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Sample records for ece polycarbonate detectors

  1. BACKGROUND TRACK DENSITY REDUCTION OF 50-HZ-HV ECE-PROCESSED THICK POLYCARBONATE DETECTORS TO IMPROVE LOWER DETECTION LIMIT.

    Science.gov (United States)

    Sohrabi, M; Hakimi, A; Soltani, Z

    2016-12-01

    A recent novel development of 50-Hz-HV ECE of 1-mm-thick and 250-µm-thick polycarbonate track detectors (PCTDs) has proved some promising results for some health physics, dosimetry and ion-beam-related applications. The method while proved having some good characteristics for some applications provided a relatively higher background track density (BGTD) in particular when very high voltages are applied to the PCTDs. In order to decrease the minimum detection limit (MDL) of the PCTDs and to further promote its applications for low dose, the BGTD was reduced by applying a layer removal methodology applying ethylendiamine (EDA). The effects of EDA concentrations (50, 60, 65, 70, 75, 80, 85 and 90 %) in water at room temperature (26°C) and soaking durations up to 100 min at different EDA concentration on BGTD reduction were studied. The thickness of the layer removed from the surface of a PCTD highly depends on the soaking time and EDA concentration; it increases as the EDA concentration increases up to for example 700 µm after 2 h of soaking in the EDA solution. After ∼10 min of soaking duration at any of the above-stated concentrations, the BGTD reaches its minimum value, a value which differs from concentration to concentration. An EDA concentration of 85 % in water provided the lowest BGTD of 64.06 ± 3.12 tracks cm(- 2); ∼6 times lower than that of its original value. It is shown that the layer removal process does not change the registration characteristics of the PCTD and its appearance significantly. The MDL of the PCTDs depends strongly on the BGTD. The MDL values for a desired confidence level were also studied by three calculation methods. The results of the BGTD and the MDL studies under different conditions applied are presented and discussed.

  2. Measurement of photoneutron doses in and out of high-energy X-ray beam of a SATURNE-20 medical linear accelerator by ECE polycarbonate detectors

    CERN Document Server

    Sohrabi, M

    1999-01-01

    Photoneutron contaminations in and out of high energy X-ray beams of the medical linear accelerator SATURNE 20 (CGR) of the Radiotherapy Department of Omeed Hospital in Isfahan, Iran, have been determined using 250 mu m polycarbonate (PC) dosimeters, in strips or in sheets, processed by electrochemical etching (ECE) using specially designed ECE chambers to etch larger sheets. A two dimensional or topographical distribution of neutron contamination was also determined in a full size beam. The neutron dose equivalents (Hn) in the beam of 18 MV X-rays at 80 cm FSD were determined to be linear functions of X-ray dose equivalents (Hx) up to 1400 cSv. The distribution of the Hn at different X-ray doses showed bell-shape profiles with maxima at the isocenter. The ratios of dose equivalents of neutrons to those of X-rays increased as the field size increased having values of 0.22%, 0.28%, 0.31% and 0.37% for field sizes of 10x10, 20x20, 30x30, and 40x40 cm sup 2 respectively. Although such neutron dose equivalents ca...

  3. ECE laboratory in the Vinča institute: Its basic characteristics and fundamentals of electrochemic etching on polycarbonate

    Directory of Open Access Journals (Sweden)

    Žunić Zora S.

    2003-01-01

    Full Text Available This paper deals with the introductory aspects of the Electrochemical Etching Laboratory installed at the VINČA Institute in the year 2003. The main purpose of the laboratory is its field application for radon and thoron large-scale survey using passive radon/thoron UFO type detectors. Since the etching techniques together with the laboratory equipment were transferred from the National Institute of Radiological Sciences, Chiba, Japan, it was necessary for both etching conditions to be confirmed and to be checked up^ i. e., bulk etching speeds of chemical etching and electrochemical etching in the VINCA Electrochemical Etching Laboratory itself. Beside this initial step, other concerns were taken into consideration in this preliminary experimental phase such as the following: the measurable energy range of the polycarbonate film, background etch pit density of the film and its standard deviation and reproducibility of the response to alpha particles for different sets of etchings.

  4. Measurement of ion beam angular distribution at different helium gas pressures in a plasma focus device by large-area polycarbonate detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sohrabi, M.; Habibi, M., E-mail: mortezahabibi@gmail.com; Ramezani, V. [Amirkabir University of Technology, Energy Engineering and Physics Department (Iran, Islamic Republic of)

    2017-02-15

    The paper presents an experimental study and analysis of full helium ion density angular distributions in a 4-kJ plasma focus device (PFD) at pressures of 10, 15, 25, and 30 mbar using large-area polycarbonate track detectors (PCTDs) (15-cm etchable diameter) processed by 50-Hz-HV electrochemical etching (ECE). Helium ion track distributions at different pressures, in particular, at the main axis of the PFD are presented. Maximum ion track density of ~4.4 × 10{sup 4} tracks/cm{sup 2} was obtained in the PCTD placed 6 cm from the anode. The ion distributions for all pressures applied are ring-shaped, which is possibly due to the hollow cylindrical copper anode used. The large-area PCTD processed by ECE proves, at the present state-of-theart, a superior method for direct observation and analysis of ion distributions at a glance with minimum efforts and time. Some observations of the ion density distributions at different pressures are reported and discussed.

  5. Development of a high efficiency personal/environmental radon dosimeter using polycarbonate detectors.

    Science.gov (United States)

    Taheri, M; Jafarizadeh, M; Baradaran, S; Zainali, Gh

    2006-12-01

    Passive radon dosimeters, based on alpha particle etched track detectors, are widely used for the assessment of radon exposure. These methods are often applied in radon dosimetry for long periods of time. In this research work, we have developed a highly efficient method of personal/environmental radon dosimetry that is based upon the detection of alpha particles from radon daughters, (218)Po and (214)Po, using a polycarbonate detector (PC). The radon daughters are collected on the filter surface by passing a fixed flow of air through it and the PC detector, placed at a specified distance from the filter, is simultaneously exposed to alpha particles. After exposure, the latent tracks on the detector are made to appear by means of an electrochemical etching process; these are proportional to the radon dose. The air flow rate and the detector-filter distance are the major factors that can affect the performance of the dosimeter. The results obtained in our experimental investigations have shown that a distance of 1.5 cm between the detector and the filter, an absorber layer of Al with a thickness of 12 microm and an air flow rate of 4 l min(-1) offer the best design parameters for a high efficiency radon dosimeter. Then, the designed dosimeter was calibrated against different values of radon exposures and the obtained sensitivity was found to be 2.1 (tracks cm(-2)) (kBq h m(-3))(-1). The most important advantages of this method are that it is reliable, fast and convenient when used for radon dose assessment. In this paper, the optimized parameters of the dosimeter structure and its calibration procedure are presented and discussed.

  6. A study of commercially-available polyethylene terephthalate (PET) and polycarbonate as nuclear track detector materials

    Science.gov (United States)

    Espinosa, G.; Golzarri, J. I.; Vazquez-Lopez, C.; Trejo, R.; Lopez, K.; Rickards, J.

    2014-07-01

    In the study of the sensitivity of materials to be used as nuclear track detectors, it was found that commercial polyethylene terephthalate (PET) from Ciel® water bottles, commercial roof cover polycarbonate, and recycled packaging strips (recycled PET), can be used as nuclear track detectors. These three commercial materials present nuclear tracks when bombarded by 2.27 MeV nitrogen ions produced in a Pelletron particle accelerator, and by fission fragments from a 252Cf source (79.4 and 103.8 MeV), after a chemical etching with a 6.25M KOH solution, or with a 6.25M KOH solution with 20% methanol, both solutions at 60±1°C. As an example, the nitrogen ions deposit approximately 1 keV/nm in the form of ionization and excitation at the surface of PET, as calculated using the SRIM code. The fission fragments deposit up to 9 keV/nm at the surface, in both cases generating sufficient free radicals to initiate the track formation process. However, 5 MeV alpha particles, typical of radon (222Rn) emissions, deposit only 0.12 keV/nm, do not present tracks after the chemical etching process. This valuable information could be very useful for further studies of new materials in nuclear track methodology.

  7. ECE Successfully Acquire Haoze

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>In order to improve sustainable development capability, optimize mineral resources, East China Mineral Exploration and Development Bureau (ECE) have worked hard to create new achievements both in the domestic and over-

  8. Taheri-Saramad x-ray detector (TSXD): A novel high spatial resolution x-ray imager based on ZnO nano scintillator wires in polycarbonate membrane

    Energy Technology Data Exchange (ETDEWEB)

    Taheri, A., E-mail: at1361@aut.ac.ir; Saramad, S.; Ghalenoei, S.; Setayeshi, S. [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of)

    2014-01-15

    A novel x-ray imager based on ZnO nanowires is designed and fabricated. The proposed architecture is based on scintillation properties of ZnO nanostructures in a polycarbonate track-etched membrane. Because of higher refractive index of ZnO nanowire compared to the membrane, the nanowire acts as an optical fiber that prevents the generated optical photons to spread inside the detector. This effect improves the spatial resolution of the imager. The detection quantum efficiency and spatial resolution of the fabricated imager are 11% and <6.8 μm, respectively.

  9. Taheri-Saramad x-ray detector (TSXD): A novel high spatial resolution x-ray imager based on ZnO nano scintillator wires in polycarbonate membrane

    Science.gov (United States)

    Taheri, A.; Saramad, S.; Ghalenoei, S.; Setayeshi, S.

    2014-01-01

    A novel x-ray imager based on ZnO nanowires is designed and fabricated. The proposed architecture is based on scintillation properties of ZnO nanostructures in a polycarbonate track-etched membrane. Because of higher refractive index of ZnO nanowire compared to the membrane, the nanowire acts as an optical fiber that prevents the generated optical photons to spread inside the detector. This effect improves the spatial resolution of the imager. The detection quantum efficiency and spatial resolution of the fabricated imager are 11% and <6.8 μm, respectively.

  10. Analyses of Additives Applied in a Polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.J. [Kunsan National University, Kunsan (Korea)

    2000-06-01

    In this study, polymer additives were extracted and separated by Soxhlet extraction method and the dissolution-precipitation method from a polycarbonate (optical grade) which completely absorbed UV light below 390 nm. Analytical techniques such as UV-V is spectroscopy, FR-IR, and HPLC were applied to analyze additives in polycarbonate. Separated materials from the polycarbonate may be a complex mixture containing additives such as UV stabilizer, antioxidants(primary and secondary), monomers, and oligomers. Several compounds such as bisphenol A, Irganox 1010, and Cyasorb UV-5411 were identified by chromatograms and UV spectra obtained from RP HPLC analysis using Bondapak C{sub 18} column, methanol mobile phase, and a photodiode array (PDA) detector. Also, the content of UV-5411 in the polycarbonate was about 0.12 wt % by a quantitative analysis through UV spectroscopy. (author). 21 refs., 2 tabs., 5 figs.

  11. Summary of ECE Presentations at EC-19

    Science.gov (United States)

    Austin, M. E.

    2017-07-01

    At the EC-19 workshop there were ten presentations in the topic of diagnosing and heating plasmas with Electron Cyclotron Emission (ECE) and Electron Bernstein Wave (EBW). Innovations continue in designs of ECE systems while tried-and-true instruments still provide adequate data to explore new areas of research. Heterodyne radiometers and Michelson interferometers carry on as the bedrock of ECE electron temperature (Te) measurements while ECE imaging systems continue expanding their capabilities. The design of the ITER-ECE diagnostic system is in its advanced stages; solutions are being found for challenges in the transmission lines and front-end calibration sources.

  12. Summary of ECE Presentations at EC-18

    Directory of Open Access Journals (Sweden)

    Taylor G.

    2015-01-01

    Full Text Available There were nine ECE and one EBE presentation at EC-18. Four of the presentations were on various aspects of ECE on ITER. The ITER ECE diagnostic has entered an important detailed preliminary design phase and faces several design challenges in the next 2-3 years. Most of the other ECE presentations at the workshop were focused on applications of ECE diagnostics to plasma measurements, rather than improvements in technology, although it was apparent that heterodyne receiver technology continues to improve. CECE, ECE imaging and EBE imaging are increasingly providing valuable insights into plasma behavior that is important to understand if future burning plasma devices, such as ITER, FNSF and DEMO, are to be successful.

  13. ESR investigations on ion beam irradiated polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Chipara, M.I. (Institute for Physics and Technology of Materials, P.O. Box MG-7, Magurele, Bucharest, R-76900 (Romania)); Grecu, V.V. (University of Bucharest, Faculty of Physics, P.O. Box MG-11, Magurele, Bucharest, R-76900 (Romania)); Notingher, P.V. (University Politehnica of Bucharest, Electrotechnical Faculty, 313, Splaiul Independentei, Str., 77206 Bucharest (Romania)); Romero, J.R. (Universidad Central de Venezuela, Facultad de Ingineria, Dept. de Fisica Aplicada, Ciudad Universitaria, Chaguaramos, Caracas (Venezuela)); Chipara, M.D. (Research Institute for Electrotechnics, 45-47 Tudor Vladimirescu, Bd., Bucharest, R-79623 (Romania))

    1994-06-01

    Electron spin resonance (ESR) investigations with a polycarbonate solid state nuclear detector, irradiated with oxygen ions, are reported. The nature of the paramagnetic defects induced by irradiation is discussed. The temperature dependence of resonance line parameters is studied. From the experimental data, obtained by ESR, spectroscopy, the activation energy for defect recombination, the average isotropic exchange integral between paramagnetic defects as well as the average distance between defects, are estimated. Correlations with latent tracks structure are discussed. ((orig.))

  14. ECE for NTM control on ITER

    Directory of Open Access Journals (Sweden)

    Westerhof E.

    2012-09-01

    Full Text Available Control of Neoclassical Tearing Modes (NTMs requires an accurate and low latency detection of the mode position. For a burning H-mode ITER plasma, simulations are conducted for both ECE detected via the equatorial port plug and along the line-of-sight of the ECCD launchers. Simulated ECE is detected using synthetic radiometers, with settings chosen to meet the required accuracy. A video bandwidth of 2 kHz is used which allows for an intermediate frequency bandwidth of BIF = 400 MHz for ECE detected via the equatorial port plug. For ECE detected via the ECCD line-of-sight, an intermediate frequency bandwidth of 1.5 GHz and 1 GHz for the 2/1 and 3/2 NTM respectively suffices for accurate location detection. For both ECE systems, the latency requirements for NTM suppression are fulfilled.

  15. New approach to ECE measurements based on Hilbert-transform spectral analysis

    Directory of Open Access Journals (Sweden)

    Pandya Hitesh Kumar B.

    2015-01-01

    Full Text Available Spectroscopy of Electron Cyclotron Emission (ECE has been established as adequate diagnostic technique for fusion research machines. Among various instruments for ECE diagnostics, only Fourier-transform spectrometers with Martin-Puplett interferometers can measure electron cyclotron radiation in a broadband frequency range from 70 to 1000 GHz. Before these measurements, a complete system including a frontend radiation collector, a transmission line, an interferometer and a radiation detector should be absolutely calibrated. A hot/cold calibration source and data-averaging technique are used to calibrate the total ECE diagnostic system. It takes long time to calibrate the ECE system because of the low power level of the calibration source and high values of the noise equivalent power (NEP of the detection system. A new technique, Hilbert-transform spectral analysis, is proposed for the ITER plasma ECE spectral measurements. An operation principle, characteristics and advantages of the corresponding Hilbert-transform spectrum analyser (HTSA based on a high-Tc Josephson detector are discussed. Due to lower NEP-values of the Josephson detector, this spectrum analyser might demonstrate shorter calibration times than that for the Martin-Puplett interferometer.

  16. ECE Measurements of Helical Plasmas in LHD

    Science.gov (United States)

    Nagayama, Y.; Inagaki, S.; Ito, Y.; Kawahata, K.; Sasao, H.; de Vries, P.

    1999-11-01

    This paper presents ECE measurements on LHD, which is the l=2, n=10 heriotron with the major radius of 3.8 m, with the averaged minor radius of 60 cm and with the helical field of up to 3 T. The ECE is collected from both inner and outer sides, since the magnetic field has a peaked profile. ECE is detcted with Michelson, GPC and 70 GHz and 140 GHz radiometers. The LHD plasma is generated using ECH of up to 1 MW and is heated using NBI of up to 8 GW. Notch filters reduce the ECH leakage. The polarization of ECE is theoretically and experimentally investigated in the heriotoron system, where the field angle rotates -30 to 30^o. The polarization follows as the field angle changes. Since the density profile is flat, ECE is cut off in the edge region in the high density LHD plasma. An interesting observation is the breathing phenomena, which is as follows: the electron temperature and other plasma parameters oscillate with frequency of 0.5-1Hz like a sine-wave when the NBI power is about 1 MW.

  17. ECE Imaging Bandwidth Upgrade for TEXTOR

    Science.gov (United States)

    Domier, C. W.; Zhang, P.; Luhmann, N. C., Jr.; Park, H. K.; van de Pol, M. J.; Spakman, G. W.; Jaspers, R.; Donne, A. J. H.

    2007-11-01

    The 128 channel 2-D Electron Cyclotron Emission (ECE) Imaging system collects time-resolved 16x8 images of electron temperature profiles and fluctuations on the TEXTOR tokamak. This instrument was upgraded in February 2007 with new wideband ECE electronics which increased the instantaneous frequency coverage by >50% to 6.4 GHz with a corresponding increase in horizontal plasma coverage. Frequency extenders have been developed to combine modules together to double the instantaneous coverage to 12.8 GHz. Technical details regarding both the electronics upgrade and the frequency extenders as well as the preliminary physics results will be presented. Implementation of a similar but new ECEI instrument on the DIII-D tokamak will be extensively discussed.

  18. Gender and professionalisation in the Danish ECE workforce

    DEFF Research Database (Denmark)

    Nielsen, Steen Baagøe

    and the linking of these strategies, which in the international literature is often considered two sides of the same coin. Through the narratives of men and women in the ECE workforce in Denmark the paper discusses experiences of men and women in ECE institutions, and consequences for training and the transition...

  19. ECE imaging of electron temperature and electron temperature fluctuations (invited)

    NARCIS (Netherlands)

    Deng, B.H.; Domier, C.W.; N C Luhmann Jr.,; Brower, D.L.; Cima, G.; Donne, A. J. H.; Oyevaar, T.; van de Pol, M.J.

    2001-01-01

    Electron cyclotron emission imaging (ECE imaging or ECEI) is a novel plasma diagnostic technique for the study of electron temperature profiles and fluctuations in magnetic fusion plasma devices. Instead of a single receiver located in the tokamak midplane as in conventional ECE radiometers, ECEI sy

  20. Radiation effects in polycarbonate capacitors

    Directory of Open Access Journals (Sweden)

    Vujisić Miloš

    2009-01-01

    Full Text Available The aim of this paper is to examine the influence of neutron and gamma irradiation on the dissipation factor and capacitance of capacitors with polycarbonate dielectrics. The operation of capacitors subject to extreme conditions, such as the presence of ionizing radiation fields, is of special concern in military industry and space technology. Results obtained show that the exposure to a mixed neutron and gamma radiation field causes a decrease of capacitance, while the loss tangent remains unchanged.

  1. Update on the status of the ITER ECE diagnostic design

    Science.gov (United States)

    Taylor, G.; Austin, M. E.; Basile, A.; Beno, J. H.; Danani, S.; Feder, R.; Houshmandyar, S.; Hubbard, A. E.; Johnson, D. W.; Khodak, A.; Kumar, R.; Kumar, S.; Ouroua, A.; Padasalagi, S. B.; Pandya, H. K. B.; Phillips, P. E.; Rowan, W. L.; Stillerman, J.; Thomas, S.; Udintsev, V. S.; Vayakis, G.; Walsh, M.; Weeks, D.

    2017-07-01

    Considerable progress has been made on the design of the ITER electron cyclotron emission (ECE) diagnostic over the past two years. Radial and oblique views are still included in the design in order to measure distortions in the electron momentum distribution, but the oblique view has been redirected to reduce stray millimeter radiation from the electron cyclotron heating system. A major challenge has been designing the 1000 K calibration sources and remotely activated mirrors located in the ECE diagnostic shield module (DSM) in the equatorial port plug #09. These critical systems are being modeled and prototypes are being developed. Providing adequate neutron shielding in the DSM while allowing sufficient space for optical components is also a significant challenge. Four 45-meter long low-loss transmission lines transport the 70-1000 GHz ECE from the DSM to the ECE instrumentation room. Prototype transmission lines are being tested, as are the polarization splitter modules that separate O-mode and X-mode polarized ECE. A highly integrated prototype 200-300 GHz radiometer is being tested on the DIII-D tokamak in the USA. Design activities also include integration of ECE signals into the ITER plasma control system and determining the hardware and software architecture needed to control and calibrate the ECE instruments.

  2. A Synoptic Snapshot of the East Cape Eddy (ECE)

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; LIU Qinyu

    2005-01-01

    A synoptic snapshot in this study is made for the East Cape Eddy (ECE) based on the World Ocean Circulation Experiment (WOCE) P14C Hydrographic Section and Shipboard ADCP velocity vector data collected in September 1992.The ECE is an anticyclonic eddy, barotropically structured and centered at 33.64°S and 176.21°E, with warm and salinouscored subsurface water. The radius of the eddy is of the order O (110 km) and the maximum circumferential velocity is O(40cms-1); as a result, the relative vorticity is estimated to be O (7 × 10-6s-1). Due to the existence of the ECE, the mixed layer north of New Zealand becomes deeper, reaching a depth of 300 m in the austral winter. The ECE plays an important role in the formation and distribution of the Subtropical Mode Water (STMW) over a considerable area in the South Pacific.

  3. Click Chemistry in Functional Aliphatic Polycarbonates.

    Science.gov (United States)

    Dai, Yu; Zhang, Xiaojin; Xia, Fan

    2017-10-01

    Click chemistry, one of the most important methods in conjugation, plays an extremely significant role in the synthesis of functional aliphatic polycarbonates, which are a group of biodegradable polymers containing carbonate bonds in their main chains. To date, more than 75 articles have been reported on the topic of click chemistry in functional aliphatic polycarbonates. However, these efforts have not yet been highlighted. Six categories of click reactions (alkyne-azide reaction, thiol-ene reaction, Michael addition, epoxy-amine/thiol reaction, Diels-Alder reaction, and imine formation) that have been afforded for further post-polymerization modification of polycarbonates are reviewed. Through this review, a comprehensive understanding of functional aliphatic polycarbonates aims to afford insight on the design of polycarbonates for further post-polymerization modification via click chemistry and the expectation of the practical application. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Gender and professionalisation in the Danish ECE workforce

    DEFF Research Database (Denmark)

    Nielsen, Steen Baagøe

    to practice. The research highlights the importance of reflecting gender aspects at an important step of vocational carreers. ECE research, practice and policy have to regard gender equity as a basic aspect of diversity and equality in ECE. The research explores and sheds light on the parallel difficulties...... of the gender equal recruitment and the strategies of professionalization. The aim is to discuss future possibilities of policies targeted at recruiting men....

  5. Bacterial isolates degrading aliphatic polycarbonates.

    Science.gov (United States)

    Suyama, T; Hosoya, H; Tokiwa, Y

    1998-04-15

    Bacteria that degrade an aliphatic polycarbonate, poly(hexamethylene carbonate), were isolated from river water in Ibaraki. Prefecture, Japan, after enrichment in liquid medium containing poly(hexamethylene carbonate) suspensions as carbon source, and dilution to single cells. Four of the strains, 35L, WFF52, 61A and 61B2, degraded poly(hexamethylene carbonate) on agar plate containing suspended poly(hexamethylene carbonate). Degradation of poly(hexamethylene carbonate) was confirmed by gel permeation chromatography. Besides poly(hexamethylene carbonate), the strains were found to degrade poly(tetramethylene carbonate). The strains were characterized morphologically, physiologically, and by 16S rDNA sequence analysis. Strains 35L and WFF52 were tentatively identified as Pseudomonas sp. and Variovorax sp., respectively, while strains 61A and 61B2 constitute an unidentified branch within the beta subclass of the Proteobacteria.

  6. Extending the physics studied by ECE on ITER

    Directory of Open Access Journals (Sweden)

    Pandya H.

    2012-09-01

    Full Text Available The Electron Cyclotron Emission (ECE diagnostic provides essential information for plasma operation and for establishing performance characteristics in ITER. Recently, the design of the ITER ECE diagnostic has been taken through the conceptual design review and now entering the detailed design phase [1, 2]. The baseline ECE system on ITER permits measurements of both the X- and O-mode radiation in the frequency range from 70 GHz up to 1 THz along two lines-of-sight, perpendicular and oblique at about 10 degrees, in the equatorial port. The system as planned meets the ITER measurement requirements. Nevertheless, there are several other mm-wave diagnostics in ITER, such as HFS, LFS and plasma position reflectometry, as well as Collective Thomson scattering system, whose transmission lines allow, in principle, additional measurements of parts of the ECE spectrum with upgrades of their back-ends, improvements in filtering and/or additional receivers. A discussion of whether and how supposedly to enable such ECE measurements is given here.

  7. Status of the design of the ITER ECE diagnostic

    Directory of Open Access Journals (Sweden)

    Taylor G.

    2015-01-01

    Full Text Available The baseline design for the ITER electron cyclotron emission (ECE diagnostic has entered the detailed preliminary design phase. Two plasma views are planned, a radial view and an oblique view that is sensitive to distortions in the electron momentum distribution near the average thermal momentum. Both views provide high spatial resolution electron temperature profiles when the momentum distribution remains Maxwellian. The ECE diagnostic system consists of the front-end optics, including two 1000 K calibration sources, in equatorial port plug EP9, the 70-1000 GHz transmission system from the front-end to the diagnostics hall, and the ECE instrumentation in the diagnostics hall. The baseline ECE instrumentation will include two Michelson interferometers that can simultaneously measure ordinary and extraordinary mode ECE from 70 to 1000 GHz, and two heterodyne radiometer systems, covering 122-230 GHz and 244-355 GHz. Significant design challenges include 1 developing highly-reliable 1000 K calibration sources and the associated shutters/mirrors, 2 providing compliant couplings between the front-end optics and the polarization splitter box that accommodate displacements of the vacuum vessel during plasma operations and bake out, 3 protecting components from damage due to stray ECH radiation and other intense millimeter wave emission and 4 providing the low-loss broadband transmission system.

  8. Biodegradation of aliphatic and aromatic polycarbonates.

    Science.gov (United States)

    Artham, Trishul; Doble, Mukesh

    2008-01-01

    Polycarbonate is one of the most widely used engineering plastics because of its superior physical, chemical, and mechanical properties. Understanding the biodegradation of this polymer is of great importance to answer the increasing problems in waste management of this polymer. Aliphatic polycarbonates are known to biodegrade either through the action of pure enzymes or by bacterial whole cells. Very little information is available that deals with the biodegradation of aromatic polycarbonates. Biodegradation is governed by different factors that include polymer characteristics, type of organism, and nature of pretreatment. The polymer characteristics such as its mobility, tacticity, crystallinity, molecular weight, the type of functional groups and substituents present in its structure, and plasticizers or additives added to the polymer all play an important role in its degradation. The carbonate bond in aliphatic polycarbonates is facile and hence this polymer is easily biodegradable. On the other hand, bisphenol A polycarbonate contains benzene rings and quaternary carbon atoms which form bulky and stiff chains that enhance rigidity. Even though this polycarbonate is amorphous in nature because of considerable free volume, it is non-biodegradable since the carbonate bond is inaccessible to enzymes because of the presence of bulky phenyl groups on either side. In order to facilitate the biodegradation of polymers few pretreatment techniques which include photo-oxidation, gamma-irradiation, or use of chemicals have been tested. Addition of biosurfactants to improve the interaction between the polymer and the microorganisms, and blending with natural or synthetic polymers that degrade easily, can also enhance the biodegradation.

  9. Cadence Feedback With ECE PEDO to Monitor Physical Activity Intensity

    Science.gov (United States)

    Ardic, Fusun; Göcer, Esra

    2016-01-01

    Abstract The purpose of this study was to examine the monitoring capabilities of the equipment for clever exercise pedometer (ECE PEDO) that provides audible feedback when the person exceeds the upper and lower limits of the target step numbers per minute and to compare step counts with Yamax SW-200 (YX200) as the criterion pedometer. A total of 30 adult volunteers (15 males and 15 females) were classified as normal weight (n = 10), overweight (n = 10), and obese (n = 10). After the submaximal exercise test on a treadmill, the moderate intensity for walking was determined by using YX200 pedometer and then the number of steps taken in a minute was measured. Lower and upper limits of steps per minute (cadence) were recorded in ECE PEDO providing audible feedback when the person's walking speed gets out of the limits. Volunteers walked for 30 minutes in the individual step count range by attaching the ECE PEDO and YX200 pedometer on both sides of the waist belt in the same session. Step counts of the volunteers were recorded. Wilcoxon, Spearman correlation, and Bland–Altman analyses were performed to show the relationship and agreement between the results of 2 devices. Subjects took an average of 3511 ± 426 and 3493 ± 399 steps during 30 minutes with ECE PEDO and criterion pedometer, respectively. About 3500 steps taken by ECE PEDO reflected that this pedometer has capability of identifying steps per minute to meet moderate intensity of physical activity. There was a strong correlation between step counts of both devices (P PEDO and YX200 pedometer in the Bland–Altman analysis. Although both devices showed a strong similarity in counting steps, the ECE PEDO provides monitoring of intensity such that a person can walk in a specified time with a desired speed. PMID:26962822

  10. Optical design of the oblique Ece antenna system for JET

    Energy Technology Data Exchange (ETDEWEB)

    Sozzi, C. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy)]. E-mail: sozzi@ifp.cnr.it; Bruschi, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); Simonetto, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); DeLaLuna, E. [Asociacion EURATOM-CIEMAT, CIEMAT, Madrid (Spain); Fessey, J. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom); Riccardo, V. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom)

    2005-11-15

    Systematic disagreements between Ece and Thomson Scattering diagnostics observed in various fusion devices led to the proposal of the so called Oblique Ece diagnostics on JET. This system will allow the study of the electron distribution function at low energies to reveal deviations from the Maxwellian distribution. This paper is devoted to the design of the quasi optical antenna for this diagnostics. The physical bases of the diagnostics imply two lines of sight at about 10{sup o} and 20{sup o} respectively from the magnetic field gradient. Severe geometrical constraints are imposed by the location of the antenna. The design strategy and physical optics calculations used to validate it are presented.

