

    2016-10-01

    Full Text Available Fruits wastage is harmful to health and environment concerning spreading diseases and soil pollution, respectively. To avoid this issue, use of citrus fruit waste for the production of citric acid (CA is one of viable mean to obtain value added chemicals. Moreover, synthesis of triethyl citrate (TEC, a non-toxic plasticizer by esterification of CA with ethanol over heterogeneous catalyst would be renewable and sustainable catalytic process. In this context, parent Ultrastable Y (USY and different percentage phosphonated USY (P-USY zeolites were used for the synthesis of TEC in a closed batch reactor, for the first time. The synthesized catalysts were characterized by N2-adsorption desorption isotherm, powder X-ray diffraction (XRD and NH3 temperature programmed desorption (TPD. Effect of reaction conditions, such as the molar ratio of ethanol to CA (5:1 - 20:1, the catalyst to CA ratio (0.05 - 0.25 and reaction temperature (363-403 K, were studied in view to maximizing CA conversion and TEC yield. Phosphonated USY catalysts were found to be superior in activity (CA conversion and TEC yield than parent USY, which is attributed to the increased in total acidity with phosphonation. Among the studied catalysts, the P2USY (2% phosphorous loaded on USY was found to be an optimum catalyst with 99% CA conversion and 82% TEC yield, which is higher than the reported values. This study opens new avenues of research demonstrating principles of green chemistry such as easy separable and reusable catalyst, non-toxic product, bio-renewable synthetic route, milder operating parameters and waste minimization. Copyright © 2016 BCREC GROUP. All rights reserved Received: 12nd October 2015; Revised: 22nd December 2015; Accepted: 29th January 2016 How to Cite: Nandiwale, K.Y., Bokade, V.V. (2016. Sustainable Catalytic Process for Synthesis of Triethyl Citrate Plasticizer over Phosphonated USY Zeolite. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (3: 292

  4. Plastic deformation, residual stress, and crystalline texture measurements for in-process characterization of FCC metal alloys

    International Nuclear Information System (INIS)

    Ruud, C.O.; Jacobs, M.E.; Weedman, S.D.; Snoha, D.J.

    1989-01-01

    This paper describes the results of several on-going investigations on the measurement of plastic deformation, residual stress, and crystalline texture in nickel, copper, and aluminum base alloys by x-ray diffraction techniques. X-ray diffraction techniques have been shown to be effective in the measurement of plastic deformation, residual stress, and crystalline texture in FCC metals, from the breadth, position, and intensity of the x-ray diffraction peaks. The Ruud-Barrett position-sensitive scintillation detector has been demonstrated to be fast, non-contacting, and tolerant of detector to component distance variation -- necessary requirements for cost-effective in-process inspection of materials

  5. An analytical hierarchy process-based study on the factors affecting legislation on plastic bags in the USA.

    Science.gov (United States)

    Li, Zhongguo; Zhao, Fu

    2017-08-01

    Annually, a large number of used plastic shopping bags are released into the environment, posing significant threats to public health and wildlife. Owing to these concerns, many local, regional, and national governments around the world have passed legislation to ban or restrict the use of plastic shopping bags. However, in the USA there are only 18 states that have approved plastic bag bans/fees, and even within these states these regulations do not cover all cities or counties. There are many factors that could affect the development and implementation of these regulations. This article employs an analytical hierarchy process to analyse the factors that could impact the enactment of plastic bag regulations. Five impact factors are identified based on statistical data, that is, geographical location, interest of industry achievable, cost of living, level of economic development, and educational level of population. The weights of the five impact factors are determined and it is found that the possibility of banning or restricting plastic bags in general follows a certain pattern among all states.

  6. Ultra-low temperature process by ion shower doping technique for poly-Si TFTs on plastics

    International Nuclear Information System (INIS)

    Kim, Jong-Man; Lim, Huck; Kim, Do-Young; Jung, Ji-Sim; Kwon, Jang-Yeon; Hong, Wan-Shick; Noguchi, Takashi

    2006-01-01

    An ion doping process was performed by using a basic ion shower system. After ion doping and subsequent activation of the dopants in the Si film by excimer laser annealing (ELA), we studied the crystallinity of the Si surface using UV-reflectance spectroscopy and the sheet resistance by using 4-point probe measurements. To prevent excessive temperature increase on the plastic substrate during ion shower doping, the plasma shower was applied in a series of short pulses. As a result, dopant ions were efficiently incorporated and were activated into the a-Si film on plastic substrate after ELA. The sheet resistance decreased with increase of actual doping time, which corresponds to the incorporated dose. Also, we confirmed a distinct relationship between the crystallinity and the sheet resistance. This work shows that pulsed ion shower doping is a promising technique for ultra-low-temperature poly-Si TFTs on plastic substrates.

  7. Toolpath Strategy and Optimum Combination of Machining Parameter during Pocket Mill Process of Plastic Mold Steels Material

    Science.gov (United States)

    Wibowo, Y. T.; Baskoro, S. Y.; Manurung, V. A. T.

    2018-02-01

    Plastic based products spread all over the world in many aspects of life. The ability to substitute other materials is getting stronger and wider. The use of plastic materials increases and become unavoidable. Plastic based mass production requires injection process as well Mold. The milling process of plastic mold steel material was done using HSS End Mill cutting tool that is widely used in a small and medium enterprise for the reason of its ability to be re sharpened and relatively inexpensive. Study on the effect of the geometry tool states that it has an important effect on the quality improvement. Cutting speed, feed rate, depth of cut and radii are input parameters beside to the tool path strategy. This paper aims to investigate input parameter and cutting tools behaviors within some different tool path strategy. For the reason of experiments efficiency Taguchi method and ANOVA were used. Response studied is surface roughness and cutting behaviors. By achieving the expected quality, no more additional process is required. Finally, the optimal combination of machining parameters will deliver the expected roughness and of course totally reduced cutting time. However actually, SMEs do not optimally use this data for cost reduction.

  8. The analysis of quantitative methods for renewable fuel processes and lubricant of materials derived from plastic waste

    Science.gov (United States)

    Rajagukguk, J. R.

    2018-01-01

    Plastic has become an important component in modern life today. Its role has replaced wood and metal, given its advantages such as light and strong, corrosion resistant, transparent and easy to color and good insulation properties. The research method is used with quantitative and engineering research methods. Research objective is to convert plastic waste into something more economical and to preserve the environment surrounding. Renewable fuel and lubricant variables are simultaneously influenced significantly to the sustainable environment. This is based on Fh> Ft of 62.101> 4.737) and its significance is 0.000 sustainable, the value of correlation coefficient 0.941 or 94.1% which means there is a very strong relationship between renewable fuel variables and lubricants to the sustainable environment. And utilizing plastic waste after being processed by pyrolysis method produces liquid hydrocarbons having elements of compounds such as crude oil and renewable fuels obtained from calculations are CO2 + H2O + C1-C4 + Residual substances. Then the plastic waste can be processed by isomerization process + catalyst to lubricating oil and the result of chemical calculation obtained is CO2, H2O, C18H21 and the rest.

  9. LIMITED RUN PRODUCTION USING ALUMIDE® TOOLING FOR THE PLASTIC INJECTION MOULDING PROCESS#1

    Directory of Open Access Journals (Sweden)

    J. Combrinck

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Existing techniques for the production of conventional steel tooling for plastic injection moulding are expensive and time-consuming. As a result, many new products often do not advance beyond the prototype stage. This paper describes an investigation into the possibility of using laser sintered Alumide® (an aluminium-filled nylon material in a novel alternative process for producing hybrid rapid tooling tools. Initial experiments performed by researchers at the Central University of Technology have shown excellent results. An Alumide® tool can be manufactured in a shorter time and at a significantly lower cost than the same size direct metal laser sintered tool.

    AFRIKAANSE OPSOMMING: Bestaande tegnieke vir die vervaardiging van konvensionele staal gietstukke vir die plastiek spuit-giet proses is duur en tydrowend. Die gevolg hiervan is dat baie nuwe produkte nie verder as die prototipe stadium vorder nie. Hierdie artikel ondersoek die moontlikheid om laser gesinterde Alumide® (aluminium gevulde nylon materiaal in ’n nuwe benadering as ’n alternatiewe proses vir die vervaardiging van snel hibried-gietvorms te gebruik. Aanvanklike eksperimente uitgevoer deur navorsers aan die Sentrale Universiteit vir Tegnologie het uitstekende resultate gelewer. ’n Alumide® gietvorm kan vinniger en goedkoper vervaardig word as dieselfde grootte direk metaal gesinterde gietvorm.

  10. Emission factors of polybrominated diphenyl ethers (PBDEs) from plastics processing and recycling facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Shin-ichi; Hirai, Yasuhiro [National Institute for Environmental Studies, Tsukuba (Japan); Ota, Shizuko; Sudo, Kinichi [Ministry of Environment (Japan)

    2004-09-15

    With regard to polybrominated diphenyl ether (PBDE), there is few scientific knowledge on the emission patterns into the environment and exposure pathways to humans, and basic information is insufficient to consider what measures effective are. For the purpose of promoting risk reduction of target substances more effectively and efficiently, it is desirable to comprehend accurately the causal chain from the target substances utilization to the risk intake, and to evaluate the measures covering the whole applications of target substances. As the existing researches on the PBDE emission inventory, there are EU risk assessment report (European Chemical Bureau 2000, 2002, 2003), Danish EPA (1999), Palm et al.(2002) and Alcock et al. (2003). In addition, emissions of DecaBDE are published in TRI (Toxic Release Inventory) of US EPA. However, the primary information of the previous inventories is often the same and estimations based on the measured values are few. In light of the situation, PBDE emission concentrations from processing facilities of flame retardant plastics and recycling facilities of home electric appliances are measured in practice to presume material flow of PBDE and to estimate emission factors and inventories from each phase of life cycles. The validities of emission factors are examined in comparison to measured values of atmospheric depositions surroundings, which are close to sources.

  11. Gradient plasticity for thermo-mechanical processes in metals with length and time scales

    Science.gov (United States)

    Voyiadjis, George Z.; Faghihi, Danial

    2013-03-01

    A thermodynamically consistent framework is developed in order to characterize the mechanical and thermal behavior of metals in small volume and on the fast transient time. In this regard, an enhanced gradient plasticity theory is coupled with the application of a micromorphic approach to the temperature variable. A physically based yield function based on the concept of thermal activation energy and the dislocation interaction mechanisms including nonlinear hardening is taken into consideration in the derivation. The effect of the material microstructural interface between two materials is also incorporated in the formulation with both temperature and rate effects. In order to accurately address the strengthening and hardening mechanisms, the theory is developed based on the decomposition of the mechanical state variables into energetic and dissipative counterparts which endowed the constitutive equations to have both energetic and dissipative gradient length scales for the bulk material and the interface. Moreover, the microstructural interaction effect in the fast transient process is addressed by incorporating two time scales into the microscopic heat equation. The numerical example of thin film on elastic substrate or a single phase bicrystal under uniform tension is addressed here. The effects of individual counterparts of the framework on the thermal and mechanical responses are investigated. The model is also compared with experimental results.

  12. Processing and characterization of 3D dense chitosan pieces, for orthopedic applications, by adding plasticizers

    OpenAIRE

    Figueiredo, Lígia; Moura, Carla; Pinto, Luís F. V.; Ferreira, Frederico Castelo; Rodrigues, Alexandra

    2015-01-01

    In this work, plasticizer agents were incorporated in a chitosan based formulation, as a strategy to improve the fragile structure of chitosan based-materials. Three different plasticizers: ethylene glycol, glycerol and sorbitol, were blended with chitosan to prepare 3D dense chitosan specimens. The properties of the obtained structures were assessed for mechanical, microstructural, physical and biocompatibility behavior. The results obtained revealed that from the different specimens prepare...

  13. Processing real-world waste plastics by pyrolysis-reforming for hydrogen and high-value carbon nanotubes.

    Science.gov (United States)

    Wu, Chunfei; Nahil, Mohamad A; Miskolczi, Norbert; Huang, Jun; Williams, Paul T

    2014-01-01

    Producing both hydrogen and high-value carbon nanotubes (CNTs) derived from waste plastics is reported here using a pyrolysis-reforming technology comprising a two-stage reaction system, in the presence of steam and a Ni-Mn-Al catalyst. The waste plastics consisted of plastics from a motor oil container (MOC), commercial waste high density polyethylene (HDPE) and regranulated HDPE waste containing polyvinyl chloride (PVC). The results show that hydrogen can be produced from the pyrolysis-reforming process, but also carbon nanotubes are formed on the catalyst. However, the content of 0.3 wt.% polyvinyl chloride in the waste HDPE (HDPE/PVC) has been shown to poison the catalyst and significantly reduce the quantity and purity of CNTs. The presence of sulfur has shown less influence on the production of CNTs in terms of quantity and CNT morphologies. Around 94.4 mmol H2 g(-1) plastic was obtained for the pyrolysis-reforming of HDPE waste in the presence of the Ni-Mn-Al catalyst and steam at a reforming temperature of 800 °C. The addition of steam in the process results in an increase of hydrogen production and reduction of carbon yield; in addition, the defects of CNTs, for example, edge dislocations were found to be increased with the introduction of steam (from Raman analysis).

  14. A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation.

    Science.gov (United States)

    Wang, Chong-Qing; Wang, Hui; Huang, Luo-Luo

    2017-07-01

    A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO 4 ) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO 4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO 4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO 4 concentration 2mmolL -1 , treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL -1 . Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO 4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO 4 solution is feasible, enabling the process greener. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Polystyrene Plastic Waste Conversion into Liquid Fuel with Catalytic Cracking Process Using Al2O3 as Catalyst

    Directory of Open Access Journals (Sweden)

    Nurul Kholidah

    2018-01-01

    Full Text Available The increase in energy consumption and an increase in the plastic waste generation are two major problems that arise along with economic growth and the increase in population. Styrofoam is one type of polystyrene plastic waste that can be processed into liquid fuels by cracking process. In this study, the cracking process of polystyrene plastic waste into liquid fuel carried by the catalytic cracking process using Al2O3 as a catalyst. This study aimed to determine the effect of the catalyst weight, length of cracking time and range of temperature in the catalytic cracking process of polystyrene plastic waste into liquid fuel toward the mass and characteristics of liquid fuels produced and to determine the composition of liquid fuels produced. The catalytic cracking process of polystyrene plastic waste with catalyst was done in the fixed bed type reactor by heating the reactor with a heater, where the process took place at temperature of 150°C, 200°C, 250°C and 300°C and the length of the process was varied into 20, 40, and 60 minutes and the catalyst weight was also varied, which were 4%, 6% and 8%, while the styrofoam weight was 250 grams. From the research, the highest mass of liquid fuel derived from polystyrene catalytic cracking process was in the amount of 48.8 grams and liquid yield percentage of 19.5% at temperature of  250°C, cracking time of 60 minutes and weight of 8% catalyst, while the characteristics of liquid fuel that were approaching the characteristics of gasoline was at temperatures of 250°C, cracking time of 60 minutes and weight of 6% catalyst, in which each value of density of 0.763 g/ml, specific gravity of 0.778 and oAPI gravity of 50.2. While other liquid fuels obtained from the cracking of polystyrene were still within the tolerance range characteristic properties of gasoline. Liquid fuels produced from the catalytic cracking process was analyzed using a GC-MS, in which the analysis results indicated that liquid

  16. Retinal image quality during accommodation.

    Science.gov (United States)

    López-Gil, Norberto; Martin, Jesson; Liu, Tao; Bradley, Arthur; Díaz-Muñoz, David; Thibos, Larry N

    2013-07-01

    We asked if retinal image quality is maximum during accommodation, or sub-optimal due to accommodative error, when subjects perform an acuity task. Subjects viewed a monochromatic (552 nm), high-contrast letter target placed at various viewing distances. Wavefront aberrations of the accommodating eye were measured near the endpoint of an acuity staircase paradigm. Refractive state, defined as the optimum target vergence for maximising retinal image quality, was computed by through-focus wavefront analysis to find the power of the virtual correcting lens that maximizes visual Strehl ratio. Despite changes in ocular aberrations and pupil size during binocular viewing, retinal image quality and visual acuity typically remain high for all target vergences. When accommodative errors lead to sub-optimal retinal image quality, acuity and measured image quality both decline. However, the effect of accommodation errors of on visual acuity are mitigated by pupillary constriction associated with accommodation and binocular convergence and also to binocular summation of dissimilar retinal image blur. Under monocular viewing conditions some subjects displayed significant accommodative lag that reduced visual performance, an effect that was exacerbated by pharmacological dilation of the pupil. Spurious measurement of accommodative error can be avoided when the image quality metric used to determine refractive state is compatible with the focusing criteria used by the visual system to control accommodation. Real focusing errors of the accommodating eye do not necessarily produce a reliably measurable loss of image quality or clinically significant loss of visual performance, probably because of increased depth-of-focus due to pupil constriction. When retinal image quality is close to maximum achievable (given the eye's higher-order aberrations), acuity is also near maximum. A combination of accommodative lag, reduced image quality, and reduced visual function may be a useful

  17. From plastic to gold: a unified classification scheme for reference standards in medical image processing

    Science.gov (United States)

    Lehmann, Thomas M.

    2002-05-01

    Reliable evaluation of medical image processing is of major importance for routine applications. Nonetheless, evaluation is often omitted or methodically defective when novel approaches or algorithms are introduced. Adopted from medical diagnosis, we define the following criteria to classify reference standards: 1. Reliance, if the generation or capturing of test images for evaluation follows an exactly determined and reproducible protocol. 2. Equivalence, if the image material or relationships considered within an algorithmic reference standard equal real-life data with respect to structure, noise, or other parameters of importance. 3. Independence, if any reference standard relies on a different procedure than that to be evaluated, or on other images or image modalities than that used routinely. This criterion bans the simultaneous use of one image for both, training and test phase. 4. Relevance, if the algorithm to be evaluated is self-reproducible. If random parameters or optimization strategies are applied, reliability of the algorithm must be shown before the reference standard is applied for evaluation. 5. Significance, if the number of reference standard images that are used for evaluation is sufficient large to enable statistically founded analysis. We demand that a true gold standard must satisfy the Criteria 1 to 3. Any standard only satisfying two criteria, i.e., Criterion 1 and Criterion 2 or Criterion 1 and Criterion 3, is referred to as silver standard. Other standards are termed to be from plastic. Before exhaustive evaluation based on gold or silver standards is performed, its relevance must be shown (Criterion 4) and sufficient tests must be carried out to found statistical analysis (Criterion 5). In this paper, examples are given for each class of reference standards.

  18. EBooks and Accommodations: Is This the Future of Print Accommodation?

    Science.gov (United States)

    Cavanaugh, Terence

    2002-01-01

    This article explains the three components of eBooks: an eBook file, software to read the eBook, and a hardware device to read it on. The use of eBooks for students with special needs, the advantages of eBooks, built in accommodations, and creating accommodations are discussed. EBook resources are included. (Contains references.) (CR)

  19. Ex-situ bioremediation of Brazilian soil contaminated with plasticizers process wastes

    Directory of Open Access Journals (Sweden)

    I. D. Ferreira

    2012-03-01

    Full Text Available The aim of this research was to evaluate the bioremediation of a soil contaminated with wastes from a plasticizers industry, located in São Paulo, Brazil. A 100-kg soil sample containing alcohols, adipates and phthalates was treated in an aerobic slurry-phase reactor using indigenous and acclimated microorganisms from the sludge of a wastewater treatment plant of the plasticizers industry (11gVSS kg-1 dry soil, during 120 days. The soil pH and temperature were not corrected during bioremediation; soil humidity was corrected weekly to maintain 40%. The biodegradation of the pollutants followed first-order kinetics; the removal efficiencies were above 61% and, among the analyzed plasticizers, adipate was removed to below the detection limit. Biological molecular analysis during bioremediation revealed a significant change in the dominant populations initially present in the reactor.

  20. Hormones and phenotypic plasticity in an ecological context: linking physiological mechanisms to evolutionary processes.

    Science.gov (United States)

    Lema, Sean C

    2014-11-01

    Hormones are chemical signaling molecules that regulate patterns of cellular physiology and gene expression underlying phenotypic traits. Hormone-signaling pathways respond to an organism's external environment to mediate developmental stage-specific malleability in phenotypes, so that environmental variation experienced at different stages of development has distinct effects on an organism's phenotype. Studies of hormone-signaling are therefore playing a central role in efforts to understand how plastic phenotypic responses to environmental variation are generated during development. But, how do adaptive, hormonally mediated phenotypes evolve if the individual signaling components (hormones, conversion enzymes, membrane transporters, and receptors) that comprise any hormone-signaling pathway show expressional flexibility in response to environmental variation? What relevance do these components hold as molecular targets for selection to couple or decouple correlated hormonally mediated traits? This article explores how studying the endocrine underpinnings of phenotypic plasticity in an ecologically relevant context can provide insights into these, and other, crucial questions into the role of phenotypic plasticity in evolution, including how plasticity itself evolves. These issues are discussed in the light of investigations into how thyroid hormones mediate morphological plasticity in Death Valley's clade of pupfishes (Cyprinodon spp.). Findings from this work with pupfish illustrate that the study of hormone-signaling from an ecological perspective can reveal how phenotypic plasticity contributes to the generation of phenotypic novelty, as well as how physiological mechanisms developmentally link an organism's phenotype to its environmental experiences. © 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.

  1. Simulation by Slepian method of plastic displacements of Gaussian process excited multistory shear frame

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Ditlevsen, Ove Dalager

    2004-01-01

    The object of study is a stationary Gaussian white noise excited multi-degree-of-freedom (MDOF) linear elastic, ideal plastic, linearly damped, statically determinate oscillator with several potential elements of ideal plastic yielding. Specifically the study is exemplified for a plane multistory...... shear frame with rigid traverses where all the connecting columns except the columns in one or more of the bottom floors have finite symmetrical yield limits. The white noise excitation acts on the mass of the first floor making the movement of the elastic bottom floors simulate a ground motion...

  2. Nanoscale lamellae in an oxide dispersion strengthened steel processed by dynamic plastic deformation

    DEFF Research Database (Denmark)

    Zhang, Zhenbo; Mishin, Oleg; Tao, N. R.

    2014-01-01

    The microstructure of an oxide dispersion strengthened ferritic PM2000 steel with a strong initial (100) texture has been investigated after compression by dynamic plastic deformation (DPD) at room temperature to a strain of 2.1. Measurements using electron backscatter diffraction and transmission...

  3. Developments in Processing by Severe Plastic Deformation at the 3rd Pan American Materials Congress

    Science.gov (United States)

    Figueiredo, Roberto B.; Kawasaki, Megumi; Langdon, Terence G.

    2017-10-01

    The 3rd Pan American Materials Congress in San Diego, California, February 26-March 2, 2017, provided an opportunity to bring together many participants working in the field of severe plastic deformation. This article provides a brief review of these activities.

  4. [Monochromatic aberration in accommodation. Dynamic wavefront analysis].

    Science.gov (United States)

    Fritzsch, M; Dawczynski, J; Jurkutat, S; Vollandt, R; Strobel, J

    2011-06-01

    Monochromatic aberrations may influence the visual acuity of the eye. They are not stable and can be affected by different factors. The subject of the following paper is the dynamic investigation of the changes in wavefront aberration with accommodation. Dynamic measurement of higher and lower order aberrations was performed with a WASCA Wavefront Analyzer (Carl-Zeiss-Meditec) and a specially constructed target device for aligning objects in far and near distances on 25 subjects aged from 15 to 27 years old. Wavefront aberrations showed some significant changes in accommodation. In addition to the characteristic sphere reaction accompanying miosis and changes in horizontal prism (Z(1) (1)) in the sense of a convergence movement of the eyeball also occurred. Furthermore defocus rose (Z(2) (0)) and astigmatism (Z(2) (-2)) changed. In higher-order aberrations a decrease in coma-like Zernike polynomials (Z(3) (-1), Z(3) (1)) was found. The most obvious change appeared in spherical aberration (Z(4) (0)) which increased and changed from positive to negative. In addition the secondary astigmatism (Z(4) (-2)) and quadrafoil (Z(4) (4)) rise also increased. The total root mean square (RMS), as well as the higher-order aberrations (RMS-HO) significantly increased in accommodation which is associated with a theoretical reduction of visual acuity. An analysis of the influence of pupil size on aberrations showed significant increases in defocus, spherical aberration, quadrafoil, RMS and RMS HO by increasing pupil diameter. By accommodation-associated miosis, the growing aberrations are partially compensated by focusing on near objects. Temporal analysis of the accommodation process with dynamic wavefront analysis revealed significant delays in pupil response and changing of prism in relation to the sphere reaction. In accommodation to near objects a discrete time ahead of third order aberrations in relation to the sphere response was found. Using dynamic wavefront measurement

  5. EBSD-based techniques for characterization of microstructural restoration processes during annealing of metals deformed to large plastic strains

    DEFF Research Database (Denmark)

    Godfrey, A.; Mishin, Oleg; Yu, Tianbo

    2012-01-01

    Some methods for quantitative characterization of the microstructures deformed to large plastic strains both before and after annealing are discussed and illustrated using examples of samples after equal channel angular extrusion and cold-rolling. It is emphasized that the microstructures...... in such deformed samples exhibit a heterogeneity in the microstructural refinement by high angle boundaries. Based on this, a new parameter describing the fraction of regions containing predominantly low angle boundaries is introduced. This parameter has some advantages over the simpler high angle boundary...... on mode of the distribution of dislocation cell sizes is outlined, and it is demonstrated how this parameter can be used to investigate the uniformity, or otherwise, of the restoration processes occurring during annealing of metals deformed to large plastic strains. © (2012) Trans Tech Publications...

  6. Experimental investigations of pupil accommodation factors.

    Science.gov (United States)

    Lee, Eui Chul; Lee, Ji Woo; Park, Kang Ryoung

    2011-08-17

    PURPOSE. The contraction and dilation of the iris muscle that controls the amount of light entering the retina causes pupil accommodation. In this study, experiments were performed and two of the three factors that influence pupil accommodation were analyzed: lighting conditions and depth fixations. The psychological benefits were not examined, because they could not be quantified. METHODS. A head-wearable eyeglasses-based, eye-capturing device was designed to measure pupil size. It included a near-infrared (NIR) camera and an NIR light-emitting diode. Twenty-four subjects watched two-dimensional (2D) and three-dimensional (3D) stereoscopic videos of the same content, and the changes in pupil size were measured by using the eye-capturing device and image-processing methods: RESULTS. The pupil size changed with the intensity of the videos and the disparities between the left and right images of a 3D stereoscopic video. There was correlation between the pupil size and average intensity. The pupil diameter could be estimated as being contracted from approximately 5.96 to 4.25 mm as the intensity varied from 0 to 255. Further, from the changes in the depth fixation for the pupil accommodation, it was confirmed that the depth fixation also affected accommodation of pupil size. CONCLUSIONS. It was confirmed that the lighting condition was an even more significant factor in pupil accommodation than was depth fixation (significance ratio: approximately 3.2:1) when watching 3D stereoscopic video. Pupil accommodation was more affected by depth fixation in the real world than was the binocular convergence in the 3D stereoscopic display.

  7. Differences in the Stimulus Accommodative Convergence/Accommodation Ratio using Various Techniques and Accommodative Stimuli.

    Science.gov (United States)

    Satou, Tsukasa; Ito, Misae; Shinomiya, Yuma; Takahashi, Yoshiaki; Hara, Naoto; Niida, Takahiro

    2018-04-04

    To investigate differences in the stimulus accommodative convergence/accommodation (AC/A) ratio using various techniques and accommodative stimuli, and to describe a method for determining the stimulus AC/A ratio. A total of 81 subjects with a mean age of 21 years (range, 20-23 years) were enrolled. The relationship between ocular deviation and accommodation was assessed using two methods. Ocular deviation was measured by varying the accommodative requirement using spherical plus/minus lenses to create an accommodative stimulus of 10.00 diopters (D) (in 1.00 D steps). Ocular deviation was assessed using the alternate prism cover test in method 1 at distance (5 m) and near (1/3 m), and the major amblyoscope in method 2. The stimulus AC/A ratios obtained using methods 1 and 2 were calculated and defined as the stimulus AC/A ratios with low and high accommodation, respectively, using the following analysis method. The former was calculated as the difference between the convergence response to an accommodative stimulus of 3 D and 0 D, divided by 3. The latter was calculated as the difference between the convergence response to a maximum (max) accommodative stimulus with distinct vision of the subject and an accommodative stimulus of max minus 3.00 D, divided by 3. The median stimulus AC/A ratio with low accommodation (1.0 Δ/D for method 1 at distance, 2.0 Δ/D for method 1 at near, and 2.7 Δ/D for method 2) differed significantly among the measurement methods (P accommodation (4.0 Δ/D for method 1 at distance, 3.7 Δ/D for method 1 at near, and 4.7 Δ/D for method 2) between method 1 at distance and method 2 were statistically significant (P accommodative stimuli. However, differences caused by measurement technique may be reduced by using a high accommodative stimulus during measurements.

  8. PROFILE OF PLASTIC WATER BOTTLES WASTES PROCESSING BUSINESS UNIT FOR WASTE PICKERS

    Directory of Open Access Journals (Sweden)

    Herijanto P.

    2017-09-01

    Full Text Available Used plastic water bottles waste pickers can be categorized as one of the informal sector’s component. They work for themselves by picking up used water bottles and selling them to the waste collectors. The problem to be solved in this research is How the Most Appropriate Used Plastic Water Bottles Business Model for Waste Pickers Is that enables them to be categorized as formal sector. From the result of the interview with 120 waste pickers, 96 results were qualified to be analyzed. The interview was located in several waste collectors, which were visited by waste pickers at certain hours. The data were analyzed descriptively based on six business aspects. Specifically for production facilities, Quality Function Deployment (QFD and Value Engineering (VE analysis were performed. The results of the analysis indicate that the business is practicable for waste pickers and has the potential to enable them run a formal business sector.

  9. Detection of fast neutrons in a plastic scintillator using digital pulse processing to reject gammas

    International Nuclear Information System (INIS)

    Reeder, P.L.; Peurrung, A.J.; Hansen, R.R.; Stromswold, D.C.; Hensley, W.K.; Hubbard, C.W.

    1999-01-01

    We report on neutron-gamma discrimination in a plastic scintillator based on the time delay inherent in second and third chance neutron scattering. Because of the time delay (∼3 ns) between the first and second scattering of a neutron, calculations of gammas and neutrons in a plastic scintillator predict that a neutron signal should be significantly broader than a pulse from a gamma event. Experimentally, we have used a fast digital oscilloscope coupled to a computer to examine individual pulses from neutron or gamma induced signals in fast scintillators coupled to a fast PMT. Individual neutron-induced signals were consistent with the predictions of our model, but gamma pulses were broader than expected. We present various tests to understand this phenomenon and discuss a way to overcome this problem

  10. Analysis of the influence of plastic deformations in fatigue and crack process by numerical simulation

    International Nuclear Information System (INIS)

    Rahimian, Mohammad.

    1981-06-01

    The aim of this work is to analyze, by numerical simulation the characteristics of the stresses and deformations at the bottom of cracks when plasticity is taken into account. This analysis is performed as from theoretical results laid down in the literature and makes it possible to understand the different solutions obtained from Hencky's deformation law or from the incremental theory. The role of plastic deformation is discussed in depth in the study of fatigue cracks. The problems linked to the fixed crack are studied in the first two chapters. The problems linked to the propagation of cracks are discussed in the following chapters. The fourth chapter is an application of the preceding results and knowledge to fatigue [fr

  11. Plastic condoms.

    Science.gov (United States)

    1968-01-01

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

  12. Streptavidin-conjugated CdSe/ZnS quantum dots impaired synaptic plasticity and spatial memory process

    Energy Technology Data Exchange (ETDEWEB)

    Gao Xiaoyan [Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf (Germany); Tang Mingliang [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China); Li Zhifeng; Zha Yingying [University of Science and Technology of China, CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences (China); Cheng Guosheng [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China); Yin Shuting [Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf (Germany); Chen Jutao; Ruan Diyun; Chen Lin; Wang Ming, E-mail: wming@ustc.edu.cn [University of Science and Technology of China, CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences (China)

    2013-04-15

    Studies reported that quantum dots (QDs), as a novel probe, demonstrated a promising future for in vivo imaging, but also showed potential toxicity. This study is mainly to investigate in vivo response in the central nervous system (CNS) after exposure to QDs in a rat model of synaptic plasticity and spatial memory. Adult rats were exposed to streptavidin-conjugated CdSe/ZnS QDs (Qdots 525, purchased from Molecular Probes Inc.) by intraperitoneal injection for 7 days, followed by behavioral, electrophysiological, and biochemical examinations. The electrophysiological results show that input/output (I/O) functions were increased, while the peak of paired-pulse reaction and long-term potentiation were decreased after QDs insult, indicating synaptic transmission was enhanced and synaptic plasticity in the hippocampus was impaired. Meanwhile, behavioral experiments provide the evidence that QDs could impair rats' spatial memory process. All the results present evidences of interference of synaptic transmission and plasticity in rat hippocampal dentate gyrus area by QDs insult and suggest potential adverse issues which should be considered in QDs applications.

