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

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.

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

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.

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.

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.

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.

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

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.

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.

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.

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

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

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)

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.

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

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.

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

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.

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.)

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.

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)

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.

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.

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...

[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

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)

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.

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

DEFF Research Database (Denmark)

Jönsson, Jeppe

2008-01-01

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

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

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.

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.

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.

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.

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.

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

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.

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

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)

Magical Engineering Plastic

Energy Technology Data Exchange (ETDEWEB)

Kim, Gwang Ung

1988-01-15

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

Magical Engineering Plastic

International Nuclear Information System (INIS)

Kim, Gwang Ung

1988-01-01

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

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).

[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.

[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.

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

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...

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.

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

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.

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

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)

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

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

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.

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.

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.

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...

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

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...

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.

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.

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 ...

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.

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.

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.

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 ...

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...

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.

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.

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...

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

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.

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.

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.

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.

Plastic pikas: Behavioural flexibility in low-elevation pikas (Ochotona princeps)

Science.gov (United States)

Varner, Johanna; Horns, Joshua J.; Lambert, Mallory S.; Westberg, Elizabeth; Ruff, James; Wolfenberger, Katelyn; Beever, Erik; Dearing, M. Denise

2016-01-01

Behaviour is an important mechanism for accommodating rapid environmental changes. Understanding a species’ capacity for behavioural plasticity is therefore a key, but understudied, aspect of developing tractable conservation and management plans under climate-change scenarios. Here, we quantified behavioural differences between American pikas (Ochotona princeps) living in an atypical, low-elevation habitat versus those living in a more-typical, alpine habitat. With respect to foraging strategy, low-elevation pikas spent more time consuming vegetation and less time caching food for winter, compared to high-elevation pikas. Low-elevation pikas were also far more likely to be detected in forested microhabitats off the talus than their high-elevation counterparts at midday. Finally, pikas living in the atypical habitat had smaller home range sizes compared to those in typical habitat or any previously published home ranges for this species. Our findings indicate that behavioural plasticity likely allows pikas to accommodate atypical conditions in this low-elevation habitat, and that they may rely on critical habitat factors such as suitable microclimate refugia to behaviourally thermoregulate. Together, these results suggest that behavioural adjustments are one important mechanism by which pikas can persist outside of their previously appreciated dietary and thermal niches.

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)

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…

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.

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

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.

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.

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.

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.

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

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...

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

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

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...

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.

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.

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.

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.

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...

Plastic pikas: Behavioural flexibility in low-elevation pikas (Ochotona princeps).

Science.gov (United States)

Varner, Johanna; Horns, Joshua J; Lambert, Mallory S; Westberg, Elizabeth; Ruff, James S; Wolfenberger, Katelyn; Beever, Erik A; Dearing, M Denise

2016-04-01

Behaviour is an important mechanism for accommodating rapid environmental changes. Understanding a species' capacity for behavioural plasticity is therefore a key, but understudied, aspect of developing tractable conservation and management plans under climate-change scenarios. Here, we quantified behavioural differences between American pikas (Ochotona princeps) living in an atypical, low-elevation habitat versus those living in a more-typical, alpine habitat. With respect to foraging strategy, low-elevation pikas spent more time consuming vegetation and less time caching food for winter, compared to high-elevation pikas. Low-elevation pikas were also far more likely to be detected in forested microhabitats off the talus than their high-elevation counterparts at midday. Finally, pikas living in the atypical habitat had smaller home range sizes compared to those in typical habitat or any previously published home ranges for this species. Our findings indicate that behavioural plasticity likely allows pikas to accommodate atypical conditions in this low-elevation habitat, and that they may rely on critical habitat factors such as suitable microclimate refugia to behaviourally thermoregulate. Together, these results suggest that behavioural adjustments are one important mechanism by which pikas can persist outside of their previously appreciated dietary and thermal niches. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

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.

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.

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

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

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.)

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.

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.

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.

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.

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...

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.

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.

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.

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.

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.

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.

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)

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)

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

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.

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).

Accommodative spasm in siblings: A unique finding

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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.

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

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®.

Accommodative Amplitude in School-Age Children

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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.

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

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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.

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

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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

Hydrogen-Induced Plastic Deformation in ZnO

Science.gov (United States)

Lukáč, F.; Čížek, J.; Vlček, M.; Procházka, I.; Anwand, W.; Brauer, G.; Traeger, F.; Rogalla, D.; Becker, H.-W.

In the present work hydrothermally grown ZnO single crystals covered with Pd over-layer were electrochemically loaded with hydrogen and the influence of hydrogen on ZnO micro structure was investigated by positron annihilation spectroscopy (PAS). Nuclear reaction analysis (NRA) was employed for determination of depth profile of hydrogen concentration in the sample. NRA measurements confirmed that a substantial amount of hydrogen was introduced into ZnO by electrochemical charging. The bulk hydrogen concentration in ZnO determined by NRA agrees well with the concentration estimated from the transported charge using the Faraday's law. Moreover, a subsurface region with enhanced hydrogen concentration was found in the loaded crystals. Slow positron implantation spectroscopy (SPIS) investigations of hydrogen-loaded crystal revealed enhanced concentration of defects in the subsurface region. This testifies hydrogen-induced plastic deformation of the loaded crystal. Absorbed hydrogen causes a significant lattice expansion. At low hydrogen concentrations this expansion is accommodated by elastic straining, but at higher concentrations hydrogen-induced stress exceeds the yield stress in ZnO and plastic deformation of the loaded crystal takes place. Enhanced hydrogen concentration detected in the subsurface region by NRA is, therefore, due to excess hydrogen trapped at open volume defects introduced by plastic deformation. Moreover, it was found that hydrogen-induced plastic deformation in the subsurface layer leads to typical surface modification: formation of hexagonal shape pyramids on the surface due to hydrogen-induced slip in the [0001] direction.

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)

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).

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.

Effect of Phenylephrine on the Accommodative System

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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.

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.

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).

Privately Provided Accommodation Service Quality and Customer Satisfaction

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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.

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

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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.

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

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.

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.

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...

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.

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-02-15

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

Dislocation Processes and Frictional Stability of Faults

Science.gov (United States)

Toy, V. G.; Mitchell, T. M.; Druiventak, A.

2011-12-01

The rate dependence of frictional processes in faults in quartzofeldspathic crust is proposed to change at c. 300°C, because above this temperature asperity deformation can be accommodated by crystal plastic processes. As a consequence, the real fault contact area increases and the fault velocity strengthens. Conversely, faults at lower temperatures are velocity weakening and therefore prone to earthquake slip. We have investigated whether dislocation processes are important around faults in quartzites on seismic timescales, by inducing fault slip on a saw cut surface in novaculite blocks. Deformation was carried out at 450°C and 600°C in a Griggs apparatus. Slip rates of 8.3 x 10-7s-1 allowed total slip, u, of 0.5mm to be achieved in c. 10 minutes. Failure occurred at peak differential stresses of ~1.7 GPa and 1.4 GPa respectively, followed by significant weakening. Structures of the novaculite within and surrounding the fault surface were examined using EBSD, FIB-SEM and TEM to elucidate changes to their dislocation substructure. In the sample deformed at 450°C, a ~50μm thick layer of amorphous / non-crystalline silica was developed on the saw-cut surface during deformation. Rare clasts of the wall rock are preserved within this material. The surrounding sample is mostly composed of equant quartz grains of 5-10μm diameter that lack a preferred orientation, contain very few intercrystalline dislocations, and are divided by organised high angle grain boundaries. After deformation, most quartz grains within the sample retain their starting microstructure. However, within ~10μm of the sliding surface, dislocations are more common, and these are arranged into elongated, tangled zones (subgrain boundaries?). Microfractures are also observed. These microstructures are characteristic of deformation accommodated by low temperature plasticity. Our preliminary observations suggest that dislocation processes may be able to accommodate some deformation around fault

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.

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.

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.

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.

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

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

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.)

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.

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.

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.

[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.

Long-term follow-up of acute isolated accommodation insufficiency.

Science.gov (United States)

Lee, Jung Jin; Baek, Seung-Hee; Kim, Ungsoo Samuel

2013-04-01

To define the long-term results of accommodation insufficiency and to investigate the correlation between accommodation insufficiency and other factors including near point of convergence (NPC), age, and refractive errors. From January 2008 to December 2009, 11 patients with acute near vision disturbance and remote near point of accommodation (NPA) were evaluated. Full ophthalmologic examinations, including best corrected visual acuity, manifest refraction and prism cover tests were performed. Accommodation ability was measured by NPA using the push-up method. We compared accommodation insufficiency and factors including age, refractive errors and NPC. We also investigated the recovery from loss of accommodation in patients. Mean age of patients was 20 years (range, 9 to 34 years). Five of the 11 patients were female. Mean refractive error was -0.6 diopters (range, -3.5 to +0.25 diopters) and 8 of 11 patients (73%) had emmetropia (+0.50 to -0.50 diopters). No abnormalities were found in brain imaging tests. Refractive errors were not correlated with NPA or NPC (rho = 0.148, p = 0.511; rho = 0.319, p = 0.339; respectively). The correlation between age and NPA was not significant (rho = -395, p = 0.069). However, the correlation between age and NPC was negative (rho = -0.508, p = 0.016). Three of 11 patients were lost to follow-up, and 6 of 8 patients had permanent insufficiency of accommodation. Accommodation insufficiency is most common in emmetropia, however, refractive errors and age are not correlated with accommodation insufficiency. Dysfunction of accommodation can be permanent in the isolated accommodation insufficiency.

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.

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.

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

Radiation hardness of plastic scintillators for the Tile Calorimeter of the ATLAS detector

CERN Document Server

Jivan, Harshna; The ATLAS collaboration

2014-01-01

The Tile Calorimeter of the ATLAS detector, is a hadronic calorimeter responsible for detecting hadrons as well as accommodating for the missing transverse energy that result from the p-p collisions within the LHC. Plastic scintillators form an integral component of this calorimeter due to their ability to undergo prompt fluorescence when exposed to ionising particles. The scintillators employed are specifically chosen for their properties of high optical transmission and fast rise and decay time which enables efficient data capture since fast signal pulses can be generated. The main draw-back of plastic scintillators however is their susceptibility to radiation damage. The damage caused by radiation exposure reduces the scintillation light yield and introduces an error into the time-of flight data acquired. During Run 1 of the LHC data taking period, plastic scintillators employed within the GAP region between the Tile Calorimeter’s central and extended barrels sustained a significant amount of damage. Wit...

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...

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.

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...

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.

Interpreting Sustainability through Co-Evolution: Evidence from Religious Accommodations in Rome

Directory of Open Access Journals (Sweden)

Paola M. A. Paniccia

2017-12-01

Full Text Available In recent decades, concepts such as sustainability, innovation, and competitiveness have become fundamental for the development of tourist destinations, and thus, particularly, for the generation of value co-creation processes. To understand the role of tourism firms in these processes, more theoretical and empirical research is required. This paper addresses this need by examining the increasing role played by religious accommodations, adopting a co-evolutionary approach to sustainability and the resulting value co-creation processes. The study focuses on the dynamics of the relationship between this new hospitality model, territories, and tourists, through the analysis of six case studies localized in the historic centre of Rome (Italy. Findings show that religious accommodations can be considered as a new sustainability-oriented hospitality model that, by creating effective multi-level co-evolutionary adaptations with its territory and tourists, positively affects sustainable development as well as the generation of value co-creation processes. The paper contributes significantly both to sustainability literature and to the study of new hospitality models. Thus, theoretical and managerial implications emerge, together with suggestions for future research.

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.

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.

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.

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)

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.

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.

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.

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.

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.

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.

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

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.

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

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

Plastic debris in the open ocean

KAUST Repository

Cozar, Andres

2014-06-30

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

Plastic debris in the open ocean.

Science.gov (United States)

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

2014-07-15

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

Plastic debris in the open ocean

Science.gov (United States)

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

2014-01-01

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

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.

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.

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...

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

The conversion of waste plastics/petroleum residue mixtures to transportation fuels

International Nuclear Information System (INIS)

Ali, M.F.; Siddiqui, M.N.

2005-01-01

Plastics have become the material of choice in the modern world and its applications in the industrial field are continually increasing. Presently the plastics are manufactured for various uses such as: consumer packaging, wires, pipes, containers, bottles, appliances, electrical/electronic parts, computers and automotive parts. Most of he post consumer, plastic products are discarded and end up as mixed plastic municipal waste. The disposal of his waste has become a major social concern. Mixed plastic waste (MPW) recycling is still very much in its infancy. Approximately 20 million tons of plastic waste is generated in the United States of America, while about 15 million tons is generated throughout the Europe. With existing recycle efforts, only 7% of the MPW are recycled to produce low-grade plastic products such as plastic sacks, pipes, plastic fencing, and garden furniture. The current plastic reclamation technology options are generally grouped into the following four types: (i) Primary: The processing of plastic for use comparable to the original application. (ii) Secondary: The processing of plastics waste into new products with a lower quality level. (iii) Tertiary: The chemical or thermal processing of plastic waste to their basic hydrocarbon feedstock. The resulting raw materials are then reprocessed into plastic material or other products of the oil refining process. (iv) Quaternary: The incineration of plastics waste to recover energy. This paper deals exclusively with tertiary recycling by pyrolysis and catalytic cracking of plastics waste alone and by coprocessing with petroleum residue or heavy oils to fuels and petrochemical feedstock for further processing in existing refinery and petrochemical units. (author)

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...