  11. ECE diagnostic of high temperature ECRH heated plasmas on FTU

    Energy Technology Data Exchange (ETDEWEB)

    Zerbini, M; Buratti, P; Tudisco, O; Giruzzi, G; Bruschi, A; Cirant, S; Granucci, G; Simonetto, A; Sozzi, C; Gandini, F; Pacella, D; Fournier, K B; Finkenthal, M

    2000-01-31

    The Electron Cyclotron Emission (ECE) diagnostic on FTU tokamak is routinely performed with a Michelson interferometer with spectral range extending up to 1300 GHz. The diagnostic allowed accurate electron temperature measurements during the recent 140 Ghz Electron Cyclotron Resonance Heating (ECRH) experiments on FTU. Very accurate measurements have been performed on a wide range of electron temperatures and profile peaking. The ECE measurements have been compared with Thomson Scattering and with observations of X-ray spectra from highly stripped molybdenum ions. The suprathermal emission in these conditions has been studied.

  12. Spatial Resolution of the ECE for JET Typical Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Tribaldos, V. [Ciemat. Madrid (Spain)

    2000-07-01

    The purpose of this report is to obtain estimations of the spatial resolution of the electron cyclotron emission (ECE) phenomena for the typical plasmas found in JET tokamak. The analysis of the spatial resolution of the ECE is based on the underlying physical process of emission and a working definition is presented and discussed. In making these estimations a typical JET pulse is being analysed taking into account the magnetic configuration, the density and temperature profiles, obtained with the EFIT code and from the LIDAR diagnostic. Ray tracing simulations are performed for a Maxwellian plasma taking into account the antenna pattern. (Author) 5 refs.

  13. New millimeter-wave access for JET reflectometry and ECE

    Energy Technology Data Exchange (ETDEWEB)

    Cupido, L. [EURATOM-IST Association, Centro de Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)]. E-mail: cupido@mail.ua.pt; Luna, E. de la [Laboratorio Nacional de Fusion, Asociacion EURATOM-CIEMAT, 28040 Madrid (Spain); Antonucci, C. [Close Support Unit-EURATOM, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)] (and others)

    2005-11-15

    Millimeter-wave diagnostics at JET, mainly reflectometry, are employing state of art electronics, but are limited in performance by the existing waveguides and antenna system that are inadequate and obsolete. The use of long run waveguides with high losses and non-optimized antennas (in some cases, not pointing to relevant plasma positions) lead to difficult measurement conditions for reflectometry. The new access system presented in this article has been designed to improve the performance of reflectometry measurements and enable the installation of antennas for oblique viewing ECE. These two new antennae will allow the Ece radiation to be collected at different angles with respect to the magnetic field. This set-up, known as oblique ECE , is expected to be extremely useful in improving the interpretation of ECE temperature measurements in all fusion experiments with significant additional heating. For reflectometry, there is an urgent need to improve the edge density measurements as both the lithium beam and Thomson scattering exhibit limitations of resolution at lower densities. The project proposal states that the expected improvement in reflectometry S/N ratio is 30 dB. If realized, this will allow broad band reflectometry, for the measurement of the electron density profile, for the first time in JET.

  14. IEA SHC Task 42/ECES Annex 29 WG A1

    DEFF Research Database (Denmark)

    Ristić, Alenka; Furbo, Simon; Moser, Christoph

    2016-01-01

    An overview on the recent results on the engineering and characterization of sorption materials, PCMs and TCMs investigated in the working group WG A1 “Engineering and processing of TES materials” of IEA SHC Task 42 / ECES Annex 29 (Task 4229) entitled “Compact Thermal Energy Storage” is presented....

  15. Technical feasibility study on polycarbonate solar panels

    NARCIS (Netherlands)

    Hackmann, M.M.; Meuwissen, M.H.H.; Bots, T.L.; Buijs, J.A.H.M.; Broek, K.M.; Kinderman, R.; Tanck, O.B.F.; Schuurmans, F.M.

    2004-01-01

    This paper describes a technical feasibility study on the application of polycarbonate (PC) plates in a superstrate photovoltaic module design. The lamination process was performed in a conventional laminator apparatus using low temperature curing (100°C) ethylene-vinyl-acetate (EVA) as the potting

  16. Antistatic Polycarbonate/Copper Oxide Composite

    Science.gov (United States)

    Kovich, Michael; Rowland, George R., Jr.

    2003-01-01

    A composite material consisting of polycarbonate filled with copper oxide has been found to be suitable as an antistatic material. This material was developed to satisfy a requirement for an antistatic material that has a mass density less than that of aluminum and that exhibits an acceptably low level of outgassing in a vacuum.

  17. Photoplastic effect in polycarbonate using microhardness measurements

    Indian Academy of Sciences (India)

    R Bajpai; Sandhya Sharma; V K Vastal; B P Chandra

    2003-08-01

    Vickers microhardness indentation technique has been employed to detect the photoplastic effect in the transparent polycarbonate specimens in darkness and under mercury illumination. For low applied loads, the hardening of specimens under illumination confirms the positive photoplastic effect that causes illumination-induced increase of crosslinking (in polymer). For high applied loads the positive photoplastic effect decreases as the level of microhardness decreases.

  18. 21 CFR 177.1580 - Polycarbonate resins.

    Science.gov (United States)

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic..., manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, in accordance... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polycarbonate resins. 177.1580 Section...

  19. Co-continuous polycarbonate/ABS blends

    NARCIS (Netherlands)

    Inberg, J.P.F.; Gaymans, R.J.

    2002-01-01

    Co-continuous PC/ABS (50/50) blends were studied with a variable polybutadiene (PB) content (0–40%) in ABS. Polycarbonate (PC), styrene-acrylonitrile (SAN) and PB were blended in two steps using a twin screw extruder. Rectangular bars were injection moulded and notched Izod impact tested at

  20. ECE-imaging of the H-mode pedestal (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, B. J.; Nazikian, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Austin, M. E. [University of Texas-Austin, Austin, Texas 78712 (United States); Boom, J. E.; Classen, I. G. J. [Dutch Institute for Fundamental Energy Research, 3430 BE Nieuwegein (Netherlands); Burrell, K. H.; Snyder, P. B. [General Atomics, P.O.Box 85608, San Diego, California 92186 (United States); Domier, C. W.; Luhmann, N. C. Jr. [University of California-Davis, Davis, California 95616 (United States)

    2012-10-15

    A synthetic diagnostic has been developed that reproduces the highly structured electron cyclotron emission (ECE) spectrum radiated from the edge region of H-mode discharges. The modeled dependence on local perturbations of the equilibrium plasma pressure allows for interpretation of ECE data for diagnosis of local quantities. Forward modeling of the diagnostic response in this region allows for improved mapping of the observed fluctuations to flux surfaces within the plasma, allowing for the poloidal mode number of coherent structures to be resolved. In addition, other spectral features that are dependent on both T{sub e} and n{sub e} contain information about pedestal structure and the electron energy distribution of localized phenomena, such as edge filaments arising during edge-localized mode (ELM) activity.

  1. Infusing Technical Communication and Teamwork within the ECE Curriculum

    OpenAIRE

    KEDROWICZ, By April; WATANABE, Sundy

    2006-01-01

    This paper highlights a unique approach to infusing formal training and practice in oral and written communication and teamwork development in the Department of Electrical and Computer Engineering (ECE) at the University of Utah. Faculty and graduate (Ph.D.) students from the College of Humanities have teamed up with faculty from engineering to develop communication and teamwork instruction that is integrated into the existing engineering curriculum. These skills are used as a vehicle ...

  2. ECE RADIOMETER UPGRADE ON THE DIII-D TOKAMAK

    Energy Technology Data Exchange (ETDEWEB)

    AUSTIN, ME; LOHR, J

    2002-08-01

    OAK A271 ECE RADIOMETER UPGRADE ON THE DIII-D TOKAMAK. The electron cyclotron emission (ECE) heterodyne radiometer diagnostic on DIII-D has been upgraded with the addition of eight channels for a total of 40. The new, higher frequency channels allow measurements of electron temperature into the magnetic axis in discharges at maximum field, 2.15 T. The complete set now extends over the full usable range of second harmonic emission frequencies at 2.0 T covering radii from the outer edge inward to the location of third harmonic overlap on the high field side. Full coverage permits the measurement of heat pulses and magnetohydrodynamic (MHD) fluctuations on both sides of the magnetic axis. In addition, the symmetric measurements are used to fix the location of the magnetic axis in tokamak magnetic equilibrium reconstructions. Also, the new higher frequency channels have been used to determine central T{sub e} with good time resolution in low field, high density discharges using third harmonic ECE in the optically gray and optically thick regimes.

  3. DLC-Si protective coatings for polycarbonates

    Directory of Open Access Journals (Sweden)

    Damasceno J.C.

    2003-01-01

    Full Text Available In this work, a-C:H:Si (DLC-Si films were produced onto crystalline silicon and polycarbonate substrates by the rf-PACVD technique from gaseous mixtures of CH4 + SiH4 and C2H2 + SiH4. The effects of self-bias and gas composition upon mechanical and optical properties of the films were investigated. Micro-hardness, residual stress, surface roughness and refractive index measurements were employed for characterization. By incorporating low concentrations of silicon and by exploring the more favorable conditions for the rf-PACVD deposition technique, highly adherent DLC-Si thin films were produced with reduced internal stresses (lower than 1 GPa, high hardness (around 20 GPa and high deposition rates (up to 10 µm/h. Results that show the technological viability of this material for application as protective coatings for polycarbonates are also discussed.

  4. Bio-based polycarbonate as synthetic toolbox

    Science.gov (United States)

    Hauenstein, O.; Agarwal, S.; Greiner, A.

    2016-01-01

    Completely bio-based poly(limonene carbonate) is a thermoplastic polymer, which can be synthesized by copolymerization of limonene oxide (derived from limonene, which is found in orange peel) and CO2. Poly(limonene carbonate) has one double bond per repeating unit that can be exploited for further chemical modifications. These chemical modifications allow the tuning of the properties of the aliphatic polycarbonate in nearly any direction. Here we show synthetic routes to demonstrate that poly(limonene carbonate) is the perfect green platform polymer, from which many functional materials can be derived. The relevant examples presented in this study are the transformation from an engineering thermoplastic into a rubber, addition of permanent antibacterial activity, hydrophilization and even pH-dependent water solubility of the polycarbonate. Finally, we show a synthetic route to yield the completely saturated counterpart that exhibits improved heat processability due to lower reactivity. PMID:27302694

  5. Bio-based polycarbonate as synthetic toolbox

    Science.gov (United States)

    Hauenstein, O.; Agarwal, S.; Greiner, A.

    2016-06-01

    Completely bio-based poly(limonene carbonate) is a thermoplastic polymer, which can be synthesized by copolymerization of limonene oxide (derived from limonene, which is found in orange peel) and CO2. Poly(limonene carbonate) has one double bond per repeating unit that can be exploited for further chemical modifications. These chemical modifications allow the tuning of the properties of the aliphatic polycarbonate in nearly any direction. Here we show synthetic routes to demonstrate that poly(limonene carbonate) is the perfect green platform polymer, from which many functional materials can be derived. The relevant examples presented in this study are the transformation from an engineering thermoplastic into a rubber, addition of permanent antibacterial activity, hydrophilization and even pH-dependent water solubility of the polycarbonate. Finally, we show a synthetic route to yield the completely saturated counterpart that exhibits improved heat processability due to lower reactivity.

  6. Computational studies on ECE spectrum for ITER, in the presence of a small fraction of non-thermals and radial resolution evolution for oblique view

    Directory of Open Access Journals (Sweden)

    Subhash P.V.

    2015-01-01

    Full Text Available In tokamaks, the temperature measurement using different techniques like Electron Cyclotron Emission (ECE, Thomson scattering etc. shows differences because of various phenomena. The physical reasons for this are not entirely understood. Thus to have comprehensive understanding of these difference, the contribution from each phenomenon needs to be individually understood. The phenomenon affecting radial temperature profile measurement includes harmonics overlap, relativistic down shifting, presence of non-thermals etc. For ITER like plasma, radial temperature profiles can be obtained from the first harmonics ordinary (O mode or second harmonic extra-ordinary(X mode of ECE spectrum. It is possible that, higher harmonics produced from the non-thermals can be relativistically downshifted to second harmonics and results a deviation in the measured temperature profile. We performed a parametric study on the effect of non-thermal electrons on measured ECE temperature for ITER scenario-2. All the numerical calculations reported in this paper are performed using NOTEC computer code which is capable of handling non-thermal populations. After proper validation of numerical methods using normal electron population (without non-thermals a parametric study with non-thermals is performed. In the parametric study radial locations of non-thermals, energy of non-thermals and fraction of non-thermals are considered. This study is initially performed for normal view and later extended in to oblique views. The range of deviation of temperature over the examined parametric regime as well as the possible physical reasons will be presented. The effect of parallel component of non-thermal energy is also examined. Finally results of one set of study for oblique view (where the detector is not exactly normal to the magnetic field with non-thermal electrons are also presented. In ITER apart from an Electron Cyclotron Emission (ECE detector placed normal to magnetic field

  7. Upgraded ECE radiometer on the Tore Supra Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Segui, J.L.; Molina, D.; Goniche, M.; Maget, P.; Udintsev, V.S. [Association Euratom-CEA, Centre d' Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Antar, G.Y. [Center for Energy Research, UCSD, La Jolla CA (United States); Kraemer-Flecken, A. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Plasmaphysik

    2004-07-01

    An upgraded 32-channel heterodyne radiometer, 1 GHz spaced, is used on the Tore-Supra tokamak to measure the electron cyclotron emission (ECE) in the frequency range 78-110 GHz for the ordinary mode (O1) and 94-126.5 GHz for the extraordinary mode (X2). From now radial resolution is essentially limited by ECE relativistic effects related to electron temperature and density, not by the channels frequency spacing. For example, this leads to precise electron temperature mapping during magneto hydrodynamic activities (MHD). In the equatorial plane, we use a dual polarisation Gaussian optics lens antenna. It has low spreading and a perpendicular line-of-sight that gives ECE measurements very low refraction and Doppler effects. Assuming that the plasma is a black body and there is no overlap between ECE harmonics, one can deduce the electron temperature profile by using the first harmonic ordinary mode (O1) or the second harmonic extraordinary mode (X2). The principle radio frequency emitter (RF) has its frequencies down shifted into intermediary frequencies (IF) that span from 2 to 18 GHz in the single side band mode (SSB). It is amplified by low noise IF amplifiers before forming channels. A separate O/X mode RF front-end allows the use of an IF electronic mode selector. This gives the potentiality of simultaneous O/X mode measurements in the 94-110 GHz. RF and IF filters reject the gyrotron frequency (118 GHz) in order to perform electron temperature measurements during electron cyclotron resonance heated plasmas. A precise absolute spectral calibration is performed outside the tokamak vacuum vessel by using a 600 deg C black body hot source, a double coherent digital signal averaging (trigger, turn and clock) on the waveform generated by a mechanical chopper, and a simulated tokamak window. The use of differential electronics and strong electromagnetic shielding improves also the calibration precision. The fast and slow data acquisition systems are free of aliasing

  8. Shared Services: A Powerful Strategy to Support Sustainability of ECE Businesses

    Science.gov (United States)

    Stoney, Louise

    2009-01-01

    As Co-Founder of the Alliance for Early Childhood Finance, it is the author's job to think about how they pay for early care and education (ECE) services in the United States. Generating the operating revenue needed to establish and sustain a high-quality ECE program has never been easy--and in a recession economy it is becoming even more…

  9. Optical-Thickness Corrections to Transient Ece Temperature-Measurements in Tokamak and Stellarator Plasmas

    NARCIS (Netherlands)

    Peters, M.; Gorini, G.; Mantica, P.

    1995-01-01

    The conditions are examined under which optical thickness (tau) corrections to electron cyclotron emission (ECE) measurements of electron temperature (T-e) can be neglected. By means of simple algebra it is demonstrated that for measurements of T-e transients the ECE radiation temperature (T-rad) ca

  10. Shared Services: A Powerful Strategy to Support Sustainability of ECE Businesses

    Science.gov (United States)

    Stoney, Louise

    2009-01-01

    As Co-Founder of the Alliance for Early Childhood Finance, it is the author's job to think about how they pay for early care and education (ECE) services in the United States. Generating the operating revenue needed to establish and sustain a high-quality ECE program has never been easy--and in a recession economy it is becoming even more…

  11. Polycarbonate and co-continuous polycarbonate/ABS blends: influence of notch radius

    NARCIS (Netherlands)

    Inberg, J.P.F.; Gaymans, R.J.

    2002-01-01

    The influence of notch tip radius in the range of 1–0.002 mm was studied on polycarbonate (PC) and co-continuous PC/acrylonitrile–butadiene–styrene (ABS). Co-continuous PC/ABS blend was obtained by mixing PC and ABS containing 15% polybutadiene (PB) in a twin screw extruder. PC and PC/ABS specimens

  12. Morphology and Compatibility of Compatibilized Polyethersulfone and Polycarbonate Blends

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-bo; JIANG Dong; WU Wei-chun; JIANG Zhen-hua

    2005-01-01

    A PES-PC(polyethersulfone-polycarbonate) multi block random copolymer was synthesized with two oligomers, polyethersulfone and polycarbonate. The effects of the copolymer, as a compatibilizer, on the morphology and compatibility of the PES-PC blends were investigated. It was found that the addition of this copolymer to the PES-PC blends could improve their compatibility.

  13. Synthesis of copper nanoparticles in polycarbonate by ion implantation

    Indian Academy of Sciences (India)

    Annu Sharma; Suman Bahniwal; Sanjeev Aggarwal; S Chopra; D Kanjilal

    2011-07-01

    Copper nanoparticles have been synthesized in polycarbonate by 75 KeV Cu– ion implantation with various doses ranging from 6.4 × 1015 to 1.6 × 1017 ions/cm2 with a beam current density of 800 nA/cm2. The composites formed were structurally characterized using Ultraviolet-Visible (UV-Visible) absorption spectroscopy. The appearance of particle plasmon resonance peak, characteristic of copper nanoparticles at 603 nm in absorption spectra of polycarbonate implanted to a dose of 1.6 × 1017 ions/cm2, indicates towards the formation of copper nanoparticles in polycarbonate. Transmission electron microscopy further confirms the formation of copper nanoparticles having size ∼ 3.15 nm. The formation of copper nanoparticles in the layers carbonized by Cu– implantation has been discussed. The synthesized copper-polycarbonate nanocomposite has been found to be more conducting than polycarbonate as ascertained using current–voltage characteristics.

  14. Scratch resistance of a polycarbonate + organoclay nanohybrid

    Directory of Open Access Journals (Sweden)

    2009-10-01

    Full Text Available A polycarbonate-based nanohybrid has been created containing 1 wt% of Bentone 2010, an organically modified montmorillonite. A micro-section on the nanohybrid obtained using focused ion beam (FIB and field emission scanning electron microscopy (FESEM was employed to observe the orientation of the nanoclay inside a polycarbonate (PC matrix in the cross-section FIB-milled face. A micro-scratch tester was used to measure the scratch resistance in terms of residual (healing depth Rh under progressive load and in sliding wear. Effects of the number of scratches, normal load and scratch velocity have been evaluated as a function of nanoclay orientation. In sliding wear (multiple scratching along the same groove, our nanohybrid reaches residual depth values that remain constant after a certain number of scratches, a manifestation of strain hardening. The number of scratches to induce strain hardening decreases as the normal applied load increases. SEM was used to characterize deformation and wear mechanisms that operate on contacts and the results related to the wear data.

  15. Highly Conductive Multifunctional Graphene Polycarbonate Nanocomposites

    Science.gov (United States)

    Yoonessi, Mitra; Gaier, James R.

    2010-01-01

    Graphene nanosheet bisphenol A polycarbonate nanocomposites (0.027 2.2 vol %) prepared by both emulsion mixing and solution blending methods, followed by compression molding at 287 C, exhibited dc electrical percolation threshold of approx.0.14 and approx.0.38 vol %, respectively. The conductivities of 2.2 vol % graphene nanocomposites were 0.512 and 0.226 S/cm for emulsion and solution mixing. The 1.1 and 2.2 vol % graphene nanocomposites exhibited frequency-independent behavior. Inherent conductivity, extremely high aspect ratio, and nanostructure directed assembly of the graphene using PC nanospheres are the main factors for excellent electrical properties of the nanocomposites. Dynamic tensile moduli of nanocomposites increased with increasing graphene in the nanocomposite. The glass transition temperatures were decreased with increasing graphene for the emulsion series. High-resolution electron microscopy (HR-TEM) and small-angle neutron scattering (SANS) showed isolated graphene with no connectivity path for insulating nanocomposites and connected nanoparticles for the conductive nanocomposites. A stacked disk model was used to obtain the average particle radius, average number of graphene layers per stack, and stack spacing by simulation of the experimental SANS data. Morphology studies indicated the presence of well-dispersed graphene and small graphene stacking with infusion of polycarbonate within the stacks.

  16. Conceptual Design of the ITER ECE Diagnostic – An Update

    Directory of Open Access Journals (Sweden)

    Ouroua A.

    2012-09-01

    Full Text Available The ITER ECE diagnostic has recently been through a conceptual design review for the entire system including front end optics, transmission line, and back-end instruments. The basic design of two viewing lines, each with a single ellipsoidal mirror focussing into the plasma near the midplane of the typical operating scenarios is agreed upon. The location and design of the hot calibration source and the design of the shutter that directs its radiation to the transmission line are issues that need further investigation. In light of recent measurements and discussion, the design of the broadband transmission line is being revisited and new options contemplated. For the instruments, current systems for millimeter wave radiometers and broad-band spectrometers will be adequate for ITER, but the option for employing new state-of-the-art techniques will be left open.

  17. Study of high frequency MHD modes from ECE radiometer in Tore Supra

    Directory of Open Access Journals (Sweden)

    Dubuit N.

    2012-09-01

    Full Text Available Tore Supra ECE diagnostic has been recently upgraded to study MHD modes driven by energetic particles up to 400 kHz. To improve the measurement sensitivity, the ECE signals of the 32 channels radiometer were amplified just below the saturation limit and sources of noise were investigated in order to keep it as low as possible. With such an improvement, fast particle driven modes with frequencies up to 200 kHz were detected. A 4-channel correlation ECE system using YIG filters with tuneable frequency was also installed. It allows fine radial scans of MHD modes and correlation length measurements. For the two kinds of YIG filter in use, the minimum frequency separation between two ECE channels that could be achieved was established measuring the correlation coefficient between the respective radiation noises. Finally, by modelling the ECE radiometer taking into account the antenna radiation pattern and the vertical position of the ECE beam relative to the plasma centre we improved the data analysis tools, thus giving a better determination of the phase radial structure of ECE oscillations. The poloidal structure of MHD modes can then be identified from ECE data and, for off axis ECE lines of sight, the direction of the plasma rotation can also be determined. This method allows identifying the occurrence of an inverse cascade of electron fishbone modes ranging from m/n=4/4 to 1/1 (m and n are the poloidal and toroidal mode numbers, respectively which appears in lower hybrid current drive plasmas.

  18. Rheological properties of novel thermo-responsive polycarbonates aqueous solutions

    Institute of Scientific and Technical Information of China (English)

    王月霞; 谭业邦; 黄晓玲

    2008-01-01

    Thermo-responsive multiblock polycarbonates were facilely synthesized by covalently binding poly(ethylene glycol)(PEG) and poly(propylene glycol)(PPG) blocks,using triphosgene as coupling agent and pyridine as catalyst.The aqueous solutions of thermo-responsive polycarbonates were investigated by rheological measurements.Steady-state shear measurements reveal that the polycarbonate solutions exhibit shear-thinning behavior and the hydrophilic content has a pronounced effect on the flow behavior of the polycarbonates aqueous solutions.The shear viscosity decreases with increasing poly(ethylene oxide)(PEO) composition.The increase of viscosity with increasing concentration is probably attributed to the formation of stronger network owing to interchain entanglement of PEO block at higher concentration.When the flow curves are fitted to the power law model,flow index is obtained to be less than 1,as exhibiting typical pesudoplastic fluid.The viscoelastic properties of the system also show close dependence on the composition of polycarbonates.Temperature sweep confirms that the multiblock polycarbonates exhibit thermo-responsive properties.For 7% aqueous solution of polycarbonate with composition ratio of EO to PO of 1/1,the sol-gel transition occurs at 37 ℃,which makes the system suitable as an injectable drug delivery system.

  19. A polycarbonate ophthalmic-prescription lens series.

    Science.gov (United States)

    Davis, J K

    1978-08-01

    Improvements in polycarbonate material, production techniques, and scratch-resistant coatings, combined with a process-oriented design, have resulted in a precision lens series. Surface quality is comparable to that of untreated glass ophthalmic lenses. The repeatability of the process results in closely controlled axial power and off-axis performance. For most lens prescriptions, the ANSI Z80.1 optical-center specifications for prescription accuracy are maintained through a total field of view of 40 deg for an 8-mm range of center-of-rotation distances. Off-axis astigmatism is controlled for near-point seeing. The lenses are both lighter and thinner than those of crown glass. A scratch-resistant coating reduces the reflections normally associated with high-index (1.586) materials. Impact resistance exceeds that required by ANSI Z80.7 and is many times that required by ANSI Z80.1.

  20. Technical feasibility study on polycarbonate solar panels

    Energy Technology Data Exchange (ETDEWEB)

    Hackmann, M.M.; Meuwissen, M.H.H.; Bots, T.L.; Buijs, J.A.H.M. [TNO Industrial Technology, Eindhoven (Netherlands); Broek, K.M.; Kinderman, R. [Energy Research Center of the Netherlands, Petten (Netherlands); Tanck, O.B.F.; Schuurmans, F.M. [Shell Solar Energy, Helmond (Netherlands)

    2004-10-01

    This paper describes a technical feasibility study on the application of polycarbonate (PC) plates in a superstrate photovoltaic module design. The lamination process was performed in a conventional laminator apparatus using low temperature curing (100{sup o}C) ethylene-vinyl-acetate (EVA) as the potting material and multi-crystalline silicon-solar cells. Thermo-mechanical calculations via the finite element method were performed to support the experimental results on various layer set-ups. Both experimental and numerical results revealed that PC superstrate laminates display a certain degree of warpage after the lamination process. This warpage can be attributed to stress built up in the modules due to differences in thermal expansion between solar cells and PC. This stress build-up can be diminished by application of thicker layers of PC or EVA leading to less curved laminates. (author)

  1. Migration of bisphenol A from polycarbonate plastic of different qualities

    DEFF Research Database (Denmark)

    Pedersen, Gitte Alsing; Hvilsted, Søren; Petersen, Jens Højslev

    The study covers a review of literature and available industry information regarding release of bisphenol A from polycarbonate and the parameters affecting this bisphenol A release. Moreover in part two of the study, different samples of polycarbonate was characterised and analysed in order...... to examine the potential correlation between material specific parameters and the release of bisphenol A. It is concluded, from industry information, that only highly pure reagent grade chemicals, including additives, should be used for all polycarbonate grades to reduce photodegradation and hydrothermal...

  2. Pitfalls in Using Limitation Clauses in the International General Conditions ECE 188 and Orgalime S 2000

    DEFF Research Database (Denmark)

    Henschel, Rene Franz

    2008-01-01

    The article centers on the rules on the limitation of liability in the general conditions ECE 188 and Orgalime S 2000. ECE 188 differ considerably from S 2000, as the provisions in ECE 188 do not give the necessary consideration to the development in industry practices and legal rules, including...... the approximation and harmonization of legal systems that have taken place during the last 50 years. S 2000 reflects an international trend that increasingly recognizes the importance of striking a balance between the interests of the parties. However, in practice the parties often derogate considerably from......-balanced system with the result that the seller may end up being fully liable for any loss suffered. This is clearly reflected in national case law. International general conditions such as ECE 188 and Orgalime S 2000 should be applied with great caution, so that the parties avoid the pitfalls illustrated...

  3. Combining phylogenetic and syntenic analyses for understanding the evolution of TCP ECE genes in eudicots.

    Science.gov (United States)

    Citerne, Hélène L; Le Guilloux, Martine; Sannier, Julie; Nadot, Sophie; Damerval, Catherine

    2013-01-01

    TCP ECE genes encode transcription factors which have received much attention for their repeated recruitment in the control of floral symmetry in core eudicots, and more recently in monocots. Major duplications of TCP ECE genes have been described in core eudicots, but the evolutionary history of this gene family is unknown in basal eudicots. Reconstructing the phylogeny of ECE genes in basal eudicots will help set a framework for understanding the functional evolution of these genes. TCP ECE genes were sequenced in all major lineages of basal eudicots and Gunnera which belongs to the sister clade to all other core eudicots. We show that in these lineages they have a complex evolutionary history with repeated duplications. We estimate the timing of the two major duplications already identified in the core eudicots within a timeframe before the divergence of Gunnera and after the divergence of Proteales. We also use a synteny-based approach to examine the extent to which the expansion of TCP ECE genes in diverse eudicot lineages may be due to genome-wide duplications. The three major core-eudicot specific clades share a number of collinear genes, and their common evolutionary history may have originated at the γ event. Genomic comparisons in Arabidopsis thaliana and Solanumlycopersicum highlight their separate polyploid origin, with syntenic fragments with and without TCP ECE genes showing differential gene loss and genomic rearrangements. Comparison between recently available genomes from two basal eudicots Aquilegiacoerulea and Nelumbonucifera suggests that the two TCP ECE paralogs in these species are also derived from large-scale duplications. TCP ECE loci from basal eudicots share many features with the three main core eudicot loci, and allow us to infer the makeup of the ancestral eudicot locus.

  4. TIMAP-protein phosphatase 1-complex controls endothelin-1 production via ECE-1 dephosphorylation.

    Science.gov (United States)

    Boratkó, Anita; Veréb, Zoltán; Petrovski, Goran; Csortos, Csilla

    2016-04-01

    Endothelin induced signaling pathways can affect blood pressure and vascular tone, but the influence of endothelins on tumor cells is also significant. We have detected elevated endothelin-1 secretion from TIMAP (TGF-β inhibited membrane associated protein) depleted vascular endothelial cells. The autocrine signaling activated by the elevated endothelin-1 level through the ETB receptors evoked an angiogenic-like phenotype, the cells assumed an elongated morphology, and enhanced tube formation and wound healing abilities. The depleted protein, TIMAP, is a highly specific and abundant protein in the endothelial cells, and it is a regulatory/targeting subunit for the catalytic subunit of protein phosphatase 1 (PP1c). Protein-protein interaction between the TIMAP-PP1c complex and the endothelin converting enzyme-1 (ECE-1) was detected, the latter of which is a transmembrane protein that produces the biologically active 21-amino acid form of endothelin-1 from proendothelin. The results indicate that silencing of TIMAP induces a reduction in TIMAP-PP1c activity connected to ECE-1. This leads to an increase in the amount of ECE-1 protein in the plasma membrane and a consequent increase in endothelin-1 secretion. Similarly, activation of PKC, the kinase responsible for ECE-1 phosphorylation increased ECE-1 protein level in the membrane fraction of the endothelial cells. The elevated ECE-1 level was mitigated in time in normal cells, but was clearly preserved in TIMAP-depleted cells. Overall, our results indicate that PKC-phosphorylated ECE-1 is a TIMAP-PP1c substrate and this phosphatase complex has an important role in endothelin-1 production of EC through the regulation of ECE-1 activity.