  13. Streptavidin-conjugated CdSe/ZnS quantum dots impaired synaptic plasticity and spatial memory process

    Science.gov (United States)

    Gao, Xiaoyan; Tang, Mingliang; Li, Zhifeng; Zha, Yingying; Cheng, Guosheng; Yin, Shuting; Chen, Jutao; Ruan, Di-yun; Chen, Lin; Wang, Ming

    2013-04-01

    Studies reported that quantum dots (QDs), as a novel probe, demonstrated a promising future for in vivo imaging, but also showed potential toxicity. This study is mainly to investigate in vivo response in the central nervous system (CNS) after exposure to QDs in a rat model of synaptic plasticity and spatial memory. Adult rats were exposed to streptavidin-conjugated CdSe/ZnS QDs (Qdots 525, purchased from Molecular Probes Inc.) by intraperitoneal injection for 7 days, followed by behavioral, electrophysiological, and biochemical examinations. The electrophysiological results show that input/output ( I/ O) functions were increased, while the peak of paired-pulse reaction and long-term potentiation were decreased after QDs insult, indicating synaptic transmission was enhanced and synaptic plasticity in the hippocampus was impaired. Meanwhile, behavioral experiments provide the evidence that QDs could impair rats' spatial memory process. All the results present evidences of interference of synaptic transmission and plasticity in rat hippocampal dentate gyrus area by QDs insult and suggest potential adverse issues which should be considered in QDs applications.

  14. Streptavidin-conjugated CdSe/ZnS quantum dots impaired synaptic plasticity and spatial memory process

    International Nuclear Information System (INIS)

    Gao Xiaoyan; Tang Mingliang; Li Zhifeng; Zha Yingying; Cheng Guosheng; Yin Shuting; Chen Jutao; Ruan Diyun; Chen Lin; Wang Ming

    2013-01-01

    Studies reported that quantum dots (QDs), as a novel probe, demonstrated a promising future for in vivo imaging, but also showed potential toxicity. This study is mainly to investigate in vivo response in the central nervous system (CNS) after exposure to QDs in a rat model of synaptic plasticity and spatial memory. Adult rats were exposed to streptavidin-conjugated CdSe/ZnS QDs (Qdots 525, purchased from Molecular Probes Inc.) by intraperitoneal injection for 7 days, followed by behavioral, electrophysiological, and biochemical examinations. The electrophysiological results show that input/output (I/O) functions were increased, while the peak of paired-pulse reaction and long-term potentiation were decreased after QDs insult, indicating synaptic transmission was enhanced and synaptic plasticity in the hippocampus was impaired. Meanwhile, behavioral experiments provide the evidence that QDs could impair rats’ spatial memory process. All the results present evidences of interference of synaptic transmission and plasticity in rat hippocampal dentate gyrus area by QDs insult and suggest potential adverse issues which should be considered in QDs applications.

  15. 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.

  16. 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.

  17. Use of plastics in blast furnace processes: A contribution to ecologically and economically acceptable recycling of plastic waste; Kunststoffverwertung im Hochofen - ein Beitrag zum oekologischen und oekonomischen Recycling von Altkunststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Janz, J. [Stahlwerke Bremen GmbH (Germany)

    1996-12-31

    The use of plastics in blast furnace processes has a number of advantages. For one thing, existing facilities can be used with only slight reconstruction measures. Next, the blast furnace process does not necessarily require plastics and therefore is independent of the available plastics volume. Further, it has a high utilisation potential. For example, the Bremen blast furnace No. II has only 8 nozzles out of 32 which are suited for plastics, but it can utilize 70,000 t/a, which is more than 13 percent of the total plastics volume collected by DSD. Indepenent eco-balances have shown that there is no better technology on the market at the moment. (orig) [Deutsch] Mit der Kunststoffverwertung im Hochofen steht ein Verfahren zur Verfuegung, das sich gleich in mehrfacher Hinsicht vor der Konkurrenz auszeichnet. Im Gegensatz zu anderen Verwertungen wird eine bereits vorhandene Anlage genutzt, an der lediglich zusatzeinrichtungen benoetigt werden. Gleichzeitig wird abfallpolitische Flexibilitaet dadurch erreicht, dass der Hochofen nicht auf das Reduktionsmittel Kunststoff angewiesen ist. Von wesentlicher Bedeutung ist auch die hohe Verwertungskapazitaet eines Hochofens. Unabhaengige Oekobilanzen und eigene Messungen haben zweifelsfrei gezeigt, dass ein besseres Verfahren zur Zeit nicht auf dem Markt ist. (orig)

  18. Use of plastics in blast furnace processes: A contribution to ecologically and economically acceptable recycling of plastic waste; Kunststoffverwertung im Hochofen - ein Beitrag zum oekologischen und oekonomischen Recycling von Altkunststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Janz, J [Stahlwerke Bremen GmbH (Germany)

    1997-12-31

    The use of plastics in blast furnace processes has a number of advantages. For one thing, existing facilities can be used with only slight reconstruction measures. Next, the blast furnace process does not necessarily require plastics and therefore is independent of the available plastics volume. Further, it has a high utilisation potential. For example, the Bremen blast furnace No. II has only 8 nozzles out of 32 which are suited for plastics, but it can utilize 70,000 t/a, which is more than 13 percent of the total plastics volume collected by DSD. Indepenent eco-balances have shown that there is no better technology on the market at the moment. (orig) [Deutsch] Mit der Kunststoffverwertung im Hochofen steht ein Verfahren zur Verfuegung, das sich gleich in mehrfacher Hinsicht vor der Konkurrenz auszeichnet. Im Gegensatz zu anderen Verwertungen wird eine bereits vorhandene Anlage genutzt, an der lediglich zusatzeinrichtungen benoetigt werden. Gleichzeitig wird abfallpolitische Flexibilitaet dadurch erreicht, dass der Hochofen nicht auf das Reduktionsmittel Kunststoff angewiesen ist. Von wesentlicher Bedeutung ist auch die hohe Verwertungskapazitaet eines Hochofens. Unabhaengige Oekobilanzen und eigene Messungen haben zweifelsfrei gezeigt, dass ein besseres Verfahren zur Zeit nicht auf dem Markt ist. (orig)

  19. Accommodation of Plastic Deformation by Ultrasound-Induced Grain Rotation

    NARCIS (Netherlands)

    Dutta, R.K.; Petrov, R.H.; Hermans, M.J.M.; Richardson, I.M.

    2015-01-01

    Electron backscatter diffraction was used to investigate the softening effect in low-carbon steel [Fe-0.051C-0.002Si-0.224Mn-0.045Al (wt pct)] during tensile deformation with in situ ultrasonic treatment. A bimodal grain size distribution is observed with relatively small equiaxed grains with an

  20. Experimental and numerical analyses of pure copper during ECFE process as a novel severe plastic deformation method

    Directory of Open Access Journals (Sweden)

    M. Ebrahimi

    2014-02-01

    Full Text Available In this paper, a new severe plastic deformation method called equal channel forward extrusion (ECFE process has been proposed and investigated by experimental and numerical approaches on the commercial pure copper billets. The experimental results indicated that the magnitudes of yield strength, ultimate tensile strength and Vickers micro-hardness have been markedly improved from 114 MPa, 204 MPa and 68 HV as the annealed condition to 269 MPa, 285 MPa and 126 HV after the fourth pass of ECFE process, respectively. In addition, scanning electron microscopy observation of the samples showed that the average grain size of the as-received state which is about 22 μm has been reduced to 1.4 μm after the final pass. The numerical investigation suggested that although one pass ECFE process fabricates material with the mean effective strain magnitude of about 1, the level of imposed effective plastic strain gradually diminishes from the circumference to the center of the deformed billet.

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  2. Formosa Plastics Corporation: Plant-Wide Assessment of Texas Plant Identifies Opportunities for Improving Process Efficiency and Reducing Energy Costs

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-01-01

    At Formosa Plastics Corporation's plant in Point Comfort, Texas, a plant-wide assessment team analyzed process energy requirements, reviewed new technologies for applicability, and found ways to improve the plant's energy efficiency. The assessment team identified the energy requirements of each process and compared actual energy consumption with theoretical process requirements. The team estimated that total annual energy savings would be about 115,000 MBtu for natural gas and nearly 14 million kWh for electricity if the plant makes several improvements, which include upgrading the gas compressor impeller, improving the vent blower system, and recovering steam condensate for reuse. Total annual cost savings could be $1.5 million. The U.S. Department of Energy's Industrial Technologies Program cosponsored this assessment.

  3. 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 " ...

  4. Priorities in Accommodating office user preferences : Impact on office users decision to stay or go

    NARCIS (Netherlands)

    Remøy, HT; van der Voordt, Theo

    2014-01-01

    Purpose When current accommodation is unsatisfactory, office organisations consider relocating to new accommodation that optimally facilitates their main processes and supports image and financial yield. However, due to high vacancy levels, public opinion and governmental awareness oppose new office

  5. Accommodating for plant modifications

    International Nuclear Information System (INIS)

    Weirich, P.H.

    1977-01-01

    Modification to a nuclear power plant may have different causes: 1) new instructions by the authorities; 2) changes of the marginal conditions on the construction site; 3) progress in the technological development. - Examples from different plants are supposed to demonstrate how such changes influence the planning or the construction and how they are integrated in the process of preparation. A distinction can be made between modifications before the completion of the submission of the order, during the phase of preparatory planning and during the construction phase. Of great importance are especially modifications made after the beginning of the construction works, since, in general, there is little scope for technical modifications and since consequences for the time schedule are to be expected. (orig.) [de

  6. Expression of Glutamate and GABA during the Process of Rat Retinal Synaptic Plasticity Induced by Acute High Intraocular Pressure

    International Nuclear Information System (INIS)

    Zhou, Lihong; Huang, Jufang; Wang, Hui; Luo, Jia; Zeng, Leping; Xiong, Kun; Chen, Dan

    2013-01-01

    Acute high intraocular pressure (HIOP) can induce plastic changes of retinal synapses during which the expression of the presynaptic marker synaptophysin (SYN) has a distinct spatiotemporal pattern from the inner plexiform layer to the outer plexiform layer. We identified the types of neurotransmitters in the retina that participated in this process and determined the response of these neurotransmitters to HIOP induction. The model of acute HIOP was established by injecting normal saline into the anterior chamber of the rat eye. We found that the number of glutamate-positive cells increased successively from the inner part to the outer part of the retina (from the ganglion cell layer to the inner nuclear layer to the outer nuclear layer) after HIOP, which was similar to the spatiotemporal pattern of SYN expression (internally to externally) following HIOP. However, the distribution and intensity of GABA immunoreactivity in the retina did not change significantly at different survival time post injury and had no direct correlation with SYN expression. Our results suggested that the excitatory neurotransmitter glutamate might participate in the plastic process of retinal synapses following acute HIOP, but no evidence was found for the role of the inhibitory neurotransmitter GABA

  7. 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...

  8. The provision of workplace accommodations following cancer: survivor, provider, and employer perspectives.

    Science.gov (United States)

    Stergiou-Kita, Mary; Pritlove, Cheryl; van Eerd, Dwayne; Holness, Linn D; Kirsh, Bonnie; Duncan, Andrea; Jones, Jennifer

    2016-06-01

    With improvements in screening, diagnosis, and treatment, the number of persons surviving cancer and staying at or returning to work is increasing. While workplace accommodations optimize workers' abilities to participate in the workforce, there has been little in-depth investigation of the types of accommodations reported to have been provided to cancer survivors and the processes relevant to ensuring their successful implementation. We employed an exploratory qualitative method and conducted 40 semi-structured interviews with three groups: (i) cancers survivors (n = 16), (ii) health/vocational service providers (n = 16), and (iii) employer representatives (n = 8) to explore return to work and accommodation processes, successes, and challenges. An inductive thematic analysis approach was used to analyze the data. Four types of accommodations were recommended: (1) graduated return to work plans and flexible scheduling, (2) modification of work duties and performance expectations, (3) retraining and supports at the workplace, and (4) modification of the physical work environment and/or the provision of adaptive aids/technologies. Processes relevant to ensuring effective accommodations included: (1) developing knowledge about accommodations, (2) employer's ability to accommodate, (3) negotiating reasonable accommodations, (4) customizing accommodations, and (5) implementing and monitoring accommodation plans. Accommodation challenges included: (1) survivors' fears requesting accommodations, (2) developing clear and specific accommodations, (3) difficult to accommodate jobs, and (4) workplace challenges, including strained pre-cancer workplace relationships, insufficient/inflexible workplace policies, employer concerns regarding productivity and precedent setting, and limited modified duties. Accommodations need to be customized and clearly linked to survivors' specific job demands, work context, and available workplace supports. Survivors need to feel

  9. Abnormal presynaptic short-term plasticity and information processing in a mouse model of fragile X syndrome.

    Science.gov (United States)

    Deng, Pan-Yue; Sojka, David; Klyachko, Vitaly A

    2011-07-27

    Fragile X syndrome (FXS) is the most common inherited form of intellectual disability and the leading genetic cause of autism. It is associated with the lack of fragile X mental retardation protein (FMRP), a regulator of protein synthesis in axons and dendrites. Studies on FXS have extensively focused on the postsynaptic changes underlying dysfunctions in long-term plasticity. In contrast, the presynaptic mechanisms of FXS have garnered relatively little attention and are poorly understood. Activity-dependent presynaptic processes give rise to several forms of short-term plasticity (STP), which is believed to control some of essential neural functions, including information processing, working memory, and decision making. The extent of STP defects and their contributions to the pathophysiology of FXS remain essentially unknown, however. Here we report marked presynaptic abnormalities at excitatory hippocampal synapses in Fmr1 knock-out (KO) mice leading to defects in STP and information processing. Loss of FMRP led to enhanced responses to high-frequency stimulation. Fmr1 KO mice also exhibited abnormal synaptic processing of natural stimulus trains, specifically excessive enhancement during the high-frequency spike discharges associated with hippocampal place fields. Analysis of individual STP components revealed strongly increased augmentation and reduced short-term depression attributable to loss of FMRP. These changes were associated with exaggerated calcium influx in presynaptic neurons during high-frequency stimulation, enhanced synaptic vesicle recycling, and enlarged readily-releasable and reserved vesicle pools. These data suggest that loss of FMRP causes abnormal STP and information processing, which may represent a novel mechanism contributing to cognitive impairments in FXS.

  10. Accommodation training in foreign workers.

    Science.gov (United States)

    Takada, Masumi; Miyao, Masaru; Matsuura, Yasuyuki; Takada, Hiroki

    2013-01-01

    By relaxing the contracted focus-adjustment muscles around the eyeball, known as the ciliary and extraocular muscles, the degree of pseudomyopia can be reduced. This understanding has led to accommodation training in which a visual target is presented in stereoscopic video clips. However, it has been pointed out that motion sickness can be induced by viewing stereoscopic video clips. In Measurement 1 of the present study, we verified whether the new 3D technology reduced the severity of motion sickness in accordance with stabilometry. We then evaluated the short-term effects of accommodation training using new stereoscopic video clips on foreign workers (11 females) suffering from eye fatigue in Measurement 2. The foreign workers were trained for three days. As a result, visual acuity was statistically improved by continuous accommodation training, which will help promote ciliary muscle stretching.

  11. Accommodating Grief on Twitter: An Analysis of Expressions of Grief Among Gang Involved Youth on Twitter Using Qualitative Analysis and Natural Language Processing

    Science.gov (United States)

    Patton, Desmond Upton; MacBeth, Jamie; Schoenebeck, Sarita; Shear, Katherine; McKeown, Kathleen

    2018-01-01

    There is a dearth of research investigating youths’ experience of grief and mourning after the death of close friends or family. Even less research has explored the question of how youth use social media sites to engage in the grieving process. This study employs qualitative analysis and natural language processing to examine tweets that follow 2 deaths. First, we conducted a close textual read on a sample of tweets by Gakirah Barnes, a gang-involved teenaged girl in Chicago, and members of her Twitter network, over a 19-day period in 2014 during which 2 significant deaths occurred: that of Raason “Lil B” Shaw and Gakirah’s own death. We leverage the grief literature to understand the way Gakirah and her peers express thoughts, feelings, and behaviors at the time of these deaths. We also present and explain the rich and complex style of online communication among gang-involved youth, one that has been overlooked in prior research. Next, we overview the natural language processing output for expressions of loss and grief in our data set based on qualitative findings and present an error analysis on its output for grief. We conclude with a call for interdisciplinary research that analyzes online and offline behaviors to help understand physical and emotional violence and other problematic behaviors prevalent among marginalized communities. PMID:29636619

  12. Entrepreneurial management in small and medium-sized enterprises in Bulgaria (on the example of the plastics processing enterprises

    Directory of Open Access Journals (Sweden)

    Kamelia Narleva

    2018-02-01

    Full Text Available The report examines the relevance of a modern management concept - entrepreneurial management. Guidelines for the application of this management technology to small and medium-sized enterprises are presented, as well as claims on the role of entrepreneurial and managerial functions in implementing entrepreneurial management processes in plastics processing plants. The data and information were verified through a survey conducted in 2016 through a structured questionnaire, comprising twenty heads of enterprises across the North East Region of Planning in Bulgaria. The practical significance of the researched problem is taken into account by indicating an approach in the implementation of innovative solutions in management practice and the modernization of the used management technologies. The results of the conducted empirical study indirectly testify to the outstanding focus of the managers on the results of entrepreneurial management: innovation, growth and development. The human factor, in general, directly related to the results of entrepreneurial management, has complementary, service-oriented results and significance.

  13. FY 2000 research cooperation project on plastic processing technology/quality inspection technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of improving the production technology of plastic products in Saudi Arabia, the joint development was made of the formation technology/quality inspection technology of agricultural use and food packaging use polyolefin film optimum to environmental conditions of the site, in the light of the needs there, and the FY 2000 results were reported. In the field survey/joint study, for the xenon type weather resistant testing machine and the extruder of the inflation film forming machine which were transported from Japan, the following were carried out: confirmation of the situation of accepting them on the site, functional test of computer of the extruder, installation of the machine testing weather resistance, and the trial operation. In the domestic support study, the extrusion test at laboratory was conducted using the polyethylene resin produced on the site to acquire the basic data for formation stability. Further, the film formation test was made using the equipment with the same specifications as those of the equipment introduced to the site to study the performance of screw extrusion and the formation stability of film. Also conducted were the analytical test/quality evaluation of resin materials/film. (NEDO)

  14. Accommodation | Information | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Accommodation. The Academy has made arrangements to accommodate all participants who have requested for it. Details ​of accommodation ​have been sent to ​all registered participants. Volunteers at the airport will assist the participants in reaching their respective places of accommodation. For any queries ...

  15. Accommodating Elementary Students' Learning Styles.

    Science.gov (United States)

    Wallace, James

    1995-01-01

    Examines the perceptual learning style preferences of sixth- and seventh-grade students in the Philippines. Finds that the visual modality was the most preferred and the auditory modality was the least preferred. Offers suggestions for accommodating visual, tactile, and kinesthetic preferences. (RS)

  16. Geohydromechanical Processes in the Excavation Damaged Zone in Crystalline Rock, Rock Salt, and Indurated and Plastic Clays

    International Nuclear Information System (INIS)

    Tsang, Chin-Fu; Bernier, Frederic; Davies, Christophe

    2004-01-01

    The creation of an excavation disturbed zone or excavation damaged zone is expected around all man-made openings in geologic formations. Macro- and micro-fracturing, and in general a redistribution of in situ stresses and rearrangement of rock structures, will occur in this zone, resulting in drastic changes of permeability to flow, mainly through the fractures and cracks induced by excavation. Such an EDZ may have significant implications for the operation and long-term performance of an underground nuclear waste repository. Various issues of concern need to be evaluated, such as processes creating fractures in the excavation damaged zone, the degree of permeability increase, and the potential for sealing or healing (with permeability reduction) in the zone. In recent years, efforts along these lines have been made for a potential repository in four rock types-crystalline rock, salt, indurated clay, and plastic clay-and these efforts have involved field, laboratory, and theoretical studies. The present work involves a synthesis of the ideas and issues that emerged from presentations and discussions on EDZ in these four rock types at a CLUSTER Conference and Workshop held in Luxembourg in November, 2003. First, definitions of excavation disturbed and excavation damaged zones are proposed. Then, an approach is suggested for the synthesis and intercomparison of geohydromechanical processes in the EDZ for the four rock types (crystalline rock, salt, indurated clay, and plastic clay). Comparison tables of relevant processes, associated factors, and modeling and testing techniques are developed. A discussion of the general state-of-the-art and outstanding issues are also presented. A substantial bibliography of relevant papers on the subject is supplied at the end of the paper

  17. 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

  18. DETEC, a Subprogram for Simulation of the Fast-Neutron Detection Process in a Hydro-Carbonous Plastic Scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, B; Aspelund, O

    1966-07-15

    A description is given of the subprogram DETEC, which for energies below 5 MeV simulates the detection process of a fast-neutron within a large cylindrical plastic scintillator. DETEC has been coded in FORTRAN IV, and consists of a subroutine and a BLOCK-DATA subprogram. The latter is in its present form adapted to the dimensions 5 cm diam. x 8 cm of the scintillating materials NE102 and NE102A. The character of DETEC as a subprogram is manifest through the requirement of a main routine for generation of the following input parameters: 1. fast-neutron position; 2. direction; 3. energy; 4. entrance time; 5. input weight (all referred to the detector surface), and 6. the discriminator threshold. When these are provided, the virtues of DETEC are recording of the detected weight and the time elapsed prior to the detection event. The merits of DETEC are finally demonstrated in two typical applications.

  19. DETEC, a Subprogram for Simulation of the Fast-Neutron Detection Process in a Hydro-Carbonous Plastic Scintillator

    International Nuclear Information System (INIS)

    Gustafsson, B.; Aspelund, O.

    1966-07-01

    A description is given of the subprogram DETEC, which for energies below 5 MeV simulates the detection process of a fast-neutron within a large cylindrical plastic scintillator. DETEC has been coded in FORTRAN IV, and consists of a subroutine and a BLOCK-DATA subprogram. The latter is in its present form adapted to the dimensions 5 cm diam. x 8 cm of the scintillating materials NE102 and NE102A. The character of DETEC as a subprogram is manifest through the requirement of a main routine for generation of the following input parameters: 1. fast-neutron position; 2. direction; 3. energy; 4. entrance time; 5. input weight (all referred to the detector surface), and 6. the discriminator threshold. When these are provided, the virtues of DETEC are recording of the detected weight and the time elapsed prior to the detection event. The merits of DETEC are finally demonstrated in two typical applications

  20. Treatment of Partly Accommodative Esotropia With a High Accommodative Convergence-Accommodation Ratio

    NARCIS (Netherlands)

    H.J. Simonsz (Huib)

    1988-01-01

    textabstractIn the June 1987 issue of the Archives, the results were published of a study by Kushner et al1 on the treatment of accommodative convergence excess, with bilateral medial rectus recessions or recessions with 14-mm posterior fixation sutures. Posterior fixation surgery was considered an

  1. Improving productivity and quality in plastic and thin metallic plates manufacturing by using ultrasonic welding processes

    OpenAIRE

    Dehelean,D.; Oanca,O.

    2009-01-01

    The paper presents an overview of the research done at the Romanian National R&D Institute for Welding and Material Testing ISIM Timisoara in the field of ultrasonic process development. It starts with a general presentation of the value added by the welding sector in Europe. There are presented figures representing the size of the welding sector in Romania. The need of development of new high efficiency welding processes is mentioned, ultrasonic welding being one of the special welding proce...

  2. Cutting prepregs, cutting and processing polymer plastics in the manufacture of airсraft panels

    OpenAIRE

    MELUKHOV NIKITA; GRISHCHENKO TATIANA; LYUBUSHKIN VADIM

    2017-01-01

    The article presents an alternative to the solution of the problem of reduction of manual operations in manufacture. It may be achieved if cutting out prepregs and processing polymeric materials (PMP) be changed for sharp ultrasonic cutting when manufacturing components from polymeric composite materials (PCM). Described are the lines of investigations on new techniques of cutting out prepreg and processings polymeric material of the Nomex type with the use of the energy of ultrasonic waves. ...

  3. Renewable hydrocarbons for jet fuels from biomass and plastics via microwave-induced pyrolysis and hydrogenation processes

    Science.gov (United States)

    Zhang, Xuesong

    This dissertation aims to enhance the production of aromatic hydrocarbons in the catalytic microwave-induced pyrolysis, and maximize the production of renewable cycloalkanes for jet fuels in the hydrogenation process. In the process, ZSM-5 catalyst as the highly efficient catalyst was employed for catalyzing the pyrolytic volatiles from thermal decomposition of cellulose (a model compound of lignocellulosic biomass). A central composite experiment design (CCD) was used to optimize the product yields as a function of independent factors (e.g. catalytic temperature and catalyst to feed mass ratio). The low-density polyethylene (a mode compound of waste plastics) was then carried out in the catalytic microwave-induced pyrolysis in the presence of ZSM-5 catalyst. Thereafter, the catalytic microwave-induced co-pyrolysis of cellulose with low-density polyethylene (LDPE) was conducted over ZSM-5 catalyst. The results showed that the production of aromatic hydrocarbons was significantly enhanced and the coke formation was also considerably reduced comparing with the catalytic microwave pyrolysis of cellulose or LDPE alone. Moreover, practical lignocellulosic biomass (Douglas fir sawdust pellets) was converted into aromatics-enriched bio-oil by catalytic microwave pyrolysis. The bio-oil was subsequently hydrogenated by using the Raney Ni catalyst. A liquid-liquid extraction step was implemented to recover the liquid organics and remove the water content. Over 20% carbon yield of liquid product regarding lignocellulosic biomass was obtained. Up to 90% selectivity in the liquid product belongs to jet fuel range cycloalkanes. As the integrated processes was developed, catalytic microwave pyrolysis of cellulose with LDPE was conducted to improve aromatic production. After the liquid-liquid extraction by the optimal solvent (n-heptane), over 40% carbon yield of hydrogenated organics based on cellulose and LDPE were achieved in the hydrogenation process. As such, real

  4. Accommodating variation: dialects, idiolects, and speech processing.

    Science.gov (United States)

    Kraljic, Tanya; Brennan, Susan E; Samuel, Arthur G

    2008-04-01

    Listeners are faced with enormous variation in pronunciation, yet they rarely have difficulty understanding speech. Although much research has been devoted to figuring out how listeners deal with variability, virtually none (outside of sociolinguistics) has focused on the source of the variation itself. The current experiments explore whether different kinds of variation lead to different cognitive and behavioral adjustments. Specifically, we compare adjustments to the same acoustic consequence when it is due to context-independent variation (resulting from articulatory properties unique to a speaker) versus context-conditioned variation (resulting from common articulatory properties of speakers who share a dialect). The contrasting results for these two cases show that the source of a particular acoustic-phonetic variation affects how that variation is handled by the perceptual system. We also show that changes in perceptual representations do not necessarily lead to changes in production.

  5. Plastic materials and Acome's use of high energy electron processing in France

    International Nuclear Information System (INIS)

    Goavec, P.G.

    1979-01-01

    Crosslinking is the way to improve the physical properties of polymer materials, particularly at high temperatures. Radiation crosslinking being the process most suited to achieve this target in the field of fine wire and cable, Acome built, for this application, an irradiation plant: the only one to date in that industry in France. The main piece of equipment in this plant is a Radiation Dynamics electron accelerator. Although simple in its principle, the process is delicate to operate owing to the complexity of the chemistry involved in the raw materials. The successful development of this process led Acome to a new generation of upgraded wires and cables for telecommunication, signal, automotive and special applications which are finding a growing market thanks to their increased reliability. (author)

  6. Laser Processing of Carbon Fiber Reinforced Plastics - Release of Carbon Fiber Segments During Short-pulsed Laser Processing of CFRP

    Science.gov (United States)

    Walter, Juergen; Brodesser, Alexander; Hustedt, Michael; Bluemel, Sven; Jaeschke, Peter; Kaierle, Stefan

    Cutting and ablation using short-pulsed laser radiation are promising technologies to produce or repair CFRP components with outstanding mechanical properties e.g. for automotive and aircraft industry. Using sophisticated laser processing strategies and avoiding excessive heating of the workpiece, a high processing quality can be achieved. However, the interaction of laser radiation and composite material causes a notable release of hazardous substances from the process zone, amongst others carbon fiber segments or fibrous particles. In this work, amounts and geometries of the released fiber segments are analyzed and discussed in terms of their hazardous potential. Moreover, it is investigated to what extent gaseous organic process emissions are adsorbed at the fiber segments, similar to an adsorption of volatile organic compounds at activated carbon, which is typically used as filter material.

  7. A data science approach to candidate gene selection of pain regarded as a process of learning and neural plasticity.

    Science.gov (United States)

    Ultsch, Alfred; Kringel, Dario; Kalso, Eija; Mogil, Jeffrey S; Lötsch, Jörn

    2016-12-01

    The increasing availability of "big data" enables novel research approaches to chronic pain while also requiring novel techniques for data mining and knowledge discovery. We used machine learning to combine the knowledge about n = 535 genes identified empirically as relevant to pain with the knowledge about the functions of thousands of genes. Starting from an accepted description of chronic pain as displaying systemic features described by the terms "learning" and "neuronal plasticity," a functional genomics analysis proposed that among the functions of the 535 "pain genes," the biological processes "learning or memory" (P = 8.6 × 10) and "nervous system development" (P = 2.4 × 10) are statistically significantly overrepresented as compared with the annotations to these processes expected by chance. After establishing that the hypothesized biological processes were among important functional genomics features of pain, a subset of n = 34 pain genes were found to be annotated with both Gene Ontology terms. Published empirical evidence supporting their involvement in chronic pain was identified for almost all these genes, including 1 gene identified in March 2016 as being involved in pain. By contrast, such evidence was virtually absent in a randomly selected set of 34 other human genes. Hence, the present computational functional genomics-based method can be used for candidate gene selection, providing an alternative to established methods.

  8. Impacts of the manufacturing process using fiberglass reinforced plastic composite on the environment and occupational health: the automotive industry case

    Directory of Open Access Journals (Sweden)

    Cíntia Madureira Orth

    2012-06-01

    Full Text Available The production of fiberglass reinforced plastic composite parts may cause serious damages to the health of workers and/or the environment, especially due to the generation of process trimmings, noise level and gas emission.  In view of that, this essay aims at assessing the main impacts of the Molding and Finish processes of an automotive plant on the environment and occupational health. It was observed that the open molding method adopted by the studied plant is the main cause of the generation of residues and that the waste of raw materials as trimmings may reach up to 30%. The final destination of those trimmings, which represent 45% of all the residues generated by the factory, is the industrial landfill. It was also observed that, due to the use of open molds, the levels of styrene and fiber dust were above the tolerance limits, presenting risks to the health of the workers.  Therefore, the studied company should consider the possibility of adopting less aggressive technologies, such as that used in closed molds. The reduction of the negative impacts of the productive processes in their source should be part of the company’s policy. Furthermore, the prevention must be continuous and improved every day.

  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. Characterization of microcrystalline I-layer for solar cells prepared in low temperature - plastic compatible process

    KAUST Repository

    Sliz, Rafal; Ahnood, Arman; Nathan, Arokia; Myllyla, Risto; Jabbour, Ghassan E.

    2012-01-01

    Microcrystalline silicon (mc-Si) lms deposited using a Plasma Enhanced Chemical Vapour Deposition (PECVD) process constitute an important material for manufacturing low-cost, large-area thin-lm devices, such as solar cells or thin-lm transistors

  11. Study of tapping process of carbon fiber reinforced plastic composites/AA7075 stacks

    Science.gov (United States)

    D'Orazio, Alessio; Mehtedi, Mohamad El; Forcellese, Archimede; Nardinocchi, Alessia; Simoncini, Michela

    2018-05-01

    The present investigation aims at studying the tapping process of a three-layer stack constituted by two CFRP layers and a core plate in AA7075 aluminum alloy. The CFRP laminates were obtained by a pre-impregnated woven sample made up of T700 carbon fibers and a thermoset epoxy matrix. Tapping experiments were performed on a 5-axis machining center instrumented with a dynamometer to measure thrust force generated during process. A high-speed steel tool, coated with nanocomposite TiAlN, was used. According to the tool manufacturer recommendations, rotational speed and feed rate were 800 rpm and 1000 mm/min, respectively. Similar thrust force time history responses were obtained by tapping different holes, even though the vertical force increases with number of threaded holes. Furthermore, a quantitative evaluation of delamination at the periphery of entry holes was carried out. The delamination at the entry hole strongly increases with number of threaded holes.

  12. Fatigue crack propagation in UFG Ti grade 4 processed by severe plastic deformation

    Czech Academy of Sciences Publication Activity Database

    Fintová, Stanislava; Arzaghi, M.; Kuběna, Ivo; Kunz, Ludvík; Sarrazin-Baudoux, C.

    2017-01-01

    Roč. 98, MAY (2017), s. 187-194 ISSN 0142-1123 R&D Projects: GA MŠk(CZ) LQ1601; GA MŠk LM2015069 Institutional support: RVO:68081723 Keywords : Titanium * Fatigue * Crack growth * Crack closure * Equal channel angular processing Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 2.899, year: 2016 http://www.sciencedirect.com/science/article/pii/S014211231730035X

  13. Massification of Higher Education and Students' Accommodation ...

    African Journals Online (AJOL)

    Massification of Higher Education and Students' Accommodation: The ... of students' accommodation at the University of Dar es salaam (UDSM) over the past 50 years. ... and the quality of learning, as well as the quality of students' life.