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...

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.

Symptomatic accommodative disorders and asthenopia: Prevalence and association in Ghanaian children

Directory of Open Access Journals (Sweden)

Charles Darko-Takyi

2016-11-01

Full Text Available Background: There is a scarcity of data on asthenopia and accommodative disorders in children in Ghana as optometrists sometimes fail to carry out comprehensive assessments because of the lack of appropriate instruments. Aim: To establish the prevalence of asthenopic symptoms and symptomatic accommodative disorders among Junior High School children in Cape Coast metropolis (in their habitual vision state and to investigate if there are any associations between asthenopic symptoms and the disorders. Method: A prospective cross-sectional school-based study using a multistage sample of 627 participants aged 12–17 years from Junior High Schools in Cape Coast metropolis, Ghana, was conducted. Participants completed a reliable asthenopic symptoms questionnaire (Cronbach’s α = 0.866, and 220 participants who expressed two or more severe or very severe symptoms were selected for comprehensive accommodative system assessment over their habitual vision state. Results: The prevalence of symptoms of asthenopia (two or more severe or very severe and symptomatic accommodative disorders were 35.1% and 17.4% respectively. For specific symptomatic accommodative disorders, the prevalence was as follows: 7.7% accommodative insufficiency, 4.5% accommodative infacility, 1.4% accommodative excess and 3.8% accommodative fatigue. There were significant associations between some specific accommodative disorders and some specific asthenopic symptoms even though these asthenopic symptoms overlapped in other accommodative disorders. Conclusion: Specific asthenopic symptoms do not discriminate between the presences of specific types of accommodative disorders. A comprehensive accommodative system assessment with appropriate instruments is relevant to the diagnosis and management of accommodative disorders to relieve asthenopic symptoms.

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.

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.

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.

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.

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

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...

Mechanical evolution of transpression zones affected by fault interactions: Insights from 3D elasto-plastic finite element models

Science.gov (United States)

Nabavi, Seyed Tohid; Alavi, Seyed Ahmad; Mohammadi, Soheil; Ghassemi, Mohammad Reza

2018-01-01

The mechanical evolution of transpression zones affected by fault interactions is investigated by a 3D elasto-plastic mechanical model solved with the finite-element method. Ductile transpression between non-rigid walls implies an upward and lateral extrusion. The model results demonstrate that a, transpression zone evolves in a 3D strain field along non-coaxial strain paths. Distributed plastic strain, slip transfer, and maximum plastic strain occur within the transpression zone. Outside the transpression zone, fault slip is reduced because deformation is accommodated by distributed plastic shear. With progressive deformation, the σ3 axis (the minimum compressive stress) rotates within the transpression zone to form an oblique angle to the regional transport direction (∼9°-10°). The magnitude of displacement increases faster within the transpression zone than outside it. Rotation of the displacement vectors of oblique convergence with time suggests that transpression zone evolves toward an overall non-plane strain deformation. The slip decreases along fault segments and with increasing depth. This can be attributed to the accommodation of bulk shortening over adjacent fault segments. The model result shows an almost symmetrical domal uplift due to off-fault deformation, generating a doubly plunging fold and a 'positive flower' structure. Outside the overlap zone, expanding asymmetric basins subside to 'negative flower' structures on both sides of the transpression zone and are called 'transpressional basins'. Deflection at fault segments causes the fault dip fall to less than 90° (∼86-89°) near the surface (∼1.5 km). This results in a pure-shear-dominated, triclinic, and discontinuous heterogeneous flow of the transpression zone.

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.

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.)

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.

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.

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.

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.

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

International Nuclear Information System (INIS)

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

1990-01-01

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

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

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.

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.

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.

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.

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...

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

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.

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.

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…

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-10-28

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

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)

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.

Plastics Distribution and Degradation on Lake Huron Beaches

Science.gov (United States)

Zbyszewski, M.; Corcoran, P.

2009-05-01

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

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.

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

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.

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.

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...

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.

The Assessment of Accommodation and Convergence System in the Bank Employees

Directory of Open Access Journals (Sweden)

Monireh Mahjoob

2013-02-01

Full Text Available Background: Regarding the high outbreak rate of the eye disorders and problems particularly accommodation disorders and convergence insufficiency in computer users, the study tries to determine the convergence, accommodation system, condition, fusion reserves and vision dimension in bank employees (who work with computers and the control group (who are not computer users and then to compare the mentioned parameters in the two groups. Materials and Methods: In this cross-sectional and observational study a total of 44 bank employees and 44 people as the control group members were selected randomly. Initially, refractive problems were reformed, and then accommodation, convergence and vision dimension evaluative tests were conducted. The test included measuring the near point of convergence, jump convergence, phoria, accommodation range (one eye, both eyes, ease of accommodation (one eye, both eyes, positive and negative related accommodation, near fusion versions and TNO.Results: Our results showed that there was a not significant difference among the near point of convergence, jump convergence, near phoria, accommodation range (one eye and both eyes, ease of accommodation (one eye, both eyes, positive and negative related accommodation in bank employees and control group.Conclusion: Regarding the studies, the outbreak rate of accommodation and convergence disorders is higher in bank employees than the control group which would be due to over working with computer within a fixed interval.

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.

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...

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

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.

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...

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.

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.

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.

Accommodation stresses in hydride precipitates by synchrotron x-ray diffraction

International Nuclear Information System (INIS)

Santisteban, J R; Vicente, M A; Vizcaino, P; Banchik, A D; Almer, J

2012-01-01

Hydride-forming materials (Zr, Ti, Nb, etc) are affected by a sub-critical crack growth mechanism that involves the diffusion of H to the stressed region ahead of a crack, followed by nucleation and fracture of hydrides at the crack tip [1]. The phenomenon is intermittent, with the crack propagating through the hydride and stopping when it reaches the matrix. By repeating these processes, the crack propagates through a component at a rate that is highly dependent on the temperature history of the component. Most research effort to understand this phenomenon has occurred within the nuclear industry, as it affects the safe operation of pressure tubes (Zr2.5%Nb) and the long-term storage of nuclear fuel (Zircaloy cladding). Stress-induced hydride formation is a consequence of the volume dilatation that accompanies hydride formation (of the order of 15%), which is elastoplastically accommodated by the matrix and precipitate. Compressive stresses are expected within hydride precipitates due to the constraint imposed by the matrix. Such 'accommodation' stresses are essential ingredients in all theoretical models developed to assess the crack growth rate dependence on operational variables such as temperature, applied stress intensity factor, or overall H concentration [2]. Yet little experimental information is available about the magnitude and directionality of such accommodation stresses. Synchrotron X-ray diffraction is the only technique capable of quantifying such stresses. Here we briefly describe the fundaments of the technique, when used through an area detector placed in transmission geometry. The results of the experiments have allowed us to produce a comprehensive picture about the magnitude and origin of accommodation stresses in δ zirconium hydride platelets (author)

Short-term ionic plasticity at GABAergic synapses

Directory of Open Access Journals (Sweden)

Joseph Valentino Raimondo

2012-10-01

Full Text Available Fast synaptic inhibition in the brain is mediated by the pre-synaptic release of the neurotransmitter γ-Aminobutyric acid (GABA and the post-synaptic activation of GABA-sensitive ionotropic receptors. As with excitatory synapses, it is being increasinly appreciated that a variety of plastic processes occur at inhibitory synapses, which operate over a range of timescales. Here we examine a form of activity-dependent plasticity that is somewhat unique to GABAergic transmission. This involves short-lasting changes to the ionic driving force for the postsynaptic receptors, a process referred to as short-term ionic plasticity. These changes are directly related to the history of activity at inhibitory synapses and are influenced by a variety of factors including the location of the synapse and the post-synaptic cell’s ion regulation mechanisms. We explore the processes underlying this form of plasticity, when and where it can occur, and how it is likely to impact network activity.

The rate of change of vergence-accommodation conflict affects visual discomfort.

Science.gov (United States)

Kim, Joohwan; Kane, David; Banks, Martin S

2014-12-01

Stereoscopic (S3D) displays create conflicts between the distance to which the eyes must converge and the distance to which the eyes must accommodate. Such conflicts require the viewer to overcome the normal coupling between vergence and accommodation, and this effort appears to cause viewer discomfort. Vergence-accommodation coupling is driven by the phasic components of the underlying control systems, and those components respond to relatively fast changes in vergence and accommodative stimuli. Given the relationship between phasic changes and vergence-accommodation coupling, we examined how the rate of change in the vergence-accommodation conflict affects viewer discomfort. We used a stereoscopic display that allows independent manipulation of the stimuli to vergence and accommodation. We presented stimuli that simulate natural viewing (i.e., vergence and accommodative stimuli changed together) and stimuli that simulate S3D viewing (i.e., vergence stimulus changes but accommodative stimulus remains fixed). The changes occurred at 0.01, 0.05, or 0.25 Hz. The lowest rate is too slow to stimulate the phasic components while the highest rate is well within the phasic range. The results were consistent with our expectation: somewhat greater discomfort was experienced when stimulus distance changed rapidly, particularly in S3D viewing when the vergence stimulus changed but the accommodative stimulus did not. These results may help in the generation of guidelines for the creation and viewing of stereo content with acceptable viewer comfort.

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

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

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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…

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.

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

Pyrolysis of plastic waste for liquid fuel production as prospective energy resource

Science.gov (United States)

Sharuddin, S. D. A.; Abnisa, F.; Daud, W. M. A. W.; Aroua, M. K.

2018-03-01

The worldwide plastic generation expanded over years because of the variety applications of plastics in numerous sectors that caused the accumulation of plastic waste in the landfill. The growing of plastics demand definitely affected the petroleum resources availability as non-renewable fossil fuel since plastics were the petroleum-based material. A few options that have been considered for plastic waste management were recycling and energy recovery technique. Nevertheless, several obstacles of recycling technique such as the needs of sorting process that was labour intensive and water pollution that lessened the process sustainability. As a result, the plastic waste conversion into energy was developed through innovation advancement and extensive research. Since plastics were part of petroleum, the oil produced through the pyrolysis process was said to have high calorific value that could be used as an alternative fuel. This paper reviewed the thermal and catalytic degradation of plastics through pyrolysis process and the key factors that affected the final end product, for instance, oil, gaseous and char. Additionally, the liquid fuel properties and a discussion on several perspectives regarding the optimization of the liquid oil yield for every plastic were also included in this paper.

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%.

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.

A meta-analysis of family accommodation and OCD symptom severity.

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Wu, Monica S; McGuire, Joseph F; Martino, Charitie; Phares, Vicky; Selles, Robert R; Storch, Eric A

2016-04-01

Family accommodation in obsessive-compulsive disorder (OCD) is characterized by myriad behaviors, such as modifying family routines, facilitating avoidance, and engaging in compulsions to reduce obsessional distress. It has been linked to various deleterious outcomes including increased functional impairment and poorer treatment response for OCD. Although extant literature suggests a linear relationship between family accommodation and OCD symptom severity, the magnitude and statistical significance of this association has been inconsistent across studies, indicating that moderators may be influencing this relationship. The present study examined this relationship using meta-analytic techniques, and investigated sample-dependent (age, gender, comorbid anxiety/mood disorders) and methodological (administration method and number of items used in family accommodation measure, informant type, sample size, publication year) moderators. Forty-one studies were included in the present meta-analysis, and the overall effect size (ES) for the correlation between family accommodation and OCD symptom severity was moderate (r=.42). Moderator analyses revealed that the number of items on the family accommodation scale moderated the ES. No other sample-dependent or methodological characteristics emerged as moderators. In addition to being the first systematic examination of family accommodation moderators, these results highlight the moderate relationship between family accommodation and OCD severity that is influenced by measurement scales. Findings may be used to guide clinical care and inform future investigations by providing a more nuanced understanding of family accommodation in OCD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optical absorption in recycled waste plastic polyethylene

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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.

Gain and movement time of convergence-accommodation in preschool children.

Science.gov (United States)

Suryakumar, R; Bobier, W R

2004-11-01

Convergence-accommodation is the synkinetic change in accommodation driven by vergence. A few studies have investigated the static and dynamic properties of this cross-link in adults but little is known about convergence-accommodation in children. The purpose of this study was to develop a technique for measuring convergence-accommodation and to study its dynamics (gain and movement time) in a sample of pre-school children. Convergence-accommodation measures were examined on thiry-seven normal pre-school children (mean age = 4.0 +/- 1.31 yrs). Stimulus CA/C (sCA/C) ratios and movement time measures of convergence-accommodation were assessed using a photorefractor while subjects viewed a DOG target. Repeated measures were obtained on eight normal adults (mean age = 23 +/- 0.2 yrs). The mean sCA/C ratios and movement times were not significantly different between adults and children (0.10 D/Delta [0.61 D/M.A.], 743 +/- 70 ms and 0.11 D/Delta [0.50 D/M.A.], 787 +/- 216 ms). Repeated measures on adults showed a non-significant mean difference of 0.001 D/Delta. The results suggest that the possible differences in crystalline lens (plant) characteristics between children and adults do not appear to influence convergence-accommodation gain or duration.

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.

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...

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...

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.

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.

Triboelectrostatic separation for granular plastic waste recycling: a review.

Science.gov (United States)

Wu, Guiqing; Li, Jia; Xu, Zhenming

2013-03-01

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

Religious values and healthcare accommodations: voices from the American Muslim community.