  5. Preparation and Cytotoxicity of Novel Aliphatic Polycarbonate Synthesized from Dihydroxyacetone

    Institute of Scientific and Technical Information of China (English)

    Lian Sheng WANG; Xue Song JIANG; Hao WANG; Si Xue CHENG; Ren Xi ZHUO

    2005-01-01

    A new cyclic carbonate, 2,2-ethylenedioxypropane-1,3-diol carbonate (EOPDC), was synthesized through a two-step reaction from dihydroxyacetone dimer, and polymerized in bulk initiated by Sn(Oct)2 to give a high molecular weight polycarbonate. The structure of monomer and the polymer were characterized by FT-IR, 1H NMR, 13C NMR. The cytotoxicity of the obtained polycarbonate was investigated by MTT assay.

  6. Polycarbonate based three-phase nanocomposite dielectrics

    Science.gov (United States)

    Sain, P. K.; Goyal, R. K.; Prasad, Y. V. S. S.; Bhargava, A. K.

    2016-08-01

    Three-phase polycarbonate (PC) matrix nanocomposites are prepared using the solution method. One of the nanocomposite fillers is dielectric and the other is conducting. Lead zirconate titanate (PZT) is used as the dielectric filler. The conducting fillers, nano-Cu and multi-walled carbon nanotubes (MWCNTs), are used to make two different nanocomposites, MWCNT-PZT-PC and Cu-PZT-PC. The prepared nanocomposites are characterized using density measurement, x-ray diffractometry, scanning electron microscopy, energy dispersive x-ray spectroscopy, and differential scanning calorimetry. Percolation is absent in both three-phase nanocomposites within the study’s concentration window of conducting fillers. The dielectric properties of the nanocomposites are evaluated using a precision impedance analyser. The dielectric constant of the Cu-PZT-PC nanocomposite increases to 14 (a dissipation factor of 0.17), whereas in the case of the MWCNT-PZT-PC nanocomposite it increases to 8.5 (a dissipation factor of 0.002). The melting point of both nanocomposites decreases with respect to the control PC. The frequency (1 kHz to 1 MHz) and temperature (room temperature to 200 °C) dependence of the dielectric constant and dissipation factor are examined. For the Cu-PZT-PC nanocomposites, the dielectric constant decreases with increasing frequency, whereas in the case of the MWCNT-PZT-PC nanocomposites the dielectric constant is almost constant. The dielectric constant and dissipation factor exhibit a slight temperature dependence.

  7. Using Digital Resources for the ECE Curriculum in China: Current Needs and Future Development

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    2009-12-01

    Full Text Available Using digital resources is an important development in the Early Childhood Education (ECE curriculum in China. Guo and Wang (2005 report that 98% of urban ECE programs have computers with Internet connections, in addition to other technical facilities, which are used daily in ECE classrooms. However, the lack of curriculum-related digital resources and of a network to share them makes it difficult for teachers to share these resources for teaching. Further, this development of digital resources for ECE should consider Chinese cultures of learning (Jin & Cortazzi, 2006 in order to meet the needs of Chinese learners and maximize the learning effect. This paper focuses on the major features of digital resources in Chinese ECE and a framework for developing the content through examining existing digital resources and materials. Methods of inquiry and evaluation include the use of focus groups of kindergarten teachers in different provinces in China.The findings (Chen & Zhou, 2009; Zhou & Chen, 2009 indicate that an ECE digital resource should have features of individualization, interaction, sharing and sociability in networking in Chinese educational contexts, for supporting teaching design, practice, evaluation and reflection. An effective framework of ECE digital resources is recommended to contain three key parts:1 A Teacher Planning System to support teachers’ information searches, classified according to themes, subjects or types of activities.2 A Children’s Learning System to offer interactive learning at school or home following the classroom curriculum.3 A Family Support System to involve parents in their children’s learning and development.

  8. Nanostructured selenium for preventing biofilm formation on polycarbonate medical devices.

    Science.gov (United States)

    Wang, Qi; Webster, Thomas J

    2012-12-01

    Biofilms are a common cause of persistent infections on medical devices as they are easy to form and hard to treat. The objective of this study was for the first time to coat selenium (a natural element in the body) nanoparticles on the surface of polycarbonate medical devices (such as those used for medical catheters) and to examine their effectiveness at preventing biofilm formation. The size and distribution of selenium coatings were characterized using scanning electron microscopy and atomic force microscopy. The strength of the selenium coating on polycarbonate was assessed by tape-adhesion tests followed by atomic absorption spectroscopy. Results showed that selenium nanoparticles had a diameter of 50-100 nm and were well distributed on the polycarbonate surface. In addition, more than 50% of the selenium coating survived the tape-adhesion test as larger nanoparticles had less adhesion strength to the underlying polycarbonate substrate than smaller selenium nanoparticles. Most significantly, the results of this in vitro study showed that the selenium coatings on polycarbonate significantly inhibited Staphylococcus aureus growth to 8.9% and 27% when compared with an uncoated polycarbonate surface after 24 and 72 h, respectively. Importantly, this was accomplished without using antibiotics but rather with an element (selenium) that is natural to the human body. Thus, this study suggests that coating polymers (particularly, polycarbonate) with nanostructured selenium is a fast and effective way to reduce bacteria functions that lead to medical device infections. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 3205-3210, 2012.

  9. Syntheses of aliphatic polycarbonates from 2'-deoxyribonucleosides.

    Science.gov (United States)

    Suzuki, Masato; Sekido, Toyokazu; Matsuoka, Shin-ichi; Takagi, Koji

    2011-05-01

    Poly(2'-deoxyadenosine) and poly(thymidine) constructed of carbonate linkages were synthesized by polycondensation between silyl ether and carbonylimidazolide at the 3'- and 5'-positions of the 2'-deoxyribonucleoside monomers. The N-benzoyl-2'-deoxyadenosine monomer afforded the corresponding polycarbonate together with the cyclic oligomers. However, the deprotection of the N-benzoyl group resulted in the scission of the polymer main chain. Thus, the N-unprotected 2'-deoxyadenosine monomers were examined for polycondensation. However, there was involved the undesired reaction between the adenine amino group and the carbonylimidazolide to form the carbamate linkage. In order to exclude this unfavorable reaction, dynamic protection was employed. Strong hydrogen bonding was used in place of the usual covalent bonding for reducing the nucleophilicity of the adenine amino group. Herein, 3',5'-O-diacylthymidines that form the complementary hydrogen bonding with the adenine amino group were added to the polymerization system of the N-unprotected 2'-deoxyadenosine monomer. Consequently, although the oligomers (M(n) = 1000-1500) were produced, the contents of the carbamate group were greatly reduced. The dynamic protection reagents were easily and quantitatively recovered as the MeOH soluble parts from the polymerization mixtures. In the polycondensation of the thymidine monomer, there tended to be involved another unfavorable reaction of carbonate exchange, which consequently formed the irregular carbonate linkages at not only the 3'-5' but also the 3'-3' and 5'-5' positions. Employing the well-designed monomer suppressed the carbonate exchange reaction to produce poly(thymidine) with the almost regular 3'-5'carbonate linkages.

  10. EFFECT OF CHEMICAL STRUCTURE OF POLYCARBONATES ON ENTANGLEMENT SPACING

    Institute of Scientific and Technical Information of China (English)

    Wei Ning; Wen-xiang Zhu; Bao-qing Zhang; Chun-cheng Li; Chen-yang Liu; Du-jin Wang

    2012-01-01

    The master curves of a series of aliphatic polycarbonates (APCs) with different lengths of methylene segments in the repeat unit were obtained by dynamic rheological measurements.The plateau modulus and entanglement molecular weight were determined and cross-checked by different methods.Though having distinct difference in chemical structure of repeat units,both APCs and bisphenol-A polycarbonates have the similar entanglement weight and entanglement spacing.On the other side,the plateau modulus decreases with increasing the length of the side group of atiphatic polycarbonates with different side-chain lengths in the literature.The packing length model can explain the relationship between chain structure and entanglements.

  11. Design and first plasma measurements of the ITER-ECE prototype radiometer

    Science.gov (United States)

    Austin, M. E.; Brookman, M. W.; Rowan, W. L.; Danani, S.; Bryerton, E. W.; Dougherty, P.

    2016-11-01

    On ITER, second harmonic optically thick electron cyclotron emission (ECE) in the range of 220-340 GHz will supply the electron temperature (Te). To investigate the requirements and capabilities prescribed for the ITER system, a prototype radiometer covering this frequency range has been developed by Virginia Diodes, Inc. The first plasma measurements with this instrument have been carried out on the DIII-D tokamak, with lab bench tests and measurements of third through fifth harmonic ECE from high Te plasmas. At DIII-D the instrument shares the transmission line of the Michelson interferometer and can simultaneously acquire data. Comparison of the ECE radiation temperature from the absolutely calibrated Michelson and the prototype receiver shows that the ITER radiometer provides accurate measurements of the millimeter radiation across the instrument band.

  12. Standardbetingelser i nationale og internationale køb: ECE 188, NL 01 og S 2000

    DEFF Research Database (Denmark)

    Henschel, Rene Franz

    2006-01-01

    ECE 188, NL 01 og S 2000 hører blandt dansk erhvervslivs foretrukne standardbetingelser, når det gælder handel med maskiner og andet elektrisk, mekanisk og elektronisk udstyr. I artiklen gennemgås betingelsernes baggrund og formål, ligesom deres indbyrdes forskelle og ligheder beskrives. Endvidere...... analyseres forholdet til baggrundsretten og betingelsernes mulige status som udfyldende ret. Det konkluderes, at selvom hverken ECE 188, NL 01 eller S 2000 kan tages som udtryk for almindeligt gældende udfyldende regler, så spiller de dog en vigtig rolle bl.a. i forbindelse med fortolkning og ugyldighed....... Endvidere bør anvendelsen af ECE 188 nøje overvejes, til fordel for en anvendelse af NL 01 og S 2000. Udgivelsesdato: 01112006...

  13. A Nordic approach to Early Childhood Education (ECE) and socially endangered children

    DEFF Research Database (Denmark)

    Jensen, Bente

    2009-01-01

    system fails to provide equal social and intellectual opportunities to all children, further development in this area is required. Based on an analysis of the Nordic situation, a recent Danish intervention involving some 60 centres and 2.700 pre-school children and some preliminary results are presented......Summary In this paper I examine the Nordic model, i.e. a child-centred and holistic approach, in order to discuss Early Childhood Education (ECE) as a key policy instrument for fighting social inequality. Since 1999 it has been an important goal for the Danish government to ensure equal...... into the situation in the Nordic countries shows growing awareness of how to identify target groups for ECE-intervention as well as an increased focus on pre-school school teachers' education and the need for new assessment and evaluation methods for determining best practice. Since it would appear that the ECE...

  14. Development of KSTAR ECE imaging system for measurement of temperature fluctuations and edge density fluctuationsa)

    Science.gov (United States)

    Yun, G. S.; Lee, W.; Choi, M. J.; Kim, J. B.; Park, H. K.; Domier, C. W.; Tobias, B.; Liang, T.; Kong, X.; Luhmann, N. C.; Donné, A. J. H.

    2010-10-01

    The ECE imaging (ECEI) diagnostic tested on the TEXTOR tokamak revealed the sawtooth reconnection physics in unprecedented detail, including the first observation of high-field-side crash and collective heat transport [H. K. Park, N. C. Luhmann, Jr., A. J. H. Donné et al., Phys. Rev. Lett. 96, 195003 (2006)]. An improved ECEI system capable of visualizing both high- and low-field sides simultaneously with considerably better spatial coverage has been developed for the KSTAR tokamak in order to capture the full picture of core MHD dynamics. Direct 2D imaging of other MHD phenomena such as tearing modes, edge localized modes, and even Alfvén eigenmodes is expected to be feasible. Use of ECE images of the optically thin edge region to recover 2D electron density changes during L/H mode transitions is also envisioned, providing powerful information about the underlying physics. The influence of density fluctuations on optically thin ECE is discussed.

  15. Cadence Feedback With ECE PEDO to Monitor Physical Activity Intensity: A Pilot Study.

    Science.gov (United States)

    Ardic, Fusun; Göcer, Esra

    2016-03-01

    The purpose of this study was to examine the monitoring capabilities of the equipment for clever exercise pedometer (ECE PEDO) that provides audible feedback when the person exceeds the upper and lower limits of the target step numbers per minute and to compare step counts with Yamax SW-200 (YX200) as the criterion pedometer.A total of 30 adult volunteers (15 males and 15 females) were classified as normal weight (n = 10), overweight (n = 10), and obese (n = 10). After the submaximal exercise test on a treadmill, the moderate intensity for walking was determined by using YX200 pedometer and then the number of steps taken in a minute was measured. Lower and upper limits of steps per minute (cadence) were recorded in ECE PEDO providing audible feedback when the person's walking speed gets out of the limits. Volunteers walked for 30 minutes in the individual step count range by attaching the ECE PEDO and YX200 pedometer on both sides of the waist belt in the same session. Step counts of the volunteers were recorded. Wilcoxon, Spearman correlation, and Bland-Altman analyses were performed to show the relationship and agreement between the results of 2 devices.Subjects took an average of 3511 ± 426 and 3493 ± 399 steps during 30 minutes with ECE PEDO and criterion pedometer, respectively. About 3500 steps taken by ECE PEDO reflected that this pedometer has capability of identifying steps per minute to meet moderate intensity of physical activity. There was a strong correlation between step counts of both devices (P PEDO and YX200 pedometer in the Bland-Altman analysis.Although both devices showed a strong similarity in counting steps, the ECE PEDO provides monitoring of intensity such that a person can walk in a specified time with a desired speed.

  16. Mechanical and electrical properties of polycarbonate nanotube buckypaper composite sheets

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Giang T; Park, Young-Bin; Wang Shiren; Liang Zhiyong; Wang Ben; Zhang, Chuck [High-Performance Materials Institute (HPMI), Department of Industrial and Manufacturing Engineering, Florida A and M University, Florida State University College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310-6046 (United States); Funchess, Percy; Kramer, Leslie [Lockheed Martin Missiles and Fire Control-Orlando, Orlando, FL 32819-8907 (United States)], E-mail: gte640q@yahoo.com

    2008-08-13

    The thermogravimetric, mechanical, and electrical properties of composite sheets produced by infiltrating single-wall carbon nanotube films (also known as 'buckypapers') with polycarbonate solution were characterized. The composite sheets showed improved stiffness and toughness, while the electrical conductivity decreased, as compared to a neat buckypaper. In addition, polycarbonate/buckypaper composite sheets showed higher resistance to handling and processing damages. Experimental results suggest the viability of the infiltration process as a means to toughen buckypapers and to fabricate polymer/carbon nanotube composites having high nanotube concentration and controlled nanotube structure.

  17. Commissioning of inline ECE system within waveguide based ECRH transmission systems on ASDEX upgrade

    Directory of Open Access Journals (Sweden)

    Donné A.J.H.

    2012-09-01

    Full Text Available A CW capable inline electron cyclotron emission (ECE separation system for feedback control, featuring oversized corrugated waveguides, is commissioned on ASDEX upgrade (AUG. The system is based on a combination of a polarization independent, non-resonant, Mach-Zehnder diplexer equipped with dielectric plate beam splitters [2, 3] employed as corrugated oversized waveguide filter, and a resonant Fast Directional Switch, FADIS [4, 5, 6, 7] as ECE/ECCD separation system. This paper presents an overview of the system, the low power characterisation tests and first high power commissioning on AUG.

  18. 21 CFR 175.365 - Vinylidene chloride copolymer coatings for polycarbonate film.

    Science.gov (United States)

    2010-04-01

    ... polycarbonate film. 175.365 Section 175.365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section and applied on polycarbonate film may be safely used as food-contact surfaces,...

  19. Polycarbonates: a long-term highly sensitive radon monitor

    CERN Document Server

    Pressyanov, D; Poffijn, A; Meesen, G; Deynse, A V

    2000-01-01

    An approach for long-term (either retrospective or prospective) sup 2 sup 2 sup 2 Rn measurements is proposed that is based on the combination of the high radon absorption ability of some polycarbonates with their alpha track-etch properties. The detection limit is projected to be <10 Bq m sup - sup 3 for an exposure time of 20 yr.

  20. Disarming Contankerous People: Coping with Difficult Personalities in ECE Work Settings

    Science.gov (United States)

    Hernandez, Luis; Smith, Connie Jo

    2009-01-01

    Difficult personalities come in a variety of roles in just about every setting. While types have been identified in the typical corporate and business culture, difficult work personalities also inhabit the world of early childhood education (ECE) workplaces. Because difficult people have an impact on workplace morale and productivity, the topic…

  1. Detailed Analysis of Language Development of Preschool Children in ECE Program. Technical Report No. 4.

    Science.gov (United States)

    Hines, Brainard W.

    This report is concerned with the language skills category of objectives of the Early Childhood Education (ECE) Program. The Illinois Test of Psycholinguistic Ability (ITPA) was the primary instrument used for evaluation of 3-, 4-, and 5-year-old children in three treatment groups: (1) mobile educational facility, TV, and paraprofessional, (2) TV…

  2. Results of an ECE Varying Degrees of Corrosion and Time of Application of the Technique

    Directory of Open Access Journals (Sweden)

    Espericueta-González D.E.

    2012-10-01

    Full Text Available The objective of the Electrochemical Chloride Extraction (ECE is to remove the chloride ions (Cl- which are embedded in concrete, since these ions are considered to result in accelerating the process of corrosion in steel reinforcement. The ECE is an electrochemical technique in which ions Cl- are transported to the outside of the concrete by means of an electric field. In this paper we present the results of mortar samples made in the laboratory. The specimens were previously contaminated with 2% NaCl by mass of cement, and stored in water curing tanks at constant laboratory of 95% RH for one and sixty days. Afterward, mortars underwent an ECE in times of 15, 30 and 60 days of treatment. The results obtained under these conditions show that increasing the duration of the ECE will get a higher amount of Cl-ions removed from the mortar. It should be noted that the extent of the corroded reinforcement is a critical variable in the effectiveness of the technique.

  3. Commissioning of inline ECE system within waveguide based ECRH transmission systems on ASDEX upgrade

    DEFF Research Database (Denmark)

    Bongers, W. A.; Kasparek, W.; Doelman, N.;

    2012-01-01

    with dielectric plate beam splitters [2, 3] employed as corrugated oversized waveguide filter, and a resonant Fast Directional Switch, FADIS [4, 5, 6, 7] as ECE/ECCD separation system. This paper presents an overview of the system, the low power characterisation tests and first high power commissioning on AUG....

  4. Disarming Contankerous People: Coping with Difficult Personalities in ECE Work Settings

    Science.gov (United States)

    Hernandez, Luis; Smith, Connie Jo

    2009-01-01

    Difficult personalities come in a variety of roles in just about every setting. While types have been identified in the typical corporate and business culture, difficult work personalities also inhabit the world of early childhood education (ECE) workplaces. Because difficult people have an impact on workplace morale and productivity, the topic…

  5. Water heating solar system using collector with polycarbonate absorber surface

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiz Guilherme Meira de; Sodre, Dilton; Cavalcanti, Eduardo Jose Cidade; Souza, Luiz Guilherme Vieira Meira de; Mendes, Jose Ubiragi de Lima [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)], e-mails: lguilherme@dem.ufrn.br, diltonsodre@ifba.edu.br, ubiragi@ct.ufrn.br

    2010-07-01

    It is presented s solar collector to be used in a heating water for bath system, whose main characteristics are low cost and easy fabrication and assembly processes. The collector absorber surface consists of a polycarbonate plate with an area of 1.5 m{sup 2}. The water inlet and outlet are made of PVC 50mm, and were coupled to a 6mm thick polycarbonate plate using fiberglass resin. A 200 liters thermal reservoir will be used. This reservoir is also alternative. The absorber heating system works under thermo-siphon regimen. Thermal parameters will be evaluated to prove the feasibility of the studied solar heating system to obtain bath water for a four people family. (author)

  6. Improvement program for polycarbonate capacitors. [hermetically sealed, and ac wound

    Science.gov (United States)

    Bailey, R. R.; Waterman, K. D.

    1973-01-01

    Hermetically sealed, wound, AC, polycarbonate capacitors incorporating design improvements recommended in a previous study were designed and built. A 5000 hour, 400 Hz ac life test was conducted using 384 of these capacitors to verify the adequacy of the design improvements. The improvements incorporated in the capacitors designed for this program eliminated the major cause of failure found in the preceding work, termination failure. A failure cause not present in the previous test became significant in this test with capacitors built from one lot of polycarbonate film. The samples from this lot accounted for 25 percent of the total test complement. Analyses of failed samples showed that the film had an excessive solvent content. This solvent problem was found in 37 of the total 46 failures which occurred in this test. The other nine were random failures resulting from causes such as seal leaks, foreign particles, and possibly wrinkles.

  7. Domain Structures in Nematic Liquid Crystals on a Polycarbonate Surface

    Directory of Open Access Journals (Sweden)

    Vasily F. Shabanov

    2013-08-01

    Full Text Available Alignment of nematic liquid crystals on polycarbonate films obtained with the use of solvents with different solvations is studied. Domain structures occurring during the growth on the polymer surface against the background of the initial thread-like or schlieren texture are demonstrated. It is established by optical methods that the domains are stable formations visualizing the polymer surface structures. In nematic droplets, the temperature-induced transition from the domain structure with two extinction bands to the structure with four bands is observed. This transition is shown to be caused by reorientation of the nematic director in the liquid crystal volume from the planar alignment to the homeotropic state with the pronounced radial configuration of nematic molecules on the surface. The observed textures are compared with different combinations of the volume LC orientations and the radial distribution of the director field and the disclination lines at the polycarbonate surface.

  8. Migration of 2-butoxyethyl acetate from polycarbonate infant feeding bottles

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Lund, K.H.

    2003-01-01

    An enforcement campaign was carried out to assess the migration of 2-butoxyethyl acetate (2-BEA) from polycarbonate infant feeding bottles intended for repeated use. Migration was measured by three successive migration tests into two of the European Union official food simulants: distilled water...... and 3% acetic acid testing at 40degrees C for 10 days. The Danish Veterinary and Food Administration (DVFA) has assessed that a migration above 0.33 mg for 2-BEA and a group of eight related substances kg(-1) foodstuff from plastics articles used exclusively for infants is unacceptable. Migration of 2......-BEA was found from eight of 12 bottles. However, migration above the target value of 0.33 mg kg(-1) was not observed in the third decisive test from any of the 12 different brands of polycarbonate feeding bottles. A migration of between 0.05 and 0.26 mg kg(-1) from seven of 12 bottles was measured...

  9. Use of polycarbonate plastic products and human health

    OpenAIRE

    R. K. Srivastava; Sushila Godara

    2013-01-01

    As plastic and plastic products are being used in day to day at the cost of environment pollution, the human and wild life health and has become a global concern. Researchers found link between abnormal liver enzymes in the people and Bisphenol-A (BPA). Changes in insulin resistance, reproduction system, cardiovascular and brain function are also reported. BPA is used in the production of epoxy resins, polycarbonate resins, and polyester resins. BPA can leach out of certain plastic products i...

  10. Nano-indentation of Polycarbonate and Diamine Blends

    Science.gov (United States)

    Ahuja, Suresh

    2012-02-01

    Nanoindentation of complex surfaces is of great interest from academic and industrial point of view. There are unique properties such as indentation effects resulting in strain softening and strain hardening. There is a differentiation in structure with the depth exhibited with variation of Tg. Hertzian and non-linear deformation models including usage of FEM offer opportunity in analyzing nano-indentation. In polycarbonate, the effective elastic modulus and the hardness decreases as the applied load is increased. As the hold time was increased, the effective elastic modulus and the hardness also decreased. The contact stress increases as the contact strain rate is increased. Presence of diamine(MTBD) in polycarbonate results in making the surface and bulk brittle and acts as an anti-plasticizer by increasing it modulus and reducing yield stress (hardness) and strain to break. Data on modulus and hardness of polycarbonate and blends of diamine as function of depth (strain) and strain rate are presented and compared with those of composites with silica.

  11. Electrochemical impedimetric biosensor based on a nanostructured polycarbonate substrate

    Directory of Open Access Journals (Sweden)

    Chen YS

    2012-01-01

    Full Text Available Yu-Shan Chen1, Chia-Che Wu1, Jaw-Ji Tsai2, Gou-Jen Wang1,31Department of Mechanical Engineering, National Chung-Hsing University, 2Department of Medical Education and Research, Taichung Veterans General Hospital, 3Graduate Institute of Biomedical Engineering, National Chung-Hsing University, Taichung, TaiwanAbstract: This study integrates the techniques of nanoelectroforming, hot-embossing, and electrochemical deposition to develop a disposable, low-cost, and high sensitivity nanostructure biosensor. A modified anodic aluminum oxide barrier-layer surface was used as the template for thin nickel film deposition. After etching the anodic aluminum oxide template off, a three-dimensional mold of the concave nanostructure array was created. The fabricated three-dimensional nickel mold was further used for replica molding of a nanostructure polycarbonate substrate by hot-embossing. A thin gold film was then sputtered onto the polycarbonate substrate to form the electrode, followed by deposition of an orderly and uniform gold nanoparticle layer on the three-dimensional gold electrode using electrochemical deposition. Finally, silver nanoparticles were deposited on the uniformly deposited gold nanoparticles to enhance the conductivity of the sensor. Electrochemical impedance spectroscopy analysis was then used to detect the concentration of the target element. The sensitivity of the proposed scheme on the detection of the dust mite antigen, Der p2, reached 0.1 pg/mL.Keywords: nanoelectroforming, nanostructure polycarbonate substrate, gold nanoparticles, silver nanoparticles, electrochemical impedance spectroscopy

  12. The effect of pulse current on energy saving during Electrochemical Chloride Extraction (ECE) in concrete

    DEFF Research Database (Denmark)

    Sun, Tian R.; Geiker, Mette R.; Ottosen, Lisbeth M.

    2012-01-01

    Energy consumption is a factor influencing the cost of Electrochemical Chloride Extraction (ECE) in concrete. The aims of this work were to investigate the possibility for energy saving when using a pulsed electric field during ECE and the effect of the pulsed current on removal of chloride. Four...... experiments with artificially polluted concrete under same charge transfer were conducted. Results showed that the energy consumption was decreased 15% by pulse current in experiments with 0.2 mA/cm2 current density, which was higher than that of 0.1 mA/cm2 experiments with a decrease of 9.6%. When comparing...... the voltage drop at different parts of the experimental cells, it was found that the voltage drop of the area across the concrete was the major contributor to energy consumption, and results indicated that the pulse current could decrease the voltage drop of this part by re-distribution of ions in pore fluid...

  13. Quasi 3D ECE imaging system for study of MHD instabilities in KSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Yun, G. S., E-mail: gunsu@postech.ac.kr; Choi, M. J.; Lee, J.; Kim, M.; Leem, J.; Nam, Y.; Choe, G. H. [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Lee, W.; Park, H. K. [Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Park, H.; Woo, D. S.; Kim, K. W. [School of Electrical Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Domier, C. W.; Luhmann, N. C. [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Ito, N. [KASTEC, Kyushu University, Kasuga-shi, Fukuoka 812-8581 (Japan); Mase, A. [Ube National College of Technology, Ube-shi, Yamaguchi 755-8555 (Japan); Lee, S. G. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2014-11-15

    A second electron cyclotron emission imaging (ECEI) system has been installed on the KSTAR tokamak, toroidally separated by 1/16th of the torus from the first ECEI system. For the first time, the dynamical evolutions of MHD instabilities from the plasma core to the edge have been visualized in quasi-3D for a wide range of the KSTAR operation (B{sub 0} = 1.7∼3.5 T). This flexible diagnostic capability has been realized by substantial improvements in large-aperture quasi-optical microwave components including the development of broad-band polarization rotators for imaging of the fundamental ordinary ECE as well as the usual 2nd harmonic extraordinary ECE.

  14. Preliminary study of ECE imaging concept for W7-X, using the Talbot effect in rectangular waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Daniel; Plaum, Burkhard; Kasparek, Walter; Hirth, Thomas [IGVP, Universitaet Stuttgart (Germany); Hirsch, Matthias [Max-Planck Institut fuer Plasmaphysik, Greifswald (Germany)

    2016-07-01

    For spatially resolved measurements of Electron Cyclotron Emission (ECE) in W7-X, an imaging antenna based on a corrugated rectangular waveguide can be used. The imaging characteristics of the antenna allow a simultaneous operation at multiple angles and frequencies. As a result it is possible to localize a set of points inside the plasma, where the ECE can be measured without the need of mobile components facing the plasma.

  15. Precision and Resolution on Tore-Supra Ece Electron Temperature Profile Measurements

    Science.gov (United States)

    Ségui, J. L.; Molina, D.; Goniche, M.

    2003-02-01

    A 16-channel heterodyne radiometer, 2 GHz spaced, is used on Tore-Supra to measure the electron cyclotron emission in the frequency range 78-110 GHz for the O mode and 94 -126 GHz for the Xmode. In the equatorial plane, a dual polarisation gaussian optics lens antenna, with a perpendicular line of sight (with respect to the magnetic field), gives ECE measurements with very low refraction and Doppler effects. A separate O/X mode RF front-end allows the use of an IF electronic mode selector. This improves time stability calibration and gives the potentiality of simultaneous O/X mode measurements in the 94 -110 Ghz RF band for polarisation studies. RF and IF filters reject the gyrotron frequency (118 Ghz) in order to perform temperature measurements during ECRH plasmas. A precise absolute spectral calibration is performed outside the vacuum vessel by using a 600°C black body, a digital signal averaging on the waveform generated by a mechanical chopper placed directly in front of it, and a simulation window without Fabry-Pérot effects. The calibration precision leads to ECE temperature profiles which are very consistent with Thomson scattering measurements and guarantees a good stability of the ECE profiles for small changes on the magnetic field (absolute precision +/-6%, relative precision between channels +/-3%). Post-pulse data processing takes routinely into account the total magnetic field (Bvacuum with ripple, Bpara, Bdia, Bpol, all with analytical formulations), the radial relativistic shift (analytical formulation is used), the refractionREFID="9789812705082_0032FN001"> (cut-offs detection with safety margin to avoid strong refraction), the nonthermal ECE spectraREFID="9789812705082_0032FN001"> during LHCD (using an electron density threshold criterion). These previous analytical formulations are compatible with real time processing. Relativistic radial broadening simulations show that it is useful to fulfil 32 channels (1GHz spaced).

  16. Engineering aspects of design and integration of ECE diagnostic in ITER

    Directory of Open Access Journals (Sweden)

    Udintsev V.S.