  14. Fine grained 304 ASS processed by a severe plastic deformation and subsequent annealing; microstructure and mechanical properties evaluation

    Science.gov (United States)

    Salout, Shima Ahmadzadeh; Shirazi, Hasan; Nili-Ahmadabadi, Mahmoud

    2018-01-01

    The current research is an attempt to study the effect of a novel severe plastic deformation technique so called "repetitive corrugation and straightening by rolling" (RCSR) and subsequent annealing on the microstructure and mechanical properties of AISI type 304 austenitic stainless steel. In this study, RCSR process was carried out at 200 °C on the 304 austenitic stainless steel (above Md30 temperature that is about 50 °C for this stainless steel) in order to avoid the formation of martensite phase when a high density of dislocations was introduced into the austenite phase and also high density of mechanical twins was induced in the deformed 304 austenitic stainless steel. Because of relationship between deformation temperature, stacking fault energy (SFE) and mechanisms of deformation. Thereafter subsequently, annealing treatment was applied into deformed structure in order to refine the microstructure of 304 stainless s teel. The specimens were examined by means of optical microscopy (OM), scanning electron microscopy (SEM), tensile and micro-hardness tests. The results indicate that by increasing the cycles of RCSR process (increasing applied strain), further mechanical twins are induced, the hardness and in particular, the yield stress of specimens have been increased.

  15. Accommodative spasm in siblings: A unique finding

    Directory of Open Access Journals (Sweden)

    Rutstein Robert

    2010-01-01

    Full Text Available Accommodative spasm is a rare condition occurring in children, adolescents, and young adults. A familial tendency for this binocular vision disorder has not been reported. I describe accommodative spasm occurring in a brother and sister. Both children presented on the same day with complaints of headaches and blurred vision. Treatment included cycloplegia drops and bifocals. Siblings of patients having accommodative spasm should receive a detailed eye exam with emphasis on recognition of accommodative spasm.

  16. Accommodative spasm in siblings: A unique finding

    Science.gov (United States)

    Rutstein, Robert P

    2010-01-01

    Accommodative spasm is a rare condition occurring in children, adolescents, and young adults. A familial tendency for this binocular vision disorder has not been reported. I describe accommodative spasm occurring in a brother and sister. Both children presented on the same day with complaints of headaches and blurred vision. Treatment included cycloplegia drops and bifocals. Siblings of patients having accommodative spasm should receive a detailed eye exam with emphasis on recognition of accommodative spasm. PMID:20534925

  17. The effect of mold surface topography on plastic parat in-process shrinkage in injection molding

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    2003-01-01

    An experimental study of the effect of mold surface roughness on in-process in-flow linear part shrinkage in injection molding has been carried out. The investigation is based on an experimental two-cavity tool, where the cavities have different surface topographies, but are otherwise identical....... The study has been carried out for typical commercial polystyrene and polypropylene grades. The relationship between mold surface topography and linear shrinkage has been investigated with an experimental two-cavity mold producing simple rectangular parts with the nominal dimensions 1 x 25 x 50 mm (see...... figure 1). The cavities have different surface topographies on one side, but are otherwise identical (see discussion of other contribution factors)....

  18. 46 CFR 108.143 - Accommodation space.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Accommodation space. 108.143 Section 108.143 Shipping... EQUIPMENT Construction and Arrangement Structural Fire Protection § 108.143 Accommodation space. (a) Each corridor bulkhead in an accommodation space must be an A class or B class bulkhead except if an A class...

  19. Numerical modelling of physical processes in a ballistic laboratory setup with a tapered adapter and plastic piston used for obtaining high muzzle velocities

    Science.gov (United States)

    Bykov, N. V.

    2014-12-01

    Numerical modelling of a ballistic setup with a tapered adapter and plastic piston is considered. The processes in the firing chamber are described within the framework of quasi- one-dimensional gas dynamics and a geometrical law of propellant burn by means of Lagrangian mass coordinates. The deformable piston is considered to be an ideal liquid with specific equations of state. The numerical solution is obtained by means of a modified explicit von Neumann scheme. The calculation results given show that the ballistic setup with a tapered adapter and plastic piston produces increased shell muzzle velocities by a factor of more than 1.5-2.

  20. Radiation processing of composite materials on the basis of coconut hair and plastics

    International Nuclear Information System (INIS)

    Owolabi, O.; Czvikovszky, T.

    1983-01-01

    Composite materials containing coconut hair as fibrous reinforcements and synthetic polyester resin as matrix were prepared. The coconut hair, together with the unsaturated polyester resin and other required ingredients (fillers, complexing agents, etc.) were pre-processed in a BRABENDER-type kneader or similar equipment to produce a bulk moulding compound ('BMC' or 'Premix') and later hot pressed for 10 minutes at 130 degC and 30 bars to produce sheets of 2 mm thickness. The tensile-, flexural- and impact strength of the sheets were measured and served as the main basis of comparison. The effect of increasing coconut hair percentage was studied. The effect of preirradiation of the coconut hair, pretreatment with hot sodium hydroxide solution and a combination of the two, to improve the coupling of the coconut hair and synthetic polyester were also studied. Composite materials were also made from a mixture of coconut hair and chopped glass fibers as reinforcements in the same BMC material. The radiation-treated coconut fiber gives a useful composite material for hot-press moulding. (author)

  1. FY 2000 research cooperation project on plastic processing technology/quality inspection technology; 2000 nendo kenkyu kyoryoku jigyo. Plastic kako gijutsu hinshitsukensa gijutsu ni kansuru kenkyu kyoryoku

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of improving the production technology of plastic products in Saudi Arabia, the joint development was made of the formation technology/quality inspection technology of agricultural use and food packaging use polyolefin film optimum to environmental conditions of the site, in the light of the needs there, and the FY 2000 results were reported. In the field survey/joint study, for the xenon type weather resistant testing machine and the extruder of the inflation film forming machine which were transported from Japan, the following were carried out: confirmation of the situation of accepting them on the site, functional test of computer of the extruder, installation of the machine testing weather resistance, and the trial operation. In the domestic support study, the extrusion test at laboratory was conducted using the polyethylene resin produced on the site to acquire the basic data for formation stability. Further, the film formation test was made using the equipment with the same specifications as those of the equipment introduced to the site to study the performance of screw extrusion and the formation stability of film. Also conducted were the analytical test/quality evaluation of resin materials/film. (NEDO)

  2. Melt processing and property testing of a model system of plastics contained in waste from electrical and electronic equipment.

    Science.gov (United States)

    Triantou, Marianna I; Tarantili, Petroula A; Andreopoulos, Andreas G

    2015-05-01

    In the present research, blending of polymers used in electrical and electronic equipment, i.e. acrylonitrile-butadiene-styrene terpolymer, polycarbonate and polypropylene, was performed in a twin-screw extruder, in order to explore the effect process parameters on the mixture properties, in an attempt to determine some characteristics of a fast and economical procedure for waste management. The addition of polycarbonate in acrylonitrile-butadiene-styrene terpolymer seemed to increase its thermal stability. Also, the addition of polypropylene in acrylonitrile-butadiene-styrene terpolymer facilitates its melt processing, whereas the addition of acrylonitrile-butadiene-styrene terpolymer in polypropylene improves its mechanical performance. Moreover, the upgrading of the above blends by incorporating 2 phr organically modified montmorillonite was investigated. The prepared nanocomposites exhibit greater tensile strength, elastic modulus and storage modulus, as well as higher melt viscosity, compared with the unreinforced blends. The incorporation of montmorillonite nanoplatelets in polycarbonate-rich acrylonitrile-butadiene-styrene terpolymer/polycarbonate blends turns the thermal degradation mechanism into a two-stage process. Alternatively to mechanical recycling, the energy recovery from the combustion of acrylonitrile-butadiene-styrene terpolymer/polycarbonate and acrylonitrile-butadiene-styrene terpolymer/polypropylene blends was recorded by measuring the gross calorific value. Comparing the investigated polymers, polypropylene presents the higher gross calorific value, followed by acrylonitrile-butadiene-styrene terpolymer and then polycarbonate. The above study allows a rough comparative evaluation of various methodologies for treating plastics from waste from electrical and electronic equipment. © The Author(s) 2015.

  3. Vestibular-ocular accommodation reflex in man

    Science.gov (United States)

    Clark, B.; Randle, R. J.; Stewart, J. D.

    1975-01-01

    Stimulation of the vestibular system by angular acceleration produces widespread sensory and motor effects. The present paper studies a motor effect which has not been reported in the literature, i.e., the influence of rotary acceleration of the body on ocular accommodation. The accommodation of 10 young men was recorded before and after a high-level deceleration to zero velocity following 30 sec of rotating. Accommodation was recorded continuously on an infrared optometer for 110 sec under two conditions: while the subjects observed a target set at the far point, and while they viewed the same target through a 0.3-mm pinhole. Stimulation by high-level rotary deceleration produced positive accommodation or a pseudomyopia under both conditions, but the positive accommodation was substantially greater and lasted much longer during fixation through the pinhole. It is hypothesized that this increase in accommodation is a result of a vestibular-ocular accommodation reflex.

  4. Sleep, Plasticity and the Pathophysiology of Neurodevelopmental Disorders: The Potential Roles of Protein Synthesis and Other Cellular Processes

    Directory of Open Access Journals (Sweden)

    Dante Picchioni

    2014-03-01

    Full Text Available Sleep is important for neural plasticity, and plasticity underlies sleep-dependent memory consolidation. It is widely appreciated that protein synthesis plays an essential role in neural plasticity. Studies of sleep-dependent memory and sleep-dependent plasticity have begun to examine alterations in these functions in populations with neurological and psychiatric disorders. Such an approach acknowledges that disordered sleep may have functional consequences during wakefulness. Although neurodevelopmental disorders are not considered to be sleep disorders per se, recent data has revealed that sleep abnormalities are among the most prevalent and common symptoms and may contribute to the progression of these disorders. The main goal of this review is to highlight the role of disordered sleep in the pathology of neurodevelopmental disorders and to examine some potential mechanisms by which sleep-dependent plasticity may be altered. We will also briefly attempt to extend the same logic to the other end of the developmental spectrum and describe a potential role of disordered sleep in the pathology of neurodegenerative diseases. We conclude by discussing ongoing studies that might provide a more integrative approach to the study of sleep, plasticity, and neurodevelopmental disorders.

  5. Analytical functions used for description of the plastic deformation process in Zirconium alloys WWER type fuel rod cladding under designed accident conditions

    International Nuclear Information System (INIS)

    Fedotov, A.

    2003-01-01

    The aim of this work was to improve the RAPTA-5 code as applied to the analysis of the thermomechanical behavior of the fuel rod cladding under designed accident conditions. The irreversible process thermodynamics methods were proposed to be used for the description of the plastic deformation process in zirconium alloys under accident conditions. Functions, which describe yielding stress dependence on plastic strain, strain rate and temperature may be successfully used in calculations. On the basis of the experiments made and the existent experimental data the dependence of yielding stress on plastic strain, strain rate, temperature and heating rate for E110 alloy was determined. In future the following research work shall be made: research of dynamic strain ageing in E635 alloy under different strain rates; research of strain rate influence on plastic strain in E635 alloy under test temperature higher than 873 K; research of deformation strengthening of E635 alloy under high temperatures; research of heating rate influence n phase transformation in E110 and E635 alloys

  6. Radon Infiltration in Rented Accommodation

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2017-01-01

    in homes was measured and the Buildings were registered for a series of variables describing upgrades, facilities, building components, Construction characteristics and used materials. In addition, the radon level was measured in the basement in 9 of the buildings. The mean year value of the indoor radon......Indoor radon levels were measured in 221 homes located in 53 buildings, including 28 multi-occupant houses and 25 single-family terraced houses. The homes consisted of rented accommodation located in buildings recorded as being constructed before 2010 and after the year 1850. The radon level...... radon levels exceeding 100 Bq/m3 in homes in multi-occupant houses was found to be very low, but the risk was highest on the ground floor in a building constructed with slab on ground....

  7. A Perspective on the Prowaste Concept: Efficient Utilization of Plastic Waste through Product Design and Process Innovation.

    Science.gov (United States)

    Greco, Antonio; Frigione, Mariaenrica; Maffezzoli, Alfonso; Marseglia, Alessandro; Passaro, Alessandra

    2014-07-23

    This work is aimed to present an innovative technology for the reinforcement of beams for urban furniture, produced by in-mold extrusion of plastics from solid urban waste. This material, which is usually referred to as "recycled plastic lumber", is characterized by very poor mechanical properties, which results in high deflections under flexural loads, particularly under creep conditions. The Prowaste project, founded by the EACI (European Agency for Competitiveness and Innovation) in the framework of the Eco-Innovation measure, was finalized to develop an innovative technology for selective reinforcement of recycled plastic lumber. Selective reinforcement was carried out by the addition of pultruded glass rods in specific positions with respect to the cross section of the beam, which allowed optimizing the reinforcing efficiency. The reinforcement of the plastic lumber beams with pultruded rods was tested at industrial scale plant, at Solteco SL (Alfaro, Spain). The beams obtained, characterized by low cost and weight, were commercialized by the Spanish company. The present paper presents the most relevant results of the Prowaste project. Initially, an evaluation of the different materials candidates for the reinforcement of recycled plastic lumber is presented. Plastic lumber beams produced in the industrial plant were characterized in terms of flexural properties. The results obtained are interpreted by means of beam theory, which allows for extrapolation of the characteristic features of beams produced by different reinforcing elements. Finally, a theoretical comparison with other approaches which can be used for the reinforcement of plastic lumber is presented, highlighting that, among others, the Prowaste concept maximizes the stiffening efficiency, allowing to significantly reduce the weight of the components.

  8. Processos cognitivos e plasticidade cerebral na Síndrome de Down Cognitive processes and brain plasticity in Down Syndrome

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Minetto Caldeira Silva

    2006-04-01

    discuss some of the recent discoveries related to cognitive processes in Down Syndrome, so as to show how important brain plasticity can be in development and acquisition of knowledge. To this end, we aim to discuss cognitive processes present in Down Syndrome, relating them to general concepts of brain plasticity and look at ways such knowledge can favor learning. We acknowledge that it isn't possible to exhaust the subject, but we do intend to start thinking about this issue. To do so, we begin with a review of the literature, looking at research, from the oldest to the most recent publications, in an attempt to better understand how to make use of these findings.

  9. A novel process for separation of hazardous poly(vinyl chloride) from mixed plastic wastes by froth flotation.

    Science.gov (United States)

    Wang, Jianchao; Wang, Hui; Wang, Chongqing; Zhang, Lingling; Wang, Tao; Zheng, Long

    2017-11-01

    A novel method, calcium hypochlorite (CHC) treatment, was proposed for separation of hazardous poly(vinyl chloride) (PVC) plastic from mixed plastic wastes (MPWs) by froth flotation. Flotation behavior of single plastic indicates that PVC can be separated from poly(ethylene terephthalate) (PET), poly(acrylonitrile-co-butadiene-co-styrene) (ABS), polystyrene (PS), polycarbonate (PC) and poly(methyl methacrylate) (PMMA) by froth flotation combined with CHC treatment. Mechanism of CHC treatment was examined by contact angle measurement, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Under the optimum conditions, separation of PVC from binary plastics with different particle sizes is achieved efficiently. The purity of PC, ABS, PMMA, PS and PET is greater than 96.8%, 98.5%, 98.8%, 97.4% and 96.3%, respectively. Separation of PVC from multi-plastics was further conducted by two-stage flotation. PVC can be separated efficiently from MPWs with residue content of 0.37%. Additionally, reusing CHC solution is practical. This work indicates that separation of hazardous PVC from MPWs is effective by froth flotation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Gene expression reaction norms unravel the molecular and cellular processes underpinning the plastic phenotypes of Alternanthera philoxeroides in contrasting hydrological conditions

    Directory of Open Access Journals (Sweden)

    Lexuan eGao

    2015-11-01

    Full Text Available Alternanthera philoxeroides is an amphibious invasive weed that can colonize both aquatic and terrestrial habitats. Individuals growing in different habitats exhibit extensive phenotypic variation but little genetic differentiation. Little is known about the molecular basis underlying environment-induced phenotypic changes. Variation in transcript abundance in A. philoxeroides was characterized throughout the time-courses of pond and upland treatments using RNA-Sequencing. 7,805 genes demonstrated variable expression in response to different treatments,forming 11 transcriptionally coordinated gene groups. Functional enrichment analysis of plastically expressed genes revealed pathway changes in hormone-mediated signaling, osmotic adjustment, cell wall remodeling and programmed cell death, providing a mechanistic understanding of the biological processes underlying the phenotypic changes in A. philoxeroides. Both transcriptional modulation of environmentally sensitive loci and environmentally dependent control of regulatory loci influenced the plastic responses to the environment. Phenotypic responses and gene expression patterns to contrasting hydrological conditions were compared between A. philoxeroides and its alien congener A. pungens. The terricolous A. pungens displayed limited phenotypic plasticity to different treatments. It was postulated based on gene expression comparison that the interspecific variation in plasticity between A. philoxeroides and A. pungens was not due to environmentally-mediated changes in hormone levels but to variations in the type and relative abundance of different signal transducers and receptors expressed in the target tissue.

  11. Disability disclosure and workplace accommodations among youth with disabilities.

    Science.gov (United States)

    Lindsay, Sally; Cagliostro, Elaine; Leck, Joanne; Shen, Winny; Stinson, Jennifer

    2018-03-20

    Many youths with disabilities find it challenging to disclose their medical condition and request workplace accommodations. Our objective was to explore when and how young people with disabilities disclose their condition and request workplace accommodations. We conducted 17 in-depth interviews (11 females, six males) with youth with disabilities aged 15-34 (mean age 26). We analyzed our data using an interpretive, qualitative, and thematic approach. Our results showed the timing of when youth disclosed their disability to their employer depended on disability type and severity, comfort level, type of job, and industry. Youth's strategies and reasons for disclosure included advocating for their needs, being knowledgeable about workplace rights, and accommodation solutions. Facilitators for disclosure included job preparation, self-confidence, and self-advocacy skills, and having an inclusive work environment. Challenges to disability disclosure included the fear of stigma and discrimination, lack of employer's knowledge about disability and accommodations, negative past experiences of disclosing, and not disclosing on your own terms. Our findings highlight that youth encounter several challenges and barriers to disclosing their condition and requesting workplace accommodations. The timing and process for disclosing is complex and further work is needed to help support youth with disclosing their condition. Implications for rehabilitation Clinicians, educators, and employers should emphasize the importance of mentoring and leadership programs to give youth the confidence and self-advocacy skills needed to disclose and ask for accommodations in the workplace. Clinicians should advocate for the inclusion of youth with disabilities in the workforce and educate employers on the importance of doing so. Youth with disabilities need more opportunities for employment training and particularly how to disclose their disability and request workplace accommodations.

  12. Supporting the development process for building products by the use of research portfolio analysis: A case study for wood plastics composite materials

    Directory of Open Access Journals (Sweden)

    Daniel Friedrich

    2016-06-01

    Our study evaluated European scientific projects in composites from which we derived a Research Portfolio serving as future matrix for ideation. It was found that research databanks can serve as basis for strategic innovation planning. We were able to identify several appropriate future technologies and material applications in the field of bio-based plastics composites. Our methodology particularly supports manufacturers with less formalized innovation processes.

  13. Study of combustion and emission characteristics of fuel derived from waste plastics by various waste to energy (W-t-E) conversion processes

    Science.gov (United States)

    Hazrat, M. A.; Rasul, M. G.; Khan, M. M. K.

    2016-07-01

    Reduction of plastic wastes by means of producing energy can be treated as a good investment in the waste management and recycling sectors. In this article, conversion of plastics into liquid fuel by two thermo-chemical processes, pyrolysis and gasification, are reviewed. The study showed that the catalytic pyrolysis of homogenous waste plastics produces better quality and higher quantity of liquefied fuel than that of non-catalytic pyrolysis process at a lower operating temperature. The syngas produced from gasification process, which occurs at higher temperature than the pyrolysis process, can be converted into diesel by the Fischer-Tropsch (FT) reaction process. Conducive bed material like Olivine in the gasification conversion process can remarkably reduce the production of tar. The waste plastics pyrolysis oil showed brake thermal efficiency (BTE) of about 27.75%, brake specific fuel consumption (BSFC) of 0.292 kg/kWh, unburned hydrocarbon emission (uHC) of 91 ppm and NOx emission of 904 ppm in comparison with the diesel for BTE of 28%, BSFC of 0.276 kg/kWh, uHC of 57 ppm and NOx of 855 ppm. Dissolution of Polystyrene (PS) into biodiesel also showed the potential of producing alternative transport fuel. It has been found from the literature that at higher engine speed, increased EPS (Expanded Polystyrene) quantity based biodiesel blends reduces CO, CO2, NOx and smoke emission. EPS-biodiesel fuel blend increases the brake thermal efficiency by 7.8%, specific fuel consumption (SFC) by 7.2% and reduces brake power (Pb) by 3.2%. More study using PS and EPS with other thermoplastics is needed to produce liquid fuel by dissolving them into biodiesel and to assess their suitability as a transport fuel. Furthermore, investigation to find out most suitable W-t-E process for effective recycling of the waste plastics as fuel for internal combustion engines is necessary to reduce environmental pollution and generate revenue which will be addressed in this article.

  14. Microstructure and High Temperature Plastic Deformation Behavior of Al-12Si Based Alloy Fabricated by an Electromagnetic Casting and Stirring Process

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kyung-Soo; Roh, Heung-Ryeol; Kim, Mok-Soon [Inha University, Incheon (Korea, Republic of); Kim, Jong-Ho; Park, Joon-Pyo [Research Institute of Industrial Science and Technology, Pohang (Korea, Republic of)

    2017-06-15

    An as-received EMC/S (electromagnetic casting and stirring)-processed Al-12Si based alloy billet was homogenized to examine its microstructure and high temperature plastic deformation behavior, using compressive tests over the temperature range from 623 to 743 K and a strain rate range from 1.0×10{sup -3} to 1.0×10{sup 0}s{sup -1}. The results were compared with samples processed by the direct chill casting (DC) method. The fraction of equiaxed structure for the as-received EMC/S billet(41%) was much higher than that of the as-received DC billet(6 %). All true stress – true strain curves acquired from the compressive tests exhibited a peak stress at the initial stage of plastic deformation. Flow stress showed a steady state region after the appearance of peak stress with increasing strain. The peak stress decreased with increasing temperature at a given strain rate and a decreasing strain rate at a given temperature. A constitutive equation was made for each alloy, which could be used to predict the peak stress. A recrystallized grain structure was observed in all the deformed specimens, indicating that dynamic recrystallization is the predominant mechanism during high temperature plastic deformation of both the homogenized EMC/S and DC-processed Al-12Si based alloys.

  15. Structural and mechanical behaviour of severe plastically deformed high purity aluminium sheets processed by constrained groove pressing technique

    International Nuclear Information System (INIS)

    Satheesh Kumar, S.S.; Raghu, T.

    2014-01-01

    Highlights: • High purity aluminium sheets constrained groove pressed up to plastic strain of 5.8. • Microstructural evolution studied by TEM and X-ray diffraction profile analysis. • Ultrafine grained structure with grain size ∼900 nm achieved in sheets. • Yield strength increased by 5.3 times and tensile strength doubled after first pass. • Enhanced deformation homogeneity seen with increased accumulated plastic strain. - Abstract: High purity aluminium sheets (∼99.9%) are subjected to intense plastic straining by constrained groove pressing method successfully up to 5 passes thereby imparting an effective plastic strain of 5.8. Transmission electron microscopy studies of constrained groove pressed sheets divulged significant grain refinement and the average grain sizes obtained after five pass is estimated to be ∼0.9 μm. In addition to that, microstructural evolution of constrained groove pressed sheets is characterized by X-ray diffraction peak profile analysis employing Williamson–Hall method and the results obtained fairly concur with electron microscopy findings. The tensile behaviour evolution with increased straining indicates substantial improvement of yield strength by ∼5.3 times from 17 MPa to 90 MPa during first pass corroborated to grain refinement observed. Marginal increase in strengths is noticed during second pass followed by minor drop in strengths attributed to predominance of dislocation recovery is noticed in subsequent passes. Quantitative assessment of degree of deformation homogeneity using microhardness profiles reveal relatively better strain homogeneity at higher number of passes

  16. Accommodative Ability in Prepresbyopic Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Mohammad Etezad Razavi

    2015-04-01

    Full Text Available Introduction: To compare various accommodative parameters in prepresbyopic diabetic patients with age-matched healthy individuals. Materials and Methods: Study populationconsisted of 32 younger-onset diabetic patients (30-40 years of age and 28 age-matched healthy normal individuals. Using the best correction for distance visual acuity (20.20 by Snellen chart, multiple accommodative ability tests such as near point of accommodation, accommodative amplitude, negative or positive accommodative facility and near point of convergence were measured in both groups. Results: Mean near point of accommodation in diabetic patients was significantly greater than the control group (18.5±4.4 centimeters [cm] versus 9.5±2 centimeters, p= 0.000. Mean accommodative amplitude was (5.93±1.75 Diopter (D and (10.95±2.16 Diopter in diabetics and normal individuals, respectively (p=0.000. Mean accommodation facility was (3.19±3.04 cycle/minute [cyl/min] in patients and 10.01±5.09 cycle/minute in the control group (p= 0.000. Mean positive relative accommodation was (–3.37±1.19 D in diabetic and (-2.11±0.99 D in healthy participants (p=0.000. Mean negative relative accommodation was lower in diabetic patients compared with the control group, however, this difference did not reach statistical significance (2.61±0.65 D versus (2.61±0.60 D, p= 0.23. Mean near point of convergence was (8.23±1.43 cm and (7.13±0.67 cm in normal and diabetic groups, respectively which had insignificant difference (p= 0.45. Conclusion: Majority of accommodative ability functions decreased in prepresbyopic diabetic patients. Early detection and rehabilitation of such patients with corrective near spectacles are strongly recommended.

  17. 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)

  18. 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.)

  19. Bearing-Mounting Concept Accommodates Thermal Expansion

    Science.gov (United States)

    Nespodzany, Robert; Davis, Toren S.

    1995-01-01

    Pins or splines allow radial expansion without slippage. Design concept for mounting rotary bearing accommodates differential thermal expansion between bearing and any structure(s) to which bearing connected. Prevents buildup of thermal stresses by allowing thermal expansion to occur freely but accommodating expansion in such way not to introduce looseness. Pin-in-slot configuration also maintains concentricity.

  20. 77 FR 38833 - Job Accommodation Network

    Science.gov (United States)

    2012-06-29

    ... DEPARTMENT OF LABOR Job Accommodation Network AGENCY: Office of Disability Employment Policy, Department of Labor. Announcement Type: New Notice of Availability of Funds and Solicitation for Grant... cooperative agreement to manage and operate its Job Accommodation Network (JAN), a national technical...

  1. Can current models of accommodation and vergence predict accommodative behavior in myopic children?

    Science.gov (United States)

    Sreenivasan, Vidhyapriya; Irving, Elizabeth L; Bobier, William R

    2014-08-01

    Investigations into the progression of myopia in children have long considered the role of accommodation as a cause and solution. Myopic children show high levels of accommodative adaptation, coupled with accommodative lag and high response AC/A (accommodative convergence per diopter of accommodation). This pattern differs from that predicted by current models of interaction between accommodation and vergence, where weakened reflex responses and a high AC/A would be associated with a low not high levels of accommodative adaptation. However, studies of young myopes were limited to only part of the accommodative vergence synkinesis and the reciprocal components of vergence adaptation and convergence accommodation were not studied in tandem. Accordingly, we test the hypothesis that the accommodative behavior of myopic children is not predicted by current models and whether that departure is explained by differences in the accommodative plant of the myopic child. Responses to incongruent stimuli (-2D, +2D adds, 10 prism diopter base-out prism) were investigated in 28 myopic and 25 non-myopic children aged 7-15 years. Subjects were divided into phoria groups - exo, ortho and eso based upon their near phoria. The school aged myopes showed high levels of accommodative adaptation but with reduced accommodation and high AC/A. This pattern is not explained by current adult models and could reflect a sluggish gain of the accommodative plant (ciliary muscle and lens), changes in near triad innervation or both. Further, vergence adaptation showed a predictable reciprocal relationship with the high accommodative adaptation, suggesting that departures from adult models were limited to accommodation not vergence behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Evaluation of Lumicyano™ cyanoacrylate fuming process for the development of latent fingermarks on plastic carrier bags by means of a pseudo operational comparative trial.

    Science.gov (United States)

    Farrugia, Kevin J; Deacon, Paul; Fraser, Joanna

    2014-03-01

    There are a number of studies discussing recent developments of a one-step fluorescent cyanoacrylate process. This study is a pseudo operational trial to compare an example of a one-step fluorescent cyanoacrylate product, Lumicyano™, with the two recommended techniques for plastic carrier bags; cyanoacrylate fuming followed by basic yellow 40 (BY40) dyeing and powder suspensions. 100 plastic carrier bags were collected from the place of work and the items were treated as found without any additional fingermark deposition. The bags were split into three and after treatment with the three techniques a comparable number of fingermarks were detected by each technique (average of 300 fingermarks). The items treated with Lumicyano™ were sequentially processed with BY40 and an additional 43 new fingermarks were detected. Lumicyano™ appears to be a suitable technique for the development of fingermarks on plastic carrier bags and it can help save lab space and time as it does not require dyeing or drying procedures. Furthermore, contrary to other one-step cyanoacrylate products, existing cyanoacrylate cabinets do not require any modification for the treatment of articles with Lumicyano™. To date, there is little peer reviewed articles in the literature on trials related to Lumicyano™ and this study aims to contribute to fill this gap. © 2013.

  3. A Review of Worksite Lactation Accommodations.

    Science.gov (United States)

    Hilliard, Elizabeth Dianne

    2017-01-01

    The purpose of this review was to examine workplace lactation accommodations, and their association with breastfeeding duration, and identify strategies occupational health professionals can use to promote lactation improvements. This study included literature published from 1985 through 2015 and listed in PubMed and CINAHL. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 11 articles were identified for review. Presence of a corporate lactation program, on-site child care, and return to work/telephone lactation consultation were consistently associated with breastfeeding at 6 months. Other breastfeeding accommodations (i.e., lactation spaces, lactation breaks, worksite lactation policies, and supervisor/coworker support) were not consistently associated with breastfeeding duration. Occupational health professionals can play key roles in improving the effectiveness of lactation accommodations. Assuring adequate implementation of accommodations, increasing communication and marketing of accommodations, and promoting supervisor and coworker support are areas that occupational health professionals should explore for improving lactation duration.

  4. BRANDING ORIENTATION IN THE ACCOMMODATION INDUSTRY

    Directory of Open Access Journals (Sweden)

    Melissa Li Sa Liow

    2015-04-01

    Full Text Available This paper starts by clarifying the role of branding orientation (BO among academic studies. It shortly introduces the development of the BO concepts. The empirical part consists of a search for and analysing of academic articles using a meta-analysis that consider BO in the accommodation industry. According to the results, significant appraisal of the branding building activities among higher star rating and luxury accommodation businesses are taking place due to the increasingly demanding guests. Thus, there is an upward pressure on small and medium accommodation businesses to survive or perform well. This paper recommends that scholars study the owners-managers, employees, and customer perspectives altogether, to better comprehend how large accommodation businesses displaying BO can generate superior performance. For the small and medium accommodation businesses, the emphasis is the owners-managers perceptions since they are the main decision-makers, and due to infancy of the small and medium enterprise (SME branding application.

  5. Disabling accommodation barriers: A study exploring how to better accommodate government employees with anxiety disorders.

    Science.gov (United States)

    Mellifont, Damian; Smith-Merry, Jennifer; Scanlan, Justin Newton

    2016-11-22

    Accommodating mental health in the workplace is challenging. Despite policy efforts to encourage the availability of mental health accommodations in the workplace, employees experiencing mental illness are missing out on accommodations that they need. To inform vocational rehabilitation professionals and managers in the public service of best practice accommodations for government employees with anxiety disorders. Thematic analysis was applied to data collected from the online Accommodating Government Employees with Anxiety Disorders Survey undertaken by 71 Australian public service employees diagnosed with at least one anxiety disorder. Our research results include theme and sub-theme representations of accommodations received, accommodations reported as missing, accommodations that study participants felt they couldn't request, along with rejected accommodations. From the study participants' accounts, three key findings supporting desirable vocational outcomes become apparent. First, that the availability of 'standard' flexible work arrangements, along with personalised accommodations, can assist persons with anxiety disorders (where needed) to reach and retain government positions. Second, the chief barriers reported to making accommodation requests revolve around fears of being stigmatised and penalised. Finally, there is a need for managerial decision-makers to remain open-minded, particularly when assessing requests for accommodations that may break from government norms.

  6. 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.

  7. 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.

  8. 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.

  9. Characterization and Conditions of the Internationalization Process of Companies in the Plastic Products Manufacturing Subsector in Bogota

    Directory of Open Access Journals (Sweden)

    Jackson Paul Pereira Silva

    2016-04-01

    Full Text Available This paper proposes a qualitative research by conducting surveys in 30 companies from the plastic products manufacturing subsector, based on theories of internationalization. It aims to find the main determinants of internationalization of these companies, while characterizing and analyzing evidence by contrasting practice and theory, in order to explain how the dynamics in the sector and its current state are and to propose recommendations for greater competitiveness and efficiency in foreign trade.