Science.gov (United States)

Padela, Aasim I; Gunter, Katie; Killawi, Amal; Heisler, Michele

2012-06-01

Minority populations receive a lower quality healthcare in part due to the inadequate assessment of, and cultural adaptations to meet, their culturally informed healthcare needs. The seven million American Muslims, while ethnically and racially diverse, share religiously informed healthcare values that influence their expectations of healthcare. There is limited empirical research on this community's preferences for cultural modifications in healthcare delivery. Identify healthcare accommodations requested by American Muslims. Using community-based participatory research (CBPR) methods, we partnered with four community organizations in the Greater Detroit area to design and conduct thirteen focus groups at area mosques serving African American, Arab American, and South Asian American Muslims. Qualitative content analysis utilized a framework team-based approach. Participants reported stigmatization within the healthcare system and voiced the need for culturally competent healthcare providers. In addition, they identified three key healthcare accommodations to address Muslim sensitivities: the provision of (1) gender-concordant care, (2) halal food and (3) a neutral prayer space. Gender concordance was requested based on Islamic conceptions of modesty and privacy. Halal food was deemed to be health-promoting and therefore integral to the healing process. Lastly, a neutral prayer space was requested to ensure security and privacy during worship. This study informs efforts to deliver high-quality healthcare to American Muslims in several ways. We note three specific healthcare accommodations requested by this community and the religious values underlying these requests. Healthcare systems can further cultural sensitivity, engender trust, and improve the healthcare experiences of American Muslims by understanding and then attempting to accommodate these values as much as possible.

Comparing family accommodation in pediatric obsessive-compulsive disorder, anxiety disorders, and nonanxious children.

Science.gov (United States)

Lebowitz, Eli R; Scharfstein, Lindsay A; Jones, Johnna

2014-12-01

Family accommodation describes ways in which parents modify their behavior to help a child avoid or alleviate distress caused by emotional disorders. Accommodation is associated with increased symptom severity, lower functioning, and poorer treatment outcomes. Accommodation is prevalent in childhood obsessive-compulsive disorder (OCD) and anxiety disorders (ADs) but no studies have compared accommodation in these groups or compared them to healthy controls to ascertain if accommodation is prevalent in the general population. This study addresses these gaps by comparing patterns of accommodation, factors that maintain accommodation, and its relation to symptom severity in OCD and AD, relative to healthy controls. We directly compared reports of accommodation to childhood OCD (N = 26) and AD (N = 31), and a comparison group of nonanxious (NA) children (N = 30). Mothers completed measures of accommodation (Family Accommodation Scale (FAS)/Family Accommodation Scale-Anxiety (FASA)), anxiety (Screen for Childhood Anxiety Related Emotional Disorders-Parent Report (SCARED-PR)), and OCD (Children's Yale-Brown Obsessive Compulsive Scale (CYBOCS)). Family accommodation is prevalent among mothers of children with OCD and AD. Few differences were found between the two clinical groups who reported more accommodation (F[2,84] = 23.411, P anxiety in AD (r = .426, P = .017) and OCD (r = .465, P = .017), but not in the NA group. Findings highlight family accommodation as a phenomenon that applies broadly and in a similar manner to children with AD and OCD. Evaluating accommodation provides useful information for clinical care and is an important part of the assessment of children with AD and OCD. © 2014 Wiley Periodicals, Inc.

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.)

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.

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.

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.

The influence of family accommodation on pediatric hospital experience in Canada.

Science.gov (United States)

Franck, Linda S; Ferguson, Deron; Fryda, Sarah; Rubin, Nicole

2017-08-15

The goals of our study were to describe the types of family accommodation for parents of hospitalized children and to examine their influence on the pediatric hospital experience. This multi-site cohort survey included 10 hospitals in Ontario Province, Canada. Participants were parents of inpatient children (n = 1240). Main outcome measures included ratings of three parent-reported measures of hospital experience: overall hospital experience; willingness to recommend the hospital to family or friends; and how much the accommodation type helped parent stay involved in their child's hospital care. Parents most often stayed in the child's room (74.7%), their own home (12.3%), hotel (4.0%) or a Ronald McDonald House (3.0%). Accommodation varied based on hospital, parent and child factors. Length of stay and the child's health status were significant predictors for overall hospital experience and recommending the hospital to family or friends, but accommodation type was not. Families who stayed at a Ronald McDonald House reported greater involvement in their child's care compared with other accommodation types (odds ratio: 1.54-20.73 for contrasted accommodation types). Use of different overnight accommodations for families of hospitalized pediatric patients in Canada is similar to a previous report of U.S. family hospital accommodations. In contrast to the previous U.S. findings, Canadian hospital experience scores were lower and accommodation type was not a significant predictor of overall hospital experience or willingness to recommend the hospital. In Canada, as in the U.S., families who stayed at a Ronald McDonald House reported that this accommodation type significantly improved their ability to be involved in their child's care.

Effect of different reading interfaces and conditions on the accommodation response

Directory of Open Access Journals (Sweden)

Xiao-Feng Wang

2016-04-01

Full Text Available AIM:To compare the difference of accommodation response under the variety reading conditions including computer screen, mobile phone screen and printed texts. The investigation also included the accommodation response under these conditions with different distances, brightness, dynamic and static testing status. METHODS:Thirty volunteer subjects were included with normal vision function. The reading target on computer screen, mobile screen and paper were used, respectively. Grand Seiko WAM 5500 infrared automatic refractometer was applied to measure accommodation response. The influence of different reading conditions on accommodation was compared using variance analysis with SPSS17.0.RESULTS:Accommodation lag under the computer screen with high brightness was 0.52±0.24D, that under papers was 0.73±0.28D, that under mobile phone was 0.72±0.29D. Accommodation lag under the computer screen with high brightness was less than that under mobile phones and paper, the differences were statistically significant(PCONCLUSION:Accommodation lag under the computer screen with high brightness is relatively smaller than that under mobile phone or paper. There is no significant difference between those under phones and paper. With the brightness of computers in a certain range, there is no effect for accommodation response.

Attention-deficit/hyperactivity disorder children exhibit an impaired accommodative response.

Science.gov (United States)

Redondo, Beatriz; Vera, Jesús; Molina, Rubén; García, José Antonio; Ouadi, Miriam; Muñoz-Hoyos, Antonio; Jiménez, Raimundo

2018-05-01

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common paediatric neurobehavioural disorders causing multiple functional impairments in children. Based on the relationship between the neural system that controls attention and ocular dynamics, the present study compares the magnitude and variability of accommodation between a group of non-medicated ADHD children and an age-matched control group. The magnitude and variability of the accommodative response were objectively measured in 36 children using the WAM-5500 autorefractometer for 90 consecutive seconds at three static viewing distances (500, 40, and 20 cm). Participants were divided into ADHD (n = 18) or control (n = 18) groups based on clinically validated criteria. Children with ADHD exhibited higher lags of accommodation (p = 0.024), increasing at closer viewing distances, in comparison to the control group. Marginal statistical differences were found for the variability of accommodation (p = 0.066), with the ADHD group showing a trend towards higher variability. Our analysis showed that the magnitude and variability of accommodation did not vary over time between groups (p > 0.05). Our data suggest that children with ADHD have a less accurate accommodative response. These results provide a new ocular index that could help to clarify the relationship between accommodative response and attentional deficits, which could have a direct impact on the academic, cognitive, and visual performance of ADHD children.

Guidelines for Providing Accommodations Using CASAS Assessment for Learners with Disabilities

Science.gov (United States)

CASAS - Comprehensive Adult Student Assessment Systems (NJ1), 2005

2005-01-01

These guidelines address methods for administering Comprehensive Adult Student Assessment System (CASAS) assessments using accommodations for learners with documented disabilities. The suggested accommodations for disability categories include provisions for: (1) Accommodations in test administration procedures; and (2) Use of appropriate CASAS…

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

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.

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%.

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 ...

Slepian Simulations of Plastic Displacements of Randomly Excited Hysteretic Structures

DEFF Research Database (Denmark)

Lazarov, Boyan Stefanov

2003-01-01

The object of the study is a fast simulation method for generation and analysis of the plastic response of a randomly excited MDOF oscillatro with several potential elements with elasto-plastic constitutive behavior. The oscillator is statically determinate with linear damping. The external...... approximately as a stationary Gaussian process. This requires that the standard deviation of the stationary response is not too large as compared to the plastic yield limits. The Slepian model process for the behavior of the linear response is then simply the conditional mean (linear regression) of the process...... noise excited linear oscillator obtained from the elasto-plastic oscillator by totally removing the plastic domain. Thus the key to the applicability of the method is that the oscillator has a linear domain within which the response stays for a sufficiently long time to make the random response behave...

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

[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.

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

Catalytic Pyrolysis of Waste Plastic Mixture

Science.gov (United States)

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

2018-03-01

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

Family Accommodation in Obsessive-Compulsive Disorder: A Study on Associated Variables

Directory of Open Access Journals (Sweden)

Teresa Cosentino

2015-10-01

Full Text Available The present study aimed to examine family accommodation in relatives of obsessive-compulsive disease (OCD patients. Accommodation was assessed in a sample of 31 relatives of OCD patients by means of the Family Accommodation Scale. Other variables measured as predictors of accommodation were the tendency of a family member to feel guilty, sensitivity to guilt, anxiety sensitivity and the prevalence of a passive communication style. Accommodation was found to be rather widespread in the family members who took part in our study, and they tended to show more accommodation the greater their sensitivity to guilt and the stable tendency to experience this emotion as well as anxiety sensitivity and a passive communication style. Multiple linear regression analyses showed that, among the variables considered, the family member’s sensitivity to guilt is the only factor which can predict accommodation with regard to the patient’s demands for involvement. On the other hand, the small number of family members in the sample and the lack of clinical data on patients (such as the severity, typology and duration of their obsessive-compulsive disorder pose limits to the generalizability of the results and point to the need for further research.

Stability of A-150 plastic ionization chamber response over a ∼30 year period

International Nuclear Information System (INIS)

Kroc, Thomas K.; Lennox, Arlene J.

2007-01-01

At the NIU Institute for Neutron Therapy at Fermilab, the clinical tissue-equivalent ionization chamber response is measured every treatment day using a cesium source that was configured to match readings obtained at the National Bureau of Standards. Daily measurements are performed in air using the air-to-tissue dose conversion factors given in AAPM Report no. 7. The measured exposure calibration factors have been tabulated and graphed as a function of time from 1978 to present. For A-150 plastic ionization chambers, these factors exhibit a sinusoidal variation with a period of approximately one year and amplitude of ± 1%. This variation, attributable to the hygroscopic nature of A-150 plastic, is correlated with the relative humidity of the facility, and is greater than the humidity corrections for gas described in the literature. Our data suggest that chamber calibration should be performed at least weekly to accommodate these variations

Variations in accommodation and convergence responses in a minimally controlled photorefractive setting.

Science.gov (United States)

Horwood, A M; Turner, J E; Houston, S M; Riddell, P M

2001-11-01

A remote haploscopic photorefractor, designed for assessment of accommodation and convergence in infants and clinical groups, was used to determine heterophoria accommodative convergence/accommodation (AC/A) ratios in normal naïve adults. These were compared with conventional clinical measures. Twenty-one naïve subjects were used to compare occluded and unoccluded prism cover test responses with the remote haploscopic photorefractor using a text and picture target. Although luminance was generally low for both targets, binocular vergences were appropriate for target demand in both studies. Binocular accommodation showed greater lag for the highest target accommodative demand and the less demanding target. Occlusion not only reduced vergence response, but also frequently caused a marked reduction in accommodation, especially to the picture target. Normal mean AC/A values were found, but with wide variations between individual subjects. Although mean accommodation, vergence, and AC/A values were comparable with published data, we suggest that in these conditions using naïve subjects, accommodation is frequently inaccurate, especially on occlusion, without concomitant loss of vergence, at least at low light levels. Accommodative convergence may play a less important part in, and other cues contribute more to, the near reflex than has been previously suggested.

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)....

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.

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

Plasticized chitosan/polyolefin films produced by extrusion.

Science.gov (United States)

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

2015-03-06

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

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

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

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.

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.

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.

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

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)

Family accommodation in obsessive-compulsive and anxiety disorders: a five-year update.

Science.gov (United States)

Lebowitz, Eli R; Panza, Kaitlyn E; Bloch, Michael H

2016-01-01

Family accommodation describes changes that individuals make to their behavior, to help their relative who is dealing with a psychiatric and/or psychological disorder(s), avoid or alleviate distress related to the disorder. Research on family accommodation has advanced rapidly. In this update we aim to provide a synthesis of findings from the past five years. A search of available, peer-reviewed, English language papers was conducted through PubMed and PsycINFO, cross referencing psychiatric disorders with accommodation and other family-related terms. The resulting 121 papers were individually reviewed and evaluated and the main findings were discussed. Family accommodation is common in obsessive-compulsive disorder (OCD) and in anxiety disorders, and manifests similarly across these disorders. Family accommodation is associated with more severe psychopathology and poorer clinical outcomes. Treatments have begun to focus on the reduction of family accommodation as a primary therapeutic goal and finally, neurobiological underpinnings of family accommodation are beginning to be investigated.

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.

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.