    2015-01-01

    Full Text Available ITER ECE diagnostic [1] needs not only to meet measurement requirements, but also to withstand various loads, such as electromagnetic, mechanical, neutronic and thermal, and to be protected from stray ECH radiation at 170 GHz and other millimeter wave emission, like Collective Thomson scattering which is planned to operate at 60 GHz. Same or similar loads will be applied to other millimetre-wave diagnostics [2], located both in-vessel and in-port plugs. These loads must be taken into account throughout the design phases of the ECE and other microwave diagnostics to ensure their structural integrity and maintainability. The integration of microwave diagnostics with other ITER systems is another challenging activity which is currently ongoing through port integration and in-vessel integration work. Port Integration has to address the maintenance and the safety aspects of diagnostics, too. Engineering solutions which are being developed to support and to operate ITER ECE diagnostic, whilst complying with safety and maintenance requirements, are discussed in this paper.

  17. Synthesis of NLO polycarbonates via the ring-opening polymerization of macrocyclic prepolymers

    Science.gov (United States)

    Kulig, Joseph B.; Moore, Collin G.; Brittain, William J.; Gilmour, Sandra; Perry, Joseph W.

    1994-05-01

    The synthesis and characterization of polycarbonates and polyformals is described. Copolymers of bisphenol A (BPA) and either a triphenyloxazole (1) or phenylquinoxaline (2) monomer were prepared. The polycarbonate copolymers were prepared by ring-opening polymerization of macrocyclic prepolymers using a solvent-free process. Preliminary electro- optic measurements have been performed on the polycarbonate copolymers of BPA and 1. Polyformals have also been prepared by a conventional polymerization process involving the reaction of dichloromethane with different feed ratios of BPA and either 1 or 2. The glass transition temperature of either the polyformals or polycarbonates is dramatically increased by increasing mole fractions of monomers 1 and 2.

  18. Modification of Low Refractive Index Polycarbonate for High Refractive Index Applications

    Directory of Open Access Journals (Sweden)

    Gunjan Suri

    2009-01-01

    Full Text Available Polycarbonates and polythiourethanes are the most popular materials in use today, for optical applications. Polycarbonates are of two types which fall in the category of low refractive index and medium refractive index. The present paper describes the conversion of low refractive index polycarbonates into high refractive index material by the use of a high refractive index monomer, polythiol, as an additive. Novel polycarbonates, where the properties of refractive index and Abbe number can be tailor made, have been obtained. Thermal studies and refractive index determination indicate the formation of a new polymer with improved properties and suitable for optical applications.

  19. Morphology Evolution of Polycarbonate-Polystyrene Blends During Compounding

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, Kristoffer; Johannsen, Ib;

    2001-01-01

    The morphology evolution of polycarbonate-polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, re-melt blending in a twin-screw extruder and tri-melt blending in an injection-moulding machine, was investigated using......-empirical model. The results show that the formation of co-continuous morphology strongly depends on blend composition and melt blending method, whereas the model prediction for phase inversion deviates from the experimental values. Further, we found that the initial mechanism of morphology evolution involves...

  20. Standard specification for architectural flat glass clad polycarbonate

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This specification covers the quality requirements for cut sizes of glass clad polycarbonate (GCP) for use in buildings as security, detention, hurricane/cyclic wind-resistant, and blast and ballistic-resistant glazing applications. 1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  1. Comparison of polycarbonate and cellulose acetate membrane filters for isolation of Campylobacter concisus from stool samples

    DEFF Research Database (Denmark)

    Linde Nielsen, Hans; Engberg, Jørgen; Ejlertsen, Tove

    2013-01-01

    One thousand seven hundred ninety-one diarrheic stool samples were cultivated for Campylobacter spp. We found a high prevalence of Campylobacter concisus with use of a polycarbonate filter (n = 114) compared to a cellulose acetate filter (n = 79) (P < .0001). The polycarbonate filter is superior ...

  2. Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating

    NARCIS (Netherlands)

    Ehlert, K.A.; Beumer, C.W.E.; Groot, M.C.E.

    2008-01-01

    A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after micro

  3. An Experimental Study of Bulge-Forming Polycarbonate (PC)Semisphere Shell Parts

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, a new bulge-forming technology is described to manufacture a polycarbonate semisphere shell. Some experiments have been done, and the experimental results show that this technique is feasible to form polycarbonate part. But the wall thickness distribution of the bulged specimen by this method is not so even.

  4. Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating

    NARCIS (Netherlands)

    Ehlert, K.A.; Beumer, C.W.E.; Groot, M.C.E.

    2008-01-01

    A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after

  5. Comparison of the regulated air pollutant emission characteristics of real-world driving cycle and ECE cycle for motorcycles

    Science.gov (United States)

    Chiang, Hung-Lung; Huang, Pei-Hsiu; Lai, Yen-Ming; Lee, Ting-Yi

    2014-04-01

    Motorcycles are an important means of transportation, and their numbers have increased significantly in recent years. However, motorcycles can emit significant amounts of air pollutants; therefore, the emission characteristics and driving patterns of motorcycles are necessary baseline information for the implementation of control measures for motorcycles in urban areas. The selected motorcycles were equipped with global positioning systems (GPS) to obtain speed-time data for determination of the characteristics of real-world driving parameters, and an on-board exhaust gas analyser with data logger was employed to determine the instantaneous concentration of regulated air pollutants from motorcycle exhaust. Results indicated that the time proportions of acceleration, cruising, and deceleration are different from those of the Economic Commission for Europe (ECE) driving cycle, and the time percentages of acceleration and deceleration of the ECE cycle are much less than those in Taichung city. In general, the emission factors of the Taichung motorcycle driving cycle (TMDC) were higher HC and lower NOx emission than those of the ECE cycle. The average fuel consumption of tested motorcycles on three roads during workdays was 5% higher than that on weekends. The fuel consumption in the real-world motorcycle driving cycle was also about 7% higher than that of the ECE cycle, which again indicates that the ECE cycle is unsuitable for measuring fuel consumption in the Taichung metropolitan area. Therefore, understanding the local driving cycle is necessary for developing accurate emission data for air pollution control measures for urban areas.

  6. Interdiffusion of Polycarbonate in Fused Deposition Modeling Welds

    Science.gov (United States)

    Seppala, Jonathan; Forster, Aaron; Satija, Sushil; Jones, Ronald; Migler, Kalman

    2015-03-01

    Fused deposition modeling (FDM), a now common and inexpensive additive manufacturing method, produces 3D objects by extruding molten polymer layer-by-layer. Compared to traditional polymer processing methods (injection, vacuum, and blow molding), FDM parts have inferior mechanical properties, surface finish, and dimensional stability. From a polymer processing point of view the polymer-polymer weld between each layer limits the mechanical strength of the final part. Unlike traditional processing methods, where the polymer is uniformly melted and entangled, FDM welds are typically weaker due to the short time available for polymer interdiffusion and entanglement. To emulate the FDM process thin film bilayers of polycarbonate/d-polycarbonate were annealed using scaled times and temperatures accessible in FDM. Shift factors from Time-Temperature Superposition, measured by small amplitude oscillatory shear, were used to calculate reasonable annealing times (min) at temperatures below the actual extrusion temperature. The extent of interdiffusion was then measured using neutron reflectivity. Analogous specimens were prepared to characterize the mechanical properties. FDM build parameters were then related to interdiffusion between welded layers and mechanical properties. Understating the relationship between build parameters, interdiffusion, and mechanical strength will allow FDM users to print stronger parts in an intelligent manner rather than using trial-and-error and build parameter lock-in.

  7. Electrical properties and dielectric spectroscopy of Ar+ implanted polycarbonate

    Science.gov (United States)

    Chawla, Mahak; Shekhawat, Nidhi; Aggarwal, Sanjeev; Sharma, Annu; Nair, K. G. M.

    2015-05-01

    The aim of the present paper is to study the effect of argon ion implantation on electrical and dielectric properties of polycarbonate. Specimens were implanted with 130 keV Ar+ ions in the fluence ranging from 1×1014 to 1×1016 ions cm-2. The beam current used was ˜0.40 µA cm-2. The electrical conduction behaviour of virgin and Ar+ implanted polycarbonate specimens have been studied through current-voltage (I-V characteristic) measurements. It has been observed that after implantation conductivity increases with increasing ion fluence. The dielectric spectroscopy of these specimens has been done in the frequency range of 100 kHz-100 MHz. Relaxation processes were studied by Cole-Cole plot of complex permittivity (real part of complex permittivity, ɛ' vs. imaginary part of complex permittivity, ɛ″). The Cole-Cole plots have also been used to determine static dielectric constant (ɛs), optical dielectric constant (ɛ∞), spreading factor (α), average relaxation time (τ0) and molecular relaxation time (τ). The dielectric behaviour has been found to be significantly affected due to Ar+ implantation. The possible correlation between this behaviour and the changes induced by the implantation has been discussed.

  8. Experimental study on dynamic mechanical behaviors of polycarbonate

    Science.gov (United States)

    Zhang, Wei; Gao, Yubo; Ye, Nan; Huang, Wei; Li, Dacheng

    2017-01-01

    Polycarbonate (PC) is a widely used engineering material in aerospace field, since it has excellent mechanical and optical property. In present study, both compressive and tensile tests of PC were conducted at high strain rates by using a split Hopkinson pressure bar. The high-speed camera and 2D Digital Image Correlation method (DIC) were used to analyze the dynamic deformation behavior of PC. Meanwhile, the plate impact experiment was carried out to measure the equation of state of PC in a single-stage gas gun, which consists of asymmetric impact technology, manganin gauges, PVDF, electromagnetic particle velocity gauges. The results indicate that the yield stress of PC increased with the strain rates in both dynamic compression and tension tests. The same phenomenon was similar to elasticity modulus at different strain rate. A constitutive model was used to describe the mechanical behaviors of PC accurately in different strain rates by contrast with the results of 2D-DIC. At last, The D-u Hugoniot curve of polycarbonate in high pressure was fitted by the least square method.

  9. Explosion Testing of a Polycarbonate Safe Haven Wall

    Science.gov (United States)

    Perry, Kyle A.; Meyr, Rex A.

    2016-12-01

    The MINER Act of 2006 was enacted by MSHA following the major mining accidents and required every underground coal mine to install refuge areas to help prevent future fatalities of trapped miners in the event of a disaster where the miners cannot escape. A polycarbonate safe haven wall for use in underground coal mines as component of a complete system was designed and modeled using finite element modeling in ANSYS Explicit Dynamics to withstand the MSHA required 15 psi (103.4 kPa) blast loading spanning 200 milliseconds. The successful design was constructed at a uniform height in both half-width scale and quarter-width scale in the University of Kentucky Explosives Research Team's (UKERT) explosives driven shock tube for verification of the models. The constructed polycarbonate walls were tested multiple times to determine the walls resistance to pressures generated by an explosion. The results for each test were analyzed and averaged to create one pressure versus time waveform which was then imported into ANSYS Explicit Dynamics and modeled to compare results to that which was measured during testing for model validation. This paper summarizes the results.

  10. Broad-spectrum antimicrobial polycarbonate hydrogels with fast degradability.

    Science.gov (United States)

    Pascual, Ana; Tan, Jeremy P K; Yuen, Alex; Chan, Julian M W; Coady, Daniel J; Mecerreyes, David; Hedrick, James L; Yang, Yi Yan; Sardon, Haritz

    2015-04-13

    In this study, a new family of broad-spectrum antimicrobial polycarbonate hydrogels has been successfully synthesized and characterized. Tertiary amine-containing eight-membered monofunctional and difunctional cyclic carbonates were synthesized, and chemically cross-linked polycarbonate hydrogels were obtained by copolymerizing these monomers with a poly(ethylene glycol)-based bifunctional initiator via organocatalyzed ring-opening polymerization using 1,8-diazabicyclo[5.4.0]undec-7-ene catalyst. The gels were quaternized using methyl iodide to confer antimicrobial properties. Stable hydrogels were obtained only when the bifunctional monomer concentration was equal to or higher than 12 mol %. In vitro antimicrobial studies revealed that all quaternized hydrogels exhibited broad-spectrum antimicrobial activity against Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), Pseudomonas aeruginosa (Gram-negative), and Candida albicans (fungus), while the antimicrobial activity of the nonquaternized hydrogels was negligible. Moreover, the gels showed fast degradation at room temperature (4-6 days), which makes them ideal candidates for wound healing and implantable biomaterials.

  11. Measurements of Total and Partial Charge-changing Cross Sections for 200-400 MeV/nucleon 12C in Water and Polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Toshito, T.; /CREST, Japan Sci. Tech. Corp. /KEK, Tsukuba; Kodama, K.; /Aichi U. of Education; Sihver, L.; /Chalmers U. Tech.; Yusa, K.; /Gunma U., Maebashi; Ozaki, M.; /JAXA, Sagamihara; Amako, K.; Kameoka, S.; Murakami, K.; Sasaki, T.; /KEK, Tsukuba; Aoki, S.; /Kobe U.; Ban, T.; Fukuda, T.; Komatsu, M.; Kubota, H.; Naganawa, N.; Nakamura, T.; Nakano, T.; Natsume, M.; Niwa, K.; Takahashi, S.; Yoshida, J.; /Nagoya U. /Naruto U. of Education /NIRS, Chiba /SLAC /Toho U.

    2011-11-10

    We have studied charged nuclear fragments produced by 200 - 400 MeV/nucleon carbon ions, interacting with water and polycarbonate, using a newly developed emulsion detector. Total and partial charge-changing cross sections for the production of B, Be, and Li fragments were measured and compared with both previously published measurements, and model predictions. This study is of importance for validating and improving carbon ion therapy treatment planning systems, and for estimating the radiological risks for personnel on space missions, since carbon is a significant component of the Galactic Cosmic Rays.

  12. Measurements of total and partial charge-changing cross sections for 200-400 MeV/nucleon 12C in water and polycarbonate

    CERN Document Server

    Toshito, T; Aoki, S; Asai, M; Ban, T; Fukuda, T; Fukushima, C; Kameoka, S; Kanazawa, M; Kanematsu, N; Kodama, K; Koi, T; Komatsu, M; Komori, M; Kubota, H; Murakami, K; Naganawa, N; Nakamura, T; Nakano, T; Natsume, M; Niwa, K; Ogawa, S; Ozaki, M; Sasaki, T; Sato, S; Shibasaki, M; Shibuya, H; Sihver, L; Takahashi, S; Yoshida, H; Yoshida, J; Yusa, K

    2007-01-01

    We have studied charged nuclear fragments produced by 200 - 400 MeV/nucleon carbon ions, interacting with water and polycarbonate, using a newly developed emulsion detector. Total and partial charge-changing cross sections for the production of B, Be, and Li fragments were measured and compared with both previously published measurements, and model predictions. This study is of importance for validating and improving carbon ion therapy treatment planning systems, and for estimating the radiological risks for personnel on space missions, since carbon is a significant component of the Galactic Cosmic Rays.

  13. A Nordic approach to Early Childhood Education (ECE) and socially endangered children

    DEFF Research Database (Denmark)

    Jensen, Bente

    2009-01-01

    Summary In this paper I examine the Nordic model, i.e. a child-centred and holistic approach, in order to discuss Early Childhood Education (ECE) as a key policy instrument for fighting social inequality. Since 1999 it has been an important goal for the Danish government to ensure equal opportuni......Summary In this paper I examine the Nordic model, i.e. a child-centred and holistic approach, in order to discuss Early Childhood Education (ECE) as a key policy instrument for fighting social inequality. Since 1999 it has been an important goal for the Danish government to ensure equal...... opportunities for all by starting with early intervention. This is particularly especially relevant in Denmark, where >95% of all children attend in day-care. International research shows that early interventions can make a positive difference, and as shown in American Randomised Controlled Trial (RCT) studies...... system fails to provide equal social and intellectual opportunities to all children, further development in this area is required. Based on an analysis of the Nordic situation, a recent Danish intervention involving some 60 centres and 2.700 pre-school children and some preliminary results are presented...

  14. Use of polycarbonate plastic products and human health

    Directory of Open Access Journals (Sweden)

    R. K. Srivastava

    2013-02-01

    Full Text Available As plastic and plastic products are being used in day to day at the cost of environment pollution, the human and wild life health and has become a global concern. Researchers found link between abnormal liver enzymes in the people and Bisphenol-A (BPA. Changes in insulin resistance, reproduction system, cardiovascular and brain function are also reported. BPA is used in the production of epoxy resins, polycarbonate resins, and polyester resins. BPA can leach out of certain plastic products including variety of modern goods, reusable food storage containers, eyeglass lenses, white dental fillings, sealants, medical equipments etc. In the body, BPA behaves as an estrogen receptor agonist and mimics estrogen hormone. Bisphenol-A (BPA is a widespread endocrine-disrupting chemical (EDC used as the base compound in the manufacture of polycarbonate plastics. Children and unborn and new born babies are at high risk of unwanted effects of BPA. Children suffer from chronic exposure to bisphenol A with manifestation of gastrointestinal problems, adrenal stress, immune dysfunction, toxic over load and neurological disorders. Some study in Japan has observed that more BPA can leach from polycarbonate products that have been scratched or is more than 4 years old or used bottles that have been subjected to bottle brushing or dishwashing and sterilization. People exposed to higher levels of BPA due to use of plastic food and beverages containers are more likely to develop cardiovascular diseases, diabetes and metabolic disorder. Recent studies have suggested that BPA exposure may have a role in the development of weight gain, insulin resistance, pancreatic endocrine dysfunction, thyroid hormone disruption, and several other mechanisms involved in the development of diabetes. Urinary BPA levels are found to be associated with diabetes mellitus independent of traditional diabetes risk factors. There is a concern of exposure of BPA to pregnant women that can

  15. Does Gender Make a Difference? Results from the German "Tandem Study" on the Pedagogical Activity of Female and Male ECE Workers

    Science.gov (United States)

    Brandes, Holger; Andrä, Markus; Röseler, Wenke; Schneider-Andrich, Petra

    2015-01-01

    Based on an everyday quasi-experimental situation with multiple materials, the behavior of male and female early childhood education (ECE) workers is recorded and compared. The research is based on a sample of 41 female and 41 male ECE workers, who in each case work together in tandem in a kindergarten class, as well as a control group of 12…

  16. Sulfato-bridged ECE-pincer palladium(II) complexes: structures in the solid-state and in solution, and catalytic properties

    NARCIS (Netherlands)

    Kruithof, C.A.; Berger, A.; Dijkstra, H.P.; Soulimani, F.; Visser, T.; Lutz, M.; Spek, A.L.; Klein Gebbink, R.J.M.; van Koten, G.

    2009-01-01

    ECE-pincer sulfato palladium complexes (pincer = [C(6)H(3)(CH(2)E)(2)-2,6](-); E = SPh (), SMe (), S(t)Bu (), NMe(2) ()) were synthesized and characterized. In the solid-state (X-ray determinations) and exist as neutral ECE-pincer palladium sulfato complexes with a mu(2)-O,O' bridging sulfato ligand

  17. 49 CFR Appendix C to Part 553 - Statement of Policy: Implementation of the United Nations/Economic Commission for Europe (UN/ECE...

    Science.gov (United States)

    2010-10-01

    ... of the United Nations/Economic Commission for Europe (UN/ECE) 1998 Agreement on Global Technical... 49 Transportation 6 2010-10-01 2010-10-01 false Statement of Policy: Implementation of the United Nations/Economic Commission for Europe (UN/ECE) 1998 Agreement on Global Technical...

  18. The ECE Pre-Service Teachers' Perception on Factors Affecting the Integration of Educational Computer Games in Two Conditions: Selecting versus Redesigning

    Science.gov (United States)

    Sancar Tokmak, Hatice; Ozgelen, Sinan

    2013-01-01

    This case study aimed to examine early childhood education (ECE) pre-service teachers' perception on the factors affecting integration of educational computer games to their instruction in two areas: selecting and redesigning. Twenty-six ECE pre-service teachers participated in the study. The data was collected through open-ended questionnaires,…

  19. Factors Determining the Pore Shape in Polycarbonate Track Membranes

    CERN Document Server

    Apel, P Yu; Orelovich, O L; Akimenko, S N; Sartowska, B; Dmitriev, S N

    2004-01-01

    The process of pore formation in ion-irradiated polycarbonate films on treatment with alkali solutions in the presence of a surfactant is studied. It is found that the pore shape depends on both the structure of the initial films and the peculiarities of the interaction of the surfactant with the polymer surface and the transport of the surfactant into tracks. Due to heterogeneity of the films the cross-section of a track pore channel changes along its length. The presence of the surfactant results in a further effect. Surfactant molecules adsorb on the polymer surface at the pore entries and reduce the etch rate which leads to formation of cigar-like pore channels. The use of surfactant as a component of chemical etchant enables one to control the pore shape in track membranes thus optimizing their retention and permeation characteristics.

  20. Graphene Oxide Reinforced Polycarbonate Nanocomposite Films with Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    R. Mahendran

    2016-01-01

    Full Text Available The incorporation of carbonaceous nanofillers into polymers can result in significant materials with improved physicochemical properties and novel composite functionalities. In this study, we have fabricated antibacterial, lightweight, transparent, and flexible graphene oxide (GO reinforced polycarbonate thin films by a facile and low-cost methodology. Solution blending is employed to get a homogeneous mixture of PC-GO composites at various loading of GO, and the thin films are prepared by dry-wet phase inversion technique. Thermal studies and micrographs of the films revealed the incorporation of GO in PC matrix. Microstructure of the thin films showed the homogeneous dispersion of GO at micro- and nanoscales; however, at higher loading of GO (0.7%, significant agglomeration is observed. More importantly, PC-GO composite films exhibited excellent antibacterial activities against E. coli and S. aureus, owing to the antibacterial nature of GO nanoparticles.

  1. Hollow polycarbonate fiber for Er:YAG laser light delivery.

    Science.gov (United States)

    Nakazawa, Masayuki; Shi, Yi-Wei; Matsuura, Yuji; Iwai, Katsumasa; Miyagi, Mitsunobu

    2006-05-15

    We developed hollow fibers with polycarbonate (PC) capillaries for use as a supporting tube. The PC capillaries were prepared by using a glass-drawing technique. Hollow PC fibers are safer and more flexible than hollow glass fibers because no fragments are released when the fibers are broken in various applications. Inner coating layers of silver and cyclic olefin polymer (COP) enhanced the reflection rate at the Er:YAG laser light wavelength. Using these fibers, we attained low loss for Er:YAG laser light transmission. By adjusting the drawing temperature in the fabrication of the PC capillaries, we created a smooth inner surface and uniform PC capillaries. We also demonstrated low-loss properties for visible pilot beams.

  2. Anti-biofilm activity of Fe heavy ion irradiated polycarbonate

    Science.gov (United States)

    Joshi, R. P.; Hareesh, K.; Bankar, A.; Sanjeev, Ganesh; Asokan, K.; Kanjilal, D.; Dahiwale, S. S.; Bhoraskar, V. N.; Dhole, S. D.

    2016-10-01

    Polycarbonate (PC) polymers were investigated before and after high energy heavy ion irradiation for anti-bacterial properties. These PC films were irradiated by Fe heavy ions with two energies, viz, 60 and 120 MeV, at different fluences in the range from 1 × 1011 ions/cm2 to 1 × 1013 ions/cm2. UV-Visible spectroscopic results showed optical band gap decreased with increase in ion fluences due to chain scission mainly at carbonyl group of PC which is also corroborated by Fourier transform infrared spectroscopic results. X-ray diffractogram results showed decrease in crystallinity of PC after irradiation which leads to decrease in molecular weight. This is confirmed by rheological studies and also by differential scanning calorimetric results. The irradiated PC samples showed modification in their surfaces prevents biofilm formation of human pathogen, Salmonella typhi.

  3. Thrombogenicity tests on ar-irradiated polycarbonate foils

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H., E-mail: g.ferraz@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Fisica; Delgado, Adriana O. [Universidade Federal de Sao Carlos (UFSCAR), Sorocaba, SP (Brazil); Cunha, Tatiana F. [Biosintesis P and D do Brasil, Sao Paulo, SP (Brazil); Higa, Olga Z. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia

    2013-07-01

    Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

  4. Efficiency of Electret Polycarbonate Nonwovens in Respiratory Protection Against Nanoparticles

    Directory of Open Access Journals (Sweden)

    Brochocka Agnieszka

    2017-06-01

    Full Text Available Toxicological research on the influence of noxious nanoparticles on human health indicates the need to develop efficient protective devices. In particular, this concerns respiratory protective equipment employing filtration nonwovens. This paper presents a methodology for the improvement of the filtration efficiency of electret nonwovens against nanoparticles by enriching amorphous polycarbonate (PC with additives of different electrostatic potentials. We introduced perlite granules (positive charge and amber granules (negative charge to the polymer stream in melt-blown technology. Filtration efficiency was assessed by a standard method using paraffin oil and sodium chloride aerosol, as well as by a non-standard method using NaCl nanoparticles. The experiments showed that strengthening the effects of electrostatic forces by the introduction of modifiers is a promising approach to improving the efficiency of electret nonwovens against nanoparticles.

  5. Hydrolysis of polycarbonate catalyzed by ionic liquid [Bmim][Ac].

    Science.gov (United States)

    Song, Xiuyan; Liu, Fusheng; Li, Lei; Yang, Xuequn; Yu, Shitao; Ge, Xiaoping

    2013-01-15

    Hydrolysis of polycarbonate (PC) was studied using ionic liquid 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) as a catalyst. The influences of temperature, time, water dosage and [Bmim][Ac] dosage on the hydrolysis reaction were examined. Under the conditions of temperature 140°C, reaction time 3.0 h, m([Bmim][Ac]):m(PC)=1.5:1 and m(H(2)O):m(PC)=0.35:1, the conversion of PC was nearly 100% and the yield of bisphenol A (BPA) was over 96%. The ionic liquid could be reused up to 6 times without apparent decrease in the conversion of PC and yield of BPA. The kinetics of the reaction was also investigated. The results showed that the hydrolysis of PC in [Bmim][Ac] was a first-order kinetic reaction with an activation energy of 228 kJ/mol.

  6. Methanolysis of polycarbonate catalysed by ionic liquid [Bmim][Ac].

    Science.gov (United States)

    Liu, Fusheng; Li, Lei; Yu, Shitao; Lv, Zhiguo; Ge, Xiaoping

    2011-05-15

    The methanolysis of polycarbonate (PC) was studied using ionic liquid [Bmim][Ac] as a catalyst. The effects of temperature, time, methanol dosage and [Bmim][Ac] dosage on the methanolysis reaction were examined. It was shown that the conversion of PC was nearly 100%, and the yield of bisphenol A (BPA) was over 95% under the following conditions: m([Bmim][Ac]):m(PC) = 0.75:1;m(methanol):m(PC) = 0.75:1; a reaction temperature of 90 °C and a total time of 2.5h. The ionic liquid could be reused up to 6 times with no apparent decrease in the conversion of PC and yield of BPA. The kinetics of the reaction was also investigated. The results indicated that the methanolysis of PC in [Bmim][Ac] was a first-order kinetic reaction with an activation energy of 167 kJ/mol.

  7. Volume dilatation in a polycarbonate blend at varying strain rates

    Science.gov (United States)

    Hiermaier, S.; Huberth, F.

    2012-05-01

    Impact loaded polymers show a variety of strain-rate dependent mechanical properties in their elastic, plastic and failure behaviour. In contrast to purely crystalline materials, the volume of polymeric materials can significantly change under irreversible deformations. In this paper, uni-axial tensile tests were performed in order to measure the dilatation in the Polycarbonate-Acrylnitril-Butadien-Styrol (PC-ABS) Bayblend T65. The accumulation of dilatation was measured at deformation speeds of 0.1 and 500 [ mm/ s]. Instrumented with a pair of two high-speed cameras, volume segments in the samples were observed. The change in volume was quantified as relation between the deformed and initial volumes of the segments. It was observed that the measured dilatations are of great significance for the constitutive models. This is specifically demonstrated through comparisons of stress-strain relations derived from the two camera-perspectives with isochoric relations based on single-surface observations of the same experiments.

  8. Electroporation of Biological Cells Embedded in a Polycarbonate Filter

    CERN Document Server

    Hercules, W A; Lindesay, J; Schmukler, R; Hercules, William A.; Lindesay, James; Coble, Anna; Schmukler, Robert

    2003-01-01

    The electropermeabilization of biological cell membranes by the application of an external field occurs whenever an applied field exceeds a threshold value. For fields above this threshold value but less than another critical value, the pores formed in the membrane are transient or reversible. Several mechanisms have been proposed for the formation of these transient pores. Here we examine the local electric fields generated for the configuration of cells embedded in a polycarbonate filter, both in the region in and around the pore. We consider the shear forces created in the membrane due to the gradient of the field along the surface of the membrane, and the interaction of the charged molecules in the membrane with this field. A relationship between the electric field strength and the size of the pore formed is derived.

  9. Chemoselective Alternating Copolymerization of Limonene Dioxide and Carbon Dioxide: A New Highly Functional Aliphatic Epoxy Polycarbonate.

    Science.gov (United States)

    Li, Chunliang; Sablong, Rafaël J; Koning, Cor E

    2016-09-12

    The alternating copolymerization of biorenewable limonene dioxide with carbon dioxide (CO2 ) catalyzed by a zinc β-diiminate complex is reported. The chemoselective reaction results in linear amorphous polycarbonates that carry pendent methyloxiranes and exhibit glass transition temperatures (Tg ) up to 135 °C. These polycarbonates can be efficiently modified by thiols or carboxylic acids in combination with lithium hydroxide or tetrabutylphosphonium bromide as catalysts, respectively, without destruction of the main chain. Moreover, polycarbonates bearing pendent cyclic carbonates can be quantitatively prepared by CO2 insertion catalyzed by lithium bromide.