  10. Fiscal 2000 report on results. Development of technology for intermediate processing system for recycling mixed waste plastics; 2000 nendo kongo haipra saishohinka no tame no chukan shori system gijutsu no kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    R and D was conducted concerning intermediate processing technology for recycling mixed waste plastics, a technology for processing household waste plastics such as plastic containers and packaging into plastic pellets of suitable grain sizes, with fiscal 2000 results compiled. In the development of the element technologies, an air clutch structure was added that generates rotor slip when foreign matters were engaged, thereby unnecessitating pre-sorting work for locating and removing metallic foreign matters. Addition of an air separator and a sieving machine also helped to achieve a useful-plastics recovery rate of 75% or more in the PVC separation equipment. In the operation of a demonstration plant, a continuous operation was carried out in a three-shift 24-hour system for five days, with the data obtained. Further, waste plastics to which the Containers and Packaging Recycling Law was applicable were treated, resulting in the processing capacity of 0.51 t/h and the production capacity of 0.38 t/h, which both exceeded the target. In the evaluation of the intermediate processing system, the cost of waste plastics treatment turned out to be about 50,000 yen per ton in the case of a plant having a processing capacity of 6,000 tons per year and about 30,000 yen per ton in the case of a plant of 24,000 tons per year. (NEDO)

  11. Nonverbal accommodation in health care communication.

    Science.gov (United States)

    D'Agostino, Thomas A; Bylund, Carma L

    2014-01-01

    This exploratory study examined patterns of nonverbal accommodation within health care interactions and investigated the impact of communication skills training and gender concordance on nonverbal accommodation behavior. The Nonverbal Accommodation Analysis System (NAAS) was used to code the nonverbal behavior of physicians and patients within 45 oncology consultations. Cases were then placed in one of seven categories based on patterns of accommodation observed across the interaction. Results indicated that across all NAAS behavior categories, physician-patient interactions were most frequently categorized as joint convergence, followed closely by asymmetrical-patient convergence. Among paraverbal behaviors, talk time, interruption, and pausing were most frequently characterized by joint convergence. Among nonverbal behaviors, eye contact, laughing, and gesturing were most frequently categorized as asymmetrical-physician convergence. Differences were predominantly nonsignificant in terms of accommodation behavior between pre- and post-communication skills training interactions. Only gesturing proved significant, with post-communication skills training interactions more likely to be categorized as joint convergence or asymmetrical-physician convergence. No differences in accommodation were noted between gender-concordant and nonconcordant interactions. The importance of accommodation behavior in health care communication is considered from a patient-centered care perspective.

  12. Decreased accommodation during decompensation of distance exotropia.

    Science.gov (United States)

    Horwood, Anna M; Riddell, Patricia M

    2012-04-01

    Disparity cues can be a major drive to accommodation via the convergence accommodation to convergence (CA/C) linkage, but, on decompensation of exotropia, disparity cues are extinguished by suppression so this drive is lost. This study investigated accommodation and vergence responses to disparity, blur and proximal cues in a group of distance exotropes aged between 4 and 11 years both during decompensation and when exotropic. 19 participants with distance exotropia were tested using a PlusoptiXSO4 photo refractor set in a remote haploscopic device that assessed simultaneous vergence and accommodation to a range of targets incorporating different combinations of blur, disparity and proximal cues at four fixation distances between 2 m and 33 cm. Responses on decompensation were compared with those from the same children when their deviation was controlled. Manifest exotropia was more common in the more impoverished cue conditions. When decompensated for near, mean accommodation gain for the all-cue (naturalistic) target was significantly reduced (paccommodation of 2.33 D at 33 cm. The profile of near cues usage changed after decompensation, with blur and proximity driving residual responses, but these remaining cues did not compensate for loss of accommodation caused by the removal of disparity. Accommodation often reduces on decompensation of distance exotropia as the drive from convergence is extinguished, providing a further reason to try to prevent decompensation for near.

  13. Effect of Phenylephrine on the Accommodative System

    Directory of Open Access Journals (Sweden)

    José J. Esteve-Taboada

    2016-01-01

    Full Text Available Accommodation is controlled by the action of the ciliary muscle and mediated primarily by parasympathetic input through postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia. During accommodation the pupil constricts to increase the depth of focus of the eye and improve retinal image quality. Researchers have traditionally faced the challenge of measuring the accommodative properties of the eye through a small pupil and thus have relied on pharmacological agents to dilate the pupil. Achieving pupil dilation (mydriasis without affecting the accommodative ability of the eye (cycloplegia could be useful in many clinical and research contexts. Phenylephrine hydrochloride (PHCl is a sympathomimetic agent that is used clinically to dilate the pupil. Nevertheless, first investigations suggested some loss of functional accommodation in the human eye after PHCl instillation. Subsequent studies, based on different measurement procedures, obtained contradictory conclusions, causing therefore an unexpected controversy that has been spread almost to the present days. This manuscript reviews and summarizes the main research studies that have been performed to analyze the effect of PHCl on the accommodative system and provides clear conclusions that could help clinicians know the real effects of PHCl on the accommodative system of the human eye.

  14. 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...

  15. Impact of Information Incongruity and Authors Group Membership on Assimilation and Accommodation

    Science.gov (United States)

    Moskaliuk, J.; Matschke, C.

    2018-01-01

    Learning is a complex process that can be differentiated into assimilation and accommodation. The Internet enables both types of learning through collaboration. There is, however, little research investigating the specific impact of social and information incongruity on assimilation and accommodation. The current research investigates how the…

  16. 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...

  17. Theory of the axi-symmetric extrusion process of multi-layer materials with a strong plastic nonhomogeneity

    OpenAIRE

    J. Piwnik; A. Patejuk

    2008-01-01

    A novel simplified r hcorctical solution is found lor thc strcss starcs accompanying thc proccss of cxt ri~siono f ma![ i-laycr matcrialsunder rhc conditions af axial symmetry. Thc solution i~ bawd nn ~ h mc n dcl of pcrfcct plastic material satisfying thc Trcsca yicld condition.thc Haar-Karman conditions bcing sntisficd in each layer. Thc laycrs arc chnnctcrizcd by difrercnt yicld limits and stmng plasticnonhomogeneity. In thc ncighhoi~rhoorol f thc interfaces conrinuous variation of rhc yic...

  18. Non-linearity of the response accommodative convergence to accommodation ratio.

    Science.gov (United States)

    Johnston, Miriam S; Firth, Alison Y

    2013-09-01

    Previous studies have reported variation in stimulus accommodative convergence to accommodation (AC/A) ratio across differing accommodative stimuli. Response AC/A ratio was assessed across 4 accommodative demands to determine if these differences could be due to accommodative inaccuracies to stimuli. Twenty-three student participants aged 18 to 26 years (mean age 20.3 ± 1.7 years) successfully completed all testing conditions. The modified Thorington technique was used at 4 m to measure heterophoria. The Shin Nippon SRW 5000 infrared autorefractor was used to determine accommodative change to -1.50, -3.00, -4.50, and -6.00D lens stimuli. Significant differences were found in response AC/A ratio between different minus lens stimulated accommodative demands (p accommodative stimuli, but tended to increase with accommodative demand. Significant variability in response AC/A ratio was found, both within individuals to different accommodative demands, and between individuals across the data set.

  19. On the impact of the elastic-plastic flow upon the process of destruction of the solenoid in a super strong pulsed magnetic field

    Science.gov (United States)

    Krivosheev, S. I.; Magazinov, S. G.; Alekseev, D. I.

    2018-01-01

    At interaction of super strong magnetic fields with a solenoid material, a specific mode of the material flow forms. To describe this process, magnetohydrodynamic approximation is traditionally used. The formation of plastic shock-waves in material in a rapidly increasing pressure of 100 GPa/μs, can significantly alter the distribution of the physical parameters in the medium and affect the flow modes. In this paper, an analysis of supporting results of numerical simulations in comparison with available experimental data is presented.

  20. The influence of interactions between accommodation and convergence on the lag of accommodation.

    Science.gov (United States)

    Schor, C

    1999-03-01

    Several models of myopia predict that growth of axial length is stimulated by blur. Accommodative lag has been suggested as an important source of blur in the development of myopia and this study has modeled how cross-link interactions between accommodation and convergence might interact with uncorrected distance heterophoria and refractive error to influence accommodative lag. Accommodative lag was simulated with two models of interactions between accommodation and convergence (one with and one without adaptable tonic elements). Simulations of both models indicate that both uncorrected hyperopia and esophoria increase the lag of accommodative and uncorrected myopia and exophoria decrease the lag or introduce a lead of accommodation in response to the near (40 cm) stimulus. These effects were increased when gain of either cross-link, accommodative convergence (AC/A) or convergence accommodation (CA/C), was increased within a moderate range of values while the other was fixed at a normal value (clamped condition). These effects were exaggerated when both the AC/A and CA/C ratios were increased (covaried condition) and affects of cross-link gain were negated when an increase of one cross-link (e.g. AC/A) was accompanied by a reduction of the other cross-link (e.g. CA/C) (reciprocal condition). The inclusion of tonic adaptation in the model reduced steady state errors of accommodation for all conditions except when the AC/A ratio was very high (2 MA/D). Combinations of cross-link interactions between accommodation and convergence that resemble either clamped or reciprocal patterns occur naturally in clinical populations. Simulations suggest that these two patterns of abnormal cross-link interactions could affect the progression of myopia differently. Adaptable tonic accommodation and tonic vergence could potentially reduce the progression of myopia by reducing the lag of accommodation.

  1. Theory of the axi-symmetric extrusion process of multi-layer materials with a strong plastic nonhomogeneity

    Directory of Open Access Journals (Sweden)

    J. Piwnik

    2008-03-01

    Full Text Available A novel simplified r hcorctical solution is found lor thc strcss starcs accompanying thc proccss of cxt ri~siono f ma![ i-laycr matcrialsunder rhc conditions af axial symmetry. Thc solution i~ bawd nn ~ h mc n dcl of pcrfcct plastic material satisfying thc Trcsca yicld condition.thc Haar-Karman conditions bcing sntisficd in each layer. Thc laycrs arc chnnctcrizcd by difrercnt yicld limits and stmng plasticnonhomogeneity. In thc ncighhoi~rhoorol f thc interfaces conrinuous variation of rhc yicld limit i s a~sunicdZ. hc form of thc plastic zonc nndpsitions or the contact surfi~ccss eparating rhc laycrs nrc assumcd. Shcaring strcsscs and mcan prcssurc in a longitudinal scclion o f t hccxrruded rod arc cxprcsscd in tcrms of filnctions of the axial coordinatc z. Unknown fttnctions of thc singlc coordinatc z arc dctcrmincdFrom thc yicld conditions writtcn for thc contour of thc die. Accitratc analytical relations arc dcrivcd For tllc normal strcss distribution atthc surface of contact bctwccn thc dic and thc matcrial cxlrudcd, Using thc known normal and shcar stress dislrihutions (due to Iriclion,accuratc valuc of thc lower cstimate of thc cxtrusion forcc is dctcrrnincd. Thc sotution may hc applicd lo ~ h cca scs of arbitrary numhcr oflaycrs and arbitrary h rm oithc dic. I t may bc used to a rational analysis o f ~ h pcro ccss of cxirnsiol~o f multi-lnycr cylindrical rods.

  2. Accommodative Amplitude in School-Age Children

    Directory of Open Access Journals (Sweden)

    Ikaunieks Gatis

    2017-10-01

    Full Text Available In children, intensive near-work affects the accommodation system of the eye. Younger children, due to anatomical parameters, read at smaller distance than older children and we can expect that the accommodation system of younger can be affected more than that of older children. We wanted to test this hypothesis. Some authors showed that the norms of amplitude of accommodation (AA developed by Hofstetter (1950 not always could be applied for children. We also wanted to verify these results. A total of 106 (age 7-15 children participated in the study. Distance visual acuity was measured for all children and only data of children with good visual acuity 1.0 or more (dec. units were analysed (73 children. Accommodative amplitude was measured before and after lessons using subjective push-up technique (with RAF Near Point Ruler. The results showed that the amplitude of accommodation reduced significantly (p < 0.05 during the day and decrease of AA was similar in different age groups (about ~0.70 D. Additional measurements are needed to verify that the observed changes in AA were associated with fatigue effect. The results showed lower accommodation values compared to average values calculated according to the Hofstetter equation (p < 0.05.

  3. The temporoammonic input to the hippocampal CA1 region displays distinctly different synaptic plasticity compared to the Schaffer collateral input in vivo: significance for synaptic information processing

    Directory of Open Access Journals (Sweden)

    Ayla eAksoy Aksel

    2013-08-01

    Full Text Available In terms of its sub-regional differentiation, the hippocampal CA1 region receives cortical information directly via the perforant (temporoammonic path (pp-CA1 synapse and indirectly via the tri-synaptic pathway where the last relay station is the Schaffer collateral-CA1 synapse (Sc-CA1 synapse. Research to date on pp-CA1 synapses has been conducted predominantly in vitro and never in awake animals, but these studies hint that information processing at this synapse might be distinct to processing at the Sc-CA1 synapse. Here, we characterized synaptic properties and synaptic plasticity at the pp-CA1 synapse of freely behaving adult rats. We established that field excitatory postsynaptic potentials at the pp-CA1 have longer onset latencies and a shorter time-to-peak compared to the Sc-CA1 synapse. LTP (> 24h was successfully evoked by tetanic afferent stimulation of pp-CA1 synapses. Low frequency stimulation evoked synaptic depression at Sc-CA1 synapses, but did not elicit LTD at pp-CA1 synapses unless the Schaffer collateral afferents to the CA1 region had been severed. Paired-pulse responses also showed significant differences. Our data suggest that synaptic plasticity at the pp-CA1 synapse is distinct from the Sc-CA1 synapse and that this may reflect its specific role in hippocampal information processing.

  4. 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.

  5. 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.

  6. 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)

  7. Exploring the Relationship Between Students with Accommodations and Instructor Self-Efficacy in Complying with Accommodations

    Directory of Open Access Journals (Sweden)

    Anna M. Wright

    2017-06-01

    Full Text Available The willingness and flexibility of university instructors to comply with and provide accommodations for students with disabilities is critical to academic success. The authors examine how communication between students needing accommodations and university instructors impacts instructor self-efficacy, or instructors’ perception that they can meet the accommodation. Specifically, the authors’ explored the relationship between student self-disclosure of a disability and instructor empathy, flexibility, and self-efficacy in meeting student accommodation needs. Results revealed that the more a student self-discloses about a needed accommodation, the more self-efficacy an instructor has in making that accommodation. For the low-disclosure condition, empathy and flexibility were both significant predictors of self-efficacy, whereas, for the high-disclosure condition, only flexibility was a significant predictor of self-efficacy. Finally, instructors’ levels of empathy and flexibility both decreased after reading both the high and low self-disclosure scenarios.

  8. 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.

  9. 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.

  10. 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...

  11. 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

  12. 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.

  13. Fibre Bragg Grating Sensor Signal Post-processing Algorithm: Crack Growth Monitoring in Fibre Reinforced Plastic Structures

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2016-01-01

    A novel method to assess a crack growing/damage event in fibre reinforced plastic, using conventional single mode Fibre Bragg Grating sensors embedded in the host material is presented in this article. Three different damage mechanisms that can change the sensor output, longitudinal strain εxx......, transversal stress σyy;zz, and non-uniform strain εxx(xx), were identified. These damage mechanisms were identified during the experimental testing and linked with the sensor output using a digital image correlation technique. A dedicated algorithm to extract information from the reflected spectrum...... that enables crack detection was developed. Double Cantilever Beams specimens made with glass fibre and bonded with structural adhesive, were instrumented with a Fibre Bragg Grating array embedded in the host material, and tested using an experimental fracture procedure. This method was successfully validated...

  14. Staged pyrolysis, a process for chemical separation of waste plastics; Gestufte Pyrolyse als Verfahrensprinzip zur chemischen Auftrennung von Kunststoffgemischen

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, A.; Hornung, U.; Schoeneberger, A.; Weichmann, J. [Kaiserslautern Univ. (Germany). Fachbereich Chemie; Bockhorn, H. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Chemische Technik

    1996-12-31

    It is shown that staged pyrolysis of mixed plastics (polystyrene, polyethylene, polyvinyl chloride, polyamide 6) can be carried out in spherical recirculation reactors or in cascades of spherical recirculation reactors at exact temperature levels, and that the times of residue and reaction temperatures of laboratory systems can be calculated from the formal kinetic parameters obtained in nonisothermal and isothermal investigations. (orig) [Deutsch] Es konnte gezeigt werden, dass das Prinzip der stufenweisen Pyrolyse von Kunststoffgemischen (Polystyrol, Polyethylen, Polyvinylchlorid bzw. Polyamid 6) im Kugelkreislaufreaktor und der Kaskade aus Kugelkreislaufreaktoren unter Einhaltung der exakten Temperaturniveaus realisierbar ist und die Auslegung der Laboranlage hinsichtlich der Verweilzeiten und Temperaturniveaus mit Hilfe der formalkinetischen Parameter aus nicht-isothermen und isothermen Untersuchungen moeglich ist. (orig)

  15. Staged pyrolysis, a process for chemical separation of waste plastics; Gestufte Pyrolyse als Verfahrensprinzip zur chemischen Auftrennung von Kunststoffgemischen

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, A; Hornung, U; Schoeneberger, A; Weichmann, J [Kaiserslautern Univ. (Germany). Fachbereich Chemie; Bockhorn, H [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Chemische Technik

    1997-12-31

    It is shown that staged pyrolysis of mixed plastics (polystyrene, polyethylene, polyvinyl chloride, polyamide 6) can be carried out in spherical recirculation reactors or in cascades of spherical recirculation reactors at exact temperature levels, and that the times of residue and reaction temperatures of laboratory systems can be calculated from the formal kinetic parameters obtained in nonisothermal and isothermal investigations. (orig) [Deutsch] Es konnte gezeigt werden, dass das Prinzip der stufenweisen Pyrolyse von Kunststoffgemischen (Polystyrol, Polyethylen, Polyvinylchlorid bzw. Polyamid 6) im Kugelkreislaufreaktor und der Kaskade aus Kugelkreislaufreaktoren unter Einhaltung der exakten Temperaturniveaus realisierbar ist und die Auslegung der Laboranlage hinsichtlich der Verweilzeiten und Temperaturniveaus mit Hilfe der formalkinetischen Parameter aus nicht-isothermen und isothermen Untersuchungen moeglich ist. (orig)

  16. [Energy and memory efficient calculation of the accommodation demand in the artificial accommodation system].

    Science.gov (United States)

    Nagel, J A; Beck, C; Harms, H; Stiller, P; Guth, H; Stachs, O; Bretthauer, G

    2010-12-01

    Presbyopia and cataract are gaining more and more importance in the ageing society. Both age-related complaints are accompanied with a loss of the eye's ability to accommodate. A new approach to restore accommodation is the Artificial Accommodation System, an autonomous micro system, which will be implanted into the capsular bag instead of a rigid intraocular lens. The Artificial Accommodation System will, depending on the actual demand for accommodation, autonomously adapt the refractive power of its integrated optical element. One possibility to measure the demand for accommodation non-intrusively is to analyse eye movements. We present an efficient algorithm, based on the CORDIC technique, to calculate the demand for accommodation from magnetic field sensor data. It can be shown that specialised algorithms significantly shorten calculation time without violating precision requirements. Additionally, a communication strategy for the wireless exchange of sensor data between the implants of the left and right eye is introduced. The strategy allows for a one-sided calculation of the demand for accommodation, resulting in an overall reduction of calculation time by 50 %. The presented methods enable autonomous microsystems, such as the Artificial Accommodation System, to save significant amounts of energy, leading to extended autonomous run-times. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Bio-plastic (poly-hydroxy-alkanoate) production from municipal sewage sludge in the Netherlands: a technology push or a demand driven process?

    Science.gov (United States)

    Bluemink, E D; van Nieuwenhuijzen, A F; Wypkema, E; Uijterlinde, C A

    Valorisation of components from municipal 'waste' water and sewage sludge gets more and more attention in order to come to a circular economy by developing an efficient 'waste' to value concept. On behalf of the transition team 'Grondstoffenfabriek' ('Resource factory') a preliminary research was performed for all the Dutch water boards to assess the technical and economical feasibility of poly-hydroxy-alkanoate (PHA)-production from sewage sludge, a valuable product to produce bio-plastics. This study reveals that the production of bio-plastics from sewage sludge is feasible based on technical aspects, but not yet economically interesting, even though the selling price is relatively close to the actual PHA market price. (Selling price is in this particular case the indicative cost effective selling price. The cost effective selling price covers only the total production costs of the product.) Future process optimization (maximizing the volatile fatty acids production, PHA storage capacity, etc.) and market developments are needed and will result in cost reductions of the various sub-processes. PHA-production from sewage sludge at this stage is just a technology; every further research is needed to incorporate the backward integration approach, taking into account the market demand including associated product quality aspects.

  18. 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.

  19. A comparison of circulating fluidised bed combustion and gasification power plant technologies for processing mixtures of coal, biomass and plastic waste

    International Nuclear Information System (INIS)

    McIlveen-Wright, D.R.; Huang, Y.; McMullan, J.T.; Pinto, F.; Franco, C.; Gulyurtlu, I.; Armesto, L.; Cabanillas, A.; Caballero, M.A.; Aznar, M.P.

    2006-01-01

    Environmental regulations concerning emission limitations from the use of fossil fuels in large combustion plants have stimulated interest in biomass for electricity generation. The main objective of the present study was to examine the technical and economic viability of using combustion and gasification of coal mixed with biomass and plastic wastes, with the aim of developing an environmentally acceptable process to decrease their amounts in the waste stream through energy recovery. Mixtures of a high ash coal with biomass and/or plastic using fluidised bed technologies (combustion and gasification) were considered. Experiments were carried out in laboratory and pilot plant fluidised bed systems on the combustion and air/catalyst and air/steam gasification of these feedstocks and the data obtained were used in the techno-economic analyses. The experimental results were used in simulations of medium to large-scale circulating fluidised bed (CFB) power generation plants. Techno-economic analysis of the modelled CFB combustion systems showed efficiencies of around 40.5% (and around 46.5% for the modelled CFB gasification systems) when fuelled solely by coal, which were only minimally affected by co-firing with up to 20% biomass and/or wastes. Specific investments were found to be around $2150/kWe to $2400/kWe ($1350/kWe to $1450/kWe) and break-even electricity selling prices to be around $68/MWh to $78/MWh ($49/MWh to $54/MWh). Their emissions were found to be within the emission limit values of the large combustion plant directive. Fluidised bed technologies were found to be very suitable for co-firing coal and biomass and/or plastic waste and to offer good options for the replacement of obsolete or polluting power plants. (author)

  20. 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) ...

  1. Material recycling of post-consumer polyolefin bulk plastics: Influences on waste sorting and treatment processes in consideration of product qualities achievable.

    Science.gov (United States)

    Pfeisinger, Christian

    2017-02-01

    Material recycling of post-consumer bulk plastics made up of polyolefins is well developed. In this article, it is examined which effects on waste sorting and treatment processes influence the qualities of polyolefin-recyclats. It is shown that the properties and their changes during the product life-cycle of a polyolefin are defined by its way of polymerisation, its nature as a thermoplast, additives, other compound and composite materials, but also by the mechanical treatments during the production, its use where contact to foreign materials is possible and the waste sorting and treatment processes. Because of the sum of the effects influencing the quality of polyolefin-recyclats, conclusions are drawn for the material recycling of polyolefins to reach high qualities of their recyclats. Also, legal requirements like the EU regulation 1907/2006 concerning the registration, evaluation, authorisation and restrictions on chemicals are considered.

  2. From forced migration to forced arrival: the campization of refugee accommodation in European cities.

    Science.gov (United States)

    Kreichauf, René

    2018-01-01

    In the aftermath of large refugee arrivals in 2015, EU regulations and national asylum laws were tightened, especially those regarding reception and accommodation. The current contribution introduces the concept of "campization" to explain the impact of law and policy changes on the socio-spatial configuration and functions of refugee accommodation in European capital regions. Based on qualitative research concerning case studies for Athens, Berlin, and Copenhagen, I argue that refugee accommodation has increasingly been transformed into large, camp-like structures with lowered living standards and a closed character. This is shown by the structural, functional, and socio-spatial characteristics of the accommodation in the three case studies, as well as the political and administrative objectives that determine the campization of accommodation. The contribution lastly highlights changing notions and forms of containment, exclusion, and temporality as part of campization, and links this process to current trends in asylum and urban development.

  3. The Bilingual Adaptation: How Minds Accommodate Experience

    Science.gov (United States)

    Bialystok, Ellen

    2017-01-01

    According to some estimates, more than half of the world’s population is multilingual to some extent. Because of the centrality of language use to human experience and the deep connections between linguistic and nonlinguistic processing, it would not be surprising to find that there are interactions between bilingualism and cognitive and brain processes. The present review uses the framework of experience-dependent plasticity to evaluate the evidence for systematic modifications of brain and cognitive systems that can be attributed to bilingualism. The review describes studies investigating the relation between bilingualism and cognition in infants and children, younger and older adults, and patients, using both behavioral and neuroimaging methods. Excluded are studies whose outcomes focus primarily on linguistic abilities because of their more peripheral contribution to the central question regarding experience-dependent changes to cognition. Although most of the research discussed in the review reports some relation between bilingualism and cognitive or brain outcomes, several areas of research, notably behavioral studies with young adults, largely fail to show these effects. These discrepancies are discussed and considered in terms of methodological and conceptual issues. The final section proposes an account based on “executive attention” to explain the range of research findings and to set out an agenda for the next steps in this field. PMID:28230411

  4. 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

  5. Liquid and Gaseous Fuel from Waste Plastics by Sequential Pyrolysis and Catalytic Reforming Processes over Indonesian Natural Zeolite Catalysts

    Directory of Open Access Journals (Sweden)

    Mochamad Syamsiro

    2014-08-01

    Full Text Available In this study, the performance of several differently treated natural zeolites in a sequential pyrolysis and catalytic reforming of plastic materials i.e. polypropylene (PP and polystyrene (PS were investigated. The experiments were carried out on two stage reactor using semi-batch system. The samples were degraded at 500°C in the pyrolysis reactor and then reformed at 450°C in the catalytic reformer. The results show that the mordenite-type natural zeolites could be used as efficient catalysts for the conversion of PP and PS into liquid and gaseous fuel. The treatment of natural zeolites in HCl solution showed an increase of the surface area and the Si/Al ratio while nickel impregnation increased the activity of catalyst. As a result, liquid product was reduced while gaseous product was increased. For PP, the fraction of gasoline (C5-C12 increased in the presence of catalysts. Natural zeolite catalysts could also be used to decrease the heavy oil fraction (>C20. The gaseous products were found that propene was dominated in all conditions. For PS, propane and propene were the main components of gases in the presence of nickel impregnated natural zeolite catalyst. Propene was dominated in pyrolysis over natural zeolite catalyst. The high quality of gaseous product can be used as a fuel either for driving gas engines or for dual-fuel diesel engine.

  6. Quantifying the Mechanical Properties of Materials and the Process of Elastic-Plastic Deformation under External Stress on Material

    Directory of Open Access Journals (Sweden)

    Jan Valíček

    2015-11-01

    Full Text Available The paper solves the problem of the nonexistence of a new method for calculation of dynamics of stress-deformation states of deformation tool-material systems including the construction of stress-strain diagrams. The presented solution focuses on explaining the mechanical behavior of materials after cutting by abrasive waterjet technology (AWJ, especially from the point of view of generated surface topography. AWJ is a flexible tool accurately responding to the mechanical resistance of the material according to the accurately determined shape and roughness of machined surfaces. From the surface topography, it is possible to resolve the transition from ideally elastic to quasi-elastic and plastic stress-strain states. For detecting the surface structure, an optical profilometer was used. Based on the analysis of experimental measurements and the results of analytical studies, a mathematical-physical model was created and an exact method of acquiring the equivalents of mechanical parameters from the topography of surfaces generated by abrasive waterjet cutting and external stress in general was determined. The results of the new approach to the construction of stress-strain diagrams are presented. The calculated values agreed very well with those obtained by a certified laboratory VÚHŽ.

  7. Fabrication of highly crystalline oxide thin films on plastics: Sol–gel transfer technique involving high temperature process

    Directory of Open Access Journals (Sweden)

    Hiromitsu Kozuka

    2016-09-01

    Full Text Available Si(100 substrates were coated with a polyimide (PI–polyvinylpyrrolidone (PVP mixture film, and an alkoxide-derived TiO2 gel film was deposited on it by spin-coating. The gel films were fired under various conditions with final annealing at 600–1000 °C. The PI–PVP layer was completely decomposed at such high temperatures while the TiO2 films survived on Si(100 substrates without any damages. When the final annealing temperature was raised, the crystalline phase changed from anatase to rutile, and the crystallite size and the refractive index of the films tended to increase. The TiO2 films thus fired on Si(100 substrates were transferred to polycarbonate (PC substrates by melting the surface of the plastic substrate either in a near-infrared image furnace or on a hot plate under a load. Cycles of deposition and firing were found to be effective in achieving successful transfer even for the films finally annealed at 1000 °C. X-ray photoelectron spectroscopic analyses on the film/Si(100 interface suggested that the residual carbon or carbides at the interface could be a possible factor, but not a necessary and decisive factor that allows the film transfer.

  8. Quantifying the Mechanical Properties of Materials and the Process of Elastic-Plastic Deformation under External Stress on Material

    Science.gov (United States)

    Valíček, Jan; Harničárová, Marta; Öchsner, Andreas; Hutyrová, Zuzana; Kušnerová, Milena; Tozan, Hakan; Michenka, Vít; Šepelák, Vladimír; Mitaľ, Dušan; Zajac, Jozef

    2015-01-01

    The paper solves the problem of the nonexistence of a new method for calculation of dynamics of stress-deformation states of deformation tool-material systems including the construction of stress-strain diagrams. The presented solution focuses on explaining the mechanical behavior of materials after cutting by abrasive waterjet technology (AWJ), especially from the point of view of generated surface topography. AWJ is a flexible tool accurately responding to the mechanical resistance of the material according to the accurately determined shape and roughness of machined surfaces. From the surface topography, it is possible to resolve the transition from ideally elastic to quasi-elastic and plastic stress-strain states. For detecting the surface structure, an optical profilometer was used. Based on the analysis of experimental measurements and the results of analytical studies, a mathematical-physical model was created and an exact method of acquiring the equivalents of mechanical parameters from the topography of surfaces generated by abrasive waterjet cutting and external stress in general was determined. The results of the new approach to the construction of stress-strain diagrams are presented. The calculated values agreed very well with those obtained by a certified laboratory VÚHŽ. PMID:28793645

  9. Influence of accommodative lag upon the far-gradient measurement of accommodative convergence to accommodation ratio in strabismic patients.

    Science.gov (United States)

    Miyata, Manabu; Hasebe, Satoshi; Ohtsuki, Hiroshi

    2006-01-01

    To determine the influence of the lag of accommodation (LOA) on the accommodative convergence to accommodation (AC/A) ratio measured by the far-gradient method in strabismic patients. The AC/A ratio was measured with a distance target viewed with and without -3.00 diopter (D) addition lenses in 63 patients with different types of strabismus (age range, 7-34 years; range of strabismic angle, -60 to +40 prism diopters; refractive error range, -7.33 to +6.63 D). The LOA for the same lens was measured with an open-view-type autorefractometer. The stimulus AC/A ratio and the AC/A ratio adjusted by the individually measured LOA (adjusted AC/A ratio) were compared. The mean +/- SD of the LOA to the -3.00 D lenses was 1.06 +/- 0.43 D. The mean adjusted AC/A ratio was 41% greater than the stimulus AC/A ratio. The LOA differed widely among patients (0.13 to 2.14 D), and a large LOA tended to appear in myopic or young patients. The AC/A ratio obtained using the conventional far-gradient method is significantly biased by the LOA, and thus does not always represent the actual relationship between accommodation and vergence control systems. Copyright Japanese Ophthalmological Society 2006.

  10. Photorefractive keratectomy in refractive accommodative esotropia.

    Science.gov (United States)

    Bilgihan, K; Akata, F; Or, M; Hasanreisoğlu, B

    1997-01-01

    Photorefractive keratectomy (PRK) was performed on a 19-year-old man with hyperopic astigmatism and refractive accommodative esotropia. The patient was orthophoric while wearing spectacles, but had an esotropia of 30 prism dioptres at near and distance vision without spectacles. The best corrected visual acuity of the right eye was 20/50 and of the left eye was 20/20. The excessive accommodative convergence of the patient was eliminated by correcting the hyperopic refractive error by performing PRK, and the patient became orthophoric after the treatment.

  11. ADHD symptoms and benefit from extended time testing accommodations.

    Science.gov (United States)

    Lovett, Benjamin J; Leja, Ashley M

    2015-02-01

    To investigate the relationship between ADHD symptoms, executive functioning problems, and benefit from extended time testing accommodations. College students completed a battery of measures assessing processing speed and reading fluency, reading comprehension (under two different time limits), symptoms of ADHD, executive functioning deficits, and perceptions of need for extended time. Students reporting more symptoms of ADHD and executive functioning deficits actually benefited less from extended time, and students' perceptions of their timing needs did not predict benefit. Students with more ADHD symptoms are less likely to use extended time effectively, possibly because of their associated executive functioning problems. These results suggest there may be little justification for examining a student's ADHD symptoms when making extended time accommodation decisions. © 2013 SAGE Publications.

  12. 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...

  13. Temporal changes of CB1 cannabinoid receptor in the basal ganglia as a possible structure-specific plasticity process in 6-OHDA lesioned rats.