Framing effectiveness in impact assessment: Discourse accommodation in controversial infrastructure development

Energy Technology Data Exchange (ETDEWEB)

Rozema, Jaap G., E-mail: j.rozema@uea.ac.uk [Science, Society and Sustainability (3S) Research Group, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Department of Development and Planning, Aalborg University, A.C. Meyers Vænge 15, DK-2450 København SV (Denmark); Bond, Alan J. [Science, Society and Sustainability (3S) Research Group, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); School of Geo and Spatial Sciences, Internal Box 375, North West University (Potchefstroom campus) (South Africa)

2015-01-15

There is ongoing debate about the effectiveness of impact assessment tools, which matters both because of the threat to future practice of the tools which are frequently perceived to be ineffective, and because of the disillusionment that can ensue, and controversy generated, amongst stakeholders in a decision context where opportunities for meaningful debate have not been provided. In this article we regard debate about the meaning of effectiveness in impact assessment as an inevitable consequence of increased participation in environmental decision-making, and therefore frame effectiveness based on an inclusive democracy role to mean the extent to which impact assessment can accommodate civil society discourse. Our aim is to investigate effectiveness based on this framing by looking at one type of impact assessment – environmental impact assessment (EIA) – in two controversial project proposals: the HS2 rail network in England; and the A4DS motorway in the Netherlands. Documentary analysis and interviews held with key civil society stakeholders have been deployed to identify discourses that were mobilised in the cases. EIA was found to be able to accommodate only one out of four discourses that were identified; for the other three it did not provide the space for the arguments that characterised opposition. The conclusion in relation to debate on framings of effectiveness is that EIA will not be considered effective by the majority of stakeholders. EIA was established to support decision-making through a better understanding of impacts, so its ineffectiveness is unsurprising when its role is perceived to be broader. However, there remains a need to map discourses in different decision contexts and to analyse the extent to which the range of discourses are accommodated throughout the decision process, and the role of impact assessment in those processes, before recommendations can be made to either improve impact assessment effectiveness, or whether it is

Framing effectiveness in impact assessment: Discourse accommodation in controversial infrastructure development

International Nuclear Information System (INIS)

Rozema, Jaap G.; Bond, Alan J.

2015-01-01

There is ongoing debate about the effectiveness of impact assessment tools, which matters both because of the threat to future practice of the tools which are frequently perceived to be ineffective, and because of the disillusionment that can ensue, and controversy generated, amongst stakeholders in a decision context where opportunities for meaningful debate have not been provided. In this article we regard debate about the meaning of effectiveness in impact assessment as an inevitable consequence of increased participation in environmental decision-making, and therefore frame effectiveness based on an inclusive democracy role to mean the extent to which impact assessment can accommodate civil society discourse. Our aim is to investigate effectiveness based on this framing by looking at one type of impact assessment – environmental impact assessment (EIA) – in two controversial project proposals: the HS2 rail network in England; and the A4DS motorway in the Netherlands. Documentary analysis and interviews held with key civil society stakeholders have been deployed to identify discourses that were mobilised in the cases. EIA was found to be able to accommodate only one out of four discourses that were identified; for the other three it did not provide the space for the arguments that characterised opposition. The conclusion in relation to debate on framings of effectiveness is that EIA will not be considered effective by the majority of stakeholders. EIA was established to support decision-making through a better understanding of impacts, so its ineffectiveness is unsurprising when its role is perceived to be broader. However, there remains a need to map discourses in different decision contexts and to analyse the extent to which the range of discourses are accommodated throughout the decision process, and the role of impact assessment in those processes, before recommendations can be made to either improve impact assessment effectiveness, or whether it is

Lens Accommodation, Ocular Convergence and the Brain(Physiology of Vision)

OpenAIRE

坂東, 武彦; 戸田, 春男; 安藤, 誠男; 高木, 峰夫; 吉沢, 豊久; 原, 直人; Bando, Takehiko; Toda, Haruo; Ando, Tomoo; Takagi, Mineo; Yoshizawa, Toyohisa; Hara, Naoto

1993-01-01

Experimental findings obtained by our group were reviewed, and functional significance of the visual association cortex in controlling lens accommodation and ocular convergence was discussed. By intracortical microstimulation in an extrastriate visual area in the cat, lens accommodation and vergence eye movement were evoked. In the same cortical area, a group of neurons was also activated in correlation with lens accommodation or ocular convergence. In addition, after the lesion in this area,...

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.

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

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.

Frequency of convergence and accommodative disorders in a clinical population of Mashhad, Iran.

Science.gov (United States)

Hoseini-Yazdi, Seyed Hosein; Yekta, AbbasAli; Nouri, Hosein; Heravian, Javad; Ostadimoghaddam, Hadi; Khabazkhoob, Mehdi

2015-01-01

To investigate the frequency of convergence and accommodation anomalies in an optometric clinical setting in Mashhad, Iran, and to determine tests with highest accuracy in diagnosing these anomalies. From 261 patients who came to the optometric clinics of Mashhad University of Medical Sciences during a month, 83 of them were included in the study based on the inclusion criteria. Near point of convergence (NPC), near and distance heterophoria, monocular and binocular accommodative facility (MAF and BAF, respectively), lag of accommodation, positive and negative fusional vergences (PFV and NFV, respectively), AC/A ratio, relative accommodation, and amplitude of accommodation (AA) were measured to diagnose the convergence and accommodation anomalies. The results were also compared between symptomatic and asymptomatic patients. The accuracy of these tests was explored using sensitivity (S), specificity (Sp), and positive and negative likelihood ratios (LR+, LR-). Mean age of the patients was 21.3 ± 3.5 years and 14.5% of them had specific binocular and accommodative symptoms. Convergence and accommodative anomalies were found in 19.3% of the patients; accommodative excess (4.8%) and convergence insufficiency (3.6%) were the most common accommodative and convergence disorders, respectively. Symptomatic patients showed lower values for BAF (p = .003), MAF (p = .001), as well as AA (p = .001) compared with asymptomatic patients. Moreover, BAF (S = 75%, Sp = 62%) and MAF (S = 62%, Sp = 89%) were the most accurate tests for detecting accommodative and convergence disorders in terms of both sensitivity and specificity. Convergence and accommodative anomalies are the most common binocular disorders in optometric patients. Including tests of monocular and binocular accommodative facility in routine eye examinations as accurate tests to diagnose these anomalies requires further investigation.

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

Plastic waste depolymerization as a source of energetic heating oils

Directory of Open Access Journals (Sweden)

Wołosiewicz-Głąb Marta

2017-01-01

Full Text Available In the past years there has been an increase in production and consumption of plastics, which are widely used in many areas of life. Waste generated from this material are a challenge for the whole of society, regardless of awareness of sustainable development and its technological progress. Still the method of disposal of plastic waste are focused mainly on their storage and incineration, not using energy contained there. In this paper technology for plastic waste depolymerization with characteristics of fuel oil resulting in the process, as an alternative to traditional energy carriers such as: coal, fine coal or coke used in households will be presented. Oil has a high calorific value and no doubt could replace traditional solutions which use conventional energy sources. Furthermore, the fuel resulting from this process is sulfur-free and chemically pure. The paper presents the installation for plastics waste depolymerization used in selected Polish Institute of Plastics Processing, along with the ability to use the main thermocatalytic transformation product.

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....

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.

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...

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.

Neural plasticity and its initiating conditions in tinnitus.

Science.gov (United States)

Roberts, L E

2018-03-01

Deafferentation caused by cochlear pathology (which can be hidden from the audiogram) activates forms of neural plasticity in auditory pathways, generating tinnitus and its associated conditions including hyperacusis. This article discusses tinnitus mechanisms and suggests how these mechanisms may relate to those involved in normal auditory information processing. Research findings from animal models of tinnitus and from electromagnetic imaging of tinnitus patients are reviewed which pertain to the role of deafferentation and neural plasticity in tinnitus and hyperacusis. Auditory neurons compensate for deafferentation by increasing their input/output functions (gain) at multiple levels of the auditory system. Forms of homeostatic plasticity are believed to be responsible for this neural change, which increases the spontaneous and driven activity of neurons in central auditory structures in animals expressing behavioral evidence of tinnitus. Another tinnitus correlate, increased neural synchrony among the affected neurons, is forged by spike-timing-dependent neural plasticity in auditory pathways. Slow oscillations generated by bursting thalamic neurons verified in tinnitus animals appear to modulate neural plasticity in the cortex, integrating tinnitus neural activity with information in brain regions supporting memory, emotion, and consciousness which exhibit increased metabolic activity in tinnitus patients. The latter process may be induced by transient auditory events in normal processing but it persists in tinnitus, driven by phantom signals from the auditory pathway. Several tinnitus therapies attempt to suppress tinnitus through plasticity, but repeated sessions will likely be needed to prevent tinnitus activity from returning owing to deafferentation as its initiating condition.

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

Science.gov (United States)

Xanthos, Dirk; Walker, Tony R

2017-05-15

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

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…

Relationship of ocular accommodation and motor skills performance in developmental coordination disorder.

Science.gov (United States)

Rafique, Sara A; Northway, Nadia

2015-08-01

Ocular accommodation provides a well-focussed image, feedback for accurate eye movement control, and cues for depth perception. To accurately perform visually guided motor tasks, integration of ocular motor systems is essential. Children with motor coordination impairment are established to be at higher risk of accommodation anomalies. The aim of the present study was to examine the relationship between ocular accommodation and motor tasks, which are often overlooked, in order to better understand the problems experienced by children with motor coordination impairment. Visual function, gross and fine motor skills were assessed in children with developmental coordination disorder (DCD) and typically developing control children. Children with DCD had significantly poorer accommodation facility and amplitude dynamics compared to controls. Results indicate a relationship between impaired accommodation and motor skills. Specifically, accommodation anomalies correlated with visual motor, upper limb and fine dexterity task performance. Consequently, we argue accommodation anomalies influence the ineffective coordination of action and perception in DCD. Furthermore, reading disabilities were related to poorer motor performance. We postulate the role of the fastigial nucleus as a common pathway for accommodation and motor deficits. Implications of the findings and recommended visual screening protocols are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

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)

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

Science.gov (United States)

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

2017-12-01

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

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

[Effects of visual optical stimuli for accommodation-convergence system on asthenopia].

Science.gov (United States)

Iwasaki, Tsuneto; Tawara, Akihiko; Miyake, Nobuyuki

2006-01-01

We investigated the effect on eyestrain of optical stimuli that we designed for accommodation and convergence systems. Eight female students were given optical stimuli for accommodation and convergence systems for 1.5 min immediately after 20 min of a sustained task on a 3-D display. Before and after the trial, their ocular functions were measured and their symptoms were assessed. The optical stimuli were applied by moving targets of scenery images far and near around the far point position of both eyes on a horizonal place, which induced divergence in the direction of the eye position of rest. In a control group, subjects rested with closed eyes for 1.5 min instead of applying the optical stimuli. There were significant changes in the accommodative contraction time (from far to near) and the accommodative relaxation time (from near to far) and the lag of accommodation at near target, from 1.26 s to 1.62 s and from 1.49 s to 1.63 s and from 0.5 D to 0.65 D, respectively, and in the symptoms in the control group after the duration of closed-eye rest. In the stimulus group, however, the changes of those functions were smaller than in the control group. From these results, we suggest that our designed optical stimuli for accommodation and convergence systems are effective on asthenopia following accommodative dysfunction.

Magnifications of Single and Dual Element Accommodative Intraocular Lenses: Paraxial Optics Analysis

Science.gov (United States)

Ale, Jit B; Manns, Fabrice; Ho, Arthur

2010-01-01

Purpose Using an analytical approach of paraxial optics, we evaluated the magnification of a model eye implanted with single-element (1E) and dual-element (2E) translating-optics accommodative intraocular lenses (AIOL) with an objective of understanding key control parameters relevant to their design. Potential clinical implications of the results arising from pseudophakic accommodation were also considered. Methods Lateral and angular magnifications in a pseudophakic model eye were analyzed using the matrix method of paraxial optics. The effects of key control parameters such as direction (forward or backward) and distance (0 to 2 mm) of translation, power combinations of the 2E-AIOL elements (front element power range +20.0 D to +40.0 D), and amplitudes of accommodation (0 to 4 D) were tested. Relative magnification, defined as the ratio of the retinal image size of the accommodated eye to that of unaccommodated phakic (rLM1) or pseudophakic (rLM2) model eyes, was computed to determine how retinal image size changes with pseudophakic accommodation. Results Both lateral and angular magnifications increased with increased power of the front element in 2E-AIOL and amplitude of accommodation. For a 2E-AIOL with front element power of +35 D, rLM1 and rLM2 increased by 17.0% and 16.3%, respectively, per millimetre of forward translation of the element, compared to the magnification at distance focus (unaccommodated). These changes correspond to a change of 9.4% and 6.5% per dioptre of accommodation, respectively. Angular magnification also increased with pseudophakic accommodation. 1E-AIOLs produced consistently less magnification than 2E-AIOLs. Relative retinal image size decreased at a rate of 0.25% with each dioptre of accommodation in the phakic model eye. The position of the image space nodal point shifted away from the retina (towards the cornea) with both phakic and pseudophakic accommodation. Conclusion Power of the mobile element, and amount and direction of

Crystallinity in starch plastics: consequences for material properties

NARCIS (Netherlands)

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

1997-01-01

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

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

Science.gov (United States)

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

2013-05-01

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

Partner Accommodation Moderates Treatment Outcomes for Couple Therapy for Posttraumatic Stress Disorder

Science.gov (United States)

Fredman, Steffany J.; Pukay-Martin, Nicole D.; Macdonald, Alexandra; Wagner, Anne C.; Vorstenbosch, Valerie; Monson, Candice M.