  10. Teaching in ECE: Promoting Children's Language Learning and Cooperation on Knowledge Construction in Everyday Conversations in Kindergarten

    Science.gov (United States)

    Gjems, Liv

    2013-01-01

    The intention of this study is to examine how early childhood education (ECE) teachers can promote children's language learning and the construction of knowledge about their environment in everyday conversations. Young children primarily learn through interactions with adults and peers, with conversations representing important arenas for language…

  11. Teaching in ECE: Promoting Children's Language Learning and Cooperation on Knowledge Construction in Everyday Conversations in Kindergarten

    Science.gov (United States)

    Gjems, Liv

    2013-01-01

    The intention of this study is to examine how early childhood education (ECE) teachers can promote children's language learning and the construction of knowledge about their environment in everyday conversations. Young children primarily learn through interactions with adults and peers, with conversations representing important arenas for language…

  12. Dynamic changes in the secondary structure of ECE-1 and XCE account for their different substrate specificities

    Directory of Open Access Journals (Sweden)

    Ul-Haq Zaheer

    2012-11-01

    Full Text Available Abstract Background X-converting enzyme (XCE involved in nervous control of respiration, is a member of the M13 family of zinc peptidases, for which no natural substrate has been identified yet. In contrast, it’s well characterized homologue endothelin-converting enzyme-1 (ECE-1 showed broad substrate specificity and acts as endopeptidase as well as dipeptidase. To explore the structural differences between XCE and ECE-1, homology model of XCE was built using the complex structure of ECE-1 with phosphoramidon (pdb-id: 3DWB as template. Phosphoramidon was docked into the binding site of XCE whereas phosphate oxygen of the inhibitor was used as water molecule to design the apo forms of both enzymes. Molecular dynamics simulation of both enzymes was performed to analyze the dynamic nature of their active site residues in the absence and presence of the inhibitor. Results Homology model of XCE explained the role of non-conserved residues of its S2’ subsite. Molecular dynamics (MD simulations identified the flexible transitions of F149/I150, N566/N571, W714/W719, and R145/R723 residues of ECE-1/XCE for the strong binding of the inhibitor. Secondary structure calculations using DSSP method reveals the folding of R145/R723 residue of ECE-1/XCE into β-sheet structure while unfolding of the S2’ subsite residues in aECE-1 and sustained compact folding of that of aXCE. The results evaluated are in good agreement with available experimental data, thus providing detailed molecular models which can explain the structural and specificities differences between both zinc peptidases. Conclusions Secondary structure changes of both enzymes during the simulation time revealed the importance of β-sheet structure of R145/R723 for its binding with the terminal carboxylate group of the inhibitor. Unfolding of the α-helix comprising the S2’ subsite residues in aECE-1 correlate well with its endopeptidase activity while their compact folding in aXCE may

  13. Build-up and decline of organic matter during PeECE III

    Directory of Open Access Journals (Sweden)

    K. G. Schulz

    2007-11-01

    Full Text Available Increasing atmospheric carbon dioxide (CO2 concentrations due to anthropogenic fossil fuel combustion currently change the ocean's chemistry. Increasing oceanic [CO2] and subsequent decreasing seawater pH have the potential to significantly impact marine life. Here we describe and analyze the build-up and decline of a natural phytoplankton bloom initiated during the 2005 mesocosm Pelagic Ecosystem CO2 Enrichment study (PeECE III. We show that processes of inorganic carbon uptake in mixed surface waters and organic carbon export to depth were significantly enhanced at elevated CO2, while ammonium regeneration in deep waters was substantially reduced. This has important implications for our understanding of pelagic ecosystem functioning and future carbon cycling.

  14. ECE diagnostic for the TARA tandem mirror machine using a fast-scanning Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Guharay, S.K.; Boyd, D.A.; Ellis, R.F.

    1986-08-01

    This ECE (electron cyclotron emission) diagnostic utilizes a fast-scanning Michelson interferometer to determine two parameters, the temperature and the loss cone angle, of the distribution function of the hot electrons (T-italicapprox. >100 keV) generated in the axisymmetric plug plasma of the TARA tandem mirror device. The radiation transport system employs a lens relay and a low-pass grating filter in order to transmit the synchrotron radiation over a spectral range of 2.9--18.6 cm/sup -1/. This enables us to study the emitted radiation spectrum up to the 40th harmonic of the electron--cyclotron frequency in the plug plasma (B-italic = 5 kG). Details of the design principles and the development of the diagnostic at TARA will be presented.

  15. A Nordic approach to ECE-system and social differences - a Danish trial

    DEFF Research Database (Denmark)

    Jensen, Bente

    . Preliminary results from the Danish trial: Action Competencies in Social Pedagogical Work with Socially Endangered Children (The ASP-project) based on a Bourdiean perspective - indicate that there is reason to focus more on teachers' professional skills and qualifications concerning new challenges....... It is demanding for teachers working with the entire ECE/ASPimplementation process because they have to reflect upon their own practice and role in relation to create and implement new knowledge of socially endangered children. Based on an analysis of the Nordic situation, the paper discusses preliminary results...... emphasizing the question of the challenges for the professionals working with evidencebased knowledge and learning in the ASP-project, a RCT study which aims at social innovation in 60 centres, covering 2700 preschool children....

  16. Inequality, Economic Growth and Trade Openness: a Study Case for Central and Eastern Countries (ECE

    Directory of Open Access Journals (Sweden)

    Olimpia Neagu

    2016-08-01

    Full Text Available The paper analyzes the phenomenon of income inequality in ten countries from Eastern and Central Europe (ECE, by highlighting two aspects: (1 the link between growth and income inequality; (2 the effects of trade openess and other key factors on income inequality, such as: foreign direct investment (FDI, market capitalization and educational level of labour force. The method used was the Panel Data Analysis with statistical data from the period of 2000-2014. An increasing effect in income inequality was identified due to the trade openess, the inward stock of ISD and the market capitalization and an equalizing effect in the income distribution generated by the educational level of labour force. A positive association was also found between the growth of PIB per capita level and the increase of income inequality in the examined countries.

  17. 8th Annual report 1999. UN ECE convention on long-range transboundary air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Kleemola, S.; Forsius, M. [eds.

    1999-07-01

    The Integrated Monitoring Programme (ICP IM) is part of the Effects Monitoring Strategy under the UN ECE Convention on Long-Range Transboundary Air Pollution. The main aim of ICP IM is to provide a framework to observe and understand the complex changes occurring in the external environment. This report summarizes the work carried out by the ICP IM Programme Centre and several collaborating institutes. The emphasis of the report is in the work done during the programme year 1998/99 including: - a short summary of previous data assessments - a short status report of the ICP IM activities, content of the IM database, and the present geographical coverage of the monitoring network - a documentation of the scientific strategies to carry out data assessment on two priority topics: - assessment of heavy metal pools and fluxes - assessment of cause-effect relationships for understorey vegetation - a description of the WATBAL-model for estimating monthly water balance components, including soil water fluxes. (orig.)

  18. Functional polycarbonates and their self-assemblies as promising non-viral vectors.

    Science.gov (United States)

    Seow, Wei Yang; Yang, Yi Yan

    2009-10-01

    Polycarbonates are promising biomaterials due to their biocompatibility, degradability and low toxicity. In this study, a series of COOH-functionalized polycarbonates was synthesized via an organocatalytic ring opening polymerization pathway under mild conditions. The polymers displayed a range of molecular weights (M(w): 3.1, 5.5 and 9.7 kDa) and were very narrowly distributed (polydispersity index: 1.07, 1.07 and 1.15 respectively). Aliphatic amines with different chain lengths (triethylenetetramine, tetraethylenepentamine or pentaethylenehexamine) were then conjugated onto the polycarbonate backbone using DIC/NHS chemistry. These amine-functionalized polycarbonates could form nanoparticles upon simple dissolution in water and had CMC values ranging from 22 to 45 mg/L. It was found that a longer amine chain resulted in greater buffering capacity, more positive zeta potential and smaller hydrodynamic size of the polymeric nanoparticles. Results from gel retardation assays indicated that the polymers were able to condense DNA. In-vitro studies further demonstrated that selected amine-functionalized polycarbonates could mediate efficient luciferase expression in HEK293, HepG2 and 4T1 cell lines at levels that were comparable, or even superior, to the polyethylenimine (PEI) standard. Importantly, minimal cytotoxicty was induced in the cells. These functional polycarbonates therefore have the potential to be a useful non-viral vector for gene therapy.

  19. Behavior of composite and polycarbonate plate under impact

    Directory of Open Access Journals (Sweden)

    Viot P.

    2010-06-01

    Full Text Available The use of filled composite materials in passive safety structure has significantly increased recently because of their low specific mass, stiffness and energy absorption capacities. However those new light weight materials are supposed to exhibit equal or higher performances than classical ones. Therefore interesting applications by using those materials can be thought about like in the manufacturing of aeronautical helmets. Constituted of an outer shell and an inner foam structure, helmet must protect pilots from an impact by absorbing energy as much as possible and avoid contact between head and impactor. Nowadays different standards describe the minimum required performance for shock attenuation and penetration resistance of helmets [1]. These standards are based on acceleration time history measurements recorded from an accelerometer located at the headform center of mass. For aeronautical standard, acceleration peak value is the only one parameter concerning shock attenuation. Its value must not exceed 300 g, where g = 9.81 m.s-2. Concerning penetration resistance, no contact can be accepted between the penetrating striker and the headform. The outer shell of the helmet has to resist penetration in order to absorb and to extend the input energy over the foam. The most important part of energy is dissipated by polymeric foam through collapse processes under impact [2]. Nevertheless a significant part of energy (one third [3, 4] can be dissipated by the plastic deformation of the shell and the occurrence of damage mechanisms. To obtain different dissipative phenomena, various materials were studied: a Three different kinds of polycarbonate were used. This type of material is well known for its large viscoplastic deformations without any significant hardening. In other words it is a very good candidate for helmet application because of high specific energy dissipation and a stress cut-off effect. Moreover a larger affected zone is expected

  20. Polyethylenimine-grafted polycarbonates as biodegradable polycations for gene delivery.

    Science.gov (United States)

    Wang, Chang-Fang; Lin, Yan-Xin; Jiang, Tao; He, Feng; Zhuo, Ren-Xi

    2009-09-01

    Polycations as one of non-viral vectors have gained increasing attentions. In this paper, polyethylenimine(PEI)-grafted polycarbonates (PMAC-g-PEIx) were synthesized as a kind of biodegradable polycations for gene delivery. Backbone polymer, poly(5-methyl-5-allyloxycarbonyl-trimethylene carbonate) (PMAC), was synthesized in bulk catalyzed by immobilized porcine pancreas lipase (IPPL). Then, PMAC-O, the allyl epoxidation product of PMAC, was further modified by PEIx with low molecular weight (x = 423, 800 and 1800). The MWs of PMAC-g-PEIx, measured by GPC-MALLS, were 81,900, 179,900 and 200,600 g/mol with polydispersities of 1.2, 1.4 and 1.7, respectively. PMAC-g-PEIx could form positively charged nano-sized particles (30-90 nm) with pDNA, and all the three PAMC-g-PEIx/DNA polyplexes had similar buffer capabilities. In vitro experiments demonstrated that the PAMC-g-PEIx showed much low cytotoxicity and enhanced transfection efficiency could be found in comparison with PEI25K in 293T cells. Furthermore, pre-incubation of PMAC-g-PEI1800 showed a weakening binding capacity with DNA. The biodegradability of PMAC-g-PEIx can facilitate the efficient release of pDNA from polyplexes and reduce cell cytotoxicity. These results suggested that PMAC-g-PEIx would be a promising non-viral biodegradable vector for gene delivery system.

  1. Polycarbonate-Based Blends for Optical Non-linear Applications

    Science.gov (United States)

    Stanculescu, F.; Stanculescu, A.

    2016-02-01

    This paper presents some investigations on the optical and morphological properties of the polymer (matrix):monomer (inclusion) composite materials obtained from blends of bisphenol A polycarbonate and amidic monomers. For the preparation of the composite films, we have selected monomers characterised by a maleamic acid structure and synthesised them starting from maleic anhydride and aniline derivatives with -COOH, -NO2, -N(C2H5)2 functional groups attached to the benzene ring. The composite films have been deposited by spin coating using a mixture of two solutions, one containing the matrix and the other the inclusion, both components of the composite system being dissolved in the same solvent. The optical transmission and photoluminescence properties of the composite films have been investigated in correlation with the morphology of the films. The scanning electron microscopy and atomic force microscopy have revealed a non-uniform morphology characterised by the development of two distinct phases. We have also investigated the generation of some optical non-linear (ONL) phenomena in these composite systems. The composite films containing as inclusions monomers characterised by the presence of one -COOH or two -NO2 substituent groups to the aromatic nucleus have shown the most intense second-harmonic generation (SHG). The second-order optical non-linear coefficients have been evaluated for these films, and the effect of the laser power on the ONL behaviour of these materials has also been emphasised.

  2. Cellulose nanocrystals as organic nanofillers for transparent polycarbonate films

    Energy Technology Data Exchange (ETDEWEB)

    Xu Weinan; Qin Zongyi, E-mail: phqin@dhu.edu.cn; Yu Houyong; Liu Yannan; Liu Na; Zhou Zhe; Chen Long, E-mail: happyjack@dhu.edu.cn [College of Materials Science and Engineering, Donghua University, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials (China)

    2013-04-15

    Cellulose nanocrystals (CNCs) produced by sulfuric acid hydrolysis as organic nanofillers were dispersed into polycarbonate (PC) in organic solution through a solvent exchange procedure, and their influence on the optical, mechanical, and thermal properties of the resulting composite films were studied. It is demonstrated that due to the good dispersion of the nanofillers in the polymeric matrix, the formation of strong hydrogen bonds between carbonyl groups of PC and hydroxyl groups of the CNCs can be achieved, leading to a simultaneous reinforcement effect on mechanical and thermal properties of the composite films. Moreover, it was further found that the existence of nanofillers in the composite efficiently hindered the main thermal degradation pathways of PC involving the chain scission at carbonate linkage and rearrangement of carbonate groups. Compared with neat PC, the composite film with 3 wt% CNCs has an increase of about 30.6 % in tensile strength, 27.3 % in Young's modulus, and 3.3 % in maximum decomposition temperature, but still remain quite transparent.

  3. Polycarbonate-Based Blends for Optical Non-linear Applications.

    Science.gov (United States)

    Stanculescu, F; Stanculescu, A

    2016-12-01

    This paper presents some investigations on the optical and morphological properties of the polymer (matrix):monomer (inclusion) composite materials obtained from blends of bisphenol A polycarbonate and amidic monomers. For the preparation of the composite films, we have selected monomers characterised by a maleamic acid structure and synthesised them starting from maleic anhydride and aniline derivatives with -COOH, -NO2, -N(C2H5)2 functional groups attached to the benzene ring. The composite films have been deposited by spin coating using a mixture of two solutions, one containing the matrix and the other the inclusion, both components of the composite system being dissolved in the same solvent. The optical transmission and photoluminescence properties of the composite films have been investigated in correlation with the morphology of the films. The scanning electron microscopy and atomic force microscopy have revealed a non-uniform morphology characterised by the development of two distinct phases. We have also investigated the generation of some optical non-linear (ONL) phenomena in these composite systems. The composite films containing as inclusions monomers characterised by the presence of one -COOH or two -NO2 substituent groups to the aromatic nucleus have shown the most intense second-harmonic generation (SHG). The second-order optical non-linear coefficients have been evaluated for these films, and the effect of the laser power on the ONL behaviour of these materials has also been emphasised.

  4. Modified polycarbonate urethane: synthesis, properties and biological investigation in vitro.

    Science.gov (United States)

    Szelest-Lewandowska, A; Masiulanis, B; Szymonowicz, M; Pielka, S; Paluch, D

    2007-08-01

    A new polycarbonate urethane (PCU-I) was synthesized from aliphatic monomers, i.e. polyhexamethylene carbonate diol and 4,4'-methylene-bis cyclohexane diisocyanate, a mixture of low molecular diols, and castor oil (containing mainly the triglyceride of 12-hydroxyoleic acid). The second synthesized polymer (PCU-II) did not contain castor oil. Both PCUs had good tensile strength, i.e. 32.5 and 27.8 MPa for PCU-I and PCU-II, respectively. Modification by castor oil led to a decrease in glass transition temperature (T(g) = -14 degrees C for PCU-I and -6 degrees C for PCU-II) and an increase in the softening temperature (135 and 125 degrees C for PCU-I and PCU-II, respectively). Partial crosslinking of PCU-I increased the storage modulus of elasticity and provided better resistance to sterilization by ETO and gamma radiation. Both PCUs displayed good stability when subjected to sterilization by hydrogen peroxide plasma. Neither PCU caused cytotoxic effect in mouse fibroblasts (3T3 Balb C). They also had no toxic effects on the morphotic components and did not influence changes in the hematologic parameters or plasmatic coagulation system of human blood.

  5. Electrospun aliphatic polycarbonates as tailored tissue scaffold materials.

    Science.gov (United States)

    Welle, Alexander; Kröger, Mario; Döring, Manfred; Niederer, Kerstin; Pindel, Elvira; Chronakis, Ioannis S

    2007-04-01

    Two different aliphatic polycarbonates were synthesised from CO(2) and the respective epoxides. Poly(propyl carbonate) (PPC) was prepared by heterogeneous catalysis with zinc glutarate. Poly(cyclohexyl carbonate) (PCHC) was prepared via living copolymerisation homogeneously catalysed by a 3-amino-2-cyanoimidoacrylate zinc acetate complex and subjected to electrospinning. The obtained nanofibres had a well-defined morphology free of beads along the fibres and with slightly porous structures on their surface. Subsequently, low-power deep UV irradiations, previously applied for photochemical surface modifications of two-dimensional and three-dimensional scaffolds from biostable polymers, were performed. Here, an effect on surface and bulk properties of PPC nanofibres was observed. Surface modifications of both polymers affected plasma protein adsorption. Photochemical bulk modifications observed for the first time on PPC nanofibres are indicating the possibility of spatial control of biodegradation rates, hence allow for control of the progression of host/implant interactions in vivo. In particular PPC was used for cell culture of L929 fibroblasts and primary rat hepatocytes. Even delicate primary cells showed good adhesion to the scaffolds and high viability.

  6. Preparation of Aromatic Polycarbonate Nanoparticles using Supercritical Carbon Dioxide

    Science.gov (United States)

    Lee, Jun-Young; Song, Cheong-Hun; Kim, Joong-In; Kim, Jung-Hyun

    2002-04-01

    A novel synthetic process for producing aromatic polycarbonate (PC) nanoparticles using supercritical CO2 was developed. The objective of the present research work was to synthesize high molecular weight PC nanoparticles using transesterification between bisphenol-A (BPA) and diphenyl carbonate (DPC) in supercritical CO2 which is an excellent plasticizing agent and a good solvent for phenol, a by-product of the reaction. Poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide) tri-block copolymer with CO2-phobic anchor and CO2-philic tail group was used as a stabilizer for the preparation of stable dispersions of BPA-DPC mixture in a CO2 continuous phase. As the reaction was proceeding, phenol formed from the reaction was dissolved and diffused into supercritical CO2 phase. The PC nanoparticles were isolated by simple venting of the supercritical CO2 from the reactor. Spherical morphology of PC particles was confirmed by scanning electron microscopy. Particle size and morphology of PC particles were modified upon variation of the process conditions. The resulting PC particles with a nano-size of 30-140 nm have a high molecular weight ( M w) of 3.1×105 (g/mol).

  7. Anti-biofilm activity of Fe heavy ion irradiated polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, R.P. [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Hareesh, K., E-mail: appi.2907@gmail.com [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Bankar, A. [Department of Microbiology, Waghire College, Pune 412301 (India); Sanjeev, Ganesh [Microtron Centre, Department of Studies in Physics, Mangalore University, Mangalore 574166 (India); Asokan, K.; Kanjilal, D. [Inter University Accelerator Centre, Arun Asaf Ali Marg, New Delhi 110067 (India); Dahiwale, S.S.; Bhoraskar, V.N. [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India)

    2016-10-01

    Highlights: • PC films were irradiated by 60 and 120 MeV Fe ions. • Irradiated PC films showed changes in its physical and chemical properties. • Irradiated PC also showed more anti-biofilm activity compared to pristine PC. - Abstract: Polycarbonate (PC) polymers were investigated before and after high energy heavy ion irradiation for anti-bacterial properties. These PC films were irradiated by Fe heavy ions with two energies, viz, 60 and 120 MeV, at different fluences in the range from 1 × 10{sup 11} ions/cm{sup 2} to 1 × 10{sup 13} ions/cm{sup 2}. UV-Visible spectroscopic results showed optical band gap decreased with increase in ion fluences due to chain scission mainly at carbonyl group of PC which is also corroborated by Fourier transform infrared spectroscopic results. X-ray diffractogram results showed decrease in crystallinity of PC after irradiation which leads to decrease in molecular weight. This is confirmed by rheological studies and also by differential scanning calorimetric results. The irradiated PC samples showed modification in their surfaces prevents biofilm formation of human pathogen, Salmonella typhi.

  8. Surface modification of polycarbonate in homogeneous atmospheric pressure discharge

    Energy Technology Data Exchange (ETDEWEB)

    SIra, M; Trunec, D; St' ahel, P; BursIkova, V; Navratil, Z [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic)

    2008-01-07

    A homogeneous atmospheric pressure dielectric barrier discharge was used for the surface modification of polycarbonate (PC). The discharge was generated between two planar metal electrodes, the top electrode was covered by glass and the bottom electrode was covered by a polymer sample. The discharge burned in pure nitrogen or in a mixture of nitrogen and hydrogen. The surface properties of both treated and untreated polymers were characterized by atomic force microscopy, surface free energy (SFE) measurements and x-ray photoelectron spectroscopy. The influence of the treatment time and power input to the discharge on the surface properties of polymers was studied. The ageing of treated samples was also investigated. The treatment of polymers in the homogeneous atmospheric pressure discharge was homogeneous and the polymer surfaces showed a smaller degree of roughness in comparison with the polymer surfaces treated in a filamentary discharge. The SFE of the treated PC obtained at optimum conditions was 53 mJ m{sup -2} and the corresponding contact angle of water was 38{sup 0}. The maximum decrease in the SFE during ageing was about 13%. The analysis of the chemical composition showed an increase in the nitrogen concentration in the surface layer, but almost a zero increase in the oxygen concentration. This result was discussed concerning the measured values of the SFE measurement.

  9. Chemical stability of polyether urethanes versus polycarbonate urethanes.

    Science.gov (United States)

    Tanzi, M C; Mantovani, D; Petrini, P; Guidoin, R; Laroche, G

    1997-09-15

    The relative chemical stability of two commercially available polyurethanes-Pellethane, currently used in biomedical devices, and Corethane, considered as a potential biomaterial-was investigated following aging protocols in hydrolytic and oxidative conditions (HOC, water, hydrogen peroxide, and nitric acid) and in physiological media (PHM, phosphate buffer, lipid dispersion, and bile from human donors). The chemical modifications induced on these polymers were characterized using differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and Fourier transform infrared spectroscopy (FTIR). With the exception of nitric acid, all of the aging media promoted a mild hydrolytic reaction leading to a slight molecular weight loss in both polymers. When aged in water and hydrogen peroxide, Pellethane experienced structural modifications through microdomain phase separation along with an increase of the order within the soft-hard segment domains. The incubation of Pellethane in nitric acid also resulted in an important decrease of the melting temperature of its hard segments with chain scission mechanisms. Moreover, incubation in PHM led to an increase of the order within shorter hard-segment domains. FTIR data revealed the presence of aliphatic amide molecules used as additives on the Pellethane's surface. The incubation of Corethane under the same conditions promoted an almost uniform molecular reorganization through a phase separation between the hard and soft segments as well as an increase of the short-range order within the hard-segment domains. Incubation of this polymer in nitric acid also resulted in a chain scission process that was less pronounced than that measured for the Pellethane samples. Finally, lipid adsorption occurred on the Corethane sample incubated in bile for 120 days. Overall data indicate that polycarbonate urethane presents a greater chemical stability than does polyetherurethane.

  10. Simulations with LS-DYNA for Registration Approval of a Coach according to ECE R66 Regulation

    OpenAIRE

    Schwartz, Wolfgang; Kvocic, Ch.; Lesti, Klaus; Schott, Klaus; Vaculin, Ondrej

    2004-01-01

    During the last years the increasing number of fatal coach accidents with tragic consequences for passengers showed the importance of passive safety in addition to the driver’s competence and active safety. In the European countries the certification of sufficient deformation strength when overturning is compulsory for the approval of a coach according to the ECE R66 regulation. The certification is granted after positive results from crash tests or computer simulations with partial or full b...

  11. ECE1 gene variant shows tendency toward chronic kidney disease advancement among autosomal polycystic kidney disease patients

    Directory of Open Access Journals (Sweden)

    Shiva Nagendra Reddy Annapareddy

    2016-04-01

    結論: 我們觀察到,在 ADPKD 患者間,高血壓是 CKD 病情發展的一個明顯的干擾因素。以上結果意味著,在 ADPKD 患者間,ECE1 基因變體可影響 CKD 的病情發展。

  12. Constitutive modeling of polycarbonate over a wide range of strain rates and temperatures

    Science.gov (United States)

    Wang, Haitao; Zhou, Huamin; Huang, Zhigao; Zhang, Yun; Zhao, Xiaoxuan

    2016-06-01

    The mechanical behavior of polycarbonate was experimentally investigated over a wide range of strain rates ( 10^{-4} to 5× 103 s^{-1}) and temperatures (293 to 353 K). Compression tests under these conditions were performed using a SHIMADZU universal testing machine and a split Hopkinson pressure bar. Falling weight impact testing was carried out on an Instron Dynatup 9200 drop tower system. The rate- and temperature-dependent deformation behavior of polycarbonate was discussed in detail. Dynamic mechanical analysis (DMA) tests were utilized to observe the glass ( α ) transition and the secondary ( β ) transition of polycarbonate. The DMA results indicate that the α and β transitions have a dramatic influence on the mechanical behavior of polycarbonate. The decompose/shift/reconstruct (DSR) method was utilized to decompose the storage modulus into the α and β components and extrapolate the entire modulus, the α-component modulus and the β-component modulus. Based on three previous models, namely, Mulliken-Boyce, G'Sell-Jonas and DSGZ, an adiabatic model is proposed to predict the mechanical behavior of polycarbonate. The model considers the contributions of both the α and β transitions to the mechanical behavior, and it has been implemented in ABAQUS/Explicit through a user material subroutine VUMAT. The model predictions are proven to essentially coincide with the experimental results during compression testing and falling weight impact testing.

  13. Constitutive modeling of polycarbonate over a wide range of strain rates and temperatures

    Science.gov (United States)

    Wang, Haitao; Zhou, Huamin; Huang, Zhigao; Zhang, Yun; Zhao, Xiaoxuan

    2017-02-01

    The mechanical behavior of polycarbonate was experimentally investigated over a wide range of strain rates (10^{-4} to 5× 103 s^{-1}) and temperatures (293 to 353 K). Compression tests under these conditions were performed using a SHIMADZU universal testing machine and a split Hopkinson pressure bar. Falling weight impact testing was carried out on an Instron Dynatup 9200 drop tower system. The rate- and temperature-dependent deformation behavior of polycarbonate was discussed in detail. Dynamic mechanical analysis (DMA) tests were utilized to observe the glass (α ) transition and the secondary (β ) transition of polycarbonate. The DMA results indicate that the α and β transitions have a dramatic influence on the mechanical behavior of polycarbonate. The decompose/shift/reconstruct (DSR) method was utilized to decompose the storage modulus into the α and β components and extrapolate the entire modulus, the α-component modulus and the β-component modulus. Based on three previous models, namely, Mulliken-Boyce, G'Sell-Jonas and DSGZ, an adiabatic model is proposed to predict the mechanical behavior of polycarbonate. The model considers the contributions of both the α and β transitions to the mechanical behavior, and it has been implemented in ABAQUS/Explicit through a user material subroutine VUMAT. The model predictions are proven to essentially coincide with the experimental results during compression testing and falling weight impact testing.

  14. Preliminary results of modeled ozone uptake for Fagus sylvatica L. trees at selected EU/UN-ECE intensive monitoring plots

    Energy Technology Data Exchange (ETDEWEB)

    Schaub, Marcus [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland)]. E-mail: marcus.schaub@wsl.ch; Emberson, Lisa [Stockholm Environment Institute at York, University of York, York YO10 5DD (United Kingdom); Bueker, Patrick [Stockholm Environment Institute at York, University of York, York YO10 5DD (United Kingdom); Kraeuchi, Norbert [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland)

    2007-02-15

    The objective of this study was to establish whether EU and UN-ECE/ICP-Forests monitoring data (i) provide the variables necessary to apply the flux-based modeling methods and (ii) meet the quality criteria necessary to apply the flux-based critical level concept. Application of this model has been possible using environmental data collected from the EU and UN-ECE/ICP-Forests monitoring network in Switzerland and Italy for 2000-2002. The test for data completeness and plausibility resulted in 6 out of a possible total of 20 Fagus sylvatica L. plots being identified as suitable from Switzerland, Italy, Spain, and France. The results show that the collected data allow the identification of different spatial and temporal areas and periods as having higher risk to ozone than those identified using the AOT40 approach. However, it was also apparent that the quality and completeness of the available data may severely limit a complete risk assessment across Europe. - Data sets of the EU and UN-ECE/ICP-Forests monitoring network are examined regarding their suitability for the modeling of ozone uptake in trees in the view of risk assessment.

  15. Expressions of ECE-CYC2 clade genes relating to abortion of both dorsal and ventral stamens in Opithandra (Gesneriaceae).

    Science.gov (United States)

    Song, Chun-Feng; Lin, Qi-Bing; Liang, Rong-Hua; Wang, Yin-Zheng

    2009-10-07

    ECE-CYC2 clade genes known in patterning floral dorsoventral asymmetry (zygomorphy) in Antirrhinum majus are conserved in the dorsal identity function including arresting the dorsal stamen. However, it remains uncertain whether the same mechanism underlies abortion of the ventral stamens, an important morphological trait related to evolution and diversification of zygomorphy in Lamiales sensu lato, a major clade of predominantly zygomorphically flowered angiosperms. Opithandra (Gesneriaceae) is of particular interests in addressing this question as it is in the base of Lamiales s.l., an early representative of this type zygomorphy. We investigated the expression patterns of four ECE-CYC2 clade genes and two putative target cyclinD3 genes in Opithandra using RNA in situ hybridization and RT-PCR. OpdCYC gene expressions were correlated with abortion of both dorsal and ventral stamens in Opithandra, strengthened by the negatively correlated expression of their putative target OpdcyclinD3 genes. The complement of OpdcyclinD3 to OpdCYC expressions further indicated that OpdCYC expressions were related to the dorsal and ventral stamen abortion through negative effects on OpdcyclinD3 genes. These results suggest that ECE-CYC2 clade TCP genes are not only functionally conserved in the dorsal stamen repression, but also involved in arresting ventral stamens, a genetic mechanism underlying the establishment of zygomorphy with abortion of both the dorsal and ventral stamens evolved in angiosperms, especially within Lamiales s.l.

  16. Expressions of ECE-CYC2 clade genes relating to abortion of both dorsal and ventral stamens in Opithandra (Gesneriaceae

    Directory of Open Access Journals (Sweden)

    Wang Yin-Zheng

    2009-10-01

    Full Text Available Abstract Background ECE-CYC2 clade genes known in patterning floral dorsoventral asymmetry (zygomorphy in Antirrhinum majus are conserved in the dorsal identity function including arresting the dorsal stamen. However, it remains uncertain whether the same mechanism underlies abortion of the ventral stamens, an important morphological trait related to evolution and diversification of zygomorphy in Lamiales sensu lato, a major clade of predominantly zygomorphically flowered angiosperms. Opithandra (Gesneriaceae is of particular interests in addressing this question as it is in the base of Lamiales s.l., an early representative of this type zygomorphy. Results We investigated the expression patterns of four ECE-CYC2 clade genes and two putative target cyclinD3 genes in Opithandra using RNA in situ hybridization and RT-PCR. OpdCYC gene expressions were correlated with abortion of both dorsal and ventral stamens in Opithandra, strengthened by the negatively correlated expression of their putative target OpdcyclinD3 genes. The complement of OpdcyclinD3 to OpdCYC expressions further indicated that OpdCYC expressions were related to the dorsal and ventral stamen abortion through negative effects on OpdcyclinD3 genes. Conclusion These results suggest that ECE-CYC2 clade TCP genes are not only functionally conserved in the dorsal stamen repression, but also involved in arresting ventral stamens, a genetic mechanism underlying the establishment of zygomorphy with abortion of both the dorsal and ventral stamens evolved in angiosperms, especially within Lamiales s.l.