    Directory of Open Access Journals (Sweden)

    Gabriela P Chaves-Kirsten

    Full Text Available The endocannabinoid system has been implicated in several neurobiological processes, including neurodegeneration, neuroprotection and neuronal plasticity. The CB1 cannabinoid receptors are abundantly expressed in the basal ganglia, the circuitry that is mostly affected in Parkinson's Disease (PD. Some studies show variation of CB1 expression in basal ganglia in different animal models of PD, however the results are quite controversial, due to the differences in the procedures employed to induce the parkinsonism and the periods analyzed after the lesion. The present study evaluated the CB1 expression in four basal ganglia structures, namely striatum, external globus pallidus (EGP, internal globus pallidus (IGP and substantia nigra pars reticulata (SNpr of rats 1, 5, 10, 20, and 60 days after unilateral intrastriatal 6-hydroxydopamine injections, that causes retrograde dopaminergic degeneration. We also investigated tyrosine hydroxylase (TH, parvalbumin, calbindin and glutamic acid decarboxylase (GAD expression to verify the status of dopaminergic and GABAergic systems. We observed a structure-specific modulation of CB1 expression at different periods after lesions. In general, there were no changes in the striatum, decreased CB1 in IGP and SNpr and increased CB1 in EGP, but this increase was not sustained over time. No changes in GAD and parvalbumin expression were observed in basal ganglia, whereas TH levels were decreased and the calbindin increased in striatum in short periods after lesion. We believe that the structure-specific variation of CB1 in basal ganglia in the 6-hydroxydopamine PD model could be related to a compensatory process involving the GABAergic transmission, which is impaired due to the lack of dopamine. Our data, therefore, suggest that the changes of CB1 and calbindin expression may represent a plasticity process in this PD model.

  14. A Model of Supervisor Decision-Making in the Accommodation of Workers with Low Back Pain.

    Science.gov (United States)

    Williams-Whitt, Kelly; Kristman, Vicki; Shaw, William S; Soklaridis, Sophie; Reguly, Paula

    2016-09-01

    Purpose To explore supervisors' perspectives and decision-making processes in the accommodation of back injured workers. Methods Twenty-three semi-structured, in-depth interviews were conducted with supervisors from eleven Canadian organizations about their role in providing job accommodations. Supervisors were identified through an on-line survey and interviews were recorded, transcribed and entered into NVivo software. The initial analyses identified common units of meaning, which were used to develop a coding guide. Interviews were coded, and a model of supervisor decision-making was developed based on the themes, categories and connecting ideas identified in the data. Results The decision-making model includes a process element that is described as iterative "trial and error" decision-making. Medical restrictions are compared to job demands, employee abilities and available alternatives. A feasible modification is identified through brainstorming and then implemented by the supervisor. Resources used for brainstorming include information, supervisor experience and autonomy, and organizational supports. The model also incorporates the experience of accommodation as a job demand that causes strain for the supervisor. Accommodation demands affect the supervisor's attitude, brainstorming and monitoring effort, and communication with returning employees. Resources and demands have a combined effect on accommodation decision complexity, which in turn affects the quality of the accommodation option selected. If the employee is unable to complete the tasks or is reinjured during the accommodation, the decision cycle repeats. More frequent iteration through the trial and error process reduces the likelihood of return to work success. Conclusion A series of propositions is developed to illustrate the relationships among categories in the model. The model and propositions show: (a) the iterative, problem solving nature of the RTW process; (b) decision resources necessary

  15. 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.

  16. 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.

  17. Family accommodation mediates the association between anxiety ...

    African Journals Online (AJOL)

    Objective: The link between child anxiety and maternal anxiety has been well established but the factors underlying this association are not well understood. One potential factor is family accommodation, which describes ways in which parents change their behaviour to help a child avoid or alleviate anxiety. Family ...

  18. 24 CFR 100.204 - Reasonable accommodations.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Reasonable accommodations. 100.204 Section 100.204 Housing and Urban Development Regulations Relating to Housing and Urban Development OFFICE... dog. The building has a no pets policy. It is a violation of § 100.204 for the owner or manager of the...

  19. Force and Accommodation in World Politics

    National Research Council Canada - National Science Library

    Spangler, Stanley

    1991-01-01

    ..." and "carrots" to achieve political objectives. Clearly the subject-the use of force and accommodation to achieve political ends-is a topic that has been analyzed over the years by a host of observers, ranging from Niccol Machiavelli to John F. Kennedy...

  20. 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...

  1. Transmission Electron Microscopy of Amorphous Tandem Thin-Film Silicon Modules Produced by A Roll-to-Roll Process on Plastic Foil

    DEFF Research Database (Denmark)

    Couty, P.; Duchamp, Martial; Söderström, K.

    2011-01-01

    An improvement of the photo-current is expected when amorphous silicon solar cells are grown on a ZnO texture. A full understanding of the relationship between cell structure and electrical performance is essential for the rapid development of high efficiency VHF-tandem cells on textured substrates...... a control-lost of shape fidelity is used to smooth the texture and make it compatible with subsequent layer growth. Then, we present the electrical performances of the most promising reference solar cell single junction which was obtained on a roll-to-roll foil. Finally, a tandem amorphous/amorphous Si....... At first, we present the systematic study where amorphous cells are grown on ZnO based textures. For varying the texture, the same original master LPCVD ZnO was successively transferred to nickel molds and finally transferred to the plastic foil by roll-to-roll process. From TEM images, we show how...

  2. High-Temperature Structural Analysis of a Small-Scale Prototype of a Process Heat Exchanger (IV) - Macroscopic High-Temperature Elastic-Plastic Analysis -

    International Nuclear Information System (INIS)

    Song, Kee Nam; Hong, Sung Deok; Park, Hong Yoon

    2011-01-01

    A PHE (Process Heat Exchanger) is a key component required to transfer heat energy of 950 .deg. C generated in a VHTR (Very High Temperature Reactor) to a chemical reaction that yields a large quantity of hydrogen. A small-scale PHE prototype made of Hastelloy-X was scheduled for testing in a small-scale gas loop at the Korea Atomic Energy Research Institute. In this study, as a part of the evaluation of the high-temperature structural integrity of the PHE prototype, high-temperature structural analysis modeling, and macroscopic thermal and elastic-plastic structural analysis of the PHE prototype were carried out under the gas-loop test conditions as a preliminary qwer123$ study before carrying out the performance test in the gas loop. The results obtained in this study will be used to design the performance test setup for the modified PHE prototype

  3. Assessing the accommodation response after near visual tasks using different handheld electronic devices

    Directory of Open Access Journals (Sweden)

    Aikaterini I. Moulakaki

    Full Text Available ABSTRACT Purpose: To assess the accommodation response after short reading periods using a tablet and a smartphone as well as determine potential differences in the accommodation response at various stimulus vergences using a Hartmann- Shack aberrometer. Methods: Eighteen healthy subjects with astigmatism of less than 1 D, corrected visual acuity of 20/20 or better, and normal findings in an ophthalmic examination were enrolled. Accommodation responses were obtained under three different conditions: accommodation system of the eye relaxed and visually stressed with a tablet and an smartphone for 10 min, at a distance of 0.25 m from the subject's eyes. Three measurements of accommodation response were monocularly acquired at stimulus vergences ranging from 0 to 4 D (1-D step. Results: No statistically significant differences were found in the accommodation responses among the conditions. A moderate but gradually increasing root mean square, coma-like aberration was found for every condition. Conversely, the spherical aberration decreased as stimulus vergences increased. These outcomes were identified in comparison to the one-to-one ideal accommodation response, implying that a certain lag value was present in all stimulus vergences different from 0 D. Conclusions: The results support the hypothesis that the difference between the ideal and real accommodation responses is mainly attributed to parameters associated with the accommodation process, such as the near visual acuity, depth of focus, pupil diameter, and wavefront aberrations. The wavefront aberrations were dependent on the 3-mm pupil size selected in this study. The accommoda tion response was not dependent on the electronic device employed in each condition, and it was mainly associated with young age and level of amplitude of accommodation of the subjects.

  4. [Effects of orthokeratology lenses on the magnitude of accommodative lag and accommodativeconvergence/accommodation].

    Science.gov (United States)

    Ren, Qiujin; Yue, Hui; Zhou, Qing

    2016-02-01

    To evaluate the change in accommodative lag and accommodation convergence/accommodation (AC/A) after patients with myopia wear orthokeratology lenses. 
 A total of 48 myopic subjects (a test group), who wore orthokeratology lenses regularly, and 48 myopic subjects (a control group), who wore spectacles regularly, were enrolled for this study from January 2011 to January 2013 in Optometric Center, the Forth Hospital of Changsha. Accommodative lag was measured by fused cross cylinder method, where the patients should gaze at the front optotypes 40 cm away. Gradient of the AC/A ratio was measured by Von Grafe method to check closer distance heterophoria. Accommodative lag and AC/A ratio were analyzed by statistics.
 After 1-year follow-up, accommodative lag and AC/A rate in patients with low or moderate myopia in the test group was decreased in 1, 3, 6 months or 1 year compared with that in the control group (Paccommodative lag and high AC/A rate in patients with low or moderate myopia. The relationship between accommodation and convergence is improved by orthokeratology lenses. Orthokeratology is an effective way to control myopia.

  5. Report on achievements in fiscal 1998. Development of an interim processing technology to re-commercialize mixed waste plastics; 1998 nendo kongo haipura saishohinka no tame no chukan shori system gijutsu no kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-01

    The container and package recycling law is fully enforced starting fiscal 2000. Recycling obligation is placed also on plastic containers and packages discharged from households, excepting PET bottles for beverages and soy sauce. Therefore, it is required to establish an interim processing technology to process these materials into shapes easy for re-utilization and transportation, that is a technology to manufacture granules with adequate diameters. The purpose of this research is to develop the interim processing system technology. Design, fabrication and installation were performed on an interim processing system plant (a mixed waste plastic granule manufacturing facility) that can process annually waste plastics of 3,000 tons (0.5 t/h). The plant consists of the following four pieces of equipment: (1) a pulverizer, (2) a PVC sorting device, (3) a granulating device, and (4) a sizer. After the installed interim processing system demonstration plant has been trially operated and adjusted by each device, the whole plant was given the trial operation and adjustment to have verified that all the devices function normally. In addition, in order to evaluate economy of the waste plastics interim processing, the processing cost was calculated and the economic performance was evaluated preliminarily by using the rated electric power setting and trial operation data of each device. (NEDO)

  6. Accommodation and convergence during sustained computer work.

    Science.gov (United States)

    Collier, Juanita D; Rosenfield, Mark

    2011-07-01

    With computer usage becoming almost universal in contemporary society, the reported prevalence of computer vision syndrome (CVS) is extremely high. However, the precise physiological mechanisms underlying CVS remain unclear. Although abnormal accommodation and vergence responses have been cited as being responsible for the symptoms produced, there is little objective evidence to support this claim. Accordingly, this study measured both of these oculomotor parameters during a sustained period of computer use. Subjects (N = 20) were required to read text aloud from a laptop computer at a viewing distance of 50 cm for a sustained 30-minute period through their habitual refractive correction. At 2-minute intervals, the accommodative response (AR) to the computer screen was measured objectively using a Grand Seiko WAM 5500 optometer (Grand Seiko, Hiroshima, Japan). Additionally, the vergence response was assessed by measuring the associated phoria (AP), i.e., prism to eliminate fixation disparity, using a customized fixation disparity target that appeared on the computer screen. Subjects were asked to rate the degree of difficulty of the reading task on a scale from 1 to 10. Mean accommodation and AP values during the task were 1.07 diopters and 0.74∆ base-in (BI), respectively. The mean discomfort score was 4.9. No significant changes in accommodation or vergence were observed during the course of the 30-minute test period. There was no significant difference in the AR as a function of subjective difficulty. However, the mean AP for the subjects who reported the least and greatest discomfort during the task was 1.55∆ BI and 0, respectively (P = 0.02). CVS, after 30 minutes was worse in subjects exhibiting zero fixation disparity when compared with those subjects having a BI AP but does not appear to be related to differences in accommodation. A slightly reduced vergence response increases subject comfort during the task. Copyright © 2011 American Optometric

  7. A finite difference method for off-fault plasticity throughout the earthquake cycle

    Science.gov (United States)

    Erickson, Brittany A.; Dunham, Eric M.; Khosravifar, Arash

    2017-12-01

    We have developed an efficient computational framework for simulating multiple earthquake cycles with off-fault plasticity. The method is developed for the classical antiplane problem of a vertical strike-slip fault governed by rate-and-state friction, with inertial effects captured through the radiation-damping approximation. Both rate-independent plasticity and viscoplasticity are considered, where stresses are constrained by a Drucker-Prager yield condition. The off-fault volume is discretized using finite differences and tectonic loading is imposed by displacing the remote side boundaries at a constant rate. Time-stepping combines an adaptive Runge-Kutta method with an incremental solution process which makes use of an elastoplastic tangent stiffness tensor and the return-mapping algorithm. Solutions are verified by convergence tests and comparison to a finite element solution. We quantify how viscosity, isotropic hardening, and cohesion affect the magnitude and off-fault extent of plastic strain that develops over many ruptures. If hardening is included, plastic strain saturates after the first event and the response during subsequent ruptures is effectively elastic. For viscoplasticity without hardening, however, successive ruptures continue to generate additional plastic strain. In all cases, coseismic slip in the shallow sub-surface is diminished compared to slip accumulated at depth during interseismic loading. The evolution of this slip deficit with each subsequent event, however, is dictated by the plasticity model. Integration of the off-fault plastic strain from the viscoplastic model reveals that a significant amount of tectonic offset is accommodated by inelastic deformation ( ∼ 0.1 m per rupture, or ∼ 10% of the tectonic deformation budget).

  8. 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

  9. 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.

  10. Non-dimensional characterization of the friction stir/spot welding process using a simple Couette flow model part I: Constant property Bingham plastic solution

    International Nuclear Information System (INIS)

    Buck, Gregory A.; Langerman, Michael

    2004-01-01

    A simplified model for the material flow created during a friction stir/spot welding process has been developed using a boundary driven cylindrical Couette flow model with a specified heat flux at the inner cylinder for a Bingham plastic material. Non-dimensionalization of the constant property governing equations identified three parameters that influence the velocity and temperature fields. Analytic solutions to these equations are presented and some representative results from a parametric study (parameters chosen and varied over ranges expected for the welding of a wide variety of metals) are discussed. The results also provide an expression for the critical radius (location of vanishing material velocity) as functions of the relevant non-dimensional parameters. A final study was conducted in which values for the non-dimensional heat flux parameter were chosen to produce peak dimensional temperatures on the order of 80% of the melting temperature for a typical 2000 series aluminum. Under these conditions it was discovered that the ratio of the maximum rate of shear work within the material (viscous dissipation) to the rate of energy input at the boundary due to frictional heating, ranged from about 0.0005% for the lowest pin tool rotation rate, to about 1.3% for the highest tool rotation rate studied. Curve fits to previous Gleeble data taken for a number of aluminum alloys provide reasonable justification for the Bingham plastic constitutive model, and although these fits indicate a strong temperature dependence for critical flow stress and viscosity, this work provides a simple tool for more sophisticated model validation. Part II of this study will present numerical solutions for velocity and temperature fields resulting from the non-linear coupling of the momentum and energy equations created by temperature dependent transport properties

  11. Enhanced Hot Tensile Ductility of Mg-3Al-1Zn Alloy Thin-Walled Tubes Processed Via a Combined Severe Plastic Deformation

    Science.gov (United States)

    Fata, A.; Eftekhari, M.; Faraji, G.; Mosavi Mashhadi, M.

    2018-05-01

    In the current study, combined parallel tubular channel angular pressing (PTCAP) and tube backward extrusion (TBE), as a recently developed severe plastic deformation (SPD) method, were applied at 300 °C on a commercial Mg-3Al-1Zn alloy tubes to achieve an ultrafine grained structure. Then, the microstructure, hardness, tensile properties, and fractography evaluations were done at room temperature on the SPD-processed samples. Also, to study the hot tensile ductility of the SPD-processed samples, tensile testing was performed at an elevated temperature of 400 °C, and then, the fractured surface of the tensile samples was studied. It was observed that a bimodal microstructure, with large gains surrounded by many tiny ones, was created in the sample processed by PTCAP followed by TBE. This microstructure led to reach higher hardness and higher strength at room temperature and also led to reach very high elongation to failure ( 181%) at 400 °C. Also, the value of elongation to failure for this sample was 14.1% at room temperature. The fractographic SEM images showed the occurrence of predominately ductile fracture in the samples pulled at 400 °C. This was mostly due to the nucleation of microvoids and their subsequent growth and coalescence with each other.

  12. 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

  13. Reversible paired helical filament-like phosphorylation of tau is an adaptive process associated with neuronal plasticity in hibernating animals

    NARCIS (Netherlands)

    Arendt, T; Stieler, J; Strijkstra, AM; Hut, RA; Rudiger, J; Van der Zee, EA; Harkany, T; Holzer, M; Hartig, W; Härtig, Wolfgang

    2003-01-01

    Neurofibrillary pathology [ paired helical filaments (PHFs)] formed by the microtubule-associated protein tau in a hyperphosphorylated form is a major hallmark of Alzheimer's disease and related disorders. The process of tau phosphorylation, thought to be of critical importance for PHF formation,

  14. EVALUATION OF POLLUTION PREVENTION OPTIONS TO REDUCE STYRENE EMISSIONS FROM FIBER-REINFORCED PLASTIC OPEN MOLDING PROCESSES

    Science.gov (United States)

    Pollution prevention (P2) options to reduce styrene emissions, such as new materials, and application equipment, are commercially available to the operators of open molding processes. However, information is lacking on the emissions reduction that these options can achieve. To me...

  15. Evaluation of web sites of accommodation companies

    OpenAIRE

    Çubukcu, Muhammed İhsan

    2010-01-01

    OBJECTIVE: In a situation in which present economy is called as a digital economy, all organizations have to make up their informatics infrastructures. The societies that can use and share the information by using the technology as it requires will be societies that have the power of competition; and the power of competition will just be measured by the ability of reaching the information. This applicational study includes the analysis of the web pages of the five star accommodation companies...

  16. 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).

  17. An elastic-plastic fracture mechanics based methodology to characterize cracking behavior and its application to environmental assisted processes

    International Nuclear Information System (INIS)

    Alvarez, J.A.; Gutierrez-Solana, F.

    1999-01-01

    Cracking processes suffered by new structural and piping steels when used in petroleum or other energy installations have demonstrated the need for a cracking resistance characterization methodology. This methodology, valid for both elastic and elastoplastic regimes, should be able to define crack propagation kinetics as a function of their controlling local parameters. This work summarizes an experimental and analytical methodology that has been shown to be suitable for characterizing cracking processes using compact tensile specimens, especially subcritical environmentally assisted ones, such as those induced by hydrogen in microalloyed steels. The applied and validated methodology has been shown to offer quantitative results of cracking behavior and to correlate these with the existing fracture micromechanisms. (orig.)

  18. 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.

  19. Workplace accommodations for employees with disabilities: A multilevel model of employer decision-making.

    Science.gov (United States)

    Telwatte, Apsara; Anglim, Jeromy; Wynton, Sarah K A; Moulding, Richard

    2017-02-01

    Existing research suggests that the decision to grant or deny workplace accommodations for people with disabilities is influenced by a range of legal and nonlegal factors. However, less is known about how these factors operate at the within-person level. Thus, we proposed and tested a multilevel model of the accommodation decision-making process, which we applied to better understand why people with psychological disabilities often experience greater challenges in obtaining accommodations. A sample of 159 Australian adults, composed mostly of managers and HR professionals, read 12 vignettes involving requests for accommodations from existing employees. The requests differed in whether they were for psychological or physical disabilities. For each vignette, participants rated their empathy with the employee, the legitimacy of the employee's disability, the necessity for productivity, the perceived cost, and the reasonableness, and indicated whether they would grant the accommodation. Multilevel modeling indicated that greater empathy, legitimacy, and necessity, and lower perceived cost predicted perceptions of greater reasonableness and greater granting. Accommodation requests from employees with psychological disabilities were seen as less reasonable and were less likely to be granted; much of this effect seemed to be driven by perceptions that such accommodations were less necessary for productivity. Ratings on accommodations were influenced both by general between-person tendencies and within-person appraisals of particular scenarios. The study points to a need for organizations to more clearly establish guidelines for how decision-makers should fairly evaluate accommodation requests for employees with psychological disabilities and disability more broadly. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. 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.)

  1. 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

  2. Effect of Processing Parameters on Plastic Flow and Defect Formation in Friction-Stir-Welded Aluminum Alloy

    Science.gov (United States)

    Zeng, X. H.; Xue, P.; Wang, D.; Ni, D. R.; Xiao, B. L.; Ma, Z. Y.

    2018-04-01

    The effect of processing parameters on material flow and defect formation during friction stir welding (FSW) was investigated on 6.0-mm-thick 2014Al-T6 rolled plates with an artificially thickened oxide layer on the butt surface as the marker material. It was found that the "S" line in the stir zone (SZ) rotated with the pin and stayed on the retreating side (RS) and advancing side (AS) at low and high heat inputs, respectively. When the tool rotation rate was extremely low, the oxide layer under the pin moved to the RS first and then to the AS perpendicular to the welding direction, rather than rotating with the pin. The material flow was driven by the shear stresses produced by the forces at the pin-workpiece interface. With increases of the rotation rate, the depth of the shoulder-affected zone (SAZ) first decreased and then increased due to the decreasing shoulder friction force and increasing heat input. Insufficient material flow appeared in the whole of the SZ at low rotation rates and in the bottom of the SZ at high rotation rates, resulting in the formation of the "S" line. The extremely inadequate material flow is the reason for the lack of penetration and the kissing bonds in the bottom of the SZ at extremely low and low rotation rates, respectively.

  3. Processing and evaluation of x-ray line profiles measured from nanostructured materials produced by severe plastic deformation

    International Nuclear Information System (INIS)

    KEXrber, M.; Schafler, E.; Zehetbauer, M.

    2005-01-01

    Full text: The classification of the microstructure of nanostructured materials and its relation to macroscopic properties is essential for the development and application of nanomaterials. X-ray line profile analysis is a nondestructive method yielding a series of interesting microstructural parameters: the Bragg reflection of an ideal crystal is a narrow delta-function liKEX peak. Distortions of the regular crystal lattice as well as a finite size of the coherently scattering domains lead to a significant broadening of the peak. By using physical models describing the individual types of broadening it is possible to relate the broadening of the peak to the microstructure of the material. The most successful applications to date assume mainly size and strain broadening. From these models various techniques have been developed to evaluate the same physical quantities via individual methods. Among these methods are the Williamson-Hall and Warren Averbach methods, their so called 'modified' variants and multiple-whole-profile-fitting/modeling. A number of typical problems arising during data preparation and evaluation are presented and a procedure to optimize the processing of the experimental data is given. Refs. 9 (author)

  4. 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

  5. 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...

  6. Reminder : Reimbursement of education fees / accommodation fees

    CERN Multimedia

    2003-01-01

    Your attention is drawn to the 20 km distance limit set in Article R A 8.01 of the Staff Regulations, namely, that only accommodation fees of students attending an educational establishment which is more than 20 km from the place of residence and the duty station of the member of the personnel are reimbursed by the Organization, subject to the percentage rate and maximum amounts set out in this article and in Administrative Circular N° 12. Human Resources Division Tel : 72862 / 74474

  7. Reimbursement of education fees / accommodation fees

    CERN Multimedia

    2003-01-01

    Your attention is drawn to the 20 km distance limit set in Article R A 8.01 of the Staff Regulations, namely, that only accommodation fees of students attending an educational establishment which is more than 20 km from the place of residence and the duty station of the member of the personnel are reimbursed by the Organization, subject to the percentage rate and maximum amounts set out in this article and in Administrative Circular N° 12. Human Resources Division Tel: 72862 / 74474

  8. 28 CFR 36.310 - Transportation provided by public accommodations.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Transportation provided by public... BASIS OF DISABILITY BY PUBLIC ACCOMMODATIONS AND IN COMMERCIAL FACILITIES Specific Requirements § 36.310 Transportation provided by public accommodations. (a) General. (1) A public accommodation that provides...

  9. Current challenges for pre-earthquake electromagnetic emissions: shedding light from micro-scale plastic flow, granular packings, phase transitions and self-affinity notion of fracture process

    Directory of Open Access Journals (Sweden)

    K. Eftaxias

    2013-10-01

    Full Text Available Are there credible electromagnetic (EM potential earthquake (EQ precursors? This a question debated in the scientific community and there may be legitimate reasons for the critical views. The negative view concerning the existence of EM potential precursors is enhanced by features that accompany their observation which are considered as paradox ones, namely, these signals: (i are not observed at the time of EQs occurrence and during the aftershock period, (ii are not accompanied by large precursory strain changes, (iii are not accompanied by simultaneous geodetic or seismological precursors and (iv their traceability is considered problematic. In this work, the detected candidate EM potential precursors are studied through a shift in thinking towards the basic science findings relative to granular packings, micron-scale plastic flow, interface depinning, fracture size effects, concepts drawn from phase transitions, self-affine notion of fracture and faulting process, universal features of fracture surfaces, recent high quality laboratory studies, theoretical models and numerical simulations. We try to contribute to the establishment of strict criteria for the definition of an emerged EM anomaly as a possibly EQ-related one, and to the explanation of potential precursory EM features which have been considered as paradoxes. A three-stage model for EQ generation by means of pre-EQ fracture-induced EM emissions is proposed. The claim that the observed EM potential precursors may permit a real-time and step-by-step monitoring of the EQ generation is tested.

  10. Current challenges for pre-earthquake electromagnetic emissions: shedding light from micro-scale plastic flow, granular packings, phase transitions and self-affinity notion of fracture process

    Science.gov (United States)

    Eftaxias, K.; Potirakis, S. M.

    2013-10-01

    Are there credible electromagnetic (EM) potential earthquake (EQ) precursors? This a question debated in the scientific community and there may be legitimate reasons for the critical views. The negative view concerning the existence of EM potential precursors is enhanced by features that accompany their observation which are considered as paradox ones, namely, these signals: (i) are not observed at the time of EQs occurrence and during the aftershock period, (ii) are not accompanied by large precursory strain changes, (iii) are not accompanied by simultaneous geodetic or seismological precursors and (iv) their traceability is considered problematic. In this work, the detected candidate EM potential precursors are studied through a shift in thinking towards the basic science findings relative to granular packings, micron-scale plastic flow, interface depinning, fracture size effects, concepts drawn from phase transitions, self-affine notion of fracture and faulting process, universal features of fracture surfaces, recent high quality laboratory studies, theoretical models and numerical simulations. We try to contribute to the establishment of strict criteria for the definition of an emerged EM anomaly as a possibly EQ-related one, and to the explanation of potential precursory EM features which have been considered as paradoxes. A three-stage model for EQ generation by means of pre-EQ fracture-induced EM emissions is proposed. The claim that the observed EM potential precursors may permit a real-time and step-by-step monitoring of the EQ generation is tested.

  11. Environmental analysis of plastic production processes: comparing petroleum-based polypropylene and polyethylene with biologically-based poly-beta-hydroxybutyric acid using life cycle analysis.

    Science.gov (United States)

    Harding, K G; Dennis, J S; von Blottnitz, H; Harrison, S T L

    2007-05-31

    Polymers based on olefins have wide commercial applicability. However, they are made from non-renewable resources and are characterised by difficulty in disposal where recycle and re-use is not feasible. Poly-beta-hydroxybutyric acid (PHB) provides one example of a polymer made from renewable resources. Before motivating its widespread use, the advantages of a renewable polymer must be weighed against the environmental aspects of its production. Previous studies relating the environmental impacts of petroleum-based and bio-plastics have centred on the impact categories of global warming and fossil fuel depletion. Cradle-to-grave studies report equivalent or reduced global warming impacts, in comparison to equivalent polyolefin processes. This stems from a perceived CO(2) neutral status of the renewable resource. Indeed, no previous work has reported the results of a life cycle assessment (LCA) giving the environmental impacts in all major categories. This study investigates a cradle-to-gate LCA of PHB production taking into account net CO(2) generation and all major impact categories. It compares the findings with similar studies of polypropylene (PP) and polyethylene (PE). It is found that, in all of the life cycle categories, PHB is superior to PP. Energy requirements are slightly lower than previously observed and significantly lower than those for polyolefin production. PE impacts are lower than PHB values in acidification and eutrophication.

  12. Can mergers-in-progress be unmerged in speech accommodation?

    Science.gov (United States)

    Babel, Molly; McAuliffe, Michael; Haber, Graham

    2013-01-01

    This study examines spontaneous phonetic accommodation of a dialect with distinct categories by speakers who are in the process of merging those categories. We focus on the merger of the NEAR and SQUARE lexical sets in New Zealand English, presenting New Zealand participants with an unmerged speaker of Australian English. Mergers-in-progress are a uniquely interesting sound change as they showcase the asymmetry between speech perception and production. Yet, we examine mergers using spontaneous phonetic imitation, which is phenomenon that is necessarily a behavior where perceptual input influences speech production. Phonetic imitation is quantified by a perceptual measure and an acoustic calculation of mergedness using a Pillai-Bartlett trace. The results from both analyses indicate spontaneous phonetic imitation is moderated by extra-linguistic factors such as the valence of assigned conditions and social bias. We also find evidence for a decrease in the degree of mergedness in post-exposure productions. Taken together, our results suggest that under the appropriate conditions New Zealanders phonetically accommodate to Australian English and that in the process of speech imitation, mergers-in-progress can, but do not consistently, become less merged.

  13. Can mergers-in-progress be unmerged in speech accommodation?

    Directory of Open Access Journals (Sweden)

    Molly eBabel

    2013-09-01

    Full Text Available This study examines spontaneous phonetic accommodation of a dialect with distinct categories by speakers who are in the process of merging those categories. We focus on the merger of the NEAR and SQUARE lexical sets in New Zealand English, presenting New Zealand participants with an unmerged speaker of Australian English. Mergers-in-progress are a uniquely interesting sound change as they showcase the asymmetry between speech perception and production. Yet, we examine mergers using spontaneous phonetic imitation, which is phenomenon that is necessarily a behavior where perceptual input influences speech production. Phonetic imitation is quantified by a perceptual measure and an acoustic calculation of mergedness using a Pillai-Bartlett trace. The results from both analyses indicate spontaneous phonetic imitation is moderated by extra-linguistic factors such as the valence of assigned conditions and social bias. We also find evidence for a decrease in the degree of mergedness in post-exposure productions. Taken together, our results suggest that under the appropriate conditions New Zealanders phonetically accommodate to Australian English and that in the process of speech imitation, mergers-in-progress can, but do not consistently, become less merged.

  14. Effect of heterophoria measurement technique on the clinical accommodative convergence to accommodation ratio.

    Science.gov (United States)

    Escalante, Jaime Bernal; Rosenfield, Mark

    2006-05-01

    Measurement of the stimulus accommodative convergence to accommodation (AC/A) ratio is a standard procedure in clinical optometric practice. Typically, heterophoria is assessed at several accommodative stimulus levels, and the gradient of the vergence to accommodation function computed. A number of procedures are available for the subjective measurement of heterophoria, but it is unclear whether the use of different vergence measurement techniques will alter the obtained AC/A value. Accordingly, the current study compared AC/A ratios measured using 3 clinical subjective heterophoria tests, namely the von Graefe (VG), Maddox Rod (MR), and Modified Thorington (MT) procedures. The AC/A ratio was measured in 60 visually normal subjects between 20 and 25 years of age using each of the 3 procedures listed above. The accommodative stimulus was varied by the introduction of +/-1.00 diopter (D) spherical lenses over the distance refractive correction while subjects viewed a target at a viewing distance of 40 cm. To examine the repeatability of each procedure, the AC/A ratio was measured on 2 separate occasions for each measurement technique, with the 2 sessions being separated by at least 24 hours. Mean values of stimulus AC/A ratio measured using the VG, MR, and MT procedures were 3.47, 2.99, and 2.46Delta/D, respectively. These differences were significant (p=0.0001). In addition, the coefficient of repeatability for the 3 techniques was 2.22, 1.99, and 1.20 Delta/D, respectively. Ratios obtained using the Modified Thorington technique with +/-1.00 D lenses showed the best repeatability, whereas the poorest repeatability was found with the von Graefe technique when only +1.00 D lenses were used to vary the accommodative stimulus. Accordingly, we recommend that that Modified Thorington procedure with +/-1.00 D lenses be used to quantify heterophoria during clinical measurement of the stimulus AC/A ratio.

  15. 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.

  16. 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...

  17. Supporting the development process for building products by the use of research portfolio analysis: A case study for wood plastics composite materials

    OpenAIRE

    Friedrich, Daniel; Luible, Andreas

    2016-01-01

    Today’s plastics are increasingly compounded using renewable fibres. Such composites raised the interest of the massively bulk-plastics consuming building industry. However, “green” products are still rare and their development constitutes a challenge particularly for small companies. Our study evaluated European scientific projects in composites from which we derived a Research Portfolio serving as future matrix for ideation. It was found that research databanks can serve as basis for str...

  18. 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

  19. 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.

  20. Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200 C and method of fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Carey, P.G.; Smith, P.M.; Havens, J.H.; Jones, P.

    1999-01-05

    Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100 C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired. 12 figs.