2015-01-01

Objective Partner accommodation of posttraumatic stress disorder (PTSD) symptoms (i.e., altering one’s own behaviors to minimize patient distress and/or relationship conflict due to patients’ PTSD symptoms) has been shown to be positively associated with patient and partner psychopathology and negatively associated with patient and partner relationship satisfaction cross-sectionally. However, the prognostic value of partner accommodation in treatment outcomes is unknown. The goals of the present study were to determine if partner accommodation decreases as a function of couple therapy for PTSD and if pretreatment partner accommodation moderates the efficacy of couple therapy for PTSD. Method Thirty-nine patients with PTSD and their intimate partners (n = 39) were enrolled in a randomized controlled trial of cognitive-behavioral conjoint therapy (CBCT) for PTSD (Monson & Fredman, 2012) and received CBCT for PTSD immediately or after three months of waiting. Blinded assessors determined clinician-rated PTSD symptoms and patient-rated PTSD and depressive symptoms and relationship satisfaction at baseline, mid-treatment/4 weeks of waiting, and posttreatment/12 weeks of waiting. Results Contrary to expectation, partner accommodation levels did not change over time for either treatment condition. However, baseline partner accommodation significantly moderated treatment outcomes. Higher levels of partner accommodation were associated with greater improvements in PTSD, depressive symptoms, and relationship satisfaction among patients receiving CBCT for PTSD compared with waiting list. At lower levels of partner accommodation, patients in both groups improved or remained at low levels of these outcomes. Conclusions Individuals with PTSD who have more accommodating partners may be particularly well-suited for couple therapy for PTSD. PMID:26501498

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.

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)

Pyrolysis and dehalogenation of plastics from waste electrical and electronic equipment (WEEE): a review.

Science.gov (United States)

Yang, Xiaoning; Sun, Lushi; Xiang, Jun; Hu, Song; Su, Sheng

2013-02-01

Plastics from waste electrical and electronic equipment (WEEE) have been an important environmental problem because these plastics commonly contain toxic halogenated flame retardants which may cause serious environmental pollution, especially the formation of carcinogenic substances polybrominated dibenzo dioxins/furans (PBDD/Fs), during treat process of these plastics. Pyrolysis has been proposed as a viable processing route for recycling the organic compounds in WEEE plastics into fuels and chemical feedstock. However, dehalogenation procedures are also necessary during treat process, because the oils collected in single pyrolysis process may contain numerous halogenated organic compounds, which would detrimentally impact the reuse of these pyrolysis oils. Currently, dehalogenation has become a significant topic in recycling of WEEE plastics by pyrolysis. In order to fulfill the better resource utilization of the WEEE plastics, the compositions, characteristics and dehalogenation methods during the pyrolysis recycling process of WEEE plastics were reviewed in this paper. Dehalogenation and the decomposition or pyrolysis of WEEE plastics can be carried out simultaneously or successively. It could be 'dehalogenating prior to pyrolysing plastics', 'performing dehalogenation and pyrolysis at the same time' or 'pyrolysing plastics first then upgrading pyrolysis oils'. The first strategy essentially is the two-stage pyrolysis with the release of halogen hydrides at low pyrolysis temperature region which is separate from the decomposition of polymer matrixes, thus obtaining halogenated free oil products. The second strategy is the most common method. Zeolite or other type of catalyst can be used in the pyrolysis process for removing organohalogens. The third strategy separate pyrolysis and dehalogenation of WEEE plastics, which can, to some degree, avoid the problem of oil value decline due to the use of catalyst, but obviously, this strategy may increase the cost of

Plastic Trash goes Biohybrid"-Rapid and Selective Functionalization of Inert Plastic Surfaces with Biomolecules

DEFF Research Database (Denmark)

Schiller, Stefan M; Kambhampati, Dev; Stengel, Gudrun

2010-01-01

The covalent functionalization of "inert" polymers such as polypropylene with biomolecules for biocompatible or biosensor surfaces is challenging. Here we present a powerful approach to covalently modify "inert" macromolecular surfaces with biomacromolecules reusing old plastic material. A special...... emphasis was placed on easily accessible materials and a process which is easy, fast, efficient, cheap, and reliable. "Plastic trash" (lids from Eppendorf® pipet tip containers) was used as a polymer substrate to demonstrate the use/reuse of commercial packing material to covalently modify this material...

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,...

Melt rheology and its applications in the plastics industry

CERN Document Server

Dealy, John M

2013-01-01

This is the second edition of Melt Rheology and its Role in Plastics Processing, although the title has changed to reflect its broadened scope. Advances in the recent years in rheometer technology and polymer science have greatly enhanced the usefulness of rheology in the plastics industry. It is now possible to design polymers having specific molecular structures and to predict the flow properties of melts having those structures. In addition, rheological properties now provide more precise information about molecular structure. This book provides all the information that is needed for the intelligent application of rheology in the development of new polymers, the determination of molecular structure and the correlation of processability with laboratory test data. Theory and equations are limited to what is essential for the use of rheology in the characterization of polymers, the development of new plastics materials and the prediction of plastics processing behavior. The emphasis is on information that wil...

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.

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…

Convergence and accommodation development is pre-programmed in premature infants

Science.gov (United States)

Horwood, Anna M; Toor, Sonia S; Riddell, Patricia M

2015-01-01

Purpose This study investigated whether vergence and accommodation development in pre-term infants is pre-programmed or is driven by experience. Methods 32 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 4-6 weeks post-natally. Simultaneous accommodation and convergence to a detailed target were measured using a Plusoptix PowerRefII infra-red photorefractor as a target moved between 0.33m and 2m. Stimulus/response gains and responses at 0.33m and 2m were compared by both corrected (gestational) age and chronological (post-natal) age. Results When compared by their corrected age, pre-term and full-term infants showed few significant differences in vergence and accommodation responses after 6-7 weeks of age. However, when compared by chronological age, pre-term infants’ responses were more variable, with significantly reduced vergence gains, reduced vergence response at 0.33m, reduced accommodation gain, and increased accommodation at 2m, compared to full-term infants between 8-13 weeks after birth. Conclusions When matched by corrected age, vergence and accommodation in pre-term infants show few differences from full-term infants’ responses. Maturation appears pre-programmed and is not advanced by visual experience. Longer periods of immature visual responses might leave pre-term infants more at risk of development of oculomotor deficits such as strabismus. PMID:26275135

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.

Delivery outcome among women employed in the plastics industry in Sweden and Norway.

Science.gov (United States)

Ahlborg, G; Bjerkedal, T; Egenaes, J

1987-01-01

In Sweden and Norway separate case-control studies of pregnancy outcome for the period 1973-1981 among female workers in the plastics industry were carried out with similar design. Employment records were obtained from companies producing and/or processing plastics and these were matched with the national medical birth and malformation registers. Within the cohorts of pregnancies during which the mother held employment in a plastics industry (1.397 in the Swedish and 288 in the Norwegian study), cases of stillbirths or infant deaths, selected malformations, or low birthweight (less than 2,000 g) were identified. For each case two controls from the same source were individually matched with regard to date of birth, age of mother, and parity. Exposure data concerning the 44 Swedish and ten Norwegian triplets were obtained from the employers. An increased odds ratio was found for processing of polyvinylchloride (PVC) plastics (95% CI Sweden 1.0-5.1; total material 1.1-4.5). However, processing of cold plastics yielded a higher odds ratio than processing of heated plastics. No increased odds ratio was found for processing of styrene or polyurethane plastics. Since not all of the plastics industries in the two countries participated in the studies and the number of cases was small, the result must be interpreted with caution.

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...

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.

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...

EDRP public local inquiry, UKAEA/BNFL precognition on: Contractor accommodation

International Nuclear Information System (INIS)

Scott, W.

1986-01-01

The availability of accommodation for contractors working on the proposed EDRP at Dounreay is discussed. It is predicted that the contractors could be accommodated without the need for special arrangement and with no adverse effect on the tourist industry. (U.K.)

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.

Plasticity dependent damage evolution in composites with strain-gradient effects

DEFF Research Database (Denmark)

Legarth, Brian Nyvang

2015-01-01

. (2013). In this study the reinforcement is assumed perfectly stiff and consequently only one new cohesive material parameter is introduced. Results are shown for both conventional isotropy as well as plastic anisotropy with higher-order material behavior. Due to fiber-matrix decohesion a sudden stress......A unit cell approach is adopted to numerically analyze the effect of reinforcement size on fracture evolution in metal matrix composites. The matrix material shows plastic size-effects and is modeled by an anisotropic version of the single parameter strain-gradient (higher-order) plasticity model...... by Fleck and Hutchinson (2001). The fracture process along the fiber-matrix interface is modeled using a recently proposed cohesive law extension, where plasticity affects the fracture process as both the average as well as the jump in plastic strain across the interface are accounted for Tvergaard et al...

PENGARUH PLASTICIZER PADA KARAKTERISTIK EDIBLE FILM DARI PEKTIN

Directory of Open Access Journals (Sweden)

Sang Kompiang Wirawan

2012-05-01

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

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)

Workplace Accommodation for Persons With IBD: What Is Needed and What Is Accessed.

Science.gov (United States)

Chhibba, Tarun; Walker, John R; Sexton, Kathryn; Restall, Gayle; Ivekovic, Melony; Shafer, Leigh Ann; Singh, Harminder; Targownik, Laura E; Bernstein, Charles N

2017-10-01

People with inflammatory bowel disease (IBD) often experience periods of illness that interfere with their ability to work. We aimed to understand the need for workplace accommodation during periods of acute illness among persons IBD. Participants were recruited from the population-based University of Manitoba Research Registry and received a survey including questions assessing experiences with workplace accommodations. Data were analyzed using descriptive statistics and multivariate logistic regression modelling. A total of 1143 individuals responded to the survey (46% response rate), of whom 881 had experienced IBD symptoms in the workplace and were included in the analysis. The mean age was 48.3 years (standard deviation, 10.9); 61% were female. Mean IBD duration was 20.6 years (standard deviation, 10.5). Most respondents (73%) described IBD symptoms experienced in the workplace as severe to very severe. The most commonly required accommodations were time to go to medical appointments during working hours (81%), easy access to a toilet (71%), and a chance to take a break when not feeling well (54%). Most accommodations were arranged informally or through a supervisor. The accommodations required were very or somewhat easy to arrange about half the time. Being female, having high symptom severity, and high level of current distress were associated with a need for more accommodations, difficulty implementing accommodations, and not asking for needed accommodations. This study provides important information as to the types of accommodations that are necessary, common practices arranging for these, and level of difficulty arranging accommodations. Furthermore, characteristics associated with greater need for accommodation, reluctance to ask for them, and difficulty in arranging them were identified. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Mechanisms of large strain, high strain rate plastic flow in the explosively driven collapse of Ni-Al laminate cylinders

International Nuclear Information System (INIS)

Olney, K L; Chiu, P H; Nesterenko, V F; Higgins, A; Serge, M; Weihs, T P; Fritz, G; Stover, A; Benson, D J

2014-01-01

Ni-Al laminates have shown promise as reactive materials due to their high energy release through intermetallic reaction. In addition to the traditional ignition methods, the reaction may be initiated in hot spots that can be created during mechanical loading. The explosively driven thick walled cylinder (TWC) technique was performed on two Ni-Al laminates composed of thin foil layers with different mesostructues: concentric and corrugated. These experiments were conducted to examine how these materials accommodate large plastic strain under high strain rates. Finite element simulations of these specimens with mesostuctures digitized from the experimental samples were conducted to provide insight into the mesoscale mechanisms of plastic flow. The dependence of dynamic behaviour on mesostructure may be used to tailor the hot spot formation and therefore the reactivity of the material system.

Plastic deformation mechanism of polycrystalline copper foil shocked with femtosecond laser

International Nuclear Information System (INIS)

Ye, Y.X.; Feng, Y.Y.; Lian, Z.C.; Hua, Y.Q.

2014-01-01

Plastic deformation mechanism of polycrystalline copper foil shocked with femtosecond (fs) laser has been characterized through optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Experiments of ns laser shocking copper (Cu) and fs laser shocking aluminum (Al) were also conducted for comparison. Dislocations arranged in multiple forms, profuse twins and stacking faults (SFs) coexist in the fs laser shocked copper. At small strain condition, dislocation slip is the dominant deformation mode and small amount of SFs act as complementary mechanism. With strain increasing, profuse twins and SFs form to accommodate the plastic deformation. Furthermore, new formed SFs incline to locate around the old ones because the dislocation densities there are more higher. So there is a high probability for new SFs overlapping on old ones to form twins, or connecting old ones to lengthen them, which eventually produce the phenomena that twins connect with each other or twins connect with SFs. Strain greatly influences the dislocation density. Twins and SFs are more dependent on strain rate and shock pressure. Medium stacking fault energy (SFE) of copper helps to extend partial dislocations and provides sources for forming SFs and twins.

Introducing the International Confederation of Plastic Surgery Societies: ICOPLAST.