  17. Survey of the TS-ECE Discrepancy and recent investigations in ICRF heated plasmas at Alcator C-Mod

    Directory of Open Access Journals (Sweden)

    Reinke M. L.

    2012-09-01

    Full Text Available This paper reports on a new investigation of the long-standing, unresolved discrepancy between Thomson Scattering (TS and Electron Cyclotron Emission (ECE measurements of electron temperature in high temperature tokamak plasmas. At the Alcator C-Mod tokamak, ion cyclotron range of frequency (ICRF heating is used to produce high temperature conditions where the TS- ECE discrepancy, as observed in the past at JET and TFTR, should appear. Plasmas with Te(0 up to 8 keV are obtained using three different heating scenarios: Ion Cyclotron Resonance Heating (ICRH, ICRF mode conversion heating and a combination of the two heating methods. This is done in order to explore the hypothesis that ICRH-generated fast ions may be related to the discrepancy. In all high temperature cases at C-Mod, we find no evidence for the type of discrepancy reported at JET and TFTR. Here we present the C-Mod results along with a summary of past work on the TS-ECE discrepancy.

  18. Build-up and decline of organic matter during PeECE III

    Directory of Open Access Journals (Sweden)

    K. G. Schulz

    2008-05-01

    Full Text Available Increasing atmospheric carbon dioxide (CO2 concentrations due to anthropogenic fossil fuel combustion are currently changing the ocean's chemistry. Increasing oceanic [CO2] and consequently decreasing seawater pH have the potential to significantly impact marine life. Here we describe and analyze the build-up and decline of a natural phytoplankton bloom initiated during the 2005 mesocosm Pelagic Ecosystem CO2 Enrichment study (PeECE III. The draw-down of inorganic nutrients in the upper surface layer of the mesocosms was reflected by a concomitant increase of organic matter until day t11, the peak of the bloom. From then on, biomass standing stocks steadily decreased as more and more particulate organic matter was lost into the deeper layer of the mesocosms. We show that organic carbon export to the deeper layer was significantly enhanced at elevated CO2. This phenomenon might have impacted organic matter remineralization leading to decreased oxygen concentrations in the deeper layer of the high CO2 mesocosms as indicated by deep water ammonium concentrations. This would have important implications for our understanding of pelagic ecosystem functioning and future carbon cycling.

  19. Low energy ion beam induced changes in structural and thermal properties of polycarbonate

    Science.gov (United States)

    Reheem, A. M. Abdel; Atta, A.; Maksoud, M. I. A. Abdel

    2016-10-01

    The aim of the present study is extended for obtaining relation between the collision of ion beam with polycarbonate polymer (PC) and the introduced modification of technological applications. Polycarbonate films are irradiated by a 6 keV argon ion beam extracted from locally design cold cathode ion source with different ion fluences. The films are characterized using X-ray Diffraction (XRD), Mechanical tester, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The increase in ion beam irradiation leads to an increase in the tensile strength and reduction in elongation at break for PC. TGA Analysis shows that the thermal decomposition temperature of irradiated polycarbonate changes with ion fluence. The DSC graphs show improvements in thermal stability with increase in the activation energy after ion beam irradiation. Ion penetration depths and distributions of scattered atoms are calculated using SRIM Monte Carlo simulation programs.

  20. Effect of aligned carbon nanotubes on electrical conductivity behaviour in polycarbonate matrix

    Indian Academy of Sciences (India)

    M M Larijani; E J Khamse; Z Asadollahi; M Asadi

    2012-06-01

    This article reports effects of alignment of embedded carbon nanotubes in a polycarbonate polymer matrix under magnetic, direct and alternating current electric fields on the electrical properties of the resulting nanocomposites. Composites consisting of different quantities of carbon nanotubes in a polycarbonate matrix have been prepared using a solution casting technique. The effects of field strength and nanotube concentration on the resulted network structure and conductivity of the composites were studied by in situ optical microscopy, transmission electron microscopy and four-point probe technique. The results showed that the composites prepared in the presence of field had better conductivity than those of as-prepared composites. It was also concluded that the application of alternating current electric field and magnetic field in this system led to the formation of relatively continuing networks while direct current electric field only prevented agglomeration of the carbon nanotubes in the polycarbonate matrix and created relatively uniform distribution of nanotubes in the matrix.

  1. AL-SX (H1616) Container Support: Out-gassing of Polyethylene and Polycarbonate Resins

    Energy Technology Data Exchange (ETDEWEB)

    G.Cook Story; Leon Seibel and Linda Domeier

    1999-04-01

    Out-gassing tests were carried out on samples of polyethylene and polycarbonate packaging components used within the AL-SX (H1616) shipping container and compared to known samples of high and low density polyethylene and polycarbonate. Polyethylene is used to fabricate the shipping container overpack for the MC3007A/MC4059 and 1X-Acorn; LEXAN{reg_sign} polycarbonate (General Electric) is used to fabricate the lid of the Protective Container utilized to package the MC4213/MC4240 and MC4524 for shipment in the AL-SX (H1616). Pressure was monitored up to about 650 F and all the samples showed similar increases in pressure which were only slightly above those measured for control runs using no resin sample. None of the polymer samples showed out-gassing behavior that would lead to excessive pressure increases in the H1616 within that temperature range.

  2. Propargyl-functional aliphatic polycarbonate obtained from carbon dioxide and glycidyl propargyl ether.

    Science.gov (United States)

    Hilf, Jeannette; Frey, Holger

    2013-09-01

    The synthesis of propargyl-functional poly(carbonate)s with different content of glycidyl propargyl ether (GPE) units is achieved via the copolymerization of propargyl glycidyl ether and carbon dioxide. A new type of functional poly(carbonate) synthesized directly from CO(2) and the glycidyl ether is obtained. The resulting polymers show moderate polydispersities in the range of 1.6-2.5 and molecular weights in the range of 7000-10 500 g mol(-1). The synthesized copolymers with varying number of alkyne functionalities and benzyl azide are used for the copper-catalyzed Huisgen-1,3-dipolar addition. Moreover, the presence of vicinal alkyne groups opens a general pathway to produce functional aliphatic poly(carbonate)s from a single polymer scaffold.

  3. Postpolymerization Modifications of Alkene-Functional Polycarbonates for the Development of Advanced Materials Biomaterials.

    Science.gov (United States)

    Thomas, Anthony W; Dove, Andrew P

    2016-12-01

    Functional aliphatic polycarbonates have attracted significant attention as materials for use as biomedical polymers in recent years. The incorporation of pendent functionality offers a facile method of modifying materials postpolymerization, thus enabling functionalities not compatible with ring-opening polymerization (ROP) to be introduced into the polymer. In particular, polycarbonates bearing alkene-terminated functional groups have generated considerable interest as a result of their ease of synthesis, and the wide range of materials that can be obtained by performing simple postpolymerization modifications on this functionality, for example, through radical thiol-ene addition, Michael addition, and epoxidation reactions. This review presents an in-depth appraisal of the methods used to modify alkene-functional polycarbonates postpolymerization, and the diversity of practical applications for which these materials and their derivatives have been used. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Data in support of preparation and functionalization of a clickable polycarbonate monolith

    Directory of Open Access Journals (Sweden)

    Yuanrong Xin

    2016-06-01

    Full Text Available This data article provides supplementary figures to the research article entitled, “Phase separation approach to a reactive polycarbonate monolith for “click” modifications” (Xin et al., Polymer, 2015, doi:10.1016/j.polymer.2015.04.008. Here, the nitrogen adsorption/desorption isotherms of the prepared porous polycarbonate monolith are shown to classify its inner structure and calculate the specific surface area. The monoliths were modified by using the thiol-ene click chemistry and the olefin metathesis, which was examined by contact angle measurements, FT-IR, solid state 13C NMR spectroscopy as well as thermogravimetric analysis.

  5. ESC resistance of commercial grade polycarbonates during exposure to butter and related chemicals

    DEFF Research Database (Denmark)

    Kjellander, Carina Koch; Nielsen, Tenna B; Ghanbari-Siahkali, Afshin

    2008-01-01

    Three commercial grades of polycarbonates (Lexan (R) 144, Lexan (R) 104 and Makrolon Rx1805) were studied with respect to resistance to environmental stress cracking (ESC) when exposed to butter and related chemicals. The polycarbonates (PCs) were extensively characterised to determine whether......, such as butter, cause the PCs to be less resistant to ESC under stress. The reason for this is that these chemicals and the PCs have sufficiently similar Hansen solubility parameters to allow surface conformational changes even though absorption is non-existent or extremely small. ATR-FTIR was used to detect...

  6. Air pollutants and toxic emissions of various mileage motorcycles for ECE driving cycles

    Science.gov (United States)

    Tsai, Jiun-Horng; Huang, Pei-Hsiu; Chiang, Hung-Lung

    2017-03-01

    Motorcycles were selected to determine their fuel consumption and exhaust emissions following ECE driving cycles. Exhaust constituents including CO2, CO, NOx, total hydrocarbons (THC) and hydrocarbon species (27 paraffins, 9 olefins, 16 aromatics and 15 carbonyls) were investigated for this work. The age of 10- 90% of the selected motorcycles ranged from 2.5 to 12.4 years, and their mileage ranged from 5400 to 39,300 km. CO emission ranged from 1.4 to 6.4 g/km (median value: 2.98 g/km), THC from 0.41 to 1.54 g/km (median value: 0.98 g/km), NOx from 0.16 to 0.28 g/km (median value: 0.21 g/km), CO2 from 58.9 to 62.2 g/km (median value: 60.5 g/km) and fuel consumption from 30.7 to 36.4 km/L (median value: 33.4 km/L), corresponding to the percentage cumulative data from 10 to 90% of the selected motorcycles. Results indicated that the motorcycle exhaust emission and fuel consumption depended on their mileage and ages. An increase in mileage of 1000 km resulted in an increase of 103 mg for CO emission and 14.7 mg for hydrocarbon emission and a reduction of 1.52 mg NOx emission and 0.11 km per liter fuel consumption. For various VOC groups, a mileage increase of 1000 km corresponding to the increased exhaust emission of paraffins was 6.71 mg, olefins 1.90 mg, aromatics 7.04 mg, carbonyls 0.283 mg and 67 VOC species 15.9 mg. Fuel consumption and emissions of CO and hydrocarbon increased in motorcycles over the guaranteed mileage of 15,000 km.

  7. Single-sheet identification method of heavy charged particles using solid state nuclear track detectors

    Indian Academy of Sciences (India)

    M F Zaki; A Abdel-Naby; A Ahmed Morsy

    2007-08-01

    The theoretical and experimental investigations of the penetration of charged particles in matter played a very important role in the development of modern physics. Solid state nuclear track detectors have become one of the most important tools for many branches of science and technology. An attempt has been made to examine the suitability of the single-sheet particle identification technique in CR-39 and CN-85 polycarbonate by plotting track cone length vs. residual range for different heavy ions in these detectors. So, the maximum etchable ranges of heavy ions such as 93Nb, 86Kr and 4He in CR-39 and 4He and 132Xe in CN-85 polycarbonate have been determined. The ranges of these ions in these detectors have also been computed theoretically using the Henke–Benton program. A reasonably good agreement has been observed between the experimentally and theoretically computed values.

  8. Optimization of Optical Properties of Polycarbonate Film with Thiol Gold-Nanoparticles

    Directory of Open Access Journals (Sweden)

    Claudio Larosa

    2009-09-01

    Full Text Available A new nanostructured composite film based on thiol gold nanoparticles dispersed in polycarbonate and prepared by evaporating a solution of 1-dodecanthiol gold nanoparticles and polycarbonate was developed for applications as optical lenses. Lenses with superior mechanical properties, coloring and UV ray absorption and with the same transparency as the matrix were obtained. The supporting highly transparent polycarbonate matrix and the chloroform solution of thiol gold nanoparticles, 3 nm mean size, was mixed according to a doping protocol employing different concentrations of thiol gold nanoparticles vs. polycarbonate. The presence of nanoparticles in the polymer films was confirmed by the spectrophotometric detection of the characteristic absorbance marker peak at 540–580 nm. The nanostructured films obtained show a better coverage in the UV-vis range (250–450 nm even at very low doping ratios, of the order of 1:1,000. These results offer a very promising approach towards the development of efficient nanostructured materials for applications to optical lenses.

  9. Micromachining of microchannel on the polycarbonate substrate with CO 2 laser direct-writing ablation

    Science.gov (United States)

    Qi, Heng; Chen, Tao; Yao, Liying; Zuo, Tiechuan

    2009-05-01

    Low-power CO 2 laser direct-writing ablation was used to micromachine a microchannel on the polycarbonate substrate in this work. The influence of the process parameters (the laser power, the moving velocity of the laser beam and the scanning times) on the micromachining quality (the depth, the width and their aspect ratio) of the microchannel was experimentally studied. The depth and width of microchannel both increase with the increase of the laser power and the decrease of the moving velocity of the laser beam. When higher laser power and slower moving velocity were used, the polycarbonate surface bore more heat irradiated from the CO 2 laser for longer time which results in the formation of deeper and wider molten pool, hence the ability to fabricate bigger microchannel. Because of the effect of the laser power on the depth and width of microchannels, higher aspect (depth/width) ratio could be achieved using slower moving velocity and higher laser power, and it would reach a steady state when the laser power increases to 9.0 W possibly caused by the effect of laser power on the different directions of microchannel. The polycarbonate-polycarbonate chip was bonded with hot-press bonding technique.

  10. The use of birefringence for predicting the stiffness of injection molded polycarbonate discs

    NARCIS (Netherlands)

    Neves, N.M.; Pouzada, A.S.; Voerman, J.H.D.; Powell, P.C.

    1998-01-01

    Polycarbonate discs were injection molded with different sets of molding conditions. The parameters studied were the flow rate, melt- and mold-temperature. The discs were subjected to three point support flexural tests. Those tests are specially intended for injection molded discs because of their i

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

    Directory of Open Access Journals (Sweden)

    Rokas Šakalys

    2013-08-01

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

  12. Polycarbonate as an elasto-plastic material model for simulation of the microstructure hot imprint process.

    Science.gov (United States)

    Narijauskaitė, Birutė; Palevičius, Arvydas; Gaidys, Rimvydas; Janušas, Giedrius; Sakalys, Rokas

    2013-08-22

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

  13. Measurements of diffusion parameters of methanol on gamma-irradiated polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Pietro P.J.C.G.P.O.; Araujo, Elmo S., E-mail: esa@ufpe.br, E-mail: pietropaolo@ipojuca.ifpe.edu.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Silveira, Leopoldo B.B. da [Highplastic Industria de Plasticos Ltda, Simoes Filho, BA (Brazil)

    2013-07-01

    Polycarbonate (PC) is an engineering polymer which presents interesting properties such as toughness, light weight and transparency. This material has been used for several important applications including in the medical field. In this particular application, polycarbonate has been exposed frequently to gamma irradiation and to chemical environment that can be able to product significant changes in polymer structure that may lead to future catastrophic fail and rupture. Polymer structural damages induced by gamma irradiation or chemical attack (environment stress cracking) have been studied by several research groups for many years and for many solvent-polymer systems, but few reporters present informations about the simultaneous occurrence of these effects. This present work has the goal to understand the diffusion process of methanol in polycarbonate and to determinate the diffusion parameters on polymer system under 100 kGy of gamma irradiation. Swelling experiments were performed at the samples of polycarbonate divided in two groups: PC-0 (without dose) and PC-100 (with 100 kGy of dose). Diffusion parameters (D) may be measured by slope of the sorption curve for polymers with Fickian behavior. A comparison of the D parameters was made for each set of sample. There were no significant differences on D values of sample groups observed due to the radiation effects. However, stress strain curves obtained show that methanol has great influence on mechanical behavior of PC but the radiation dose don't have significant influence on this mechanical behavior. (author)

  14. Pyrolysis kinetics and thermal decomposition behavior of polycarbonate - a TGA-FTIR study

    Directory of Open Access Journals (Sweden)

    Apaydin-Varol Esin

    2014-01-01

    Full Text Available This study covers the thermal degradation of polycarbonate by means of Thermogravimetric Analyzer coupled with Fourier transform infrared spectrometer (TGA-FTIR. Thermogravimetric analysis of polycarbonate was carried out at four different heating rates of 5, 10, 15, and 20°C per minute from 25°C to 1000°C under nitrogen atmosphere. The results indicated that polycarbonate was decomposed in the temperature range of 425-600°C. The kinetic parameters, such as activation energy, pre-exponential factor and reaction order were determined using five different kinetic models; namely Coast-Redfern, Friedman, Kissinger, Flynn-Wall-Ozawa (FWO, and Kissinger-Akahira-Sunose (KAS. Overall decomposition reaction order was determined by Coats-Redfern method as 1.5. Average activation energy was calculated as 150.42, 230.76, 216.97, and 218.56 kJ/mol by using Kissinger, Friedman, FWO, and KAS models, respectively. Furthermore, the main gases released during the pyrolysis of polycarbonate were determined as CO2, CH4, CO, H2O, and other lower molecular weight hydrocarbons such as aldehydes, ketones and carbonyls by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometer.

  15. Organocatalytic Ring-Opening Polymerization of Trimethylene Carbonate to Yield a Biodegradable Polycarbonate

    Science.gov (United States)

    Chan, Julian M. W.; Zhang, Xiangyi; Brennan, Megan K.; Sardon, Haritz; Engler, Amanda C.; Fox, Courtney H.; Frank, Curtis W.; Waymouth, Robert M.; Hedrick, James L.

    2015-01-01

    In this laboratory experiment, students work in pairs to synthesize a simple aliphatic polycarbonate via ring-opening polymerization of trimethylene carbonate using 1,8-diazabicyclo[5.4.0]undec-7-ene and thiourea as organocatalysts. Following polymer isolation, students cool the material in a dry ice/acetone bath to observe its glass-transition…

  16. Bonding polycarbonate brackets to ceramic: : Effects of substrate treatment on bond strength

    NARCIS (Netherlands)

    Özcan, Mutlu; Vallittu, Pekka K.; Peltomäki, Timo; Huysmans, Marie-Charlotte; Kalk, Warner

    2004-01-01

    This study evaluated the effects of 5 different surface conditioning methods on the bond strength of polycarbonate brackets bonded to ceramic surfaces with resin based cement. Six disc-shaped ceramic specimens (feldspathic porcelain) with glazed surfaces were used for each group. The specimens were

  17. Bonding polycarbonate brackets to ceramic : Effects of substrate treatment on bond strength

    NARCIS (Netherlands)

    Özcan, Mutlu; Vallittu, Pekka K.; Peltomäki, Timo; Huysmans, Marie-Charlotte; Kalk, Warner

    2004-01-01

    This study evaluated the effects of 5 different surface conditioning methods on the bond strength of polycarbonate brackets bonded to ceramic surfaces with resin based cement. Six disc-shaped ceramic specimens (feldspathic porcelain) with glazed surfaces were used for each group. The specimens were

  18. Polycarbonate modified with crystallisable bis-ester tetra-amide units in a reaction extrusion process

    NARCIS (Netherlands)

    Zuiderduin, W.C.J.; Gaymans, R.J.

    2008-01-01

    Dry blends of polycarbonate (PC) and a bis-ester tetra-amide were extruded at 305 °C with a mini twin screw extruder. The bis-ester tetra-amide diamide (T6T6T-dimethyl) was composed of two and a half repeat units of Nylon 6,T and had methyl ester endgroups. During the extrusion, a

  19. Study of the Polycarbonate-Urethane/Metal Contact in Different Positions during Gait Cycle

    Directory of Open Access Journals (Sweden)

    Sergio Gabarre

    2014-01-01

    Full Text Available Nowadays, a growing number of young and more active patients receive hip replacement. More strenuous activities in such patients involve higher friction and wear rates, with friction on the bearing surface being crucial to ensure arthroplasty survival in the long term. Over the last years, the polycarbonate-urethane has offered a feasible alternative to conventional bearings. A finite element model of a healthy hip joint was developed and adjusted to three gait phases (heel strike, mid-stance, and toe-off, serving as a benchmark for the assessment of the results of joint replacement model. Three equivalent models were made with the polycarbonate-urethane Tribofit system implanted, one for each of the three gait phases, after reproducing a virtual surgery over the respective healthy models. Standard body-weight loads were considered: 230% body-weight toe-off, 275% body-weight mid-stance, and 350% body-weight heel strike. Contact pressures were obtained for the different models. When comparing the results corresponding to the healthy model to polycarbonate-urethane joint, contact areas are similar and so contact pressures are within a narrower value range. In conclusion, polycarbonate-urethane characteristics are similar to those of the joint cartilage. So, it is a favorable alternative to traditional bearing surfaces in total hip arthroplasty, especially in young patients.

  20. Bisphenol-A: an estrogenic substance is released from polycarbonate flasks during autoclaving.

    Science.gov (United States)

    Krishnan, A V; Stathis, P; Permuth, S F; Tokes, L; Feldman, D

    1993-06-01

    In studies to determine whether Saccharomyces cerevisiae produced estrogens, the organism was grown in culture media prepared using distilled water autoclaved in polycarbonate flasks. The yeast-conditioned media showed the presence of a substance that competed with [3H]estradiol for binding to estrogen receptors (ER) from rat uterus. However, it soon became clear that the estrogenic substance in the conditioned media was not a product of the yeast grown in culture, but was leached out of the polycarbonate flasks during the autoclaving procedure. [3H]Estradiol displacement activity was monitored by ER RRA, and the active substance was purified from autoclaved medium using a series of HPLC steps. The final purified product was identified as bisphenol-A (BPA) by nuclear magnetic resonance spectroscopy and mass spectrometry. BPA could also be identified in distilled water autoclaved in polycarbonate flasks without the requirement of either the organism or the constituents of the culture medium. Authentic BPA was active in competitive RRAs, demonstrating an affinity approximately 1:2000 that of estradiol for ER. In functional assays, BPA (10-25 nM) induced progesterone receptors in cultured human mammary cancer cells (MCF-7) at a potency of approximately 1:5000 compared to that of estradiol. The BPA effect on PR induction was blocked by tamoxifen. In addition, BPA (25 nM) increased the rate of proliferation of MCF-7 cells assessed by [3H]thymidine incorporation. Thus, BPA exhibited estrogenic activity by both RRA and two functional bioresponse assays. Finally, MCF-7 cells grown in media prepared with water autoclaved in polycarbonate exhibited higher progesterone receptor levels than cells.grown in media prepared with water autoclaved in glass, suggesting an estrogenic effect of the water autoclaved in polycarbonate. Our findings raise the possibility that unsuspected estrogenic activity in the form of BPA may have an impact on experiments employing media autoclaved in

  1. A Study on Control Strategy of Regenerative Braking in the Hydraulic Hybrid Vehicle Based on ECE Regulations

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2013-01-01

    Full Text Available This paper establishes a mathematic model of composite braking in the hydraulic hybrid vehicle and analyzes the constraint condition of parallel regenerative braking control algorithm. Based on regenerative braking system character and ECE (Economic Commission of Europe regulations, it introduces the control strategy of regenerative braking in parallel hydraulic hybrid vehicle (PHHV. Finally, the paper establishes the backward simulation model of the hydraulic hybrid vehicle in Matlab/simulink and makes a simulation analysis of the control strategy of regenerative braking. The results show that this strategy can equip the hydraulic hybrid vehicle with strong brake energy recovery power in typical urban drive state.

  2. Characterization of saturated MHD instabilities through 2D electron temperature profile reconstruction from 1D ECE measurements

    Science.gov (United States)

    Sertoli, M.; Horváth, L.; Pokol, G. I.; Igochine, V.; Barrera, L.

    2013-05-01

    A new method for the reconstruction of two-dimensional (2D) electron temperature profiles in the presence of saturated magneto-hydro-dynamic (MHD) modes from the one-dimensional (1D) electron cyclotron emission (ECE) diagnostic is presented. The analysis relies on harmonic decomposition of the electron temperature oscillations through short time Fourier transforms and requires rigid poloidal mode rotation as the only assumption. The method is applicable to any magnetic perturbation as long as the poloidal and toroidal mode numbers m and n are known. Its application to the case of a (m, n) = (1, 1) internal kink mode on ASDEX Upgrade is presented and a new way to estimate the mode displacement is explained. For such modes, it is shown that the higher order harmonics usually visible in the ECE spectrogram arise also for the pure m = n = 1 mode and that they cannot be directly associated with m = n > 1 magnetic perturbations. This method opens up new possibilities for electron heat transport studies in the presence of saturated MHD modes and a way to disentangle the impurity density contributions from electron temperature effects in the analysis of the soft x-ray data.

  3. Registration of alpha particles in Makrofol-E nuclear track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Rammah, Y.S. [Physics Department, Faculty of Science, Menoufia University, Shebin El-Koom (Egypt); Abdalla, Ayman M., E-mail: aymanabdalla62@hotmail.com [Physics Department, Faculty of Sciences and Arts, Najran University, P. O. Box. 11001, Najran (Saudi Arabia); Promising Centre for Sensors and Electronic Devices, Faculty of Arts and Sciences, Najran University (Saudi Arabia); Ashraf, O., E-mail: osama.ashraf@edu.asu.edu.eg [Physics Department, Faculty of Education, Ain Shams University, Cairo 11575 (Egypt); Ashry, A.H. [Physics Department, Faculty of Education, Ain Shams University, Cairo 11575 (Egypt)

    2016-06-15

    Highlights: • Makrofol-E detectors have been irradiated with alpha particles and fission fragments. • Fast detection of alpha particles in Makrofol-E detectors. • Bulk etching rate was calculated from fission track diameters. - Abstract: Fast detection of alpha particles in the range from 1 to 5 MeV in Makrofol-E polycarbonate nuclear track detectors (PCTDs) using a new chemical etchant was investigated. {sup 252}Cf and {sup 241}Am-thin open sources were used for irradiating Makrofol-E detectors with fission fragments and alpha particles in air at normal pressure and temperature (NPT). A chain of experimental work has been carried out using new etchants to register alpha particle in short time in Makrofol-E polycarbonate detectors. The etching efficiency were exhibited a clear dependence on the amount of methanol in the etching solution and etching time. The optimized chemical condition obtained at this stage of development for 200 μm Makrofol-E detectors are (8 ml of 10 N NaOH + 2 ml CH{sub 3}OH) etching solutions at 60 °C for 3 h. In this study; it is possible to observe energy detection windows for Makrofol-E detectors according to applied etching duration. Makrofol-E introduced the characteristic Bragg peak, which indicates the advantages of this detector as alpha spectrometer. Consequently, the suggested new etchant can be developed for heavy ions detection and monitoring radon levels and its daughters.

  4. Effect of alkali treatment on the morphology and tensile properties of Cordia dichotoma fabric/polycarbonate composites

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2013-05-01

    Full Text Available Advances in Polymer Technology, Vol. 32, No. 3, 2013 Effect of Alkali Treatment on the Morphology and Tensile Properties of Cordia Dichotoma Fabric/Polycarbonate Composites J. JAYARAMUDU, G. SIVAMOHAN REDDY, K. VARAPRASAD, E. R. SADIKU Department...

  5. On the effect of the fiber orientation on the flexural stiffness of injection molded short fiber reinforced polycarbonate plates

    NARCIS (Netherlands)

    Neves, N.M.; Isdell, G.; Pouzada, A.S.; Powell, P.C.

    1998-01-01

    The through-thickness fiber orientation distribution of injection molded polycarbonate plates was experimentally determined by light reflection microscopy and manual digitization of polished cross sections. Fiber length distribution was determined by pyrolysis tests followed by image analysis. A sta

  6. Characterization of Environmental Dust in the Dammam Area and Mud After-Effects on Bisphenol-A Polycarbonate Sheets

    Science.gov (United States)

    Yilbas, Bekir Sami.; Ali, Haider; Al-Aqeeli, Naseer; Khaled, Mazen M.; Said, Syed; Abu-Dheir, Numan; Merah, Necar; Youcef-Toumi, Kamal; Varanasi, Kripa K.

    2016-04-01

    Owing to recent climate changes, dust storms are increasingly common, particularly in the Middle East region. Dust accumulation and subsequent mud formation on solid surfaces in humid environments typically have adverse effects on surface properties such as optical transmittance, surface texture, and microhardness. This is usually because the mud, which contains alkaline and ionic species, adheres strongly to the surface, often through chemical bonds, and is therefore difficult to remove. In this study, environmental dust and the after-effects of mud formed on a polycarbonate sheet, which is commonly used as a protective glass in photovoltaic cells. Ionic compounds (OH-) are shown to significantly affect the optical, mechanical, and textural characteristics of the polycarbonate surface, and to increase the adhesion work required to remove the dry mud from the polycarbonate surface upon drying. Such ability to modify characteristics of the polycarbonate surface could address the dust/mud-related limitations of superhydrophobic surfaces.

  7. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  8. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  9. Coatings prepared from waterborne polyurethane dispersions obtained with polycarbonates of 1,6-hexanediol of different molecular weights

    OpenAIRE

    García Pacios, Vanesa; Jofre-Reche, José Antonio; Costa, Víctor; Colera, Manuel; Martín-Martínez, José Miguel

    2013-01-01

    Waterborne polyurethane dispersions (PUDs) were synthesized with polycarbonates of 1,6-hexanediol of different molecular weight (500–3000 Da) and their properties, adhesion (Hatch adhesion) and coatings on stainless steel properties (Pencil hardness, Persoz hardness, gloss at 60°, chemical resistance, yellowness index) were characterized. The hatch adhesion of the polyurethane coatings to stainless steel was very good and decreased slightly by increasing the molecular weight of the polycarbon...

  10. Coatings prepared from waterborne polyurethane dispersions obtained with polycarbonates of 1,6-hexanediol of different molecular weights

    OpenAIRE

    García Pacios, Vanesa; Jofre-Reche, José Antonio; Costa, Víctor; Colera, Manuel; Martín-Martínez, José Miguel

    2013-01-01

    Waterborne polyurethane dispersions (PUDs) were synthesized with polycarbonates of 1,6-hexanediol of different molecular weight (500–3000 Da) and their properties, adhesion (Hatch adhesion) and coatings on stainless steel properties (Pencil hardness, Persoz hardness, gloss at 60°, chemical resistance, yellowness index) were characterized. The hatch adhesion of the polyurethane coatings to stainless steel was very good and decreased slightly by increasing the molecular weight of the polycarbon...