  1. Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200.degree. C and method of fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Carey, Paul G. (Mountain View, CA); Smith, Patrick M. (San Ramon, CA); Havens, John (San Diego, CA); Jones, Phil (Marlborough, GB)

    1999-01-01

    Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100.degree. C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired.

  2. Phacoemulsification and implantation of an accommodating IOL after PRK.

    Science.gov (United States)

    Aslanides, loannis M; Plainis, Sotiris; Kumar, Vinod; Ginis, Harilaos

    2006-01-01

    To present a case of phacoemulsification and implantation of an accommodating intraocular lens (IOL) in a patient with cataract formation after previous refractive surgery. A 50-year-old man, who initially had photorefractive keratectomy to correct moderate myopia, developed a cataract in one eye. He subsequently underwent phacoemulsification and implantation of a 1CU accommodating IOL, as he wished to remain spectacle independent. The patient's distance vision was fully restored. However, accommodative function, which was assessed using subjective and novice objective techniques, was only partially restored. Although the accommodating IOL fully restored the patient's distance vision, accommodative function was only partially restored.

  3. 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.

  4. [Comparison study on subjective and objective measurements of the accommodative convergence to accommodation ratio].

    Science.gov (United States)

    Xu, Jing-jing; Xu, Dan; Huang, Tao; Jiang, Jian; Lü, Fan

    2012-05-01

    To detect the accommodative convergence to accommodation (AC/A) ratios measured respectively by objective and subjective methods. The differences and its relative factors were explored. Forty young volunteers were measured by eye tracker to get the amount of convergence when fixating at the target at 100 cm, 50 cm, 33 cm and 25 cm and were measured by infrared auto-refractor to get corresponding accommodative responses. AC/A ratio based on these two measurements were compared with the calculated and the gradient AC/A ratio from Von Graefe tests. Mean value of stimulated AC/A ratio measured by eye tracker was higher than the calculated and gradient AC/A ratio by Von Graefe method (P = 0.003, 0.001). There are statistic correlation (r = 0.871, P = 0.000) and difference (P = 0.000) between stimulated AC/A ratio and response AC/A ratios both measured by eye tracker, and the difference trends to be greater with the higher AC/A ratio. The objective AC/A ratio is usually higher than the clinical subjective measurement because of more proximal effect. The response AC/A ratio measured objectively may reveal realistically the mutual effect and relationship between accommodation and convergence and it seems to be more credible to be the monitor parameter on progression of myopia in clinics.

  5. 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 ...

  6. 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.

  7. The standpoint of persons with hearing loss on work disparities and workplace accommodations.

    Science.gov (United States)

    Shaw, Lynn; Tetlaff, Britta; Jennings, Mary Beth; Southall, Kenneth E

    2013-01-01

    The perspectives of persons who live and work with hearing loss were sought to examine workplace accommodation challenges and strategies. A convenience sample of seven older adults with hearing loss participated in in-depth interviews. A systematic grounded theory approach informed the study design and analysis. Categories of facilitators and challenges in the data were identified through axial coding and clustering. Core categories of social processes emerged through constant comparison and theoretical sampling of the data to reveal the actions and interactions used to negotiate or implement adaptations or workplace accommodations. Persons with hearing loss use a realm of strategies to live and work with a hearing loss. Social processes used to navigate the challenges to working with hearing loss and to manage optimal work performance included: self-accommodation, self-advocacy, self-management of hearing loss, and lobbying. Success in overcoming work disparities for persons with hearing loss requires individuals to take control of identifying their needs within the workplace and at home, and to negotiate for specific accommodations. These strategies and processes draw attention to the need for a repository on contextualized workplace accommodation strategies for improving communication and hearing in the workplace. Further to this a best practice guide for use by workers, employers, and work rehabilitation and health care workers is indicated.

  8. The Failure to Construct Proof Based on Assimilation and Accommodation Framework from Piaget

    Science.gov (United States)

    Netti, Syukma; Nusantara, Toto; Subanji; Abadyo; Anwar, Lathiful

    2016-01-01

    The purpose of this article is to describe the process of a proof construction. It is more specific on the failure of the process. Piaget's frameworks, assimilation and accommodation, were used to analyze it. Method of this research was qualitative method. Data were collected by asking five students working on problems of proof using think aloud…

  9. Caste-biased gene expression in a facultatively eusocial bee suggests a role for genetic accommodation in the evolution of eusociality.

    Science.gov (United States)

    Jones, Beryl M; Kingwell, Callum J; Wcislo, William T; Robinson, Gene E

    2017-01-11

    Developmental plasticity may accelerate the evolution of phenotypic novelty through genetic accommodation, but studies of genetic accommodation often lack knowledge of the ancestral state to place selected traits in an evolutionary context. A promising approach for assessing genetic accommodation involves using a comparative framework to ask whether ancestral plasticity is related to the evolution of a particular trait. Bees are an excellent group for such comparisons because caste-based societies (eusociality) have evolved multiple times independently and extant species exhibit different modes of eusociality. We measured brain and abdominal gene expression in a facultatively eusocial bee, Megalopta genalis, and assessed whether plasticity in this species is functionally linked to eusocial traits in other bee lineages. Caste-biased abdominal genes in M. genalis overlapped significantly with caste-biased genes in obligately eusocial bees. Moreover, caste-biased genes in M. genalis overlapped significantly with genes shown to be rapidly evolving in multiple studies of 10 bee species, particularly for genes in the glycolysis pathway and other genes involved in metabolism. These results provide support for the idea that eusociality can evolve via genetic accommodation, with plasticity in facultatively eusocial species like M. genalis providing a substrate for selection during the evolution of caste in obligately eusocial lineages. © 2017 The Author(s).

  10. Accommodating life sciences on the Space Station

    Science.gov (United States)

    Arno, Roger D.

    1987-01-01

    The NASA Ames Research Center Biological Research Project (BRP) is responsible for identifying and accommodating high priority life science activities, utilizing nonhuman specimens, on the Space Station and is charged to bridge the gap between the science community and the Space Station Program. This paper discusses the approaches taken by the BRP in accomodating these research objectives to constraints imposed by the Space Station System, while maintaining a user-friendly environment. Consideration is given to the particular research disciplines which are given priority, the science objectives in each of these disciplines, the functions and activities required by these objectives, the research equipment, and the equipment suits. Life sciences programs planned by the Space Station participating partners (USA, Europe, Japan, and Canada) are compared.

  11. Processing demands upon cognitive, linguistic, and articulatory functions promote grey matter plasticity in the adult multilingual brain: Insights from simultaneous interpreters.

    Science.gov (United States)

    Elmer, Stefan; Hänggi, Jürgen; Jäncke, Lutz

    2014-05-01

    Until now, considerable effort has been made to determine structural brain characteristics related to exceptional multilingual skills. However, at least one important question has not yet been satisfactorily addressed in the previous literature, namely whether and to which extent the processing demands upon cognitive, linguistic, and articulatory functions may promote grey matter plasticity in the adult multilingual brain. Based on the premise that simultaneous interpretation is a highly demanding linguistic task that places strong demands on executive and articulatory functions, here we compared grey matter volumes between professional simultaneous interpreters (SI) and multilingual control subjects. Thereby, we focused on a specific set of a-priori defined bilateral brain regions that have previously been shown to support neurocognitional aspects of language control and linguistic functions in the multilingual brain. These regions are the cingulate gyrus, caudate nucleus, frontal operculum (pars triangularis and opercularis), inferior parietal lobe (IPL) (supramarginal and angular gyrus), and the insula. As a main result, we found reduced grey matter volumes in professional SI, compared to multilingual controls, in the left middle-anterior cingulate gyrus, bilateral pars triangularis, left pars opercularis, bilateral middle part of the insula, and in the left supramarginal gyrus (SMG). Interestingly, grey matter volume in left pars triangularis, right pars opercularis, middle-anterior cingulate gyrus, and in the bilateral caudate nucleus was negatively correlated with the cumulative number of interpreting hours. Hence, we provide first evidence for an expertise-related grey matter architecture that may reflect a composite of brain characteristics that were still present before interpreting training and training-related changes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. The Improvement of the Accommodation Offer in Vojvodina (Serbia as a Factor of its Competitiveness on the Market

    Directory of Open Access Journals (Sweden)

    Svetlana Vukosav

    2009-06-01

    Full Text Available The accommodation offer, particularly hotel industry in Vojvodina is experiencing significant changes today both in quality and in quantity compared to the period 10 years ago. These positive changes and the improvement of the receptive base are a direct consequence of the transition process, ownership transformation and investment in accommodation facilities, which is reflected through the constant increase of foreign tourists, foreign exchange input, as well as market share and competitiveness of certain types of accommodation. Investments in the accommodation offer in Vojvodina are one of the priorities in the Strategy of Tourism Development of Serbia, where a significant increase in the number of accommodation units in the Province is expected.

  13. 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...

  14. Workplace accommodations for people with mental illness: a scoping review.

    Science.gov (United States)

    McDowell, Caitlin; Fossey, Ellie

    2015-03-01

    Disability discrimination legislation means that employees with a disability or mental illness are legally entitled to reasonable workplace accommodations that enable them to work effectively and safely. This scoping review aims to investigate the types of workplace accommodations provided for people with mental illness, and their costs and benefits. A literature search was conducted using five electronic databases. Peer reviewed research articles published between 1993 and June 2013 were included in this scoping review and their quality was assessed. Opinion papers, reports, and case descriptions were excluded. Nine studies explored workplace accommodations for people with mental illness. The most commonly reported work-related accommodations were flexible scheduling/reduced hours, modified training and supervision, and modified job duties/descriptions. The least common type of accommodation was physical modification to the workplace. For employees with persistent mental illness who were accessing a supported employment agency, the majority of accommodations related to support from the job coach or employment specialist, such as facilitating communication with the employer during hiring or on the job. The quality of the studies varied considerably and the benefits of the accommodations are not yet well documented. There is limited evidence that a larger number of workplace accommodations are associated with longer job tenure. Workplace accommodations appear to be important to support employees with mental illness, but more accessible information about how disability discrimination legislation applies to this population is needed. Future research should address the implementation and effectiveness of mental health-related workplace accommodations.

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

    NARCIS (Netherlands)

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

    2017-01-01

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

  16. The effect of longitudinal chromatic aberration on the lag of accommodation and depth of field.

    Science.gov (United States)

    Jaskulski, Mateusz; Marín-Franch, Iván; Bernal-Molina, Paula; López-Gil, Norberto

    2016-11-01

    Longitudinal chromatic aberration is present in all states of accommodation and may play a role in the accommodation response and the emmetropisation process. We study the change of the depth of field (DOFi) with the state of accommodation, taking into account the longitudinal chromatic aberration. Subjective DOFi was defined as the range of defocus beyond which the blur of the target (one line of optotypes of 0.1 logMAR shown on a black-and-white microdisplay, seen through different colour filters) was perceived as objectionable. The subject's eye was paralysed and different, previously-measured accommodative states (corresponding to the accommodative demands of 0D, 2D and 4D) were simulated with a deformable mirror. Different colour conditions (monochromatic red, green and blue and polychromatic (white) were tested. The DOFi was measured subjectively, using a motorised Badal system. Taking as reference the average accommodative response for the white stimulus, the blue response exhibits on average a lead of 0.45 ± 0.09D, the green a negligible lead of 0.07 ± 0.02D and red a lag of 0.49 ± 0.10D. The monochromatic DOFi, calculated by averaging DOFi over the red, green and blue colour conditions for each accommodative demand was 1.10 ± 0.10D for 0D, 1.20 ± 0.08D for 2D, and 1.26 ± 0.40D for 4D. The polychromatic white DOFi were greater than the average monochromatic DOFi by 19%, 9% and 14% for 0D, 2D, and 4D of accommodative demand, respectively. The longitudinal chromatic aberration causes a dioptric shift of the monochromatic accommodation response. The study did not reveal this shift to depend on the accommodative demand or to have an effect on the DOFi. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

  17. 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.

  18. 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.

  19. 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...

  20. 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)

  1. 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 ...

  2. Marketing of Accommodation services : Case-Hotel Azam Cameroon

    OpenAIRE

    Youkam, Germaine

    2012-01-01

    Cameroon is Africa in miniature with a lot of tourist attractions owing to its geological and cultural diversity. Natural features include beaches, deserts, mountains, rainforests, and savannas. Accommodation services have been a grand phenomenon within the tourism industry in Cameroon. The accommodation sector has developed tremendously within the past decades. The objective of this research work was to find about out the marketing of accommodation services in Cameroon with Hotel Azam as...

  3. Evaluation of Accommodation Companies Recreation Activities in İstanbul

    OpenAIRE

    Aslı ALBAYRAK

    2012-01-01

    Recreation activities represent quality of company, image and attractiveness for both staying guests and day use guests. At the same time recreation can be important income source for accommodation companies. This study investigate the web page of 82 five star accommodation company in Istanbul from the side of recreation activities. At the end of the study find that most of accommodation company don't have in place recreation activities, recreation tab and representation about activities in t...

  4. A NOVELTY MODEL OF ONLINE ACCOMMODATION PRESENTATION AND DISCOVERY

    OpenAIRE

    Sjekavica, Tomo; Žitnik, Marjan; Miličević, Mario

    2017-01-01

    Extreme expansion of digital technologies and social networks in recent years has had a huge impact on the travel market and online tourism. Along with the digitalization of tourism and travel business, every day more and more accommodation bookings take place online. Most popular online travel web sites are commonly charging provision for the accommodation booking and don't allow direct contact with the accommodation owners. Today tourists demand more for their money, so they are more likely...

  5. Location as a determinant of accommodation prices: managerial approach

    OpenAIRE

    Napierała, Tomasz; Leśniewska, Katarzyna

    2014-01-01

    In the presentation authors discuss the location-based factors’ impact on accommodation prices. The aim of the presentation is to compare the results of qualitative and quantitative research on location-based determinants of accommodation prices in Lodz Metropolitan Area (Poland). The authors employ methodological triangulation (Yeung 2000), both to explore statistical significance of location-based determinants of accommodation prices, and to present managerial opinions about the influence o...

  6. Transcript expression plasticity as a response to alternative larval host plants in the speciation process of corn and rice strains of Spodoptera frugiperda.

    Science.gov (United States)

    Silva-Brandão, Karina Lucas; Horikoshi, Renato Jun; Bernardi, Daniel; Omoto, Celso; Figueira, Antonio; Brandão, Marcelo Mendes

    2017-10-16

    Our main purpose was to evaluate the expression of plastic and evolved genes involved in ecological speciation in the noctuid moth Spodoptera frugiperda, the fall armyworm (FAW); and to demonstrate how host plants might influence lineage differentiation in this polyphagous insect. FAW is an important pest of several crops worldwide, and it is differentiated into host plant-related strains, corn (CS) and rice strains (RS). RNA-Seq and transcriptome characterization were applied to evaluate unbiased genetic expression differences in larvae from the two strains, fed on primary (corn) and alternative (rice) host plants. We consider that genes that are differently regulated by the same FAW strain, as a response to different hosts, are "plastic". Otherwise, differences in gene expression between the two strains fed on the same host are considered constitutive differences. Individual performance parameters (larval and pupal weight) varied among conditions (strains vs. hosts). A total of 3657 contigs was related to plastic response, and 2395 contigs were differentially regulated in the two strains feeding on preferential and alternative hosts (constitutive contigs). Three molecular functions were present in all comparisons, both down- and up-regulated: oxidoreductase activity, metal-ion binding, and hydrolase activity. Metabolization of foreign chemicals is among the key functions involved in the phenotypic variation of FAW strains. From an agricultural perspective, high plasticity in families of detoxifying genes indicates the capacity for a rapid response to control compounds such as insecticides.

  7. Reciprocal osmotic challenges reveal mechanisms of divergence in phenotypic plasticity in the killifish Fundulus heteroclitus.

    Science.gov (United States)

    Brennan, Reid S; Galvez, Fernando; Whitehead, Andrew

    2015-04-15

    The killifish Fundulus heteroclitus is an estuarine species with broad physiological plasticity, enabling acclimation to diverse stressors. Previous work suggests that freshwater populations expanded their physiology to accommodate low salinity environments; however, it is unknown whether this compromises their tolerance to high salinity. We used a comparative approach to investigate the mechanisms of a derived freshwater phenotype and the fate of an ancestral euryhaline phenotype after invasion of a freshwater environment. We compared physiological and transcriptomic responses to high- and low-salinity stress in fresh and brackish water populations and found an enhanced plasticity to low salinity in the freshwater population coupled with a reduced ability to acclimate to high salinity. Transcriptomic data identified genes with a conserved common response, a conserved salinity-dependent response and responses associated with population divergence. Conserved common acclimation responses revealed stress responses and alterations in cell-cycle regulation as important mechanisms in the general osmotic response. Salinity-specific responses included the regulation of genes involved in ion transport, intracellular calcium, energetic processes and cellular remodeling. Genes diverged between populations were primarily those showing salinity-specific expression and included those regulating polyamine homeostasis and the cell cycle. Additionally, when populations were matched with their native salinity, expression patterns were consistent with the concept of 'transcriptomic resilience', suggesting local adaptation. These findings provide insight into the fate of a plastic phenotype after a shift in environmental salinity and help to reveal mechanisms allowing for euryhalinity. © 2015. Published by The Company of Biologists Ltd.

  8. DISEÑO DE UN SISTEMA DE GESTIÓN DE LA CALIDAD EN EL PROCESO DE ALOJAMIENTO EN EL HOTEL “GRAN CARIBE VILLA TORTUGA” / DESIGN OF A QUALITY MANAGEMENT SYSTEM IN THE PROCESS OF ACCOMMODATION IN "GRAN CARIBE VILLA TORTUGA” HOTEL

    Directory of Open Access Journals (Sweden)

    Marilet Cazañas-Rivero

    2011-03-01

    Full Text Available

    Teniendo en cuenta el desarrollo de la industria turística y la necesidad de la excelencia competitiva, se concibe este trabajo en el Hotel “Gran Caribe Villa Tortuga” con el objetivo central de diseñar un Sistema de Gestión de la Calidad que permita la mejora del proceso de Alojamiento en este Hotel. Después de un diagnóstico inicial se demostró la necesidad de realizar cambios significativos en la instalación, donde existen dificultades en cuanto a la gestión de la calidad adecuada a las características del Hotel, en el cual no se toman acciones que permitan resolver dichas deficiencias. Se elaboró un procedimiento para el diseño del Sistema de gestión de la Calidad en el Hotel “Gran Caribe Villa Tortuga”. El diseño del Sistema de Gestión de la Calidad en el área de Alojamiento brinda a la dirección del Hotel el estado actual de la calidad de los servicios en esta área, mediante la aplicación de las técnicas utilizadas y ofrece las estrategias a seguir para lograr un mejor servicio.

    Abstract

    Taking into account the development of the tourist industry and the necessity of the competitive excellence it is conceived this work in the “Gran Caribe Villa Tortuga” Hotel, focusing in the design of a Quality Management System that allows the improvement of the process of Accommodation in this Hotel. After an initial diagnosis, it was demonstrated the necessity of carrying out significant changes in the facilities. There are some difficulties regarding quality management suited to the characteristics of the Hotel in which actions that allow solving these deficiencies are not carried out. It was elaborated a procedure for the design of the Quality Management System in the “Gran Caribe Villa Tortuga” Hotel. The design of the Quality Management System in the Accommodation area provides the Hotel management with the current state of service quality in this area by means of the

  9. 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.)

  10. Perception of service quality in agrotourism accommodations: Impact on guest loyalty and re-visit intentions

    Directory of Open Access Journals (Sweden)

    Chryssoula Chatzigeorgiou

    2017-03-01

    Full Text Available This study presents the development of a conceptual model that demonstrates the dynamic nature of the relationship between service quality and guest satisfaction in the agrotourism accommodation sector, based on theories derived from social psychology and previous research in the marketing, management, and services literature. The model was tested using sample data from guests of four different agrotourism firms, and was modified because of empirical results. The final model improves understanding of the relationship between service quality and guest satisfaction because these constructs were examined from the process perspective of an agrotourism accommodation experience; it portrays service quality and satisfaction in the context of a complete system.

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

    Science.gov (United States)

    Corcoran, Patricia L

    2015-08-01

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

  12. 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.

  13. Vergence driven accommodation with simulated disparity in myopia and emmetropia.

    Science.gov (United States)

    Maiello, Guido; Kerber, Kristen L; Thorn, Frank; Bex, Peter J; Vera-Diaz, Fuensanta A

    2018-01-01

    The formation of focused and corresponding foveal images requires a close synergy between the accommodation and vergence systems. This linkage is usually decoupled in virtual reality systems and may be dysfunctional in people who are at risk of developing myopia. We study how refractive error affects vergence-accommodation interactions in stereoscopic displays. Vergence and accommodative responses were measured in 21 young healthy adults (n=9 myopes, 22-31 years) while subjects viewed naturalistic stimuli on a 3D display. In Step 1, vergence was driven behind the monitor using a blurred, non-accommodative, uncrossed disparity target. In Step 2, vergence and accommodation were driven back to the monitor plane using naturalistic images that contained structured depth and focus information from size, blur and/or disparity. In Step 1, both refractive groups converged towards the stereoscopic target depth plane, but the vergence-driven accommodative change was smaller in emmetropes than in myopes (F 1,19 =5.13, p=0.036). In Step 2, there was little effect of peripheral depth cues on accommodation or vergence in either refractive group. However, vergence responses were significantly slower (F 1,19 =4.55, p=0.046) and accommodation variability was higher (F 1,19 =12.9, p=0.0019) in myopes. Vergence and accommodation responses are disrupted in virtual reality displays in both refractive groups. Accommodation responses are less stable in myopes, perhaps due to a lower sensitivity to dioptric blur. Such inaccuracies of accommodation may cause long-term blur on the retina, which has been associated with a failure of emmetropization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effect of Vision Therapy on Accommodation in Myopic Chinese Children

    Directory of Open Access Journals (Sweden)

    Martin Ming-Leung Ma

    2016-01-01

    Full Text Available Introduction. We evaluated the effectiveness of office-based accommodative/vergence therapy (OBAVT with home reinforcement to improve accommodative function in myopic children with poor accommodative response. Methods. This was a prospective unmasked pilot study. 14 Chinese myopic children aged 8 to 12 years with at least 1 D of lag of accommodation were enrolled. All subjects received 12 weeks of 60-minute office-based accommodative/vergence therapy (OBAVT with home reinforcement. Primary outcome measure was the change in monocular lag of accommodation from baseline visit to 12-week visit measured by Shinnipon open-field autorefractor. Secondary outcome measures were the changes in accommodative amplitude and monocular accommodative facility. Results. All participants completed the study. The lag of accommodation at baseline visit was 1.29 ± 0.21 D and it was reduced to 0.84 ± 0.19 D at 12-week visit. This difference (−0.46 ± 0.22 D; 95% confidence interval: −0.33 to −0.58 D is statistically significant (p<0.0001. OBAVT also increased the amplitude and facility by 3.66 ± 3.36 D (p=0.0013; 95% confidence interval: 1.72 to 5.60 D and 10.9 ± 4.8 cpm (p<0.0001; 95% confidence interval: 8.1 to 13.6 cpm, respectively. Conclusion. Standardized 12 weeks of OBAVT with home reinforcement is able to significantly reduce monocular lag of accommodation and increase monocular accommodative amplitude and facility. A randomized clinical trial designed to investigate the effect of vision therapy on myopia progression is warranted.

  15. Reflection of a shock wave from a thermally accommodating wall - Molecular simulation.

    Science.gov (United States)

    Deiwert, G. S.

    1973-01-01

    Reflection of a plane shock wave from a wall has been simulated on a microscopic scale using a direct simulation Monte Carlo technique of the type developed by Bird. A monatomic gas model representing argon was used to describe the fluid medium and a simple one-parameter accommodation coefficient model was used to describe the gas-surface interaction. The influence of surface accommodation was studied parametrically by varying the accommodation coefficient from zero to one. Results are presented showing the temporal variations of flow field density, and mass, momentum, and energy fluxes to the wall during the shock wave reflection process. The energy flux was used to determine the wall temperature history. Comparisons with experiment are found to be satisfactory where data are available.

  16. Near-unity mass accommodation coefficient of organic molecules of varying structure.

    Science.gov (United States)

    Julin, Jan; Winkler, Paul M; Donahue, Neil M; Wagner, Paul E; Riipinen, Ilona

    2014-10-21

    Atmospheric aerosol particles have a significant effect on global climate, air quality, and consequently human health. Condensation of organic vapors is a key process in the growth of nanometer-sized particles to climate relevant sizes. This growth is very sensitive to the mass accommodation coefficient α, a quantity describing the vapor uptake ability of the particles, but knowledge on α of atmospheric organics is lacking. In this work, we have determined α for four organic molecules with diverse structural properties: adipic acid, succinic acid, naphthalene, and nonane. The coefficients are studied using molecular dynamics simulations, complemented with expansion chamber measurements. Our results are consistent with α = 1 (indicating nearly perfect accommodation), regardless of the molecular structural properties, the phase state of the bulk condensed phase, or surface curvature. The results highlight the need for experimental techniques capable of resolving the internal structure of nanoparticles to better constrain the accommodation of atmospheric organics.

  17. 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....

  18. 28 CFR 30.10 - How does the Attorney General make efforts to accommodate intergovernmental concerns?

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false How does the Attorney General make... the Attorney General make efforts to accommodate intergovernmental concerns? (a) If a state process... form as the Attorney General in his or her discretion deems appropriate. The Attorney General may also...

  19. TARDEC FIXED HEEL POINT (FHP): DRIVER CAD ACCOMMODATION MODEL VERIFICATION REPORT

    Science.gov (United States)

    2017-11-09

    Public Release Disclaimer: Reference herein to any specific commercial company, product , process, or service by trade name, trademark, manufacturer , or...not actively engaged HSI until MSB or the Engineering Manufacturing and Development (EMD) Phase, resulting in significant design and cost changes...and shall not be used for advertising or product endorsement purposes. TARDEC Fixed Heel Point (FHP): Driver CAD Accommodation Model Verification

  20. 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)

  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. Accommodating World Englishes in Developing EFL Learners' Oral Communication

    Science.gov (United States)

    Mukminatien, Nur

    2012-01-01

    This article aims to discuss issues of World Englishes (WEs) and the implications in ELT. It explores the extent to which WEs are taken into account as emerging English varieties different from inner circle varieties, how WEs should be accommodated by English teachers, and which standard to adopt to accommodate learner's linguistic needs for…

  3. The Evolution of the Number of Tourists accommodated in Arad

    Directory of Open Access Journals (Sweden)

    Sergiu Rusu

    2014-12-01

    Full Text Available The paper analyses the evolution of the number of tourists accommodated in Arad between January 2006 and September 2009. For this purpose we have used the statistics data from the official sites. As variables we chose: X – independent variable - Total tourist arrival and accommodated in Arad, Y - dependent variable - Tourists staying in hotels.

  4. Regional Sign Language Varieties in Contact: Investigating Patterns of Accommodation

    Science.gov (United States)

    Stamp, Rose; Schembri, Adam; Evans, Bronwen G.; Cormier, Kearsy

    2016-01-01

    Short-term linguistic accommodation has been observed in a number of spoken language studies. The first of its kind in sign language research, this study aims to investigate the effects of regional varieties in contact and lexical accommodation in British Sign Language (BSL). Twenty-five participants were recruited from Belfast, Glasgow,…

  5. New Compact Accommodometer to Measure Accommodation Amplitude as a Biomarker.

    Science.gov (United States)

    Ide, Takeshi; Negishi, Kazuno; Yamaguchi, Takefumi; Hara, Shuya; Toda, Ikuko; Tsubota, Kazuo

    2012-01-01

    This study aimed to evaluate a newly designed compact accommodometer (CA) and compare this with a conventional accommodometer for measuring accommodation as a biomarker for aging and lifestyle. This is an observational case series. Accommodative amplitude was measured using 2 different accommodometers in 114 patients. We obtained the data of the near-point accommodation amplitude. Subsequently, we used smoking habit as an example of lifestyle-related factor to evaluate its effect on the accommodative power. The first part of the study included 60 eyes of 60 men and 54 eyes of 54 women, with a mean (SD) age of 43.8 (12.9) years (range, 18-58 years). There was a consistency within each measuring method despite a significant difference between the 2 devices (P the second part of the study, we found a significant correlation between age and accommodative amplitude both in smokers and in nonsmokers. The accommodative amplitude of the smoker group was significantly lower than that of the nonsmoker group (P the conventional accommodometer for measuring accommodative amplitude as an aging biomarker. Lifestyle factors can affect the magnitude of accommodation, which can be measured by this newly developed CA.

  6. Testing the Contingency Theory of Accommodation in Public Relations.

    Science.gov (United States)

    Cancel, Amanda E.; Mitrook, Michael A.; Cameron, Glen T.

    1999-01-01

    Interviews 18 public-relations professionals to provide grounding and refinement of the contingency theory of accommodation in public relations. Supports a continuum from pure accommodation to pure advocacy and a matrix of variables affecting the continuum. Concludes that the practitioners' view of their communication world offers validity to the…

  7. Chromatic aberration, accommodation, and color preference in asthenopia.

    Science.gov (United States)

    Drew, Stefanie A; Borsting, Eric; Stark, Lawrence R; Chase, Chris

    2012-07-01

    Asthenopia is a common problem associated with near work and reports suggest that colored lenses or overlays may be applied to reduce symptoms. In this study, we examine the relationship between eyestrain, color preferences, and function of the accommodation and vergence system. Specifically, we examine whether symptomatic observers select colors that reduce accommodative demand based on longitudinal chromatic aberration (LCA). Forty-seven undergraduate students participated in this study. Visual discomfort symptoms were assessed using the Conlon survey. A Mark 2 Intuitive Colorimeter was used to obtain optimal colored light preferences. LCA was modeled using the Chromatic Eye and spectral power density data. A comprehensive evaluation of accommodation and vergence was performed following standard procedures. A significant negative correlation (r = -0.51) was found between eyestrain symptoms and the International Commission on Illumination (CIE) v' axis of colors preferences. Additionally, a significant negative correlation (r = -0.31) was found between eyestrain symptoms and LCA accommodation. Two thirds of the participants in the high discomfort group chose colors that decreased accommodative demand. Accommodative amplitude and vergence facility also correlated with LCA, accounting for 25% of the variance. The color preferences of individuals are systematically influenced by the functioning of their accommodation and vergence systems with increased symptomatology resulting in color selections that reduce LCA accommodative stimulus demand.

  8. Privately Provided Accommodation Service Quality and Customer Satisfaction

    Directory of Open Access Journals (Sweden)

    Joshua Mugambwa

    2016-04-01

    Full Text Available Privately provided accommodation is a growing service in Uganda’s higher education sector due to education liberalization and demand for education. This research took a case study of Nsamizi Training Institute of Social Development (NTISD to determine the relationship between privately provided accommodation service quality and customer satisfaction. Specifically, the objectives of the study were (a to find out the relationship between security and NTISD students’ satisfaction with privately provided accommodation, and (b to find out the hierarchical level of importance of NTISD student satisfaction of the three service quality dimensions (reliability, security, and tangibles with privately provided accommodation. Using quantitative and qualitative modes of data analysis and a sample of 300 students from 20 private hostels, this study established a strong positive significant relationship between security and satisfaction regarding privately provided accommodation. This implies that accommodation service providers should increase the quality of security so as to increase the satisfaction of students regarding privately provided accommodation. The study established the hierarchical order of importance from the most important service quality dimension, respectively, as follows: reliability, security, and tangibles. Therefore, private accommodation service managers should pay extra attention to the dimensions in the same order.

  9. Study on accommodation by autorefraction and dynamic refraction in children

    Directory of Open Access Journals (Sweden)

    Prabhakar Srinivasapur Krishnacharya

    2014-10-01

    Conclusions: The performance of TOPCON AR RM-8000B autorefractor was comparable to dynamic retinoscopy. Presence of many children, and in turn, large number of accommodative response data in 11–13 and 14–15 years group is probably linked to prolonged reading/writing. The accuracy and the agreement of the actual accommodative measurements revealed after cycloplegia.

  10. Equivalent refractive index of the human lens upon accommodative response

    NARCIS (Netherlands)

    Hermans, E.A.; Dubbelman, M.; van der Heijde, R.G.L.; Heethaar, R.M.

    2008-01-01

    PURPOSE.: To experimentally verify the suggestion of Gullstrand (1909), i.e., that the equivalent refractive index of the human lens increases with accommodation. METHODS.: The left eye of five subjects was focused on different accommodation stimuli, while the right eye was imaged with Scheimpflug

  11. INFLUENCE RESEARCH OF COLD PLASTIC DEFORMATION ON DIFFUSION SATURATION PROCESS BY CARBON AND BORON OF THE LOW-CARBON AND BORON-CONTAINING ALLOYS

    Directory of Open Access Journals (Sweden)

    N. Yu. Filonenko

    2010-06-01

    Full Text Available This work is devoted to the study of influence of cold prestrain with degree of deformation within the range 0…40 % on diffusion saturation with boron and carbon for low-carbon and boron steels. It is determined that the plastic prestrain with degree of deformation 20 % at temperature 750 °С for the low-carbon steel promote increasing of boron-cementation layer thickness by 25 % and microhardness of perlite layer by 20 %.