Science.gov (United States)

Rakhorst, Hinne A; Badran, Hassan; Clarke, Howard M; Cooter, Rodney; Evans, Gregory R D; Kirschbaum, Julio Daniel; Koh, Kyung Suk; Lazier, Carol; Murphy, Robert X; Nakatsuka, Takashi; Piccolo, Nelson Sarto; Perks, Graeme

2017-09-01

This article describes the formation of the International Confederation of Plastic Surgery Societies (ICOPLAST) as a novel, transparent, dynamic, and proactive confederation of national plastic surgery societies. ICOPLAST aspires to provide a voice for the entire international community of plastic surgeons. ICOPLAST has been designed to benefit the patient, plastic surgery as a profession, and each individual plastic surgeon. Its principal objective is to enhance international communication, education, and advocacy processes to ultimately improve patient outcomes for plastic surgery patients globally. The new ICOPLAST's focus is to add true value for patients. ICOPLAST's evolution, philosophy, governance, and bylaws are explained and all societies worldwide are encouraged and cordially invited to join. An open and warm invitation is provided. Additional information is found at www.ICOPLAST.org.

Recycling of plastic: accounting of greenhouse gases and global warming contributions.

Science.gov (United States)

Astrup, Thomas; Fruergaard, Thilde; Christensen, Thomas H

2009-11-01

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 plastic waste was received at a material recovery facility (MRF) and processed for granulation and subsequent downstream use. In the three alternatives, plastic was assumed to be substituting virgin plastic in new products, wood in low-strength products (outdoor furniture, fences, etc.), and coal or fuel oil in the case of energy utilization. GHG accounting was organized in terms of indirect upstream emissions (e.g. provision of energy, fuels, and materials), direct emissions at the MRF (e.g. fuel combustion), and indirect downstream emissions (e.g. avoided emissions from production of virgin plastic, wood, or coal/oil). Combined, upstream and direct emissions were estimated to be roughly between 5 and 600 kg CO(2)-eq. tonne( -1) of plastic waste depending on treatment at the MRF and CO(2) emissions from electricity production. Potential downstream savings arising from substitution of virgin plastic, wood, and energy fuels were estimated to be around 60- 1600 kg CO(2)-eq. tonne( -1) of plastic waste depending on substitution ratios and CO(2) emissions from electricity production. Based on the reviewed data, it was concluded that substitution of virgin plastic should be preferred. If this is not viable due 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.

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

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide.

Science.gov (United States)

Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

2013-05-10

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

The Size Spectrum as Tool for Analyzing Marine Plastic Pollution

KAUST Repository

Martí, E.

2016-12-02

Marine plastic debris spans over six orders of magnitude in lineal size, from microns to meters. The broad range of plastic sizes mainly arises from the continuous photodegradation and fragmentation affecting the plastic objects. Interestingly, this time-dependent process links, to some degree, the size to the age of the debris. The variety of plastic sizes gives the possibility to marine biota to interact and possible take up microplastics through numerous pathways. Physical processes such as sinking and wind-induced transport or the chemical adsorption of contaminants are also closely related to the size and shape of the plastic items. Likewise, available sampling techniques should be considered as partial views of the marine plastic size range. This being so and given that the size is one of the most easily measurable plastic traits, the size spectrum appears as an ideal frame to arrange, integrate, and analyze plastic data of diverse nature. In this work, we examined tens of thousands of plastic items sampled from across the world with the aim of (1) developing and standardizing the size-spectrum tool to study marine plastics, and (2) assembling a global plastic size spectrum (GPSS) database, relating individual size measurements to abundance, color (129 tons), polymer type, and category (rigid fragments, films, threads, foam, pellets, and microbeads). Using GPSS database, we show for instance the dependence of plastic composition on the item size, with high diversity of categories for items larger than 1 cm and a clear dominance (~90%) of hard fragments below, except for the size interval corresponding to microbeads (around 0.5 mm). GPSS database depicts a comprehensive size-based framework for analyzing the marine plastic pollution, enabling the comparison of size-related studies or the testing of hypothesis.

Waste Plastic Converting into Hydrocarbon Fuel Materials

Energy Technology Data Exchange (ETDEWEB)

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

2010-09-15

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

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...

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.

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.

Cellular Signal Mechanisms of Reward-Related Plasticity in the Hippocampus

Directory of Open Access Journals (Sweden)

Masako Isokawa

2012-01-01

Full Text Available The hippocampus has the extraordinary capacity to process and store information. Consequently, there is an intense interest in the mechanisms that underline learning and memory. Synaptic plasticity has been hypothesized to be the neuronal substrate for learning. Ca2+ and Ca2+-activated kinases control cellular processes of most forms of hippocampal synapse plasticity. In this paper, I aim to integrate our current understanding of Ca2+-mediated synaptic plasticity and metaplasticity in motivational and reward-related learning in the hippocampus. I will introduce two representative neuromodulators that are widely studied in reward-related learning (e.g., ghrelin and endocannabinoids and show how they might contribute to hippocampal neuron activities and Ca2+-mediated signaling processes in synaptic plasticity. Additionally, I will discuss functional significance of these two systems and their signaling pathways for its relevance to maladaptive reward learning leading to addiction.

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

Simulation of finite-strain inelastic phenomena governed by creep and plasticity

Science.gov (United States)

Li, Zhen; Bloomfield, Max O.; Oberai, Assad A.

2017-11-01

Inelastic mechanical behavior plays an important role in many applications in science and engineering. Phenomenologically, this behavior is often modeled as plasticity or creep. Plasticity is used to represent the rate-independent component of inelastic deformation and creep is used to represent the rate-dependent component. In several applications, especially those at elevated temperatures and stresses, these processes occur simultaneously. In order to model these process, we develop a rate-objective, finite-deformation constitutive model for plasticity and creep. The plastic component of this model is based on rate-independent J_2 plasticity, and the creep component is based on a thermally activated Norton model. We describe the implementation of this model within a finite element formulation, and present a radial return mapping algorithm for it. This approach reduces the additional complexity of modeling plasticity and creep, over thermoelasticity, to just solving one nonlinear scalar equation at each quadrature point. We implement this algorithm within a multiphysics finite element code and evaluate the consistent tangent through automatic differentiation. We verify and validate the implementation, apply it to modeling the evolution of stresses in the flip chip manufacturing process, and test its parallel strong-scaling performance.

Improving Meaningful Use of Accommodations by Multilingual Learners

Science.gov (United States)

Shafer Willner, Lynn; Mokhtari, Kouider

2018-01-01

For more than two decades, accommodations have served as the primary strategy for ensuring the valid participation of multilingual learners (MLLs) in high-stakes summative assessments. Using historical analyses of the evolution of testing accommodation guidelines and related instructional practices, the authors explain how the application of…

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...

Machining of Fibre Reinforced Plastic Composite Materials

Science.gov (United States)

2018-01-01

Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented. PMID:29562635

Machining of Fibre Reinforced Plastic Composite Materials

Directory of Open Access Journals (Sweden)

Alessandra Caggiano

2018-03-01

Full Text Available Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented.

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

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.

An initial study of family accommodation in children and adolescents with chronic tic disorders.

Science.gov (United States)

Storch, Eric A; Johnco, Carly; McGuire, Joseph F; Wu, Monica S; McBride, Nicole M; Lewin, Adam B; Murphy, Tanya K

2017-01-01

This initial study examined the nature, incidence, and clinical correlates of family accommodation in youth with tic disorders, and validated a brief self-report measure of tic-related family accommodation, the Tic Family Accommodation Scale (TFAS). Seventy-five youth aged 6-18 who were diagnosed with a tic disorder and their parent completed a diagnostic clinical interview, and clinician and parent-report measures of tic severity, depressive symptoms, anxiety symptoms, behavioral problems, family accommodation and impairment. An exploratory factor analysis of the TFAS showed a two-factor structure, with good internal consistency for the Total score, Modification of Child Environment and Modification of Parent Environment subscales (α = 0.88, 0.86, and 0.81, respectively). Family accommodation was not associated with tic severity. Family accommodation was associated with increased anxiety and depressive symptoms, higher externalizing, rule breaking, aggressive behaviors and social problems, and with greater tic-related functional impairment. Anxiety and externalizing problems (but not depressive symptoms) predicted family accommodation when controlling for tic severity. Family accommodation predicted high levels of functional impairment over and above the effect of tic severity, anxiety, depression and externalizing problems. Family accommodation is a common phenomenon for youth with tic disorders, with modifications typically encompassing changes to the child and/or parent environments. Accommodation was not associated with tic severity, but was related to higher levels of anxiety, depressive symptoms, externalizing symptoms, aggression, and rule breaking behaviors. Results suggest that other emotional symptoms are more likely to drive accommodation practices than the tic symptoms per se.

Plastics and environmental health: the road ahead.

Science.gov (United States)

North, Emily J; Halden, Rolf U

2013-01-01

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

Plastics and Environmental Health: The Road Ahead

Science.gov (United States)

North, Emily J.; Halden, Rolf U.

2013-01-01

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

Thermal Microstructural Stability of AZ31 Magnesium after Severe Plastic Deformation

Energy Technology Data Exchange (ETDEWEB)

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

2015-03-01

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

[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.

The evolution of phenotypic plasticity in fish swimming

Science.gov (United States)

Oufiero, Christopher E.; Whitlow, Katrina R.

2016-01-01

Abstract Fish have a remarkable amount of variation in their swimming performance, from within species differences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the ability to plastically respond to a myriad of environmental changes. The plasticity of fish swimming has been observed on whole-organismal traits such as burst speed or critical swimming speed, as well as underlying phenotypes such as muscle fiber types, kinematics, cardiovascular system, and neuronal processes. Whether the plastic responses of fish swimming are beneficial seems to depend on the environmental variable that is changing. For example, because of the effects of temperature on biochemical processes, alterations of fish swimming in response to temperature do not seem to be beneficial. In contrast, changes in fish swimming in response to variation in flow may benefit the fish to maintain position in the water column. In this paper, we examine how this plasticity in fish swimming might evolve, focusing on environmental variables that have received the most attention: temperature, habitat, dissolved oxygen, and carbon dioxide variation. Using examples from previous research, we highlight many of the ways fish swimming can plastically respond to environmental variation and discuss potential avenues of future research aimed at understanding how plasticity of fish swimming might evolve. We consider the direct and indirect effects of environmental variation on swimming performance, including changes in swimming kinematics and suborganismal traits thought to predict swimming performance. We also discuss the role of the evolution of plasticity in shaping macroevolutionary patterns of diversity in fish swimming. PMID:29491937

A study on compound contents for plastic injection molding products of metallic resin pigment

International Nuclear Information System (INIS)

Park, Young Whan; Kwak, Jae Seob; Lee, Gyu Sang

2016-01-01

Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated

A study on compound contents for plastic injection molding products of metallic resin pigment

Energy Technology Data Exchange (ETDEWEB)

Park, Young Whan; Kwak, Jae Seob [Dept. of Mechanical Engineering, Pukyong National University, Busan (Korea, Republic of); Lee, Gyu Sang [Alliance Molding Engineering TeamLG Electronics Inc., Osan (Korea, Republic of)

2016-12-15

Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated.

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.

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 " ...

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...

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.

Phyllosphere yeasts rapidly break down biodegradable plastics

Science.gov (United States)

2011-01-01

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

A Dyadic Perspective on Speech Accommodation and Social Connection: Both Partners’ Rejection Sensitivity Matter

Science.gov (United States)

Aguilar, Lauren; Downey, Geraldine; Krauss, Robert; Pardo, Jennifer; Lane, Sean; Bolger, Niall

2014-01-01

Objective Findings from confederate paradigms predict that mimicry is an adaptive route to social connection for rejection sensitive individuals (Lakin et al., 2008). However, dyadic perspectives predict that whether mimicry leads to perceived connection depends on the rejection sensitivity (RS) of both partners in an interaction. Method We investigated these predictions in 50 college women who completed a dyadic cooperative task in which members were matched or mismatched in being dispositionally high or low in RS. We used a psycholinguistics paradigm to assess, through independent listeners’ judgments (N = 162), how much interacting individuals accommodate phonetic aspects of their speech toward each other. Results Results confirmed predictions from confederate paradigms in matched RS dyads. However, mismatched dyads showed an asymmetry in levels of accommodation and perceived connection: Those high in RS accommodated more than their low RS partner but emerged feeling less connected. Meditational analyses indicated that low RS individuals’ nonaccommodation in mismatched dyads helped explain their high RS partners’ relatively low perceived connection to them. Conclusions Establishing whether mimicry is an adaptive route to social connection requires analyzing mimicry as a dyadic process influenced by the needs of each dyad member. PMID:25393028

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.)

Effects of positive relative accommodation on adolescent pseudomyopia with visual training

Directory of Open Access Journals (Sweden)

Jiang Yue

2014-04-01

Full Text Available AIM:To investigate the changes of the positive relative accommodation in adolescent pseudomyopia with visual training.METHODS: A total of 42 cases(84 eyeswere randomly divided into the visual training group and the control group. Visual acuity, average refraction of two groups 4wk after the training were measured, as well as positive relative accommodation(5mwere checked before the training and repeated 1, 2, 4wk after the training. Correlation analysis were given.RESULTS: There was statistically significant difference in visual acuity 4wk after the training between the two groups(PP>0.05. There was statistically significant difference in positive relative accommodation(5m1, 2, 4wk after the training between the two groups(PPCONCLUSION: Visual training has significant effect on the positive relative accommodation on adolescent pseudomyopia.

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.