  11. Electroless synthesis of lepidocrocite ({gamma}-FeOOH) nanotubes in ion track etched polycarbonate templates

    Energy Technology Data Exchange (ETDEWEB)

    Neetzel, C., E-mail: Neetzel@ca.tu-darmstadt.de [Darmstadt University of Technology, Department of Materials Science, Materials Analysis Group, D-64287 Darmstadt (Germany); Gasi, T.; Ksenofontov, V.; Felser, C. [Johannes Gutenberg University of Mainz, Institute of Inorganic and Analytical Chemistry, D-55128 Mainz (Germany); Ionescu, E. [Darmstadt University of Technology, Department of Materials Science, Dispersive Solids, D-64287 Darmstadt (Germany); Ensinger, W. [Darmstadt University of Technology, Department of Materials Science, Materials Analysis Group, D-64287 Darmstadt (Germany)

    2012-07-01

    In this study, we describe the electroless synthesis of lepidocrocite ({gamma}-FeOOH) nanotubes produced in ion track etched polycarbonate foils. The foils act as templates after they had been irradiated with heavy ions to produce latent tracks that were etched with a desired diameter. Templates are used to fabricate shape formed 1D nanostructures in general. The synthesis of lepidocrocite nanotubes was carried out in a simple two-step method: firstly, particles were formed by precipitation in aqueous solution; secondly, nanotubes were produced by the deposition of the particles inside the nanochannels of the polycarbonate template. Solvent effects were considered to achieve homogeneous growth resulting in well-defined nanotubes of constant wall thickness along the tube axis. Lepidocrocite nanotubes were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Raman, and Moessbauer spectroscopy.

  12. Enzyme-catalyzed polycondensation reactions for the synthesis of aromatic polycarbonates and polyesters.

    Science.gov (United States)

    Rodney, R L; Allinson, B T; Beckman, E J; Russell, A J

    1999-11-20

    Aromatic polymers are widely used in products ranging from optical lenses to milk bottles because of their strength, thermal durability, and high glass transition temperatures. All of the commonly used routes employed to generate aromatic polycarbonates and polyesters generate large amounts of waste as by-products and require high energy input. For these reasons, alternate routes to aromatic polymers which involve either less energy input or less waste generation are being investigated. One such route may be enzymatic. Herein we describe enzyme-catalyzed AA-BB condensation polymerizations to form aromatic polycarbonates and polyesters with six different aromatic diols and molecular weights of up to 5,200 Daltons are generated. In addition, for reactions with benzenedimethanol the enzyme exhibits regioselectivity for parahydroxyls over meta- and orthohydroxyls.

  13. Impact of the structure of biocompatible aliphatic polycarbonates on siRNA transfection ability.

    Science.gov (United States)

    Frère, Antoine; Kawalec, Michal; Tempelaar, Sarah; Peixoto, Paul; Hendrick, Elodie; Peulen, Olivier; Evrard, Brigitte; Dubois, Philippe; Mespouille, Laetitia; Mottet, Denis; Piel, Géraldine

    2015-03-09

    RNAi therapeutics are promising therapeutic tools that have sparked the interest of many researchers. In an effort to provide a safe alternative to PEI, we have designed a series of new guanidinium- and morpholino-functionalized biocompatible and biodegradable polycarbonate vectors. The impact of different functions (morpholino-, guanidinium-, hydrophobic groups) of the architecture (linear homopolymer to dumbbell-shape) and of the molecular weight of these copolymers on their capacity to form polyplexes and to decrease the expression of two epigenetic regulators of gene expression, HDAC7 and HDAC5, was evaluated. The use of one of these polymers combining morpholine and guanidine functions at the ratio >1 and hydrophobic trimethylene carbonate groups showed a significant decrease of mRNA and protein level in HeLa cells, similar to PEI. These results highlight the potential of polycarbonate vectors for future in vivo application as an anticancer therapy.

  14. Femtosecond laser fabrication of linear graphitized microstructures in a bulk of polycarbonate samples

    Science.gov (United States)

    Ganin, D. V.; Lapshin, K. E.; Obidin, A. Z.; Vartapetov, S. K.

    2016-08-01

    We have fabricated high aspect ratio straight and curved graphitized lines inside of polycarbonate samples by using a femtosecond laser. Use of a spherical lens with high NA to focusing femtosecond pulse in the bulk of material leads to self-diffraction of laser beam and formation a filamentary structure. We fabricated two kinds of graphitized lines. The first type is a straight line extended in the direction of the laser beam. This type of lines was created by femtosecond laser scanning without pulse overlapping. The second type of graphitized lines is curved lines, which was created by scanning with a significant overlapping of focal spot. We determined conditions of the formation of straight graphitized lines by one femtosecond pulse with diameter about 2 pm and length greater than 1 mm in polycarbonate samples. Mechanism of formation and potential applications of these structures are also discussed.

  15. Comparison of quasistatic to impact mechanical properties of multiwall carbon nanotube/polycarbonate composites

    Energy Technology Data Exchange (ETDEWEB)

    Brühwiler, Paul A.; Barbezat, Michel; Necola, Adly; Kohls, Doug J.; Bunk, Oliver; Schaefer, Dale W.; Pötschke, Petra (PSI); (EMMPA); (UCIN); (Leibniz)

    2010-10-22

    We report the quasistatic tensile and impact penetration properties (falling dart test) of injection-molded polycarbonate samples, as a function of multiwall carbon nanotube (MWNT) concentration (0.0-2.5%). The MWNT were incorporated by dilution of a commercial MWNT/polycarbonate masterbatch. The stiffness and quasistatic yield strength of the composites increased approximately linearly with MWNT concentration in all measurements. The energy absorbed in fracture was, however, a negative function of the MWNT concentration, and exhibited different dependencies in quasistatic and impact tests. Small-angle x-ray scattering (SAXS) showed that the dispersion of the MWNT was similar at all concentrations. The negative effects on energy absorption are attributed to agglomerates remaining in the samples, which were observed in optical microscopy and SAXS. Overall, there was a good correspondence between static and dynamic energy absorption.

  16. Controlled nanodot fabrication by rippling polycarbonate surface using an AFM diamond tip

    OpenAIRE

    2014-01-01

    The single scratching test of polymer polycarbonate (PC) sample surface using an atomic force microscope (AFM) diamond tip for fabricating ripple patterns has been studied with the focus on the evaluation of the effect of the tip scratching angle on the pattern formation. The experimental results indicated that the different oriented ripples can be easily machined by controlling the scratching angles of the AFM. And, the effects of the normal load and the feed on the ripples formation and the...

  17. Open-cell foams of polyethylene terephthalate/bisphenol a polycarbonate blend

    OpenAIRE

    Gong, Pengjian; Ohshima, Masahiro

    2014-01-01

    Open microcellular foams of polyethylene terephthalate (PET)/polycarbonate (PC) blends were prepared by controlling their foaming behavior at the interface between these two polymers. Interface modification was a crucial factor in governing the foaming behavior and cell morphology of the blend foams: annealing at 280°C, i.e., conducting the transesterification reaction, generates a PET-b-PC copolymer, which lowers the interfacial tension, increases the affinity between PET and PC, and decreas...

  18. Studies of Elastic Properties on Stretch Films of Polycarbonate by Brillouin Scattering.

    Science.gov (United States)

    1982-02-22

    axis or shear modulus about the axis may not be significantly affected. However, in polymers, 1 21such as poly(ethylene terephthalate ) , polyethylene ...although the C33 values for the unstretched poly-- (ethylene terephthalate ) ( PET ) and polypropylene (PP) films are lower than that for the PC film...AD-Al12 208 UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY F/6 11/9 STUDIES OF ELASTIC PROPERTIES ON STRETCH FILMS OF POLYCARBONATE -ETC(U) FEA 82 0 LIU

  19. Tensile Deformation and Adiabatic Heating in Post-Yield Response of Polycarbonate

    Science.gov (United States)

    2015-11-01

    strain histories for max and gage length and b) stress-strain behavior of PC at intermediate rate for max and gage length 8 3.4 Rate Effects on... frame . To determine the variations in yield and post-yield response at different locations of the gage area of the specimen, digital image...significant rate-sensitive mechanical response. 15. SUBJECT TERMS polycarbonate, tension, rate effects , thermal, heating 16. SECURITY CLASSIFICATION OF

  20. Synthesis and Characterization of Novel Aliphatic Polycarbonates Bearing Pendant Allyl Ether Groups

    Institute of Scientific and Technical Information of China (English)

    Gang LIU; Feng HE; Yan Ping WANG; Jun FENG; Ren Xi ZHUO

    2006-01-01

    A new six-membered cyclic carbonate monomer, 5-allyloxytrimethylene carbonate (ATMC), was synthesized starting from glycerol, and the corresponding polycarbonates,poly(5-allyloxytrimethylene carbonate)(PATMC) were further synthesized by ring-opening polymerization in bulk at 150 ℃ using stannous octanoate as an initiator. The structures of the monomer and the polymers were confirmed by IR, 1H-NMR, 13C-NMR, and GPC analysis.

  1. Polycarbonate modified with crystallisable bis-ester tetra-amide units in a reaction extrusion process

    NARCIS (Netherlands)

    Zuiderduin, W.C.J.; Gaymans, R.J.

    2008-01-01

    Dry blends of polycarbonate (PC) and a bis-ester tetra-amide were extruded at 305 °C with a mini twin screw extruder. The bis-ester tetra-amide diamide (T6T6T-dimethyl) was composed of two and a half repeat units of Nylon 6,T and had methyl ester endgroups. During the extrusion, a trans-esterificati

  2. Cole-cole analysis and electrical conduction mechanism of N{sup +} implanted polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Mahak; Shekhawat, Nidhi; Aggarwal, Sanjeev, E-mail: write2sa@gmail.com; Sharma, Annu [Department of Physics, Kurukshetra University, Kurukshetra 136119 (India); Nair, K. G. M. [Consultant, UGC-DAE Consortium for Scientific Research, Kalpakkam Node, Kokilamedu 603104, Tamil Nadu (India)

    2014-05-14

    In this paper, we present the analysis of the dielectric (dielectric constant, dielectric loss, a.c. conductivity) and electrical properties (I–V characteristics) of pristine and nitrogen ion implanted polycarbonate. The samples of polycarbonate were implanted with 100 keV N{sup +} ions with fluence ranging from 1 × 10{sup 15} to 1 × 10{sup 17} ions cm{sup −2}. The dielectric measurements of these samples were performed in the frequency range of 100 kHz to 100 MHz. It has been observed that dielectric constant decreases whereas dielectric loss and a.c. conductivity increases with increasing ion fluence. An analysis of real and imaginary parts of dielectric permittivity has been elucidated using Cole-Cole plot of the complex permittivity. With the help of Cole-Cole plot, we determined the values of static dielectric constant (ε{sub s}), optical dielectric constant (ε{sub ∞}), spreading factor (α), average relaxation time (τ{sub 0}), and molecular relaxation time (τ). The I–V characteristics were studied using Keithley (6517) electrometer. The electrical conduction behaviour of pristine and implanted polycarbonate specimens has been explained using various models of conduction.

  3. Experimental and theoretical studies of agglomeration effects in multi-walled carbon nanotube-polycarbonate melts

    Directory of Open Access Journals (Sweden)

    2009-12-01

    Full Text Available In this study we report on morphological and rheological characterization of multi-walled carbon nanotube (MWNT-polycarbonate composites produced by injection molding. The main focus is to carry out nonlinear viscoelastic experiments that allow following the structural rearrangements of carbon nanotubes in the polycarbonate melt. Small angle X-ray scattering reveals only a slight orientation of MWNTs in the as-received samples, i.e. after application of extremely high shear rates. Thus, the main structural effect observed during the stress growth experiment is the breakage of MWNT agglomerates. To study this effect in detail a flocculation experiment, in which the sample undergoes oscillatory deformation first at a small strain amplitude in the linear regime succeeded by higher amplitudes in the nonlinear regime, has been carried out. The agglomeration process manifests itself in an increase of the storage and loss moduli in the linear regime, whereas the deagglomeration process does vice versa. The corresponding effects can be described in the frame of a superposition approach that takes into account the stress contribution of the polycarbonate matrix, the hydrodynamic reinforcement due to embedded nanotubes and the viscoelastic stress due to the presence of a MWNT-network.

  4. Solid, double-metal cyanide catalysts for synthesis of hyperbranched polyesters and aliphatic polycarbonates

    Indian Academy of Sciences (India)

    Joby Sebastian; Srinivas Darbha

    2014-03-01

    Fe-Zn and Co-Zn double-metal cyanide (DMC) complexes exhibit highly efficient and selective catalytic activity for synthesis of hyperbranched polyesters (glycerol-succinic acid (G-SA) and glycerol-adipic acid (G-AA)) and aliphatic polycarbonates (via., alternative co-polymerization of cyclohexene oxide and CO2), respectively. The influence of method of preparation of DMC, in particular the mode of addition of reagents, on its physicochemical and catalytic properties was investigated. Co-Zn DMC was found highly selective for polycarbonate (than polyethers) formation. Catalysts prepared using tert-butanol and PEG-4000 as complexing and co-complexing agents, respectively, were found superior to those prepared without these agents. Apart from its role as a coordinating ligand, tert-butanol activated the Lewis acidic Zn2+ sites for reactions in polyester and polycarbonate formation. Hydrophobicity, micro-mesoporosity, acid strength and the amount of coordinated complexing agent are some of the crucial factors influenced the catalytic activity of DMC complexes.

  5. Effect of chemical substituents on the structure of glassy diphenyl polycarbonates.

    Science.gov (United States)

    Sulatha, M S; Natarajan, Upendra

    2011-02-24

    Polycarbonates offer a wide variety of physical property behavior that is difficult to predict due to complexities at the molecular scale. Here, the physical structure of amorphous glassy polycarbonates having aliphatic and cycloaliphatic chemical groups is explored through atomistic simulations. The influence of chemical structure on solubility parameter, torsion distributions, radial distribution function, scattering structure factor, orientation distributions of phenylene rings and carbonate groups, and free volume distributions, leading to interchain packing effects, are shown. The effect of the cyclohexyl ring at the isopropylidene carbon as compared to the effect of the methyl groups positioned on the phenylene rings results in a larger reduction in the solubility parameter (δ). The interchain distance estimated for polycarbonates in this work is in the range of 5-5.8 Å. The o-methyl groups on the phenylene rings, as compared to a cyclohexyl ring, lead to higher interchain distances. The highest interchain distance is observed with a trimethylcyclohexylidene group at the isopropylidene carbon. Atomistic simulations reveal two different types of packing arrangement of nearest-neighbor chains in the glassy state, one type of which agrees with the NMR experimental data. The fundamental insights provided here can be utilized for design of chemical structures for tailored macroscopic properties.

  6. Preparation and Characterization of Polycarbonate Modified Multiple-walled Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    YU Jin-Gang; HUANG Ke-Long; LIU Su-Qin; TANG Jin-Chun

    2008-01-01

    To prepare polymer/carbon nanotube composites, polycarbonate was chosen to modify multiple-walled carbon nanotubes. Poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)], poly(butylene-co-ε-caprolactone carbonate),and poly[(propylene oxide)-co-(carbon dioxide)-co-(maleic anhydride)] were the polycarbonates which were used to modify multiple-walled carbon nanotubes, but only soluble poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)] modified multiple-walled carbon nanotubes could be obtained. Thermogravimetric analysis clearly indicated that more polycarbonates were attached to soluble poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)] modified multiple-walled carbon nanotubes. The formation of surface functional groups and changes of nanotube structures and morphology were monitored by infrared spectroscopy, scanning electron microscopy and transmission electron microscopy, respectively. Because of their solubility and bioactive moieties,poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)] modified multiple-walled carbon nanotubes may find their potential use in drug delivery.

  7. Stability of Atmospheric-Pressure Plasma Induced Changes on Polycarbonate Surfaces

    Science.gov (United States)

    Sharma, Rajesh; Holcomb, Edward; Trigwell, Steve

    2006-01-01

    Polycarbonate films are subjected to plasma treatment in a number of applications such as improving adhesion between polycarbonate and silicon alloy in protective and optical coatings. The changes in surface chemistry due to plasma treatment have tendency to revert back. Thus stability of the plasma induced changes on polymer surfaces over desired time period is very important. The objective of this study was to examine the effect of ageing on atmospheric pressure helium-plasma treated polycarbonate (PC) sample as a function of treatment time. The ageing effects were studied over a period of 10 days. The samples were plasma treated for 0.5, 2, 5 and 10 minutes. Contact angle measurements were made to study surface energy changes. Modification of surface chemical structure was examined using, X-ray Photoelectron Spectroscopy (XPS). Contact angle measurements on untreated and plasma treated surfaces were made immediately, 24, 48, 72 and 96 hrs after treatment. Contact angle decreased from 93 deg for untreated sample to 30 deg for sample plasma treated for 10 minutes. After 10 days the contact angles for the 10 minute plasma treated sample increased to 67 deg, but it never reverted back to that of untreated surface. Similarly the O/C ratio increased from 0.136 for untreated sample to 0.321 for 10 minute plasma treated sample indication increase in surface energy.

  8. Gaseous Detectors: Charged Particle Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Hilke, H J

    2011-01-01

    Gaseous Detectors in 'Charged Particle Detectors - Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Subsection '3.1.2 Gaseous Detectors' of Section '3.1 Charged Particle Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.1.2 Gaseous Detectors 3.1.2.1 Introduction 3.1.2.2 Basic Processes 3.1.2.2.1 Gas ionization by charged particles 3.1.2.2.1.1 Primary clusters 3.1.2.2.1.2 Cluster size distribution 3.1.2.2.1.3 Total number of ion pairs 3.1.2.2.1.4 Dependence of energy deposit on particle velocity 3.1.2.2.2 Transport of...

  9. Ontwikkeling en selectie van een methode voor de bepaling van hydronium ter vervanging van de methode die in het kader van het ECE-EMEP-project is voorgeschreven

    NARCIS (Netherlands)

    Neele J; Slob W; Reijnders HFR

    1989-01-01

    In de afdeling Algemene Analytische Methoden en Ionchromatografie van het Laboratorium voor Anorganische Chemie werd hydronium bepaald volgens de methode, die in het ECE-EMEP kader is voorgeschreven en berust op de "Gran's plot"-methode. Door de grotere hoeveelheid te analyseren

  10. Korean Early Childhood Educators' Multi-Dimensional Teacher Self-Efficacy and ECE Center Climate and Depression Severity in Teachers as Contributing Factors

    Science.gov (United States)

    Kim, Yeon Ha; Kim, Yang Eun

    2010-01-01

    This study investigated profiles of South Korean early childhood educators' teacher self-efficacy and contributing factors to teacher self-efficacy. The contributing factors were examined with a focus on early childhood education (ECE) center climate and depression severity in teachers as well as teacher and classroom characteristics. The results…

  11. IEA SHC Task 42/ECES Annex 29 – A Simple Tool for the Economic Evaluation of Thermal Energy Storages

    DEFF Research Database (Denmark)

    Rathgeber, Christoph; Hiebler, Stefan; Lävemann, Eberhard;

    2016-01-01

    Within the framework of IEA SHC Task 42 / ECES Annex 29, a simple tool for the economic evaluation of thermal energy storages has been developed and tested on various existing storages. On that account, the storage capacity costs (costs per installed storage capacity) of thermal energy storages...... have been evaluated via a Top-down and a Bottom-up approach. The Top-down approach follows the assumption that the costs of energy supplied by the storage should not exceed the costs of energy from the market. The maximum acceptable storage capacity costs depend on the interest rate assigned......, seasonal heat storage is only economical via large sensible hot water storages. Contrary, if the annual number of storage cycles is sufficiently high, all thermal energy storage technologies can become competitive....

  12. IEA SHC Task 42/ECES Annex 29 – A Simple Tool for the Economic Evaluation of Thermal Energy Storages

    DEFF Research Database (Denmark)

    Rathgeber, Christoph; Hiebler, Stefan; Lävemann, Eberhard

    2016-01-01

    Within the framework of IEA SHC Task 42 / ECES Annex 29, a simple tool for the economic evaluation of thermal energy storages has been developed and tested on various existing storages. On that account, the storage capacity costs (costs per installed storage capacity) of thermal energy storages...... have been evaluated via a Top-down and a Bottom-up approach. The Top-down approach follows the assumption that the costs of energy supplied by the storage should not exceed the costs of energy from the market. The maximum acceptable storage capacity costs depend on the interest rate assigned...... to the capital costs, the intended payback period of the user class (e.g. industry or building), the reference energy costs, and the annual number of storage cycles. The Bottom-up approach focuses on the realised storage capacity costs of existing storages. The economic evaluation via Top-down and Bottom...

  13. Diffusion of suprathermal electrons measured by means of ECRH and 2nd harmonic ECE O-mode

    Energy Technology Data Exchange (ETDEWEB)

    Schokker, B.C.; Jaspers, R.J.E.; Lopes Cardozo, N.J. (FOM-Instituut voor Plasmafysica, Rijnhuizen (Netherlands))

    1991-01-01

    In the study of anomalous transport in thermonuclear plasmas, the diffusion of suprathermal electrons deserves special attention. From certain energies onward electrons are effectively collisionless, and therefore follow the field lines. Thus, they can be used to probe the stochasticity of the magnetic field structure. For high energy, electrons are eventually insensitive to magnetic stochasticity as their curvature B-drift becomes larger than the radial correlation length of the turbulence. Hence, by studying the confinement of collisionless electrons in different energy ranges, both the level of magnetic turbulence and the radial correlation length can be established. A study of the confinement of suprathermal electrons has been reported by Kwon et al, who used measurements of hard X-ray in ASDEX. This study focussed on runaway electrons in the MeV-range, created in the start-up phase of the discharge. In this paper, we concentrate on the transport of suprathermal electrons with an energy of a few times T[sub e]. The advantages of this approach are that (a) the curvature B-drift of these electrons is small, so that the transport is sensitive to small scale magnetic turbulence, and (b) as we shall show, a local study of the diffusion of these electrons can be made using ECE spectroscopy. We describe experiments performed in the RTP tokamak, in which ECRH O-mode was launched from the low-field side. In this way, a population of suprathermals in the center of the plasma is almost instantaneously raised in perpendicular energy. This population is diagnosed by ECE with a grating polychromator in the optically thin 2nd harmonic O-mode. (author) 2 refs., 4 figs.

  14. Pixel Detectors

    OpenAIRE

    Wermes, Norbert

    2005-01-01

    Pixel detectors for precise particle tracking in high energy physics have been developed to a level of maturity during the past decade. Three of the LHC detectors will use vertex detectors close to the interaction point based on the hybrid pixel technology which can be considered the state of the art in this field of instrumentation. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as the very harsh...

  15. Registration of alpha particles in Makrofol-E nuclear track detectors

    Science.gov (United States)

    Rammah, Y. S.; Abdalla, Ayman M.; Ashraf, O.; Ashry, A. H.

    2016-06-01

    Fast detection of alpha particles in the range from 1 to 5 MeV in Makrofol-E polycarbonate nuclear track detectors (PCTDs) using a new chemical etchant was investigated. 252Cf and 241Am-thin open sources were used for irradiating Makrofol-E detectors with fission fragments and alpha particles in air at normal pressure and temperature (NPT). A chain of experimental work has been carried out using new etchants to register alpha particle in short time in Makrofol-E polycarbonate detectors. The etching efficiency were exhibited a clear dependence on the amount of methanol in the etching solution and etching time. The optimized chemical condition obtained at this stage of development for 200 μm Makrofol-E detectors are (8 ml of 10 N NaOH + 2 ml CH3OH) etching solutions at 60 °C for 3 h. In this study; it is possible to observe energy detection windows for Makrofol-E detectors according to applied etching duration. Makrofol-E introduced the characteristic Bragg peak, which indicates the advantages of this detector as alpha spectrometer. Consequently, the suggested new etchant can be developed for heavy ions detection and monitoring radon levels and its daughters.

  16. Metal Detectors.

    Science.gov (United States)

    Harrington-Lueker, Donna

    1992-01-01

    Schools that count on metal detectors to stem the flow of weapons into the schools create a false sense of security. Recommendations include investing in personnel rather than hardware, cultivating the confidence of law-abiding students, and enforcing discipline. Metal detectors can be quite effective at afterschool events. (MLF)

  17. Optical Detectors

    Science.gov (United States)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  18. Optics design for J-TEXT ECE imaging with field curvature adjustment lens

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Y.; Zhao, Z.; Liu, W. D.; Xie, J., E-mail: jlxie@ustc.edu.cn [School of Physics, University of Science and Technology of China, Anhui 230026 (China); Hu, X.; Muscatello, C. M.; Domier, C. W.; Luhmann, N. C.; Chen, M.; Ren, X. [University of California at Davis, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Zhuang, G.; Yang, Z. [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-11-15

    Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas. Of particular importance has been microwave electron cyclotron emission imaging (ECEI) for imaging T{sub e} fluctuations. Key to the success of ECEI is a large Gaussian optics system constituting a major portion of the focusing of the microwave radiation from the plasma to the detector array. Both the spatial resolution and observation range are dependent upon the imaging optics system performance. In particular, it is critical that the field curvature on the image plane is reduced to decrease crosstalk between vertical channels. The receiver optics systems for two ECEI on the J-TEXT device have been designed to ameliorate these problems and provide good performance with additional field curvature adjustment lenses with a meniscus shape to correct the aberrations from several spherical surfaces.

  19. Migration of bisphenol A from plastic baby bottles, baby bottle liners and reusable polycarbonate drinking bottles.

    Science.gov (United States)

    Kubwabo, C; Kosarac, I; Stewart, B; Gauthier, B R; Lalonde, K; Lalonde, P J

    2009-06-01

    Human exposure to bisphenol A (BPA) has recently received special attention. It has been shown that exposure to BPA may occur through the consumption of beverages or foods that have been in contact with polycarbonate (PC) plastic containers or epoxy resins in food packaging. A BPA migration study was conducted using a variety of plastic containers, including polycarbonate baby bottles, non-PC baby bottles, baby bottle liners, and reusable PC drinking bottles. Water was used to simulate migration into aqueous and acidic foods; 10% ethanol solution to simulate migration to low- and high-alcoholic foods; and 50% ethanol solution to simulate migration to fatty foods. By combining solid-phase extraction, BPA derivatization and analysis by GC-EI/MS/MS, a very low detection limit at the ng l(-1) level was obtained. Migration of BPA at 40 degrees C ranged from 0.11 microg l(-1) in water incubated for 8 h to 2.39 microg l(-1) in 50% ethanol incubated for 240 h. Residual BPA leaching from PC bottles increased with temperature and incubation time. In comparison with the migration observed from PC bottles, non-PC baby bottles and baby bottle liners showed only trace levels of BPA. Tests for leachable lead and cadmium were also conducted on glass baby bottles since these represent a potential alternative to plastic bottles. No detectable lead or cadmium was found to leach from the glass. This study indicated that non-PC plastic baby bottles, baby bottle liners and glass baby bottles might be good alternatives for polycarbonate bottles.

  20. Aluminium metallisation of argon and oxygen plasma-modified polycarbonate thin film surfaces

    Science.gov (United States)

    Rastomjee, C. S.; Keil, M.; Sotobayashi, H.; Bradshaw, A. M.; Lamont, C. L. A.; Gador, D.; Umbach, E.

    1998-12-01

    The influence of plasma treatment on the metallisation of polycarbonate surfaces was studied using X-ray absorption spectroscopy (XAFS) and core level X-ray photoelectron spectroscopy (XPS). Thin films of two different molecules were chosen: bis-phenol-A polycarbonate with phenol endgroups (P-PC) prepared ex situ by the spin-coating technique onto MoTe 2{0001}surfaces, and the model compound bis-phenol-A polycarbonate ( n=1) with tert-butyl phenyl endgroups (tBP-PC) evaporated in situ in UHV onto Cu{110}, Ag{100} and Ag{111} surfaces with film thicknesses of up to several monolayers. Surfaces of untreated samples and of samples which were pre-treated with either an inert argon or a reactive oxygen microwave plasma were metallised with Al (evaporated by electron beam heating) at film thicknesses ranging from the sub-monolayer region up to several monolayers. For the untreated surface, XAFS and XPS spectra suggest that the Al reacts with the carbonate groups leading to a breaking of the CO double bonds (and/or a reduction in bond order) as well as formation of Al oxide, Al hydroxide and Al-O-C linkages. A study of the time-dependent oxidation of the evaporated Al leads to the conclusion that Al slowly diffuses to the reactive sites in the first few subsurface layers of the polymer. Argon plasma treatment of samples leads to a reduction in the number of carbonyl groups in the near surface region. After metal deposition a higher ratio of metallic, non-reacted, Al was observed covering the polycarbonate surface and the diffusion rate into the polymer bulk seems to be higher than in the case of the untreated surface. Oxygen plasma treatment leads to the creation of additional CO containing species which also react with the Al in the subsequent metallisation process. Here, the ratio of oxidised Al on the polymer surface is higher than observed for untreated and argon plasma pre-treated polymer surfaces.

  1. Stock sheets of polycarbonate as inexpensive low-order optical wave plates

    Science.gov (United States)

    Kavanaugh, James; Green, Adam

    2008-04-01

    We show that commercially available transparent polycarbonate sheets often have linear retardances in the quarter- to half-wave range for visible light. Sheets with thicknesses from 1/16'' to 3/16'' act as zero- to third-order retarders that are modestly stable with temperature and uniform with position. By adjusting the sheets' tilt and orientation angles, they can be tuned to desired retardances, although they are not as sensitive to these parameters as are higher-order wave plates. Since they are readily available and inexpensive, these sheets make good candidates as easily machined, large-aperture wave plates for general laboratory use.

  2. Modifications induced in the polycarbonate Makrofol KG polymer by Li (50 MeV) ion irradiation

    Indian Academy of Sciences (India)

    Jaskiran Kaur; S K Chakarvarti; D Kanjilal; Surinder Singh

    2009-04-01

    Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 m, spin coated on GaAs substrate were irradiated with 50 MeV Li ion (+3 charge state). Build-in modifications due to irradiation were studied using FTIR and XRD characterizations. Considerable changes have been observed in the polymer while varying the fluence from 1E11 ion/cm2 to 1E13 ion/cm2 Li ions. AFM images of the surface modifications caused by ion irradiation on the polymer are also presented.

  3. Simulation of polycarbonate-CNT nanocomposite dosimeter based on electrical characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Malekie, Shahryar; Ziaie, Farhood; Ataee Naeini, Mehran [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Application Research School

    2016-12-15

    In this research work, the electrical behavior of polycarbonate-carbon nanotube composite, over the radiation absorbed dose under a fixed DC voltage was investigated via finite element method. The predicted electrical percolation threshold value in the composite was validated by experimental results published by other scientists. The absorbed dose value was considered as multiplying of heat capacity and temperature rise of the composite, regarding the calorimetric approach. Results show that this kind of composite can be applied for monitoring and radiation protection utilizations.