  12. Use of microscopy techniques in failure analysis of the plastic injection molded parts to prevent the risks of serial defects in the assembly processes

    Directory of Open Access Journals (Sweden)

    Braga Ion Cristian

    2017-01-01

    Full Text Available Nowadays, the plastic injected molded parts are components used in the automobile for both exterior and interior. A mechatronic device uses those molded parts for actuating in order to reach some effect; therefore they should be durable and aesthetically satisfying the customer requirements. The aim of this paper is to present the use of microscopy techniques in failure analysis of plastic molded parts as part of a mechatronic device in order to prevent the risks of cracking occurred in the serial assembly production. Due to the constraints, the thin walls are used in some small plastic parts and they can be broken in the next assembly steps, but the detection of the defects is not facile. At the validation of the batch, the sampling parts are tested to simulate the breakage and the tear zone is investigated using microscopy techniques. The information is used as a feedback to adjust the injection parameters, reference samples being created by experiments to support the team to reduce the time for adjusting the parameters.

  13. Cultural value orientations, internalized homophobia, and accommodation in romantic relationships.

    Science.gov (United States)

    Gaines, Stanley O; Henderson, Michael C; Kim, Mary; Gilstrap, Samuel; Yi, Jennifer; Rusbult, Caryl E; Hardin, Deletha P; Gaertner, Lowell

    2005-01-01

    In the present study, we examined the impact of cultural value orientations (i.e., the personally oriented value of individualism, and the socially oriented values of collectivism, familism, romanticism, and spiritualism) on accommodation (i.e., voice and loyalty, rather than exit and neglect, responses to partners' anger or criticism) in heterosexual and gay relationships; and we examined the impact of internalized homophobia (i.e., attitudes toward self, other, and disclosure) on accommodation specifically in gay relationships. A total of 262 heterosexuals (102 men and 162 women) and 857 gays (474 men and 383 women) participated in the present study. Consistent with hypotheses, among heterosexuals and gays, socially oriented values were significantly and positively related to accommodation (whereas the personally oriented value of individualism was unrelated to accommodation); and among gays in particular, internalized homophobia was significantly and negatively related to accommodation. Implications for the study of heterosexual and gay relationships are discussed.

  14. Evidence that convergence rather than accommodation controls intermittent distance exotropia.

    Science.gov (United States)

    Horwood, Anna M; Riddell, Patricia M

    2012-03-01

    This study considered whether vergence drives accommodation or accommodation drives vergence during the control of distance exotropia for near fixation. High accommodative convergence to accommodation (AC/A) ratios are often used to explain this control, but the role of convergence to drive accommodation (the CA/C relationship) is rarely considered. Atypical CA/C characteristics could equally, or better, explain common clinical findings. Nineteen distance exotropes, aged 4-11 years, were compared while controlling their deviation with 27 non-exotropic controls aged 5-9 years. Simultaneous vergence and accommodation responses were measured to a range of targets incorporating different combinations of blur, disparity and looming cues at four fixation distances between 2 m and 33 cm. Stimulus and response AC/A and CA/C ratios were calculated. Accommodation responses for near targets (p = 0.017) and response gains (p = 0.026) were greater in the exotropes than in the controls. Despite higher clinical stimulus AC/A ratios, the distance exotropes showed lower laboratory response AC/A ratios (p = 0.02), but significantly higher CA/C ratios (p = 0.02). All the exotropes, whether the angle changed most with lenses ('controlled by accommodation') or on occlusion ('controlled by fusion'), used binocular disparity not blur as their main cue to target distance. Increased vergence demand to control intermittent distance exotropia for near also drives significantly more accommodation. Minus lens therapy is more likely to act by correcting overaccommodation driven by controlling convergence, rather than by inducing blur-driven vergence. The use of convergence as a major drive to accommodation explains many clinical characteristics of distance exotropia, including apparently high near stimulus AC/A ratios. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  15. 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)

  16. A review of non-strabismic accommodative and vergence anomalies in school-age children. Part 2: Accommodative anomalies

    Directory of Open Access Journals (Sweden)

    Samuel O. Wajuihian

    2015-08-01

    Full Text Available Comfortable reading and the performance of related near point activities involve efficient accommodative and vergence systems. However, accommodative and convergence anomalies are associated with various symptoms of asthenopia that impair efficient near point tasks. In Part 1 of this two-part article, studies on vergence anomalies were reviewed. In the current paper (Part 2, anomalies of accommodation are reviewed. The aims of the latter paper were to derive the prevalence and distribution estimates of anomalies of accommodation in school-age children and address variations in the study methods and findings. Despite variations in the study methods and findings, anomalies of accommodation are prevalent among school-age populations. Variations and limitations of previous studies are discussed and recommendations for improving future studies are suggested.

  17. 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.

  18. 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.

  19. 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

  20. Plastic Pollution from Ships

    OpenAIRE

    Čulin, Jelena; Bielić, Toni

    2016-01-01

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

  1. 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.

  2. 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...

  3. Medial rectus Faden operations with or without recession for partially accommodative esotropia associated with a high accommodative convergence to accommodation ratio.

    Science.gov (United States)

    Akar, Serpil; Gokyigit, Birsen; Sayin, Nihat; Demirok, Ahmet; Yilmaz, Omer Faruk

    2013-01-01

    To evaluate the results of Faden operations on the medial rectus (MR) muscles with or without recession for the treatment of partially accommodative esotropia associated with a high accommodative convergence to accommodation (AC : A) ratio and to determine whether there was a decrease in the effects of posterior fixation over time. In this retrospective study, 108 of 473 patients who underwent surgery for partially accommodative esotropia with a high AC : A ratio received Faden operations on both MR muscles, and 365 received symmetric MR muscle recessions combined with a Faden operation. For the Faden operation, a satisfactory outcome of 76.9% at 1 month postoperation, decreased to 71.3% by the final follow-up visit (mean 4.8 years). A moderate positive correlation was observed between the increase in the postoperative near deviation and postoperative time. For the Faden operations combined with MR recession, a satisfactory outcome of 78.9% at 1 month post-operation, decreased to 78.4% by the final follow-up visit. A Faden operation of the MR muscles with or without recession is an effective surgical option for treating partially accommodative esotropia associated with a high AC : A ratio. For Faden operations of the MR muscles without recession, the effects of the posterior fixation decline over time.

  4. 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.

  5. 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...

  6. 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.

  7. Family accommodation in adult obsessive–compulsive disorder: clinical perspectives

    Directory of Open Access Journals (Sweden)

    Albert U

    2017-09-01

    Full Text Available Umberto Albert, Alessandra Baffa, Giuseppe Maina Rita Levi Montalcini Department of Neuroscience, A.O.U. San Luigi Gonzaga, University of Turin, Turino, Italy Abstract: The term accommodation has been used to refer to family responses specifically related to obsessive–compulsive (OC symptoms: it encompasses behaviors such as directly participating in compulsions, assisting a relative with obsessive–compulsive disorder (OCD when he/she is performing a ritual, or helping him/her to avoid triggers that may precipitate obsessions and compulsions. At the opposite side, family responses to OCD may also include interfering with the rituals or actively opposing them; stopping accommodating OC symptoms or actively interfering with their performance is usually associated with greater distress and sometimes even with aggressive behaviors from the patients. This article summarizes progress of the recent research concerning family accommodation in relatives of patients with OCD. Family accommodation is a prevalent phenomenon both among parents of children/adolescents with OCD and relatives/caregivers of adult patients. It can be measured with a specific instrument, the Family Accommodation Scale, of which there are several versions available for use in clinical practice. The vast majority of both parents of children/adolescents with OCD and family members of adult patients show at least some accommodation; providing reassurances to obsessive doubts, participating in rituals and assisting the patient in avoidance are the most frequent accommodating behaviors displayed by family members. Modification of routine and modification of activities specifically due to OC symptoms have been found to be equally prevalent. Specific characteristics of patients (such as contamination/washing symptoms and of relatives (the presence of anxiety or depressive symptoms or a family history positive for another anxiety disorder are associated with a higher degree of family

  8. Space Station Freedom - Accommodation for technology R&D

    Science.gov (United States)

    Holt, Alan C.

    1989-01-01

    The paper examines the features of the accommodation equipment designed for the candidate technology payloads of the Space Station, which include magnetic plasma thruster systems and a hypothetical advanced electromagnetic propulsion system utilizing high-temperature superconductivity materials. The review of the accommodation-equipment concepts supports the assumption that some propulsion technologies can be tested on the Space Station while being attached externally to the station's truss structure. For testing technologies with inherent operation or performance hazards, space platforms and smaller free-flyers coordinated with the Space Station can be used. Diagrams illustrating typical accommodation equipment configurations are included.

  9. Microgravity Flight: Accommodating Non-Human Primates

    Science.gov (United States)

    Dalton, Bonnie P.; Searby, Nancy; Ostrach, Louis

    1995-01-01

    thermoregulation, muscular, and cardiac responses to weightlessness. In contrast, the five completed Cosmos/Bion flights, lacked the metabolic samples and behavioral task monitoring, but did facilitate studies of the neurovestibular system during several of the flights. The RRF accommodated two adult 8-11 kg rhesus monkeys, while the Russian experiments and hardware were configured for a younger animal in the 44 kg range. Both the American and Russian hardware maintained a controlled environmental system, specifically temperature, humidity, a timed lighting cycle, and had means for providing food and fluids to the animal(s). Crew availability during a Shuttle mission was to be an optimal condition for retrieval and refrigeration of the animal urine samples along with a manual calcein injection which could lead to greater understanding of bone calcium incorporation. A special portable bioisolation glove box was under development to support this aspect of the experiment profile along with the capability of any contingency human intervention. As a result of recent U.S./Russian negotiations, funding for Space Station, and a series of other events, the SLS-3 mission was cancelled and applicable Rhesus Project experiments incorporated into the Russian Bion 11 and 12 missions. A presentation of the RRF and COSMOS/Bion rhesus hardware is presented along with current plans for the hardware.

  10. 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

  11. 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

  12. Accommodation, accommodative convergence, and response AC/A ratios before and at the onset of myopia in children.

    Science.gov (United States)

    Gwiazda, Jane; Thorn, Frank; Held, Richard

    2005-04-01

    The purpose of this study was to investigate accommodation, accommodative convergence, and AC/A ratios before and at the onset of myopia in children. Refractive error, accommodation, and phorias were measured annually over a period of 3 years in 80 6- to 18-year-old children (mean age at first visit = 11.1 years), including 26 who acquired myopia of at least -0.50 D and 54 who remained emmetropic (-0.25 to + 0.75 D). Refraction was measured by noncycloplegic distance retinoscopy. Concomitant measures of accommodation and phorias were taken for letter targets at 4.0 m and 0.33 m using the Canon R-1 open field-of-view autorefractor with an attached motorized Risley prism and Maddox rod. The accommodation and phoria measurements were used to calculate response AC/A ratios. Compared with children who remained emmetropic, those who became myopic had elevated response AC/A ratios at 1 and 2 years before the onset of myopia, in addition to at onset and 1 year later (t's = -2.97 to -4.04, p accommodation. Accommodative convergence was significantly greater in myopes only at onset. These findings suggest that the abnormal oculomotor factors found before the onset of myopia may contribute to myopigenesis by producing hyperopic retinal defocus when a child is engaged in near-viewing tasks.

  13. 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.

  14. 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.

  15. 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

  16. The strain accommodation in Ti–28Nb–12Ta–5Zr alloy during warm deformation

    International Nuclear Information System (INIS)

    Farghadany, E.; Zarei-Hanzaki, A.; Abedi, H.R.; Dietrich, D.; Lampke, T.

    2014-01-01

    The warm deformation behavior of a β-type Ti alloys, composing of Ti–27.96Nb–11.97Ta–5.02Zr %wt, (so called TNTZ alloy), has been investigated in the present work in a warm deformation temperature. A variety of deformation features are characterized in the material microstructure after applied warm deformation scheme. The XRD analysis confirms an enhancement in martensite volume fraction. The electron back scatter diffractometry (EBSD) elucidates that the martensite has been mainly formed by laterally at the vicinity of different types of deformation bands. Both the well-known twining systems in TNTZ series have been occurred during deformation. The micro-shear bands, which are defined as highly concentrated plastic strain regions, are characterized in the deformed microstructure. The micro-shear bands are severely formed in the regions, which accommodate the most amount of applied strain

  17. Accommodating Oversize and Overweight Loads : Instructor and Student Guide

    Science.gov (United States)

    2012-08-01

    This instructor and student guide is designed to guide the instructor in conveying information at the district level concerning Research Project 0-6404 Accommodating Oversize and Overweight Loads. The specific information focuses on the Bryan D...

  18. Occlusal accommodation and mouthguards for prevention of orofacial trauma.

    LENUS (Irish Health Repository)

    Geary, Julian Lindsay

    2009-01-01

    The aim of this study was to investigate the effect of two types of occlusal accommodation on the arch separation in centric and eccentric arch positions and to assess the opposing tooth contacts in professionally made, thermoformed sports mouthguards.

  19. Amplitude of Accommodation and its Relation to Refractive Errors

    Directory of Open Access Journals (Sweden)

    Abraham Lekha

    2005-01-01

    Full Text Available Aims: To evaluate the relationship between amplitude of accommodation and refractive errors in the peri-presbyopic age group. Materials and Methods: Three hundred and sixteen right eyes of 316 consecutive patients in the age group 35-50 years who attended our outpatient clinic were studied. Emmetropes, hypermetropes and myopes with best-corrected visual acuity of 6/6 J1 in both eyes were included. The amplitude of accommodation (AA was calculated by measuring the near point of accommodation (NPA. In patients with more than ± 2 diopter sphere correction for distance, the NPA was also measured using appropriate soft contact lenses. Results: There was a statistically significant difference in AA between myopes and hypermetropes ( P P P P P P >0.5. Conclusion: Our study showed higher amplitude of accommodation among myopes between 35 and 44 years compared to emmetropes and hypermetropes

  20. Accommodation Paralysis after Pheniramine Maleate Injection: A Case Report.

    Science.gov (United States)

    Bingol Kiziltunc, Pinar; Atilla, Huban; Yalcindag, F Nilufer

    2013-01-01

    We present a case in which Gilbert syndrome was diagnosed following a neuro-ophthalmic complaint. Adverse effects of drugs as well as various systemic, neurological, and local ocular pathologies can cause accommodative insufficiency and loss of accommodation. A 29-year-old man was admitted to an ophthalmology department with blurred vision and diagnosed as suffering from acute accommodation paralysis. He had a history of being given a pheniramine maleate injection for pruritus 20 days previously. Symptoms began immediately following the injection. After systemic evaluation and laboratory tests, he was diagnosed as having Gilbert syndrome. His complaints and symptoms recovered in approximately a further 10 days. Metabolism of pheniramine maleate can be impaired in Gilbert syndrome and anticholinergic effects can cause accommodation paralysis.

  1. Micromechanics of transformation-induced plasticity and variant coalescence

    International Nuclear Information System (INIS)

    Marketz, F.; Fischer, F.D.; University for Mining and Metallurgy, Leoben; Tanaka, K.

    1996-01-01

    Quantitative micromechanics descriptions of both transformation-induced plasticity (TRIP) associated with the martensitic transformation in an Fe-Ni alloy and of variant coalescence in a Cu-Al-Ni shape memory alloy are presented. The macroscopic deformation behavior of a polycrystalline aggregate as a result of the rearrangements within the crystallites is modelled with the help of a finite element based periodic microfield approach. In the case of TRIP the parent→martensite transformation is described by microscale thermodynamic and kinetic equations taking into account internal stress states. The simulation of a classical experiment on TRIP allows to quantify the Magee-effect and the Greenwood-Johnson effect. Furthermore, the development of the martensitic microstructure is studied with respect to the stress-assisted transformation of preferred variants. In the case of variant coalescence the strain energy due to internal stress states has an important influence on the mechanical behavior. Formulating the reorientation process on the size scale of self-accommodating plate groups in terms of the mobility of the boundaries between martensitic variants the macroscopic behavior in uniaxial tension is predicted by an incremental modelling procedure. Furthermore, influence of energy dissipation on the overall behavior is quantified. (orig.)

  2. A systematic review of workplace disclosure and accommodation requests among youth and young adults with disabilities.

    Science.gov (United States)

    Lindsay, Sally; Cagliostro, Elaine; Carafa, Gabriella

    2017-08-10

    The objective of this systematic review is to critically appraise the literature on disability disclosure and workplace accommodations for youth and young adults with disabilities. Systematic searches of nine international databases identified 27 studies meeting our inclusion criteria. These studies were analyzed with respect to the characteristics of the participants, methodology, results of the studies and the quality of the evidence. Among the 27 studies, 18,419 participants (aged 14-33, mean 23.9 years) were represented across seven countries. Barriers to disability disclosure and requests for workplace accommodations were found at the individual (i.e., disability type, severity, poor self-concept, and advocacy skills), employment (i.e., type of industry, and working conditions, lack of supports), and societal levels (i.e., stigma/discrimination). Facilitators of disability disclosure included individual factors (i.e., knowledge of supports and workplace rights, self-advocacy skills), employment (i.e., training/supports, effective communication with employers, realizing the benefits of accommodations), and societal factors (i.e., positive attitudes toward people with disabilities). There was little consensus on the processes and timing of how disability should be discussed in the workplace among youth with disabilities. Our findings highlight the complexities of disability disclosure for youth with disabilities. More studies are needed to explore issues of workplace disclosure and accommodations for young people to improve disclosure strategies and the process of providing appropriate accommodations. Implications for Rehabilitation Clinicians, educators, and parents should support youth to become self-aware and build self-advocacy skills so they can make an informed decision about how and when to disclose their condition to employers. Clinicians, educators, and employers should help youth with disabilities to understand the benefits of disclosing their

  3. Occlusal accommodation and mouthguards for prevention of orofacial trauma.

    Science.gov (United States)

    Geary, Julian Lindsay; Clifford, Thomas Joseph; Kinirons, Martin James

    2009-01-01

    The aim of this study was to investigate the effect of two types of occlusal accommodation on the arch separation in centric and eccentric arch positions and to assess the opposing tooth contacts in professionally made, thermoformed sports mouthguards. Maxillary and mandibular alginate impressions, a wax interocclusal record of centric occlusion together with maxillary/condylar face-bow registrations, were recorded clinically for 10 undergraduate dental students who are sports activist volunteers of the School of Medicine and Dentistry, Queen's University Belfast. Two ethylene vinyl acetate thermoformed maxillary mouthguards were made for each player (N = 20) using a standardised procedure. Ten mouthguards served both as the control (i.e. the non-accommodated) group and also the accommodated, occlusally 'imprinted' group. The other 10 mouthguards served as the accommodated, occlusally 'ground' group. Casts were articulated, each non-accommodated and accommodated mouthguard was seated and the extent of the interocclusal opening was recorded in all three arch relationships. The number of mouthguard and mandibular tooth contacts were also recorded in each position. The increased vertical occlusal dimension that was found in the presence of non-accommodated mouthguards equated to the full-sheet thickness of the material that was used to form the mouthguards. Only mouthguards accommodated by grinding retained high levels of occlusal contact in all arch relationships that were tested. Within the limitations of this study, the modification of the occlusal surface made by flat grinding reduced the arch separation in eccentric movements and increased the opposing tooth contacts in custom-made mouthguards. This may contribute to increased comfort, compliance and the protective effect of these appliances thus resulting in a reduction of injuries to the teeth, arches and soft tissues.

  4. ICT Adoption and Development: Issues in Rural Accommodation

    OpenAIRE

    Reino, Sofia; Frew, Andrew J; Albacete-Saez, Carlos

    2010-01-01

    Purpose – The work described in this paper is of direct relevance to those with an interest in the phenomena surrounding ICT (Information and Communication Technologies) adoption by the rural accommodation sector. The paper provides the results from a preliminary study, which examined differences in the level of inter-firm technology adoption between rural and urban accommodation establishments within a major tourism destination, Scotland. Design/methodology/approach – A survey was conducted,...

  5. 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.

  6. 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.

  7. 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

  8. Corneal changes with accommodation using dual Scheimpflug photography.

    Science.gov (United States)

    Sisó-Fuertes, Irene; Domínguez-Vicent, Alberto; del Águila-Carrasco, Antonio; Ferrer-Blasco, Teresa; Montés-Micó, Robert

    2015-05-01

    To assess whether corneal parameters and aberrations are affected by accommodation. Optics Department, University of Valencia, Valencia, Spain. Prospective cross-sectional study. The Galilei G4 dual Scheimpflug device was used to obtain data on the anterior and posterior axial curvatures, total corneal power (TCP), and corneal pachymetry from 3 corneal zones (central: 0.0 up to 4.0 mm; paracentral or mid: 4.0 up to 7.0 mm; peripheral: 7.0 up to 10.0 mm) in young emmetropic eyes in the unaccommodated and 4 accommodated states (from -1.0 to -4.0 diopters [D] in 1.0 D steps). The 2nd-, 3rd-, and 4th-order aberrations as well as the root mean square (RMS) were also determined for the entire cornea at the same accommodative demands. The study evaluated 7 subjects (12 eyes). No significant changes in any measured parameter were found during accommodation for any corneal zone (P > .05). Statistically significant differences were found in the various corneal zones when it was assumed they were constant with accommodation (P the high standard deviation values. Different parameters in various zones of the cornea as well as corneal aberrations were stable during accommodation. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  9. Convergence and Accommodation Development Is Preprogrammed in Premature Infants.

    Science.gov (United States)

    Horwood, Anna M; Toor, Sonia S; Riddell, Patricia M

    2015-08-01

    This study investigated whether vergence and accommodation development in preterm infants is preprogrammed or is driven by experience. Thirty-two healthy infants, born at mean 34 weeks gestation (range, 31.2-36 weeks), were compared with 45 healthy full-term infants (mean 40.0 weeks) over a 6-month period, starting at 4 to 6 weeks postnatally. Simultaneous accommodation and convergence to a detailed target were measured using a Plusoptix PowerRefII infrared photorefractor as a target moved between 0.33 and 2 m. Stimulus/response gains and responses at 0.33 and 2 m were compared by both corrected (gestational) age and chronological (postnatal) age. When compared by their corrected age, preterm and full-term infants showed few significant differences in vergence and accommodation responses after 6 to 7 weeks of age. However, when compared by chronological age, preterm infants' responses were more variable, with significantly reduced vergence gains, reduced vergence response at 0.33 m, reduced accommodation gain, and increased accommodation at 2 m compared to full-term infants between 8 and 13 weeks after birth. When matched by corrected age, vergence and accommodation in preterm infants show few differences from full-term infants' responses. Maturation appears preprogrammed and is not advanced by visual experience. Longer periods of immature visual responses might leave preterm infants more at risk of development of oculomotor deficits such as strabismus.

  10. Hyperelastic modelling of the crystalline lens: Accommodation and presbyopia

    Science.gov (United States)

    Lanchares, Elena; Navarro, Rafael; Calvo, Begoña

    2012-01-01

    Purpose The modification of the mechanical properties of the human crystalline lens with age can be a major cause of presbyopia. Since these properties cannot be measured in vivo, numerical simulation can be used to estimate them. We propose an inverse method to determine age-dependent change in the material properties of the tissues composing the human crystalline lens. Methods A finite element model of a 30-year-old lens in the accommodated state was developed. The force necessary to achieve full accommodation in a 30-year-old lens of known external geometry was computed using this model. Two additional numerical models of the lens corresponding to the ages of 40 and 50 years were then built. Assuming that the accommodative force applied to the lens remains constant with age, the material properties of nucleus and cortex were estimated by inverse analysis. Results The zonular force necessary to reshape the model of a 30-year-old lens from the accommodated to the unaccommodated geometry was 0.078 newton (N). Both nucleus and cortex became stiffer with age. The stiffness of the nucleus increased with age at a higher rate than the cortex. Conclusions In agreement with the classical theory of Helmholtz, on which we based our model, our results indicate that a major cause of presbyopia is that both nucleus and cortex become stiffer with age; therefore, a constant value of the zonular forces with aging does not achieve full accommodation, that is, the accommodation capability decreases.

  11. Direct electroplating of plastic for advanced electrical applications

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  12. 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

  13. 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...

  14. Effects of Accommodation, Vergence and Pupil Diameter on Size Estimation When Viewing Displays

    National Research Council Canada - National Science Library

    Charman, W

    1995-01-01

    ... subtense but lying at different distances, allied to errors in accommodation. Thus an error in accommodation, caused perhaps by the tendency of the accommodation system to revert to its somewhat myopic tonic or resting state (Toates, 1972...

  15. Comparative study of the accommodative convergence/accommodation after refractive correction

    Directory of Open Access Journals (Sweden)

    Peng-Fei Lin

    2013-11-01

    Full Text Available AIM: To study the ortho-k lens and frame glasses in patients with juvenile myopia the influence of the accommodative convergence/accommodation(AC/A, further clear the effectiveness of controlling the myopia development and security.METHODS: Randomly select 60 patients to our hospital check-up successfully with ortho-k lens of juvenile myopia patients as experimental group, and 60 cases were randomly selected given frame glasses as control group. we observed two groups of patients before and after refractive correction the changes of AC/A and spherical equivalent. Observation time was 1 month, 3 months, 6 months, 1 year.RESULTS: The AC/A of experimental group worn glasses before and after 1 month, 3 months, 6 months, 1 year were 4.05±2.03, 3.05±1.85, 3.31±1.02, 3.14±1.64 and 3.20±1.55,respectively with statistically significant difference(PP>0.05. Three months after worn glasses there was significant difference(PP>0.05. Wearing glasses after 1 month, 6 months, 12 months, the two groups had significant difference(PP>0.05. Spherical equivalent, observation time was 1 year: experimental group spherical equivalent degrees increased by 0.38±0.35DS, the control group spherical equivalent degrees increased by 0.84±0.56DS, the two groups were statistically significant difference(PCONCLUSION: Both groups could reduce the AC/A value. The experimental group than the control group was better and faster to improve the relationship between the adjustment and collection. The AC/A value was on the high side after myopic degree growth. The ortho-k lens is an effective lens for the moderate myopia.It can more effectively control the growth of juvenile myopia than frame glasses, which is an effective way to control myopia. The mechanism of improving his visual function remains to be further studied.

  16. Optimising Tertiary Student Accommodation within University Neighbourhoods

    OpenAIRE

    Ike, Nnenna; Baldwin, Claudia; Lathouras, Athena

    2017-01-01

    Tertiary students’ activities within neighbourhoods adjacent to universities engender positive and negative impacts that have consequences for neighbourhood sustainability. This might lead to studentification, a process that triggers physical, economic and socio-cultural transformation of university towns. Where non-student residents perceive negative impacts, it can lead to conflict and resentment towards the student population, mistrust between student and local resident groups and a decrea...

  17. Private actions in the construction of a tourist destination. Boutique accommodation in Purmamarca, province of Jujuy, Argentina

    Directory of Open Access Journals (Sweden)

    Tania Porcaro

    2014-09-01

    Full Text Available Purmamarca, a small town located in Quebrada de Humahuaca (World Heritage, UNESCO, 2003, province of Jujuy, suffered a great transformation since the last years of the 20th century. This process is the result of touristic promotion within de province and private actions, both at regional and national scale, turning this town of about 500 inhabitants, into one of the main development poles of this activity. Even though Purmamarca still has a small stable population, its profile has completely changed, from low productivity peasant agriculture to a recreation and rest center for high level society from the largest cities in the country. This paper belongs to a series of studies published by its authors, who are interested in analysing material and cultural transformations of Purmamarca and Quebrada de Humahuaca, focusing on touristic processes. The objective of this article is to describe the development of new accommodation that influenced in the transformation of Purmamarca and to analyse their links to some of the new international tendencies in accommodation. In order to reach that goal, the characteristics and evolution of Purmamarca’s accommodation were studied, through the use of various sources, such as accommodation and tourism authorities websites, touristic brochures, information collected through local surveys and interviews, statistic information and bibliographic resources. The results of this research indicate that the growth in the amount of accommodation, since the beginning of 2000, is high for this small town. These accommodations are characterized by little capacity, personalized attention, exclusive services, and are directed to a select audience, many of them being identified as boutique hotels. These accommodations make their mark in Purmamarca and participate in the transformation processes of this town.

  18. Accommodative intraocular lens versus standard monofocal intraocular lens implantation in cataract surgery.

    Science.gov (United States)

    Ong, Hon Shing; Evans, Jennifer R; Allan, Bruce D S

    2014-05-01

    Following cataract surgery and intraocular lens (IOL) implantation, loss of accommodation or postoperative presbyopia occurs and remains a challenge. Standard monofocal IOLs correct only distance vision; patients require spectacles for near vision. Accommodative IOLs have been designed to overcome loss of accommodation after cataract surgery. To define (a) the extent to which accommodative IOLs improve unaided near visual function, in comparison with monofocal IOLs; (b) the extent of compromise to unaided distance visual acuity; c) whether a higher rate of additional complications is associated the use of accommodative IOLs. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 9), Ovid MEDLINE, Ovid MEDLINE in-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily Update, Ovid OLDMEDLINE (January 1946 to October 2013), EMBASE (January 1980 to October 2013), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 10 October 2013. We include randomised controlled trials (RCTs) which compared implantation of accommodative IOLs to implantation of monofocal IOLs in cataract surgery. Two authors independently screened search results, assessed risk of bias and extracted data. All included trials used the 1CU accommodative IOL (HumanOptics, Erlangen, Germany) for their intervention group. One trial had an additional arm with the AT-45 Crystalens accommodative IOL (Eyeonics Vision). We performed a separate analysis comparing 1CU and AT-45 IOL. We included four RCTs, including 229 participants (256 eyes

  19. Finite element modelling of radial lentotomy cuts to improve the accommodation performance of the human lens.

    Science.gov (United States)

    Burd, H J; Wilde, G S

    2016-04-01

    The use of a femtosecond laser to form planes of cavitation bubbles within the ocular lens has been proposed as a potential treatment for presbyopia. The intended purpose of these planes of cavitation bubbles (referred to in this paper as 'cutting planes') is to increase the compliance of the lens, with a consequential increase in the amplitude of accommodation. The current paper describes a computational modelling study, based on three-dimensional finite element analysis, to investigate the relationship between the geometric arrangement of the cutting planes and the resulting improvement in lens accommodation performance. The study is limited to radial cutting planes. The effectiveness of a variety of cutting plane geometries was investigated by means of modelling studies conducted on a 45-year human lens. The results obtained from the analyses depend on the particular modelling procedures that are employed. When the lens substance is modelled as an incompressible material, radial cutting planes are found to be ineffective. However, when a poroelastic model is employed for the lens substance, radial cuts are shown to cause an increase in the computed accommodation performance of the lens. In this case, radial cuts made in the peripheral regions of the lens have a relatively small influence on the accommodation performance of the lens; the lentotomy process is seen to be more effective when cuts are made near to the polar axis. When the lens substance is modelled as a poroelastic material, the computational results suggest that useful improvements in lens accommodation performance can be achieved, provided that the radial cuts are extended to the polar axis. Radial cuts are ineffective when the lens substance is modelled as an incompressible material. Significant challenges remain in developing a safe and effective surgical procedure based on this lentotomy technique.

  20. 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.

  1. Measurements of tangential momentum accommodation coefficient for various gases in plane microchannel

    OpenAIRE

    Graur , I; Perrier , Pierre; Ghozlani , W ,; Méolans , J.Gilbert

    2009-01-01

    International audience; Mass flow rate measurements in a single silicon microchannel were carried out for various gases in isothermal steady flows. The results obtained from hydrodynamic to near free molecular regime by using a powerful experimental platform allowed us to deduce interesting information, notably about the reflection/accommodation process at the wall. In the 0–0.3 Knudsen range, a continuum analytic approach was derived from the NS equations, associated with first or second ord...

  2. 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.

  3. 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%.

  4. Numerical study of effects of accommodation coefficients on slip phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Jae; Kwon, Oh Joon [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    An unstructured mesh Navier-Stokes solver employing a Maxwell slip boundary condition was developed. The present flow solver was applied to the simulation of flows around an axisymmetric hollow cylinder in a Mach 10.4 free stream, known as Calspan-UB Research Center (CUBRC) Run 14 case, and the velocity slip and the temperature jump on the cylinder surface were investigated. The effect of tangential momentum and thermal accommodation coefficients used in the Maxwell condition was also investigated by adjusting their values. The results show that the reverse flow region is developed on the body surface due to the interaction between the shock and the boundary layer. Also, the shock impingement makes pressure high. The flow properties on the surface agree well with the experimental data, and the velocity slip and the temperature jump vary consistently with the local Knudsen number change. The accommodation coefficients affect the slip phenomena and the size of the flow region. The slip phenomena become larger when both tangential momentum and thermal accommodation coefficients are decreased. However, the range of the reverse flow region decreases when the momentum accommodation coefficient is decreased. The characteristics of the momentum and thermal accommodation coefficients also are overlapped when they are altered together.

  5. Comparison of tests of accommodation for computer users.

    Science.gov (United States)

    Kolker, David; Hutchinson, Robert; Nilsen, Erik

    2002-04-01

    With the increased use of computers in the workplace and at home, optometrists are finding more patients presenting with symptoms of Computer Vision Syndrome. Among these symptomatic individuals, research supports that accommodative disorders are the most common vision finding. A prepresbyopic group (N= 30) and a presbyopic group (N = 30) were selected from a private practice. Assignment to a group was determined by age, accommodative amplitude, and near visual acuity with their distance prescription. Each subject was given a thorough vision and ocular health examination, then administered several nearpoint tests of accommodation at a computer working distance. All the tests produced similar results in the presbyopic group. For the prepresbyopic group, the tests yielded very different results. To effectively treat symptomatic VDT users, optometrists must assess the accommodative system along with the binocular and refractive status. For presbyopic patients, all nearpoint tests studied will yield virtually the same result. However, the method of testing accommodation, as well as the test stimulus presented, will yield significantly different responses for prepresbyopic patients. Previous research indicates that a majority of patients prefer the higher plus prescription yielded by the Gaussian image test.