Micro-scale measurements of plastic strain field, and local contributions of slip and twinning in TWIP steels during in situ tensile tests

Energy Technology Data Exchange (ETDEWEB)

Yang, H.K. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Laboratoire de Mécanique des Solides, Ecole Polytechnique, CNRS UMR7649, Université Paris-Saclay, 91128 Palaiseau (France); Doquet, V., E-mail: doquet@lms.polytechnique.fr [Laboratoire de Mécanique des Solides, Ecole Polytechnique, CNRS UMR7649, Université Paris-Saclay, 91128 Palaiseau (France); Zhang, Z.F. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

2016-08-30

In-situ tensile tests were carried out on Fe22Mn0.6C and Fe22Mn0.6C3Al (wt%) twinning-induced plasticity (TWIP) steels specimens covered with gold micro-grids. High resolution atomic force microscopy (AFM) and scanning electron microscope (SEM) images were periodically captured. The latter were used for measurements of the plastic strain field, using digital image correlation (DIC). Although no meso-scale localization bands appeared, some areas were deformed three times more than average. Plastic deformation inside the grains was more heterogeneous in Fe22Mn0.6C, but at meso-scale, the degree of strain heterogeneity was not higher, at least up to 12% strain. Plastic deformation started from grain boundaries or annealing twin boundaries in both materials, due to a high elastic anisotropy of the grains. An original method based on DIC was developed to estimate the twin fraction in grains that exhibit a single set of slip/twin bands. Deformation twinning accommodated 60–80% of the plastic strain in some favorably oriented grains, from the onset of plastic flow in Fe22Mn0.6C, but was not observed in the Al-bearing steel until 12% strain. The back stress was important in both materials, but significantly higher in Fe22Mn0.6C.

Micro-scale measurements of plastic strain field, and local contributions of slip and twinning in TWIP steels during in situ tensile tests

International Nuclear Information System (INIS)

Yang, H.K.; Doquet, V.; Zhang, Z.F.

2016-01-01

In-situ tensile tests were carried out on Fe22Mn0.6C and Fe22Mn0.6C3Al (wt%) twinning-induced plasticity (TWIP) steels specimens covered with gold micro-grids. High resolution atomic force microscopy (AFM) and scanning electron microscope (SEM) images were periodically captured. The latter were used for measurements of the plastic strain field, using digital image correlation (DIC). Although no meso-scale localization bands appeared, some areas were deformed three times more than average. Plastic deformation inside the grains was more heterogeneous in Fe22Mn0.6C, but at meso-scale, the degree of strain heterogeneity was not higher, at least up to 12% strain. Plastic deformation started from grain boundaries or annealing twin boundaries in both materials, due to a high elastic anisotropy of the grains. An original method based on DIC was developed to estimate the twin fraction in grains that exhibit a single set of slip/twin bands. Deformation twinning accommodated 60–80% of the plastic strain in some favorably oriented grains, from the onset of plastic flow in Fe22Mn0.6C, but was not observed in the Al-bearing steel until 12% strain. The back stress was important in both materials, but significantly higher in Fe22Mn0.6C.

Dynamic distance direct ophthalmoscopy, a novel technique to assess accommodation in children

Directory of Open Access Journals (Sweden)

Mihir Kothari

2012-01-01

Full Text Available Aim: To describe and compare dynamic distance direct ophthalmoscopy (DDDO with dynamic retinoscopy (DR in assessment of accommodation in children. Materials and Methods: This prospective observational study had four components. Component 1: to understand the characteristic digital images of DDDO. Component 2: to compare DDDO with DR for detection of accommodative defects in children (1-16 years. Component 3: to compare DDDO with DR for the detection of completeness of pharmacologically induced cycloplegia in children (5-16 years and Component 4: to assess which one of the two techniques was more sensitive to detect onset of cycloplegia after instillation of 1% cyclopentolate eye drops. Results: Component 1: image analysis of DDDO on two subjects (7 years and 35 years demonstrated superior pupillary crescent that progressively disappeared with increasing accommodation. Concurrently an inferior crescent appeared that became bigger in size with increasing accommodation. Component 2: the prevalence of defects in accommodation was 3.3% (33/1000 children. Three had unilateral accommodation failure. Sensitivity of DDDO was 94%, specificity 100%, positive predictive value 100%, negative predictive value 99%, and clinical agreement (kappa 0.97. Component 3: in the detection of completeness of pharmacologically induced cycloplegia (n=30, the sensitivity of DDDO was 94%, specificity 96%, positive predictive value 97%, negative predictive value 93% and kappa 0.9. DR had two false positives. DDDO had one false negative. Component 4: DDDO detected onset of pharmacologically induced cycloplegia 5 min earlier than DR (n=5. Conclusion: DDDO is a novel, simple, clinical and reliable method to assess accommodation in young children. This test can assess the accommodative response of both eyes simultaneously.

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

Inspecting plastic deformation of Pd by means of fractal geometry

International Nuclear Information System (INIS)

Eftekhari, Ali

2007-01-01

The influence of phase transformation-induced plastic deformation in Pd|H system on the electrode surface was investigated. Since the Pd surface is subject of severe plastic deformation during this process, the structure and roughness of the electrode surface significantly change. Quantitative analysis of the electrode surfaces for comparative study of such changes is a valuable tool to inspect the plastic deformation induced. Fractal dimension can be used as a quantitative measure for this purpose. Since inappropriate methods may lead to significant errors, an appropriate approach was proposed for the determination of fractal dimensions in such systems. It was demonstrated that the surface roughness generated is mainly due to the plastic deformation induced, not the other side processes, as the electrodes were coated with a uniform layer of gold with thickness smaller than 10 nm. Since plastic deformation is due to hydrogen insertion/extraction and occurs in atomic-scale, it is necessary to divide structural changes appeared in nano- and micro-scale

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.)

Accommodation services for competitive tourism in Sub-Saharan Africa: Historical evidence from Malawi

Directory of Open Access Journals (Sweden)

Magombo Alice

2017-12-01

Full Text Available The accommodation services sector is a vital underpinning of the competitiveness of destinations in especially emerging tourism regions of the global economy. Within the environment of Africa building the competitiveness of countries as tourism destinations is inseparable from the challenge of establishing a network of different forms of accommodation at competitive prices and internationally acceptable quality standards. This paper uses a longitudinal approach to analyse the development of the accommodation services sector in one African country - Malawi - which is scaling up its tourism industry. Using historical evidence the objective is to examine the unfolding evolution of accommodation services as a factor in enhancing tourism destination competitiveness. The chequered pathway followed in Malawi to building the country’s network of hotels and small-scale accommodation establishments is traced from the colonial period to post-independence developments. It is argued that in understanding the historical evolution of accommodation services policy re-orientations have been significant drivers of change.

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,…

Accommodative insufficiency in a student population in Iran.

Science.gov (United States)

Hashemi, Hassan; Khabazkhoob, Mehdi; Nabovati, Payam; Shahraki, Fatemeh Azad; Ostadimoghaddam, Hadi; Faghihi, Mohammad; Aghamirsalim, Mohamadreza; Doostdar, Asgar; Yekta, Abbasali

2018-05-22

To determine the prevalence of accommodative insufficiency (AI) and its relation with age, gender, and refractive errors in a college-age student population in Iran. The present study was conducted cross-sectionally in 2017. All students had optometric tests including measurement of visual acuity, objective and subjective refraction, as well as binocular vision and accommodative examinations. Amplitude of accommodation was measured with the Donders' push-up method using the Royal Air Force (RAF) rule. Monocular accommodative facility was measured with ±2.00diopter flipper lenses. The accommodative response was tested using dynamic retinoscopy with the monocular estimation method (MEM). The prevalence of AI in the studied population was 4.07% (95% CI: 2.61-5.52). The rate was 6.04% (95% CI: 3.58-8.50) in females and 2.01% (95% CI: 0.53-3.48) in males, and logistic regression showed a significantly higher odds of AI in females (OR=3.14, 95% CI: 1.33-7.45, p-value=0.009). The prevalence of AI was 2.59% (95% CI: 0.55-7.56) in the 18-19-year-old age group and 4.08% (95% CI: 0.09-8.07) in the 24-25-year-old group (p-value=0.848). The prevalence of AI among emmetropic, myopic, and hyperopic individuals was 3.74% (95% CI: 1.88-5.61), 4.44% (95% CI: 2.07-6.81), and 5.26% (95% CI: 4.79-16.32), respectively (p-value=0.869). In the multiple regression model, only gender showed significant relationship with AI (Odds ratio=3.14, 95% CI: 1.33-7.45; p-values=0.009). The prevalence of AI in the present study is lower than the most prevalence rates reported in previous studies. In the present study, gender and AI showed a strong association, such that AI prevalence was significantly higher in females than males. Copyright © 2018 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

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.

Photolithographic Synthesis of High-Density DNA and RNA Arrays on Flexible, Transparent, and Easily Subdivided Plastic Substrates.

Science.gov (United States)

Holden, Matthew T; Carter, Matthew C D; Wu, Cheng-Hsien; Wolfer, Jamison; Codner, Eric; Sussman, Michael R; Lynn, David M; Smith, Lloyd M

2015-11-17

The photolithographic fabrication of high-density DNA and RNA arrays on flexible and transparent plastic substrates is reported. The substrates are thin sheets of poly(ethylene terephthalate) (PET) coated with cross-linked polymer multilayers that present hydroxyl groups suitable for conventional phosphoramidite-based nucleic acid synthesis. We demonstrate that by modifying array synthesis procedures to accommodate the physical and chemical properties of these materials, it is possible to synthesize plastic-backed oligonucleotide arrays with feature sizes as small as 14 μm × 14 μm and feature densities in excess of 125 000/cm(2), similar to specifications attainable using rigid substrates such as glass or glassy carbon. These plastic-backed arrays are tolerant to a wide range of hybridization temperatures, and improved synthetic procedures are described that enable the fabrication of arrays with sequences up to 50 nucleotides in length. These arrays hybridize with S/N ratios comparable to those fabricated on otherwise identical arrays prepared on glass or glassy carbon. This platform supports the enzymatic synthesis of RNA arrays and proof-of-concept experiments are presented showing that the arrays can be readily subdivided into smaller arrays (or "millichips") using common laboratory-scale laser cutting tools. These results expand the utility of oligonucleotide arrays fabricated on plastic substrates and open the door to new applications for these important bioanalytical tools.

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.

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

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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.

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...

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) ...

Workplace accommodations for persons with physical disabilities: evidence synthesis of the peer-reviewed literature.

Science.gov (United States)

Padkapayeva, Kathy; Posen, Andrew; Yazdani, Amin; Buettgen, Alexis; Mahood, Quenby; Tompa, Emile

2017-10-01

To identify and synthesize research evidence on workplace accommodations used by employers to recruit, hire, retain, and promote persons with physical disabilities. A structured search of six electronic journal databases was undertaken to identify peer-reviewed literature on the topic published from January 1990 to March 2016. Articles describing or evaluating workplace disability accommodation policies and practices were given a full-text review. Topic experts were contacted to identify additional studies. Details on specific accommodations described in 117 articles were synthesized and organized into three groups comprised of a total of 12 categories. The majority of studies did not rigorously evaluate effectiveness or cost-effectiveness of the accommodations under study. This evidence synthesis provides an overview of the peer-reviewed literature of value to occupational rehabilitation professionals and employers seeking guidance on workplace accommodation policies and practices for persons with physical disabilities. A wide range of accommodation options is available for addressing physical, social, and attitudinal barriers to successful employment. Besides physical/technological modifications, accommodations to enhance workplace flexibility and worker autonomy and strategies to promote workplace inclusion and integration are important. More comprehensive reporting and evaluations of the effectiveness of accommodations in research literature are needed to develop best practices for accommodating persons with disabilities. Implications for rehabilitation There is a substantial peer-reviewed literature that provides insights into the barriers for persons with physical disabilities and the workplace accommodation practices to address them, though rigorous evaluations of effectiveness and cost-effectiveness are uncommon. Attitudinal and social barriers stemming from stereotypes, ignorance and lack of knowledge are as important as physical barriers to employment for

Problems and accommodation strategies reported by computer users with rheumatoid arthritis or fibromyalgia.

Science.gov (United States)

Baker, Nancy A; Rubinstein, Elaine N; Rogers, Joan C

2012-09-01

Little is known about the problems experienced by and the accommodation strategies used by computer users with rheumatoid arthritis (RA) or fibromyalgia (FM). This study (1) describes specific problems and accommodation strategies used by people with RA and FM during computer use; and (2) examines if there were significant differences in the problems and accommodation strategies between the different equipment items for each diagnosis. Subjects were recruited from the Arthritis Network Disease Registry. Respondents completed a self-report survey, the Computer Problems Survey. Data were analyzed descriptively (percentages; 95% confidence intervals). Differences in the number of problems and accommodation strategies were calculated using nonparametric tests (Friedman's test and Wilcoxon Signed Rank Test). Eighty-four percent of respondents reported at least one problem with at least one equipment item (RA = 81.5%; FM = 88.9%), with most respondents reporting problems with their chair. Respondents most commonly used timing accommodation strategies to cope with mouse and keyboard problems, personal accommodation strategies to cope with chair problems and environmental accommodation strategies to cope with monitor problems. The number of problems during computer use was substantial in our sample, and our respondents with RA and FM may not implement the most effective strategies to deal with their chair, keyboard, or mouse problems. This study suggests that workers with RA and FM might potentially benefit from education and interventions to assist with the development of accommodation strategies to reduce problems related to computer use.

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...

Derivative criteria of plasticity anddurability of metal materials

Directory of Open Access Journals (Sweden)

Gustov Yuriy Ivanovich

Full Text Available Criteria of plasticity and durability derivative of standard indicators of plasticity (δ, ψ and durability (σ , σ are offered. Criteria К and К follow from the equation of relative indicators of durability and plasticity. The purpose of the researches is the establishment of interrelation of derivative criteria with the Page indicator. The values of derivative criteria were defined for steels 50X and 50XH after processing by cold, and also for steels 50G2 and 38HGN after sorbitizing. It was established that the sum of the offered derivative criteria of plasticity and durability С considered for the steels is almost equal to unit and corresponds to a square root of relative durability and plasticity criterion C . Both criteria testify to two-unity opposite processes of deformation and resistance to deformation. By means of the equations for S and С it is possible to calculate an indicator of uniform plastic deformation of σ and through it to estimate synergetic criteria - true tension and specific energy of deformation and destruction of metal materials. On the basis of the received results the expressions for assessing the uniform and concentrated components of plastic deformation are established. The preference of the dependence of uniform relative lengthening from a cubic root of criterion К , and also to work of the criteria of relative lengthening and relative durability is given. The advantage of the formulas consists in simplicity and efficiency of calculation, in ensuring necessary accuracy of calculation of the size δ for the subsequent calculation of structural and power (synergetic criteria of reliability of metals.

A self-consistent anisotropic approach for the simulation of plastic deformation and texture development of polycrystals: Application to zirconium alloys

International Nuclear Information System (INIS)

Lebensohn, R.A.; Tome, C.N.

1993-01-01

The authors present in this work a visco-plastic self-consistent (VPSC) anisotropic approach for modeling the plastic deformation of polycrystals, together with a thorough discussion of the assumptions involved and the range of application of such approach. They use the VPSC model for predicting texture development during rolling and axisymmetric deformation of zirconium alloys, and to calculate the yield locus and the Lankford coefficient of rolled Zircaloy sheet. They compare the results with experimental data and find that they are in good agreement with the available experimental evidence. They also compare the VPSC prediction with the ones of a Full Constraints approach and observe that they differ both quantitatively and qualitatively: according with the predictions of the VPSC scheme, deformation is accommodated mostly by the soft systems, the twinning activity is much lower, and fewer systems are active, in average, per grain. These results are a consequence of having accounted for the grain interaction with its surroundings, which is a crucial aspect when modeling plastically anisotropic materials

Direct liquefaction of plastics and coprocessing of coal with plastics

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

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

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.

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.

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.

Holocene reef development where wave energy reduces accommodation

Science.gov (United States)

Grossman, Eric E.; Fletcher, Charles H.

2004-01-01

Analyses of 32 drill cores obtained from the windward reef of Kailua Bay, Oahu, Hawaii, indicate that high wave energy significantly reduced accommodation space for reef development in the Holocene and produced variable architecture because of the combined influence of sea-level history and wave exposure over a complex antecedent topography. A paleostream valley within the late Pleistocene insular limestone shelf provided accommodation space for more than 11 m of vertical accretion since sea level flooded the bay 8000 yr BP. Virtually no net accretion (pile-up of fore-reef-derived rubble (rudstone) and sparse bindstone, and (3) a final stage of catch-up bindstone accretion in depths > 6 m. Coral framestone accreted at rates of 2.5-6.0 mm/yr in water depths > 11 m during the early Holocene; it abruptly terminated at ~4500 yr BP because of wave scour as sea level stabilized. More than 4 m of rudstone derived from the upper fore reef accreted at depths of 6 to 13 m below sea level between 4000 and 1500 yr BP coincident with late Holocene relative sea-level fall. Variations in the thickness, composition, and age of these reef facies across spatial scales of 10-1000 m within Kailua Bay illustrate the importance of antecedent topography and wave-related stress in reducing accommodation space for reef development set by sea level. Although accommodation space of 6 to 17 m has existed through most of the Holocene, the Kailua reef has been unable to catch up to sea level because of persistent high wave stress.

Data-driven in computational plasticity

Science.gov (United States)

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

2018-05-01

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

The impact of regulatory approaches targeting collaborative economy in the tourism accommodation sector:

DEFF Research Database (Denmark)

Dredge, Dianne; Gyimóthy, Szilvia; Birkbak, Andreas

This paper has been commissioned by the European Commission’s DG GROWTH to examine the impact of regulatory approaches targeting collaborative economy in the tourism accommodation sector in the cities of Barcelona, Berlin, Amsterdam and Paris. In relation to tourism, the growth of the collaborative...... economy peer-to-peer accommodation sector has significant impacts for traditional tourism industry structures and relationships. The growth of the collaborative economy peer-to-peer accommodation market has led to a diversification of accommodation stock, it has led to increased competition, and it has...... governments and host communities are also raising concerns over the impact of unregulated tourist accommodation within residential neighbourhoods and the conflicts that are emerging due to the changing commercial nature of traditional residential areas close to city centres. In many cities across Europe...

Electrical properties of Lupinus angustifolius L. stem. II. Accommodation and anode break excitation

Directory of Open Access Journals (Sweden)

Tadeusz Zawadzki

2015-01-01

Full Text Available Under electrical stimulation of Lupinus stem phenomena of accommodation and anode break excitation appear. Their characteristic is the same as in the axon or nerve. Only their duration is about 103-104 longer in plants. The constant characterizing the rate of accommodation was calculated. A limiting threshold value was found beyond which excitation occurs, irrespective of the rate of stimulus rise (voltage gradient. The accommodation rate is approximately constant, whereas the range of accommodation varies and is dependent on the difference between the rheobase value and the limiting threshold value. Hence plants with a low rheobase are characterized by a wider range of accommodation. It is suggested that the changes in potential (including AP recorded on the stem surface are connected with changes of the potential on cell membranes (Sibaoka, 1962.

Feasibility study of injection mouldable conductive plastic for the hearing aid applications

DEFF Research Database (Denmark)

Merca, Timea D.den; Lindberg, Torbjörn; Islam, Aminul

2016-01-01

Electrically conductive polymers can combine the advantage of plastic processing with the unique electrical properties which are usually found in metals. This article presents a feasibility study of an electrically conductive plastic for hearing aid antennas. Focus will be placed to critically......) 3D measuring system in comparison with an ideal copper antenna at 2.4 GHz. An analysis of the association between the conductive plastic processing parameters in regards to its electrical performance is discussed and evaluated....

Brain plasticity and recovery of cognitive functions

Directory of Open Access Journals (Sweden)

Anja Čuš

2011-10-01

Full Text Available Through its capacity of plastic changes, the adult brain enables successful dealing with new demands of everyday life and recovery after an acquired brain damage either spontaneously or by the help of rehabilitation interventions. Studies which explored the effects of cognitive training in the normal population report on different types of changes in the performance of cognitive tasks as well as different types of changes in brain activation patterns.Following practice, brain activation can change in its extent, intensity or location, while cognitive processes can become more efficient or can be replaced by different processes.After acquired brain damage plastic changes are somewhat different. After the injury, the damaged brain area can either gradually regain its previous function, or different brain regions are recruited to perform that function.Studies of spontaneous and guided recovery of cognitive functions have revealed both types of plastic changes that follow each other, as well as significant correlations between these changes and improvement on the behavioural level.

[Magnetic resonance imaging study of effects of accommodation on human lens morphological characters].

Science.gov (United States)

Zheng, Sui-lian; Zhang, Ai; Shi, Jian-jing; Zhou, Yun-xin

2013-11-05

To evaluate the effects of accommodation on lens morphological characters. From January 2011 to June 2011, magnetic resonance images of eyes were acquired from 30 subjects aged 20 to 24 years during accommodation and at rest. The optimal images were analyzed by Autocad 2010 to obtain the total lens cross-sectional area (CSA) and CSA of anterior and posterior portions of lens, anterior chamber depth, lens thickness, lens diameter, vitreous chamber depth and axial length during accommodation and at rest. Paired-t test was performed. The anterior curvature radius (mm), posterior curvature radius (mm), CSA of anterior portion (mm(2)), CSA of posterior portion (mm(2)), total lens CSA (mm(2)) was (8.7 ± 0.8), (6.2 ± 0.5), (7.5 ± 2.1), (12.0 ± 2.6), (20 ± 4) during relaxed accommodation; anterior curvature radius (mm), posterior curvature radius (mm), CSA of anterior portion (mm(2)), CSA of posterior portion (mm(2)), total lens CSA (mm(2)) was (7.1 ± 1.3), (5.6 ± 0.5), (14.7 ± 2.9), (12.2 ± 2.1) and (27 ± 4) during accommodation. The total lens CSA (t = -11.556, P 0.05) under a statistically independent accommodative state. There was significant difference in the anterior chamber depth (t = 4.366, P 0.05) and axial length (t = 0.418, P > 0.05) under accommodative states. During accommodation, the anterior chamber depth decreases, lens thickness increases and diameter of lens decreases while anterior portions and total lens CSA increase. There are insignificant changes in posterior portions of lens CSA, vitreous chamber depth and axial length. The accommodative changes in CSA indicate that the anterior portion of lens may be related with the properties of anterior capsule and lens material, the position of zonular attachments and the location of fetal nucleus. Helmholtz theory is supported.

Elastic-plastic analysis using an efficient formulation of the finite element method

International Nuclear Information System (INIS)

Aamodt, B.; Mo, O.

1975-01-01

Based on the flow theory of plasticity, the von Mises or the Tresca yield criterion and the isotropic hardening law, an incremental stiffness relationship can be established for a finite element model of the elasto-plastic structure. However, instead of including all degrees of freedom and all finite elements of the total model in a nonlinear solution process, a separation of elastic and plastic parts of the structure can be carried out. Such a separation can be obtained by identifying elastic parts of the structure as 'elastic' superelements and elasto-plastic parts of the structure as 'elasto-plastic' superelements. Also, it may be of advantage to use several levels of superelements in modelling the elastic parts of the structure. For the 'elasto-plastic' superelements the specific plastic computations such as updating of the incremental stiffness matrix and subsequent reduction (i.e. static condensation of all degrees of freedom being local to the superelements) have to be carried out repeatedly during the nonlinear solution process. The solution of the nonlinear equations is performed utilizing a combination of load incrementation and equilibrium interations. The present method of analysis is demonstrated for two larger examples of elasto-plastic analysis. (Auth.)

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...

Recovery of PET from packaging plastics mixtures by wet shaking table.

Science.gov (United States)

Carvalho, M T; Agante, E; Durão, F

2007-01-01

Recycling requires the separation of materials appearing in a mass of wastes of heterogeneous composition and characteristics, into single, almost pure, component/material flows. The separation of materials (e.g., some types of plastics) with similar physical properties (e.g., specific gravity) is often accomplished by human sorting. This is the case of the separation of packaging plastics in municipal solid wastes (MSW). The low cost of virgin plastics and low value of recycled plastics necessitate the utilization of low cost techniques and processes in the recycling of packaging plastics. An experimental study was conducted to evaluate the feasibility of production of a PET product, cleaned from PVC and PS, using a wet shaking table. The wet shaking table is an environmentally friendly process, widely used to separate minerals, which has low capital and operational costs. Some operational variables of the equipment, as well as different feed characteristics, were considered. The results show that the separation of these plastics is feasible although, similarly to the mineral field, in somewhat complex flow sheets.

Comparative reference of accommodation tension in schoolchildren of junior classes depending on emotional state

Directory of Open Access Journals (Sweden)

L. E. Fedorischeva

2013-01-01

Full Text Available Purpose: to study the change of adaptation mechanisms in children of junior classes during working on close distance depending on their psychoemotional state.Methods: 52 children of the second classes of grammar school were included into the study. There were allocated 30 emotional labile schoolchildren with choleric temperament. The children were examined by pediatrician, neurologist and in laboratory. Standard ophthalmic examination was performed. Accommodation was examined by subjective (reserve of relative accommodation and objective (familiar tone of accommodation methods.Results: All children had low reserve of relative accommodation (RRA and high familiar tone of accommodation (FTA in the end of educational week especially in emotional labile children. After course of treatment (hygiene of visual activity; restoration of accommodation and therapy of visual tiredness; gymnastics for cervical spine; preparations with microelements, vitamins C,E, B-carotene; fenibute RRA was increased and FTA was decreased even in emotional labile children.Conclusion: There is correlation between refractive-accommodative apparatus and psychoemotional state in schoolchildren ofjunior classes.

Comparative reference of accommodation tension in schoolchildren of junior classes depending on emotional state

Directory of Open Access Journals (Sweden)

L. E. Fedorischeva

2014-07-01

Full Text Available Purpose: to study the change of adaptation mechanisms in children of junior classes during working on close distance depending on their psychoemotional state.Methods: 52 children of the second classes of grammar school were included into the study. There were allocated 30 emotional labile schoolchildren with choleric temperament. The children were examined by pediatrician, neurologist and in laboratory. Standard ophthalmic examination was performed. Accommodation was examined by subjective (reserve of relative accommodation and objective (familiar tone of accommodation methods.Results: All children had low reserve of relative accommodation (RRA and high familiar tone of accommodation (FTA in the end of educational week especially in emotional labile children. After course of treatment (hygiene of visual activity; restoration of accommodation and therapy of visual tiredness; gymnastics for cervical spine; preparations with microelements, vitamins C,E, B-carotene; fenibute RRA was increased and FTA was decreased even in emotional labile children.Conclusion: There is correlation between refractive-accommodative apparatus and psychoemotional state in schoolchildren ofjunior classes.

Transfusion Refusal and the Shifting Limits of Multicultural Accommodation.