  6. Work accommodations and natural supports for maintaining employment.

    Science.gov (United States)

    Corbière, Marc; Villotti, Patrizia; Lecomte, Tania; Bond, Gary R; Lesage, Alain; Goldner, Elliot M

    2014-06-01

    Job tenure for people with severe mental disorders, even for those enrolled in supported employment programs, is typically brief. Few studies to date have investigated the relationship between accommodations and natural supports available in the workplace, and job tenure for this population. The main objectives of this study were to develop and to validate a new measure to describe work accommodations and natural supports available in the workplace and to determine which of them are significantly related to job tenure for participants enrolled in supported employment services. In total, 124 people with a severe mental disorder enrolled in supported employment programs and who obtained only one competitive employment at the 9-month follow-up answered the Work Accommodation and Natural Support Scale (WANSS). They also provided information regarding their disclosure (or non-) of mental disorders in the workplace and the length of their job tenure. Confirmatory factor analysis conducted on the WANSS showed 40 items distributed on 6 dimensions (e.g., Schedule flexibility). Correlation results showed that disclosure was significantly related to the number of work accommodations and natural supports available in the workplace. Survival analyses indicated that one WANSS dimension was more salient in predicting job tenure: Supervisor and coworker supports. The WANSS is a valid and useful tool to assess work accommodations and natural supports available in the workplace that employment specialists could use in their practice.

  7. A survey of anthropometry and physical accommodation in ergonomics curricula.

    Science.gov (United States)

    Garneau, Christopher J; Parkinson, Matthew B

    2016-01-01

    The size and shape of users are an important consideration for many products and environments. Designers and engineers in many disciplines must often accommodate these attributes to meet objectives such as fit and safety. When practitioners have academic training in addressing these issues, it is typically through courses in Human Factors/Ergonomics (HF/E). This paper investigates education related to physical accommodation and offers suggestions for improvement. A survey was conducted wherein 21 instructors at 18 universities in the United States provided syllabi for 29 courses, which were analysed to determine topics related to anthropometry and resources used for the courses. The results show that within the U.S., anthropometry is covered in the majority of courses discussing physical ergonomics, but important related concepts were often omitted (e.g., digital human modelling, multivariate accommodation and variability across global populations). Curricula could be improved by incorporating more accurate anthropometry, multivariate problems and interactive online tools. This paper describes a study investigating collegiate ergonomics courses within the U.S. in the area of physical accommodation. Course schedules and texts were studied for their treatment of several topics related to accommodating the spatial requirements (anthropometry) of users. Recommendations are made for improving course curricula.

  8. Caffeine intake is associated with pupil dilation and enhanced accommodation.

    Science.gov (United States)

    Abokyi, S; Owusu-Mensah, J; Osei, K A

    2017-04-01

    PurposeIt is purported that caffeine, an autonomic stimulant, affects visual performance. This study sought to assess whether caffeine intake was associated with changes in pupil size and/or amplitude of accommodation.Patients and methodsA double-masked, crossover study was conducted in 50 healthy subjects of age range 19 to 25 years. Subjects were randomized to treatments such that subjects consumed either 250 mg caffeine drink or vehicle on separate days. Amplitude of accommodation was measured by the push-up technique, and pupil size using a millimeter ruler fixed to a slit lamp biomicroscope in dim illumination (5 lux). Amplitude of accommodation and pupil size were taken at baseline, and at 30, 60 and 90 min time points post treatment. Repeated measures one-way ANOVA and paired t-test were used in analyzing data.ResultsAmplitude of accommodation and pupil size after caffeine intake were significantly greater than vehicle (Pcaffeine beverage was associated with significant increases in amplitude of accommodation and pupil size with time (Pcaffeine. This study suggests caffeine may have some influence on visual functions.

  9. Acidogenic fermentation of the organic fraction of municipal solid waste and cheese whey for bio-plastic precursors recovery - Effects of process conditions during batch tests.

    Science.gov (United States)

    Girotto, Francesca; Lavagnolo, Maria Cristina; Pivato, Alberto; Cossu, Raffaello

    2017-12-01

    The problem of fossil fuels dependency is being addressed through sustainable bio-fuels and bio-products production worldwide. At the base of this bio-based economy there is the efficient use of biomass as non-virgin feedstock. Through acidogenic fermentation, organic waste can be valorised in order to obtain several precursors to be used for bio-plastic production. Some investigations have been done but there is still a lack of knowledge that must be filled before moving to effective full scale plants. Acidogenic fermentation batch tests were performed using food waste (FW) and cheese whey (CW) as substrates. Effects of nine different combinations of substrate to inoculum (S/I) ratio (2, 4, and 6) and initial pH (5, 7, and 9) were investigated for metabolites (acetate, butyrate, propionate, valerate, lactate, and ethanol) productions. Results showed that the most abundant metabolites deriving from FW fermentation were butyrate and acetate, mainly influenced by the S/I ratio (acetate and butyrate maximum productions of 21.4 and 34.5g/L, respectively, at S/I=6). Instead, when dealing with CW, lactate was the dominant metabolite significantly correlated with pH (lactate maximum production of 15.7g/L at pH = 9). Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 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.

  11. 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.)

  12. 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?

  13. 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.)

  14. 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.

  15. 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.

  16. Stability of surface plastic flow in large strain deformation of metals

    Science.gov (United States)

    Viswanathan, Koushik; Udapa, Anirduh; Sagapuram, Dinakar; Mann, James; Chandrasekar, Srinivasan

    We examine large-strain unconstrained simple shear deformation in metals using a model two-dimensional cutting system and high-speed in situ imaging. The nature of the deformation mode is shown to be a function of the initial microstructure state of the metal and the deformation geometry. For annealed metals, which exhibit large ductility and strain hardening capacity, the commonly assumed laminar flow mode is inherently unstable. Instead, the imposed shear is accommodated by a highly rotational flow-sinuous flow-with vortex-like components and large-amplitude folding on the mesoscale. Sinuous flow is triggered by a plastic instability on the material surface ahead of the primary region of shear. On the other hand, when the material is extensively strain-hardened prior to shear, laminar flow again becomes unstable giving way to shear banding. The existence of these flow modes is established by stability analysis of laminar flow. The role of the initial microstructure state in determining the change in stability from laminar to sinuous / shear-banded flows in metals is elucidated. The implications for cutting, forming and wear processes for metals, and to surface plasticity phenomena such as mechanochemical Rehbinder effects are discussed.

  17. 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.

  18. Transfusion Refusal and the Shifting Limits of Multicultural Accommodation.

    Science.gov (United States)

    DeMichelis, Carey

    2017-12-01

    The refusal of blood products by Jehovah's Witness patients has provoked court proceedings, social science research, and contemporary fiction, all of which emphasize a seemingly intractable conflict between religious and secular ways of being. This article takes a different approach, focusing instead on the space that Witness patients have carved out for their accommodation in a major pediatric research hospital. Using discourse analysis and interview data, I map the way moralizing discourses surrounding Witness families have shifted over the past 70 years alongside advancements in bloodless medicine. I argue that Witnesses have helped to enable their present accommodation and recognition by marshaling particular forms of economic, human, and social capital, and consider whether their success might be attainable by other treatment-resisting patient groups. Thus, this article explores the shifting limits of multicultural accommodation and the conditions that make understanding, collaboration, and compromise possible.

  19. Disabilities in the workplace: recruitment, accommodation, and retention.

    Science.gov (United States)

    Davis, Linda

    2005-07-01

    Who has never had a need for accommodation to perform a job because of age-related changes, gender issues related to family care, religious practices, health status, or disability? Who has never had the benefit of universal accommodations designed to provide access for individuals with disabilities, such as using the handicap button to open a door when one's arms are loaded? All of society has had the benefit of inclusion of individuals with disabilities within the work force. Occupational health nurses are essential to accommodating new employees with disabilities, assisting ill or injured employees in returning to work, and changing attitudes toward disabled workers. Additionally, nurses have the skills and knowledge for leading and managing newly emerging disease management programs for workers with disabilities caused by chronic illness.

  20. Spasm of accommodation associated with closed head trauma.

    Science.gov (United States)

    Chan, R V Paul; Trobe, Jonathan D

    2002-03-01

    Spasm of accommodation, creating pseudomyopia, is generally associated with miosis and excess convergence as part of spasm of the near reflex. It may also exist as an isolated entity, usually attributed to psychogenic causes. We present six cases of accommodative spasm associated with closed head injury. All patients were male, ranging in age between 16 and 37 years. The degree of pseudomyopia, defined as the difference between manifest and cycloplegic refraction, was 1.5 to 2 diopters. A 3-year trial of pharmacologically induced cycloplegia in one patient did not lead to reversal of the spasm when the cycloplegia was stopped. All patients required the manifest refraction to see clearly at distance. The pseudomyopia endured for at least 7 years following head trauma. This phenomenon may represent traumatic activation or disinhibition of putative brain stem accommodation centers in young individuals.

  1. Eco-Evo-Devo: developmental symbiosis and developmental plasticity as evolutionary agents.

    Science.gov (United States)

    Gilbert, Scott F; Bosch, Thomas C G; Ledón-Rettig, Cristina

    2015-10-01

    The integration of research from developmental biology and ecology into evolutionary theory has given rise to a relatively new field, ecological evolutionary developmental biology (Eco-Evo-Devo). This field integrates and organizes concepts such as developmental symbiosis, developmental plasticity, genetic accommodation, extragenic inheritance and niche construction. This Review highlights the roles that developmental symbiosis and developmental plasticity have in evolution. Developmental symbiosis can generate particular organs, can produce selectable genetic variation for the entire animal, can provide mechanisms for reproductive isolation, and may have facilitated evolutionary transitions. Developmental plasticity is crucial for generating novel phenotypes, facilitating evolutionary transitions and altered ecosystem dynamics, and promoting adaptive variation through genetic accommodation and niche construction. In emphasizing such non-genomic mechanisms of selectable and heritable variation, Eco-Evo-Devo presents a new layer of evolutionary synthesis.

  2. Computer-animated model of accommodation and presbyopia.

    Science.gov (United States)

    Goldberg, Daniel B

    2015-02-01

    To understand, demonstrate, and further research the mechanisms of accommodation and presbyopia. Private practice, Little Silver, New Jersey, USA. Experimental study. The CAMA 2.0 computer-animated model of accommodation and presbyopia was produced in collaboration with an experienced medical animator using Autodesk Maya animation software and Adobe After Effects. The computer-animated model demonstrates the configuration and synchronous movements of all accommodative elements. A new classification of the zonular apparatus based on structure and function is proposed. There are 3 divisions of zonular fibers; that is, anterior, crossing, and posterior. The crossing zonular fibers form a scaffolding to support the lens; the anterior and posterior zonular fibers work reciprocally to achieve focused vision. The model demonstrates the important support function of Weiger ligament. Dynamic movement of the ora serrata demonstrates that the forces of ciliary muscle contraction store energy for disaccommodation in the elastic choroid. The flow of aqueous and vitreous provides strong evidence for our understanding of the hydrodynamic interactions during the accommodative cycle. The interaction may result from the elastic stretch in the choroid transmitted to the vitreous rather than from vitreous pressue. The model supports the concept that presbyopia results from loss of elasticity and increasing ocular rigidity in both the lenticular and extralenticular structures. The computer-animated model demonstrates the structures of accommodation moving in synchrony and might enhance understanding of the mechanisms of accommodation and presbyopia. Dr. Goldberg is a consultant to Acevision, Inc., and Bausch & Lomb. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  3. Sustainable fibre materials for replacing plastics in 3D-forming applications

    OpenAIRE

    Jacobsen, Eirik Ulsaker

    2017-01-01

    Plastic is a very broad family of materials that may provide a wide array of mechanical properties depending on the plastic or production method in question. This is why many industries have chosen plastic as their material of choice for the production of anything from plastic bags to underground piping. There is, however, a prominent issue concerning the heavy environmental impact of plastic. This is both due to the processing of crude oil and lack of biodegradability which in turn impact na...

  4. Analysis on the accommodation of renewable energy in northeast China

    Science.gov (United States)

    Liu, Jun; Zhang, Jinfang; Tian, Feng; Mi, Zhe

    2017-01-01

    The accommodation and curtailment of renewable energy in northeast China have attracted much attention with the rapid growth of wind and solar power generation. Large amount of wind power has been curtailed or abandoned in northeast China due to several reasons, such as, the redundancy of power supplies, inadequate power demands, imperfect power structure with less flexibility and limited cross-regional transmission capacity. In this paper, we use multi-area production simulation to analyse the accommodation of renewable energy in northeast China by 2020. Furthermore, we suggest the measures that could be adopted in generation, grid and load side to reduce curtailment of renewables.

  5. Persistent accommodative spasm nine years after head trauma.

    Science.gov (United States)

    Bohlmann, B J; France, T D

    1987-09-01

    Spasm of the near reflex is most often seen on a functional basis in young adults with underlying emotional problems. In particular, when convergence spasm is associated with miosis on attempted lateral gaze, a functional basis for the disorder should be suspected. Patients who experience spasm of the near reflex following trauma commonly follow a benign course with spontaneous resolution of their ocular complaints within 1-2 years. Accommodative spasm, manifested by pseudomyopia, or spasm of convergence, alone, or in combination with miosis, may be found as isolated signs of spasm of the near reflex. We report a patient who continues to demonstrate accommodative spasm 9 years after a motor vehicle accident.

  6. EVALUATION OF SERVICES’ QUALITY IN UPPER SILESIA ACCOMMODATION FACILITIES

    Directory of Open Access Journals (Sweden)

    Iwona Cieślik

    2013-12-01

    Full Text Available This paper presents the results of study about impact of accommodation services’ quality, particularly quality of work and qualifications of staff, on the guests’ opinion, and thus promoting the accommodation facilities, and making a choice of a hotel in the Upper Silesia. The study involved 200 people, taking into account their gender, age, place of residence, education and occupational status. The research tool was a survey questionnaire. The results indicate close correlation between the quality of staff services (individual approach, aesthetics, discretion, understanding and the customer is satisfaction. Particular attention was paid to the quality of service by the guests with high professional status, and higher education.

  7. 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.

  8. Recycling of plastic: accounting of greenhouse gases and global warming contributions

    DEFF Research Database (Denmark)

    Astrup, Thomas; Fruergaard, Thilde; Christensen, Thomas Højlund

    2009-01-01

    Major greenhouse gas (GHG) emissions related to plastic waste recycling were evaluated with respect to three management alternatives: recycling of clean, single-type plastic, recycling of mixed/contaminated plastic, and use of plastic waste as fuel in industrial processes. Source-separated plasti...... to a mixture of different plastic types and/or contamination, the plastic should be used for energy utilization. Recycling of plastic waste for substitution of other materials such as wood provided no savings with respect to global warming....

  9. [The behavior of fiber-reinforced plastics during laser cutting].

    Science.gov (United States)

    Emmrich, M; Levsen, K; Trasser, F J

    1992-06-01

    The pattern of the organic emissions, which are produced by processing of fibre reinforced plastics (epoxy resins reinforced by aramid and glass fibres and phenol resins reinforced by aramid fibre) with laser beam was studied and the concentrations of the main components determined. Despite the application of plastic materials with different chemical structures, the observed patterns are very similar. Mainly aromatic hydrocarbons are emitted, especially benzene and toluene, as well as some heteroatom-containing aromatic hydrocarbons (e.g. phenol). By use of oxygen as process gas the emissions during cutting of glass fibre reinforced plastics can be reduced, while they will be constantly high with aramid fibre reinforced plastics.

  10. Yellow filters can improve magnocellular function: motion sensitivity, convergence, accommodation, and reading.

    Science.gov (United States)

    Ray, N J; Fowler, S; Stein, J F

    2005-04-01

    The magnocellular system plays an important role in visual motion processing, controlling vergence eye movements, and in reading. Yellow filters may boost magnocellular activity by eliminating inhibitory blue input to this pathway. It was found that wearing yellow filters increased motion sensitivity, convergence, and accommodation in many children with reading difficulties, both immediately and after three months using the filters. Motion sensitivity was not increased using control neutral density filters. Moreover, reading-impaired children showed significant gains in reading ability after three months wearing the filters compared with those who had used a placebo. It was concluded that yellow filters can improve magnocellular function permanently. Hence, they should be considered as an alternative to corrective lenses, prisms, or exercises for treating poor convergence and accommodation, and also as an aid for children with reading problems.

  11. 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

  12. 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

  13. The plastic-associated microorganisms of the North Pacific Gyre

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  14. Environmental sustainability: plastic's evolving role in the automotive life cycle

    International Nuclear Information System (INIS)

    Jekel, L.; Tam, E.K.L.

    2002-01-01

    One method of assessing the sustainability of manufactured products involves performing a life cycle analysis for a product and comparing it to alternative ones, or else examining if individual stages of the product can be modified. LCA applications are being used more extensively, especially in the automotive and related industries. Automotive plastics in particular are being scrutinized with much greater care. Plastic components have replaced metal ones in vehicle manufacturing to improve vehicle fuel efficiency and aesthetics. However, at the end of a vehicle's life, recycling rates for plastic are negligible when compared to those of steel. In order to gain the full environmental benefits of using plastic as a vehicle material, plastics must be recycled at the end of a vehicle's life, especially given their increasing use. While a variety of processes have been developed for the recycling of automotive plastics, the challenges of sorting, processing, and finally recycling a heterogeneous mixture of used plastics have yet to be effectively solved. A preliminary life cycle assessment of a plastic automotive fascia demonstrates the usefulness of this eco-balance technique in evaluating potential improvements to manufacturing and end-of-life processes. Improving the manufacturing process may reduce environmental burdens to a larger extent than just recycling the plastic. (author)

  15. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita

    2010-01-01

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

  16. Will phenotypic plasticity affecting flowering phenology keep pace with climate change?

    Science.gov (United States)

    Richardson, Bryce A; Chaney, Lindsay; Shaw, Nancy L; Still, Shannon M

    2017-06-01

    Rising temperatures have begun to shift flowering time, but it is unclear whether phenotypic plasticity can accommodate projected temperature change for this century. Evaluating clines in phenological traits and the extent and variation in plasticity can provide key information on assessing risk of maladaptation and developing strategies to mitigate climate change. In this study, flower phenology was examined in 52 populations of big sagebrush (Artemisia tridentata) growing in three common gardens. Flowering date (anthesis) varied 91 days from late July to late November among gardens. Mixed-effects modeling explained 79% of variation in flowering date, of which 46% could be assigned to plasticity and genetic variation in plasticity and 33% to genetics (conditional R 2  = 0.79, marginal R 2  = 0.33). Two environmental variables that explained the genetic variation were photoperiod and the onset of spring, the Julian date of accumulating degree-days >5 °C reaching 100. The genetic variation was mapped for contemporary and future climates (decades 2060 and 2090), showing flower date change varies considerably across the landscape. Plasticity was estimated to accommodate, on average, a ±13-day change in flowering date. However, the examination of genetic variation in plasticity suggests that the magnitude of plasticity could be affected by variation in the sensitivity to photoperiod and temperature. In a warmer common garden, lower-latitude populations have greater plasticity (+16 days) compared to higher-latitude populations (+10 days). Mapped climatypes of flowering date for contemporary and future climates illustrate the wide breadth of plasticity and large geographic overlap. Our research highlights the importance of integrating information on genetic variation, phenotypic plasticity and climatic niche modeling to evaluate plant responses and elucidate vulnerabilities to climate change. Published 2016. This article is a U.S. Government work and is in the

  17. 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.

  18. 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.

  19. Effects of combined therapy in 80 cases of accommodative esotropia

    Directory of Open Access Journals (Sweden)

    Qi Liu

    2013-10-01

    Full Text Available AIM: To investigate a comprehensive treatment for accommodative esotropia.METHODS: Eighty patients with accommodative esotropia were analyzed. All cases wore corrective glasses 7d after mydriasis by 10g/L atropine. The pupils were all comprehensively trained. If the position of the esotropic eyes could not be corrected by spectacles and both eyes had similar visual acuity in one year, surgical intervention was taken to correct the position. Refraction, visual acuity, visual function and strabismus degree change before and after treatment were evaluated.RESULTS: One year after wearing glasses, 50 cases had corrected eye position through correction and 30 cases were partially accommodative esotropia. Ten cases of esotropia degree >+15△ which could not be complete corrected by cure correction got surgical intervention. Seven cases of them got normal eye positions and 3 cases were over corrected 10△-20△. After comprehensive treatment of 3 years, the cure rate of amblyopia was 88.7%.CONCLUSION: The treatment for accommodative esotropia is a comprehensive course. It is necessary to pay attention to eye position correction, but also for the treatment of amblyopia, while paying attention to establish binocular vision.

  20. Health Care Provider Accommodations for Patients with Communication Disorders

    Science.gov (United States)

    Burns, Michael I.; Baylor, Carolyn; Dudgeon, Brian J.; Starks, Helene; Yorkston, Kathryn

    2017-01-01

    Health care providers can experience increased diffculty communicating with adult patients during medical interactions when the patients have communication disorders. Meeting the communication needs of these patients can also create unique challenges for providers. The authors explore Communication Accommodation Theory (H. Giles, 1979) as a guide…

  1. Accommodative load from handheld game consoles in kindergarten children.

    Science.gov (United States)

    Sakata, T; Miyao, M; Ishigaki, H; Shiraiwa, Y; Ishihara, S; Furuta, M; Kondo, T; Toyoshima, H

    2001-07-01

    We analyzed and compared the visual accommodation of kindergarten children who were gazing fixedly at images from three different sources: Nintendo Game Boy DMG-01(TM) (non-backlit type game console: NBGC), NEC PC EnginePI-TG6(TM) (color backlit-type game console: CBGC) and a cartoon drawing (drawing). Subjects for the experiment were 13 4- to 5-year-old kindergarten children. The contrast ratios were, in the order, 1.1 (NBGC), 3.1 (drawing), and 3.4 (CBGC). These values show that the contrast of the NBGC screen was considerably lower than the others. The mean accommodative power increased when looking at all three types of image: a drawing (1.75±0.52 D; mean±S.D.), CBGC (1.82±0.61 D), and NBGC (2.26±0.50 D). Compared with the other 2 targets, NBGC required stronger accommodation, indicating that the legibility of the NBGC was poor. Repeated measures ANOVA was used for the values of accommodation for each type of target. There were significant differences among the 3 targets (p<0.01). Significant differences were seen between NBGC and drawings (p<0.01) and NBGC and CBGC (p<0.05) using paired Scheffe test, but not between CBGC and drawings. This supports the finding that the legibility of NBGC is low due to dark and low contrast screens with poor resolution.

  2. Translation Accommodations Framework for Testing English Language Learners in Mathematics

    Science.gov (United States)

    Solano-Flores, Guillermo

    2012-01-01

    The present framework is developed under contract with the Smarter Balanced Assessment Consortium (SBAC) as a conceptual and methodological tool for guiding the reasonings and actions of contractors in charge of developing and providing test translation accommodations for English language learners. The framework addresses important challenges in…

  3. Accommodation, Cafes and Restaurants. Industry Training Monograph No. 8.

    Science.gov (United States)

    Dumbrell, Tom

    Australia's accommodation, cafes, and restaurants industry represents more than half of the nation's total tourism and hospitality employment. It accounts for roughly 4.5% of all jobs in Australia (400,000 workers). Since 1987, the number of jobs in the sector has risen from about 257,000 to about 372,000. Approximately 57% of employees are…

  4. Cultural value orientations, internalized homophobia, and accommodation in romantic relationships

    NARCIS (Netherlands)

    Gaines, S.O.; Henderson, M.C.; Kim, M.; Gilstrap, S.; Yi, J.; Rusbult, C.E.; Hardin, D.P.; Gaertner, L.A.

    2005-01-01

    In the present study, we examined the impact of cultural value orientations (i.e., the personally oriented value of individualism, and the socially oriented values of collectivism, familism, romanticism, and spiritualism) on accommodation (i.e., voice and loyalty, rather than exit and neglect,

  5. Cooperating or competing in three languages : Cultural accommodation or alienation?

    NARCIS (Netherlands)

    Gargalianou, Vasiliki; Urbig, Diemo; Van Witteloostuijn, Arjen

    2017-01-01

    Purpose - The purpose of this paper is to study the effect of using foreign languages on cooperative behavior in a prisoner's dilemma setting. The cultural accommodation hypothesis suggests that people are less cooperative in English, associated with the Anglophone cultural cluster, than in French,

  6. 23 CFR 645.211 - State transportation department accommodation policies.

    Science.gov (United States)

    2010-04-01

    ... ENGINEERING AND TRAFFIC OPERATIONS UTILITIES Accommodation of Utilities § 645.211 State transportation... effects of any loss of productive agricultural land or any impairment of the productivity of any agricultural land that would result from the disapproval. The environmental and economic effects on productive...

  7. ACCOMMODATION INFRASTRUCTURE AND TOURISM FLOWS ON FELEACU HILL (CLUJ COUNTY

    Directory of Open Access Journals (Sweden)

    DANIELA-LIVIA GHEORGHIEȘ

    2016-06-01

    Full Text Available Accommodation Infrastructure and Tourism Flows on Feleacu Hill (Cluj County. Feleacu Hill experienced tourism development between 2001 and 2015. The INS data indicates that the number of accommodation units increased from one (2001 to four (2015 and there are a few more which are not registered in the INS database. The accommodation capacity increases, as many guesthouses are expanding their premises to receive more tourists and new accommodation units emerge, such as Hotel Premier in Vâlcele (Feleacu commune. Tourism flows also registered a highly positive trend. The number of arrivals increased from 95 tourists in 2002 to 7791 tourists in 2015. However, there was a downturn between 2009 and 2012, due to the economic crisis and the opening of the Turda – Gilău motorway (A3, which redirected transit routes outside the region and led to the closure of Paradis Hotel in 2012. Since 2012, the number of arrivals and overnight stays increased steadily due to the development of new forms of tourism – rural tourism, agrotourism, extreme tourism and complex tourism, materialized in growing numbers of tourists at the two guesthouses in Ciurila commune (“La Mesteceni” and “Domeniul Regilor”. Tourism brings obvious benefits to the rural communities on Feleacu Hill, even if the average duration of stay is still low.

  8. Accommodating Students' Sensory Learning Modalities in Online Formats

    Science.gov (United States)

    Allison, Barbara N.; Rehm, Marsha L.

    2016-01-01

    Online classes have become a popular and viable method of educating students in both K-12 settings and higher education, including in family and consumer sciences (FCS) programs. Online learning dramatically affects the way students learn. This article addresses how online learning can accommodate the sensory learning modalities (sight, hearing,…

  9. 7 CFR 1744.30 - Automatic lien accommodations.

    Science.gov (United States)

    2010-01-01

    ... Government mortgage to secure the private lender notes including, but not limited to, those of the private... affiliated companies with the proceeds of private lender notes qualifying for an automatic lien accommodation... forth in this section. (b) Private lender responsibility. The private lender is responsible for ensuring...

  10. a comparative study of the gradient accommodative convergence

    African Journals Online (AJOL)

    power by the eye in order to maintain a clear images as objects ... to work harmoniously for clear single binocular vision to be ... a balance between accommodation and convergence ... activity of life of the child especially with respect to school ...

  11. Teaching Disability Employment Discrimination Law: Accommodating Physical and Mental Disabilities

    Science.gov (United States)

    Kulow, Marianne DelPo

    2012-01-01

    Disability employment discrimination is often treated summarily in legal environment courses. This is actually a topic with significant practical application in the workplace since managers are often those who are confronted with accommodation requests. It is therefore desirable to include a class with hands-on exercises for students to begin to…

  12. Acute Effect of Caffeine on Amplitude of Accommodation and Near ...

    African Journals Online (AJOL)

    Caffeine is widely consumed in kola nuts and in other products in Sub-Saharan Africa. We examined the acute effect of caffeine on the amplitude of accommodation and near point of convergence of healthy Nigerians. Forty volunteers between ages of 20 and 27 years with refractive power± 0.50 DS were employed.

  13. Effect of third-order aberrations on dynamic accommodation.

    Science.gov (United States)

    López-Gil, Norberto; Rucker, Frances J; Stark, Lawrence R; Badar, Mustanser; Borgovan, Theodore; Burke, Sean; Kruger, Philip B

    2007-03-01

    We investigate the potential for the third-order aberrations coma and trefoil to provide a signed cue to accommodation. It is first demonstrated theoretically (with some assumptions) that the point spread function is insensitive to the sign of spherical defocus in the presence of odd-order aberrations. In an experimental investigation, the accommodation response to a sinusoidal change in vergence (1-3D, 0.2Hz) of a monochromatic stimulus was obtained with a dynamic infrared optometer. Measurements were obtained in 10 young visually normal individuals with and without custom contact lenses that induced low and high values of r.m.s. trefoil (0.25, 1.03 microm) and coma (0.34, 0.94 microm). Despite variation between subjects, we did not find any statistically significant increase or decrease in the accommodative gain for low levels of trefoil and coma, although effects approached or reached significance for the high levels of trefoil and coma. Theoretical and experimental results indicate that the presence of Zernike third-order aberrations on the eye does not seem to play a crucial role in the dynamics of the accommodation response.

  14. Usage of CISS and Conlon surveys in eye accommodation studies

    Science.gov (United States)

    Panke, Karola; Svede, Aiga; Jaschinski, Wolfgang; Krumina, Gunta

    2017-08-01

    To date, there is no assessment of more than one survey used for a clinical research study that address subjects with and without symptoms related to accommodative or binocular vision disorders. Thus, the purpose of this study was to investigate two different surveys - CISS and Conlon for the same subject group and analyse also critical visual function parameters. Monocular and binocular accommodative response for 20 subjects was measured for dominant eye with openfield infrared autorefractometer (Shin-Nippon SRW-5000) at three distances (24 cm, 30 cm and 40 cm). Subjects were divided into symptomatic and asymptomatic group using cut off score 21 for CISS and 20 for Conlon survey. We found positive exponential growth relationship between CISS and Conlon scores (R² = 0.7), but separation between symptomatic and asymptomatic group differed significantly depending on which survey was used. We found positive correlation between Conlon score and exophoria at 30 cm (r=0.41, p=0.01) and 24 cm (r=0.27, p=0.03). Relationship between subjective symptoms and following clinical parameters - accommodation lag (r accommodation (r convergence near point (r = 0.26, p < 0.05) were not significant. Our results confirmed that using different subjective symptom surveys can provide different results within the same subject group, therefore we recommend to use surveys as a part of case history and tool to measure patient satisfaction and results of treatment effectiveness instead of using them for clinical trials as a criteria to divide symptomatic and asymptomatic group.

  15. Symptomatology associated with accommodative and binocular vision anomalies

    Directory of Open Access Journals (Sweden)

    Ángel García-Muñoz

    2014-10-01

    Conclusions: There is a wide disparity of symptoms related to accommodative and binocular dysfunctions in the scientific literature, most of which are associated with near vision and binocular dysfunctions. The only psychometrically validated questionnaires that we found (n=3 were related to convergence insufficiency and to visual dysfunctions in general and there no specific questionnaires for other anomalies.

  16. Cooperating or competing in three languages : Cultural accommodation or alienation?

    NARCIS (Netherlands)

    Gargalianou, Vasiliki; Urbig, D.; van Witteloostuijn, Arjen

    Purpose The purpose of this paper is to study the effect of using foreign languages on cooperative behavior in a prisoner’s dilemma setting. The cultural accommodation hypothesis suggests that people are less cooperative in English, associated with the Anglophone cultural cluster, than in French,

  17. The changing accommodation landscape of Free State, 1936-2010 ...

    African Journals Online (AJOL)

    From the 1970s the pattern of hotels becomes more closely linked to tourism market considerations and areas of potential demand for leisure and business travellers. In spatial terms, a polarization of the accommodation sector is observed and paralleled by the hollowing out and closure of hotels in many small towns.

  18. Accommodating multilingualism in IT classrooms in the Free State ...

    African Journals Online (AJOL)

    This article explores the language context of Information Technology (IT) classes in the Free State province. An overview of the multilingual context within which the research was done is provided through a brief historical background of language accommodation and recognition in South Africa in general, and then ...

  19. Factors influencing pricing in the accommodation sector in South Africa

    Directory of Open Access Journals (Sweden)

    Engelina du Plessis

    2011-12-01

    Full Text Available Price is a significant factor of competitiveness. Price is a complex issue and is determined by a variety of demand and supply factors. These factors also differ from industry to industry. The purpose of this article is to determine the factors that influence pricing in the South African accommodation sector. In order to generate proper data, a survey was conducted at various South African accommodation establishments that were obtained from the databases of the three major associations in the accommodation sector. Two-hundred and forty seven questionnaires completed by managers from accommodation establishments were used in this research. Principal component factor analyses with Varimax rotation in STATISTICA were carried out. These resulted in ten factors, namely environmental qualities, amenities, image, management factor, positioning, quality service factor, infrastructure service factor, location, marketing and product quality factor. The results revealed that the major factors in pricing are service quality, image and product quality. Consequently this article can be used to assist managers in pricing and in obtaining a better competitive position in the industry by revising management structures and marketing campaigns. Keywords and phrases: Tourism industry, price competitiveness, service quality, image, product quality, entrepreneur and factor analysis

  20. 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.