  4. Hollow polycarbonate waveguides with inner Cu coatings for delivery of terahertz radiation.

    Science.gov (United States)

    Harrington, James; George, Roshan; Pedersen, Pal; Mueller, Eric

    2004-10-18

    Terahertz (THz) radiation has important applications in spectroscopy, imaging, and space science. Fiber optics for the THz region have been limited to rigid hollow metallic waveguides or short lengths of solid-core transparent dielectrics such as sapphire and plastic. We have fabricated flexible, hollow polycarbonate waveguides with interior Cu coatings for broadband THz transmission using simple liquid-phase chemistry techniques. The losses for these hollow-core guides were measured using a tunable, cw single-mode far IR laser. The losses for the best guides were found to be less than four dB/m and the single mode of the laser was preserved for the smaller bore waveguides.

  5. In-situ SEM and Stereomicroscope Study Delamination Evolution of Glass Fabric Reinforced Polycarbonate Composite

    Institute of Scientific and Technical Information of China (English)

    WANG Jun-bo; LI Ying-ming; XUE Ji-wen; SUN Yong-qi; ZHENG Shui-rong; SUN Man-lin

    2002-01-01

    The main objective of this study is to investigate the dynamic processes of the interlaminar fracture of the glass woven fabric reinforced polycarbonate composites through in- situ observation of specimen under mode I loading by SEM and stereomicroscope. The results show that the evolution processes of interlaminar damage consist of micro-crack initiation, growth and coalescence and advance forward of the main crack tip. The mode of crack propagation in fabric composite observed here seem to be the propagation along interface, interface change and fabric separation.

  6. Synthesis of optically clear polymeric materials for high temperature windows. [preparation of phenolphthalein polycarbonate resin

    Science.gov (United States)

    Pannell, C. E.; Magner, J. E.

    1973-01-01

    A polymer has been developed that has excellent potential for use as windows in spacecraft as well as conventional aircraft. This polymer, phenolphthalein polycarbonate, has outstanding thermal properties, e.g., in place of melting or burning, it produces an insulating charred foam that closes off transmission of radiant heat through the window. This fact, coupled with an oxygen index of 0.43 and a 177 C tensile strength of 58 mega Newtons/sq m, makes this polymer a prime candidate for further development. Pilot plant preparation in a 20 gallon Pfaudler kettle was accomplished and large test specimens were prepared for evaluations.

  7. Cs2CO3-promoted polycondensation of CO2with diols and dihalides for the synthesis of miscellaneous polycarbonates

    KAUST Repository

    Chen, Zuliang

    2016-07-12

    A one-pot protocol for the direct synthesis of polycarbonates through polycondensation of diols, dihalides and CO2 in the presence of Cs2CO3 is described. The conditions were optimized by studying the polycondensation of CO2 with 1,4-phenylenedimethanol and 1,4-dibromobutane as model monomers. Then, diols and dihalides with different spacers between the reactive groups including aliphatic, aromatic and poly(ethylene glycol) were tested under optimal conditions. Miscellaneous polycarbonates exhibiting molar masses in the range of 43 000 g mol-1 (GPC) and conversion higher than 96% could be obtained. The proposed mechanism rules out the possibility of ether linkage formation during polycondensation and accounts for the creation of carbonate linkages in two different ways. The thermal properties of the synthesized polycarbonates were unveiled by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). © 2016 The Royal Society of Chemistry.

  8. Chemical structure-optical property understanding in bisphenyls and substituted polycarbonates by molecular simulations: Role of polarizabilities and conformations

    Science.gov (United States)

    Natarajan, Upendra; Sulatha, M. S.

    2005-03-01

    We present calculations of polarizability tensors, optical anisotropy of organic molecules, repeating units and polymer chains of several bisphenyls, bisphenol carbonates and polycarbonates with a variety of chemical substitutions.^1,2 Theoretical calculations of polarizabilities and optical birefringence of several newer structures having specific side-group substitutions which render low birefringence, not previously reported, is also shown here. Our method combines VOSRIS scheme^3, molecular geometry and conformations from force-field simulations and accurate anisotropic polarizability tensors. Aliphatic, aliphatic aromatic and cycloaliphatic substitutions reduce optical anisotropy in relation to bisphenol A polycarbonate. Calculated /x of these structurally modified polycarbonates^2 follows linear behavior with respect to experimentally observed melt stress-optical coefficient (Cm). *J. Phys. Chem. A, 107, 97 (2003) *Macromolecules, 36, 2944 (2003) *P.J. Flory, Statistical Mechanics of Chain Molecules, Wiley Interscience, New York (1969)

  9. Segment Orientation and Optical Birefringence of Amorphous Polymers Under Tensile Deformation: Novel Computational Method applied to Different Glassy Polycarbonates

    Science.gov (United States)

    Natarajan, Upendra; Sulatha, M. S.

    2005-03-01

    Orientation dependent optical properties of Bisphenol A polycarbonate and two aliphatic substituted polycarbonates in glassy phase have been studied by atomistic modeling using molecular mechanics simulations under tensile deformation. Probability distributions and orientation functions show that phenylene rings and carbonate groups vectors along the main chain orient towards stretching direction following deformation. Interchain packing of rings and carbonates become ordered with strain. Efficient computational approach for calculation of optical birefringence of amorphous polymers is presented and applied to the polycarbonates in detail. Polarizability anisotropy of the polymer segments and chain as a function of deformation is calculated by combining information on the conformations and group polarizabilities, and used to estimate birefringence during deformation. Simulated and experimental values for segment orientation and bulk birefringence are in very good agreement. Effect of the optical properties of atomic groups on bulk birefringence is brought forth for the first time by molecular simulation for polymers other than polyethylene.

  10. Evaluation of failure characteristics and bond strength after ceramic and polycarbonate bracket debonding: effect of bracket base silanization.

    Science.gov (United States)

    Ozcan, M; Finnema, K; Ybema, A

    2008-04-01

    The objectives of this study were to evaluate the effect of silanization on the failure type and shear-peel bond strength (SBS) of ceramic and polycarbonate brackets, and to determine the type of failure when debonded with either a universal testing machine or orthodontic pliers. Silanized and non-silanized ceramic and polycarbonate brackets (N = 48, n = 24 per bracket type) were bonded to extracted caries-free human maxillary central incisors using an alignment apparatus under a weight of 750 g. All bonded specimens were thermocycled 1000 times (5-55 degrees C). Half of the specimens from each group were debonded with a universal testing machine (1 mm/minute) to determine the SBS and the other half by an operator using orthodontic debonding pliers. Failure types of the enamel surface and the bracket base were identified both from visual inspection and digital photographs using the adhesive remnant index (ARI) and base remnant index (BRI). As-received ceramic brackets showed significantly higher bond strength values (11.5 +/- 4.1 MPa) than polycarbonate brackets [6.3 +/- 2.7 MPa; (P = 0.0077; analysis of variance (ANOVA)]. Interaction between bracket types and silanization was not significant (P = 0.4408). Silanization did not significantly improve the mean SBS results either for the ceramic or polycarbonate brackets (12.9 +/- 3.7 and 6.3 +/- 2.7 MPa, respectively; P = 0.4044; two-way ANOVA, Tukey-Kramer adjustment). There was a significant difference between groups in ARI scores for ceramic (P = 0.0991) but not polycarbonate (P = 0.3916; Kruskall-Wallis) brackets. BRI values did not vary significantly for ceramic (P = 0.1476) or polycarbonate (P = 0.0227) brackets. Failure type was not significantly different when brackets were debonded with a universal testing machine or with orthodontic debonding pliers. No enamel damage was observed in any of the groups.

  11. Tropospheric ozone and adverse crop response : results of some italian experiments carried out within UN/ECE during 1994; Ozono troposferico e danni su colture agricole : risulati di alcuni esperimenti italiani condotti in ambito UN/ECE nel 1994

    Energy Technology Data Exchange (ETDEWEB)

    Fumagalli, I. [Ente Nazionale per l`Energia Elettrica, Milan (Italy); Mignanego, L. [Phytos sns, Milan (Italy)

    1995-12-01

    Within the international co-operative programme on the effects of air pollutants on crops (ICP-Crops) promoted by the UN/ECE convention on long-range transboundary air pollution, a series of experiments were performed in Italy on different crops. Results on bean and white clover of the 1994 experimental season carried out at a field site near Milan are presented. The aim of the trial was to assess the effects of tropospheric ozone on bean plants and white clover exposed to ambient air and treated with the antioxidant ethylene diurea (EDU). Additionally bean plants and white clover were exposed to filtered (F) and unfiltered (NF) air in open-top chambers. Bean plants were sowed in june and harvested in september, two experiments with white clover were conducted from may to september. Mai parameters investigated have been ozone visible injury on leaves, photosynthesis, number and dry weight at final harvest. Air quality data and the diagnostic features of plants about this trial allow to identify ozone as an important air pollutant with levels often above threshold for phytotoxic effects.

  12. Tropospheric ozone and adverse crop response : results of some italian experiments carried out within UN/ECE during 1994; Ozono troposferico e danni su colture agricole : risulati di alcuni esperimenti italiani condotti in ambito UN/ECE nel 1994

    Energy Technology Data Exchange (ETDEWEB)

    Fumagalli, I. [Ente Nazionale per l`Energia Elettrica, Milan (Italy); Mignanego, L. [Phytos sns, Milan (Italy)

    1995-12-01

    Within the international co-operative programme on the effects of air pollutants on crops (ICP-Crops) promoted by the UN/ECE convention on long-range transboundary air pollution, a series of experiments were performed in Italy on different crops. Results on bean and white clover of the 1994 experimental season carried out at a field site near Milan are presented. The aim of the trial was to assess the effects of tropospheric ozone on bean plants and white clover exposed to ambient air and treated with the antioxidant ethylene diurea (EDU). Additionally bean plants and white clover were exposed to filtered (F) and unfiltered (NF) air in open-top chambers. Bean plants were sowed in june and harvested in september, two experiments with white clover were conducted from may to september. Mai parameters investigated have been ozone visible injury on leaves, photosynthesis, number and dry weight at final harvest. Air quality data and the diagnostic features of plants about this trial allow to identify ozone as an important air pollutant with levels often above threshold for phytotoxic effects.

  13. Evaluation of sulphonated polycarbonate membranes for fuel cells; Avaliacao de membranas de policarbonato sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Isabela M.M.; Gomes, Ana C.; Pessan, Luiz A. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Engenharia de Materiais], e-mail: isabelamuglia@gmail.com; Paranhos, Caio [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2011-07-01

    Fuel cells based on ion conducting polymer membranes offer an alternative for the conventional energetic matrices. Among many advantages of this system, we can mention the reduction on the emission of pollutants, high efficiency and simplicity. This work presents the modification of polycarbonate by sulfonation reaction using acetyl sulfate, in order to increase the conductor ionic character of the membranes used as electrolytes for hydrogen fuel cells. The sulfonated polycarbonate membranes were obtained by casting and then characterized by Fourier transform infrared spectroscopy, water vapor transmission, differential scanning calorimetry, thermogravimetric analysis and viscosimetry. (author)

  14. A water-soluble polycarbonate with dimethylamino pendant groups prepared by enzyme-catalyzed ring-opening polymerization.

    Science.gov (United States)

    Zhang, Xiaojin; Cai, Mengmeng; Zhong, Zhenlin; Zhuo, Renxi

    2012-04-23

    A water-soluble polycarbonate with dimethylamino pendant groups, poly(2-dimethylaminotrimethylene carbonate) (PDMATC), is synthesized and characterized. First, the six-membered carbonate monomer, 2-dimethylaminotrimethylene carbonate (DMATC), is prepared via the cyclization reaction of 2-(dimethylamino)propane-1,3-diol with triphosgene in the presence of triethylamine. Although the attempted ring-opening polymerization (ROP) of DMATC with Sn(Oct)(2) as a catalyst fails, the ROP of DMATC is successfully carried out with Novozym-435 as a catalyst to give water-soluble aliphatic polycarbonate PDMATC with low cytotoxicity and good degradability.

  15. DUMAND detector

    CERN Multimedia

    This object is one of the 256 other detectors of the DUMAND (Deep Underwater Muon And Neutrino Detection) experiment. The goal of the experiment was the construction of the first deep ocean high energy neutrino detector, to be placed at 4800 m depth in the Pacific Ocean off Keahole Point on the Big Island of Hawaii. A few years ago, a European conference with Cosmic experiments was organized at CERN as they were projects like DUMAND in Hawaii. Along with the conference, a temporary exhibition was organised as well. It was a collaboration of institutions from Germany, Japan, Switzerland and the U.S.A. CERN had borrowed equipment and objects from different institutes around the world, including this detector of the DUMAND experiment. Most of the equipment were sent back to the institutes, however this detector sphere was offered to a CERN member of the personnel.

  16. Directed Hierarchical Patterning of Polycarbonate Bisphenol A Glass Surface along Predictable Sites

    Directory of Open Access Journals (Sweden)

    Mazen Khaled

    2015-01-01

    Full Text Available This paper reports a new approach in designing textured and hierarchical surfaces on polycarbonate bisphenol A type glass to improve hydrophobicity and dust repellent application for solar panels. Solvent- and vapor-induced crystallization of thermoplastic glass polycarbonate bisphenol A (PC is carried out to create hierarchically structured surfaces. In this approach dichloromethane (DCM and acetone are used in sequence. Samples are initially immersed in DCM liquid to generate nanopores, followed by exposing to acetone vapor resulting in the generation of hierarchical structure along the interporous sites. The effects of exposure time on the size, density, and distance of the generated spherules and gaps are studied and correlated with the optical transmittance and contact angle measurements at the surface. At optimized exposure time a contact angle of 98° was achieved with 80% optical transmittance. To further increase the hydrophobicity while maintaining optical properties, the hierarchical surfaces were coated with a transparent composite of tetraethyl orthosilicate as precursor and hexamethyldisilazane as silylation agent resulting in an average contact angle of 135.8° and transmittance of around 70%. FTIR and AFM characterization techniques are employed to study the composition and morphology of the generated surfaces.

  17. Electrical properties and dielectric spectroscopy of Ar{sup +} implanted polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Mahak, E-mail: mahak.chawla@gmail.com; Shekhawat, Nidhi; Aggarwal, Sanjeev; Sharma, Annu [Department of Physics, Kurukshetra University, Kurukshetra - 136119 (India); Nair, K. G. M. [Consultant, UGC-DAE Consortium for Scientific Research, Kalpakkam Node, Kokilamedu-603104, Tamilnadu (India)

    2015-05-15

    The aim of the present paper is to study the effect of argon ion implantation on electrical and dielectric properties of polycarbonate. Specimens were implanted with 130 keV Ar{sup +} ions in the fluence ranging from 1×10{sup 14} to 1×10{sup 16} ions cm{sup −2}. The beam current used was ∼0.40 µA cm{sup −2}. The electrical conduction behaviour of virgin and Ar{sup +} implanted polycarbonate specimens have been studied through current-voltage (I-V characteristic) measurements. It has been observed that after implantation conductivity increases with increasing ion fluence. The dielectric spectroscopy of these specimens has been done in the frequency range of 100 kHz-100 MHz. Relaxation processes were studied by Cole-Cole plot of complex permittivity (real part of complex permittivity, ε′ vs. imaginary part of complex permittivity, ε″). The Cole-Cole plots have also been used to determine static dielectric constant (ε{sub s}), optical dielectric constant (ε{sub ∞}), spreading factor (α), average relaxation time (τ{sub 0}) and molecular relaxation time (τ). The dielectric behaviour has been found to be significantly affected due to Ar{sup +} implantation. The possible correlation between this behaviour and the changes induced by the implantation has been discussed.

  18. Synthesis and Characterization of Polycarbonate Copolymers Containing Benzoyl Groups on the Side Chain for Scratch Resistance

    Directory of Open Access Journals (Sweden)

    Hohyoun Jang

    2016-01-01

    Full Text Available The purpose of this study was to enhance the scratch resistance of polycarbonate copolymer by using 3,3′-dibenzoyl-4,4′-dihydroxybiphenyl (DBHP monomer, containing benzoyl moieties on the ortho positions. DBHP monomer was synthesized from 4,4′-dihydroxybiphenyl and benzoyl chloride, followed by the Friedel-Craft rearrangement reaction with AlCl3. The polymerizations were conducted following the low-temperature procedure, which is carried out in methylene chloride by using triphosgene, triethylamine, bisphenol-A, and DBHP. The chemical structures of the polycarbonate copolymers were confirmed by 1H-NMR. The thermal properties of copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry, and also surface morphologies were assessed by atomic force microscopy. The scratch resistance of homopolymer film (100 μm changed from 6B to 1B, and the contact angle of a sessile water drop onto the homopolymer film also increased.

  19. Electrical Properties of Single-Walled/Multi-Walled Carbon-Nanotubes Filled Polycarbonate Nanocomposites

    Science.gov (United States)

    Sain, P. K.; Goyal, R. K.; Prasad, Y. V. S. S.; Bhargava, A. K.

    2017-01-01

    The work focused on development of flexible and light weight polycarbonate based nanocomposites containing single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) prepared by solution method for electronic applications. X-ray diffractometry (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used for the characterization. XRD confirmed the presence of CNTs in the nanocomposites. TEM and SEM both revealed the dispersion of CNTs in the matrix. Percolation threshold was found to occur at 0.5 vol.% for SWCNTs and 4 vol.% for MWCNTs filled polycarbonate nanocomposites. The electrical conductivity, relative dielectric constant and dissipation factor of the nanocomposites were increased abruptly above percolation threshold. The maximum achieved electrical conductivity and the relative dielectric constant of the nanocomposites was found 10-4 S/cm and 108, respectively in both the nanocomposites. The best achieved combination of relative dielectric constant and dissipation factor was found in 1 vol.% SWCNT-PC nanocomposite. The relative dielectric constant of the nanocomposites was almost temperature independent from room temperature to 200°C.

  20. Pulse laser particulate separation from polycarbonate: surface acoustic wave and thermomechanical mechanisms

    Science.gov (United States)

    Arif, S.; Armbruster, O.; Kautek, W.

    2013-05-01

    The mechanisms of graphite particle and polystyrene-co-divinyl benzene microsphere removal from flat polycarbonate substrates by nanosecond pulse laser interaction at 532 nm were studied both experimentally and theoretically. These model contaminants exhibited an extremely contrasting behavior in respect to phase separation and collateral damage to the polycarbonate substrate. Opaque graphite particles within the irradiated spot area either desorbed due to their thermal expansion or undertook vaporization/ablation. The transparent polystyrene microspheres caused local ablation of the substrate in their optical near-field. This process led to the removal of the particles, but eradicated the available cleaning fluence window. The opaque graphite particles, on the other hand, showed efficient clearance, particularly in a practicable cleaning window above 0.5~J/cm2 and low pulse numbers of about two. Besides the mechanisms occurring within the irradiated spot, a separation process in the proximity beyond the laser spot (more than double the Gaussian radius) could be related to the action of high-amplitude surface acoustic waves (SAW). A minimum surface acceleration of 109~cm/s2 was calculated to be sufficient to overcome the adhesion forces in this particle separation model.

  1. THERMAL properties and morphology of Polypropylene/Polycarbonate/Polypropylene-Graft-Maleic anhydride blends

    Directory of Open Access Journals (Sweden)

    Mat-Shayuti M. S.

    2016-01-01

    Full Text Available This work investigates the effect of blending polycarbonate (PC into polypropylene (PP matrix polymer on thermal properties and morphology. The blends, containing 5% to 35% of polycarbonate and 5% compatibilizer, were compounded using twin-screw extruder and fabricated into standard tests samples using injection or compression molding. The compatibilizer used was polypropylene-graft-maleic anhydride (PP-g-MA. Thermogravimetric analysis (TGA showed improved thermal degradation temperature of PP/PC/PP-g-MA blends compared to pure PP. As PC content increased, the thermal degradation temperature also improved. The highest improvement of thermal degradation temperature was 23.3%, demonstrated by 60/35/5 composition. It was found that the thermal stability of PP/PC blends was improved with the addition of PP-g-MA. PP-g-MA was suspected to enhance the phase adhesion between PP and PC, thus improving thermal stability. Microscopy analysis showed PC reinforcement phase existed as particulates dispersed in PP matrix phase. PC also was in irregular shapes of fibers or flakes in certain compositions, depending on PC fraction and compatibilizer content.

  2. Marine ecosystem community carbon and nutrient uptake stoichiometry under varying ocean acidification during the PeECE III experiment

    Directory of Open Access Journals (Sweden)

    R. G. J. Bellerby

    2007-12-01

    Full Text Available Inorganic carbon and nutrient biogeochemical responses were studied during the 2005 Pelagic Ecosystem CO2 Enrichment (PeECE III study. Inverse analysis of the temporal inorganic carbon dioxide system and nutrient variations was used to determine the net community stoichiometric uptake characteristics of a natural pelagic ecosystem production perturbed over a range of pCO2 scenarios (350, 700 and 1050 μatm. Nutrient uptake showed no sensitivity to CO2 treatment. There was enhanced carbon production relative to nutrient consumption in the higher CO2 treatments which was positively correlated with the initial CO2 concentration. There was no significant calcification response to changing CO2 in Emiliania huxleyi by the peak of the bloom and all treatments exhibited low particulate inorganic carbon production (~15 μmol kg−1. With insignificant air-sea CO2 exchange across the treatments, the enhanced carbon uptake was due to increase organic carbon production. The inferred cumulative C:N:P stoichiometry of organic production increased with CO2 treatment from 1:6.3:121 to 1:7.1:144 to 1:8.25:168 at the height of the bloom. This study discusses how ocean acidification may incur modification to the stoichiometry of pelagic production and have consequences for ocean biogeochemical cycling.

  3. Evidence of blocking effects on 3-keV Ne7+ ions guided through nanocapillaries in polycarbonate

    NARCIS (Netherlands)

    Stolterfoht, N.; Hellhammer, R.; Sulik, B.; Juhasz, Z.; Bayer, V.; Trautmann, C.; Bodewits, E.; Hoekstra, R.

    2011-01-01

    We studied the dynamic properties of ion guiding through nanocapillaries etched in insulating polycarbonate (PC). Capillaries with diameters of 95 and 165 nm and a length of 10 mu m were used. In a further sample, the capillaries had a diameter of 175 nm and a length of 30 mu m. A few additional

  4. Hydrolysis of polycarbonate in sub-critical water in fused silica capillary reactor with in situ Raman spectroscopy

    Science.gov (United States)

    Pan, Z.; Chou, I.-Ming; Burruss, R.C.

    2009-01-01

    The advantages of using fused silica capillary reactor (FSCR) instead of conventional autoclave for studying chemical reactions at elevated pressure and temperature conditions were demonstrated in this study, including the allowance for visual observation under a microscope and in situ Raman spectroscopic characterization of polycarbonate and coexisting phases during hydrolysis in subcritical water. ?? 2009 The Royal Society of Chemistry.

  5. Antimicrobial and antifouling hydrogels formed in situ from polycarbonate and poly(ethylene glycol) via Michael addition.

    Science.gov (United States)

    Liu, Shao Qiong; Yang, Chuan; Huang, Yuan; Ding, Xin; Li, Yan; Fan, Wei Min; Hedrick, James L; Yang, Yi-Yan

    2012-12-18

    A novel class of antimicrobial cationic polycarbonate/PEG hydrogels are designed and synthesized by Michael addition chemistry. These hydrogels demonstrate strong broad-spectrum antimicrobial activities against various clinically isolated multidrug-resistant microbes. Moreover, they exhibit nonfouling properties and prevent the substrate from microbial adhesion. These antimicrobial and antifouling gels are promising materials as catheter coatings and wound dressings to prevent infections.

  6. STUDIES ON MISCIBILITY OF POLY (ε-CAPROLACTONE) AND ALIPHATIC POLYCARBONATE BLENDS AND DETERMINATION OF THEIR INTERACTION PARAMETER

    Institute of Scientific and Technical Information of China (English)

    CHEN Li; HUANG Yuhui; SONG Mo; CONG Guangmin

    1992-01-01

    In this paper the miscibility of poly (ε-caprolactone) (PCL) and aliphatic polycarbonate (AP C) is studied by using DSC. The results show that PCL and APC are miscible in all ranges of composition. The interaction parameter between the polymers is calculated from the melting point depression data. Using optical microscope, the shapes of the PCL spherulites in the blends are observed.

  7. Evaluation of failure characteristics and bond strength after ceramic and polycarbonate bracket debonding : effect of bracket base silanization

    NARCIS (Netherlands)

    Ozcan, M.; Finnema, K.; Ybema, A.

    2008-01-01

    The objectives of this study were to evaluate the effect of silanization on the failure type and shear-peel bond strength (SBS) of ceramic and polycarbonate brackets, and to determine the type of failure when debonded with either a universal testing machine or orthodontic pliers. Silanized and non-s

  8. Mechanical, thermal and morphological characterization of polycarbonate/oxidized carbon nanofiber composites produced with a lean 2-step manufacturing process.

    Science.gov (United States)

    Lively, Brooks; Kumar, Sandeep; Tian, Liu; Li, Bin; Zhong, Wei-Hong

    2011-05-01

    In this study we report the advantages of a 2-step method that incorporates an additional process pre-conditioning step for rapid and precise blending of the constituents prior to the commonly used melt compounding method for preparing polycarbonate/oxidized carbon nanofiber composites. This additional step (equivalent to a manufacturing cell) involves the formation of a highly concentrated solid nano-nectar of polycarbonate/carbon nanofiber composite using a solution mixing process followed by melt mixing with pure polycarbonate. This combined method yields excellent dispersion and improved mechanical and thermal properties as compared to the 1-step melt mixing method. The test results indicated that inclusion of carbon nanofibers into composites via the 2-step method resulted in dramatically reduced ( 48% lower) coefficient of thermal expansion compared to that of pure polycarbonate and 30% lower than that from the 1-step processing, at the same loading of 1.0 wt%. Improvements were also found in dynamic mechanical analysis and flexural mechanical properties. The 2-step approach is more precise and leads to better dispersion, higher quality, consistency, and improved performance in critical application areas. It is also consistent with Lean Manufacturing principles in which manufacturing cells are linked together using less of the key resources and creates a smoother production flow. Therefore, this 2-step process can be more attractive for industry.

  9. Calorimeter detectors

    CERN Document Server

    de Barbaro, P; The ATLAS collaboration

    2013-01-01

    Although the instantaneous and integrated luminosity in HL-LHC will be far higher than the LHC detectors were originally designed for, the Barrel calorimeters of the four experiments are expected to continue to perform well  throughout the Phase II program. The conditions for the End-Cap calorimeters are far more challenging and whilst some detectors will require relatively modest changes, others require far more substantial upgrades. We present the results of longevity and performance studies for the calorimeter systems of the four main LHC experiments and outline the upgrade options under consideration. We include a discussion of the R&D required to make the final technology choices for the upgraded detectors.

  10. Pixel detectors

    CERN Document Server

    Passmore, M S

    2001-01-01

    positions on the detector. The loss of secondary electrons follows the profile of the detector and increases with higher energy ions. studies of the spatial resolution predict a value of 5.3 lp/mm. The image noise in photon counting systems is investigated theoretically and experimentally and is shown to be given by Poisson statistics. The rate capability of the LAD1 was measured to be 250 kHz per pixel. Theoretical and experimental studies of the difference in contrast for ideal charge integrating and photon counting imaging systems were carried out. It is shown that the contrast differs and that for the conventional definition (contrast = (background - signal)/background) the photon counting device will, in some cases, always give a better contrast than the integrating system. Simulations in MEDICI are combined with analytical calculations to investigate charge collection efficiencies (CCE) in semiconductor detectors. Different pixel sizes and biasing conditions are considered. The results show charge shari...

  11. Polycarbonate crowns for primary teeth revisited: Restorative options, technique and case reports

    Directory of Open Access Journals (Sweden)

    Karthik Venkataraghavan

    2014-01-01

    Full Text Available Esthetics by definition is the science of beauty - that particular detail of an animate or inanimate object that makes it appealing to the eye. In the modern, civilized, and cosmetically conscious world, well-contoured and well-aligned white teeth set the standard for beauty. Such teeth are not only considered attractive but are also indicative of nutritional health, self esteem, hygienic pride, and economic status. Numerous treatment approaches have been proposed to address the esthetics and retention of restorations in primary teeth. Even though researchers have claimed that certain restorations are better than the others, particularly owing to the issues mentioned above, the search for the ideal esthetic restoration for the primary teeth continues. This paper revisits and attempts to reintroduce the full coverage restoration, namely, polycarbonate crown, for use in primary anterior teeth.

  12. Design Concepts of Polycarbonate-Based Intervertebral Lumbar Cages: Finite Element Analysis and Compression Testing

    Directory of Open Access Journals (Sweden)

    J. Obedt Figueroa-Cavazos

    2016-01-01

    Full Text Available This work explores the viability of 3D printed intervertebral lumbar cages based on biocompatible polycarbonate (PC-ISO® material. Several design concepts are proposed for the generation of patient-specific intervertebral lumbar cages. The 3D printed material achieved compressive yield strength of 55 MPa under a specific combination of manufacturing parameters. The literature recommends a reference load of 4,000 N for design of intervertebral lumbar cages. Under compression testing conditions, the proposed design concepts withstand between 7,500 and 10,000 N of load before showing yielding. Although some stress concentration regions were found during analysis, the overall viability of the proposed design concepts was validated.

  13. Improving electrical conductivity in polycarbonate nanocomposites using highly conductive PEDOT/PSS coated MWCNTs

    KAUST Repository

    Zhou, Jian

    2013-07-10

    We describe a strategy to design highly electrically conductive polycarbonate nanocomposites by using multiwalled carbon nanotubes (MWCNTs) coated with a thin layer of poly(3,4-ethylenedioxythiophene)/ poly(styrenesulfonate), a conductive polymer. We found that this coating method improves the electrical properties of the nanocomposites in two ways. First, the coating becomes the main electrical conductive path. Second, the coating promotes the formation of a percolation network at a low filler concentration (0.3 wt %). To tailor the electrical properties of the conductive polymer coating, we used a polar solvent ethylene glycol, and we can tune the final properties of the nanocomposite by controlling the concentrations of the elementary constituents or the intrinsic properties of the conductive polymer coating. This very flexible technique allows for tailoring the properties of the final product. © 2013 American Chemical Society.

  14. Path (un)predictability of two interacting cracks in polycarbonate sheets using Digital Image Correlation

    Science.gov (United States)

    Koivisto, J.; Dalbe, M.-J.; Alava, M. J.; Santucci, S.

    2016-08-01

    Crack propagation is tracked here with Digital Image Correlation analysis in the test case of two cracks propagating in opposite directions in polycarbonate, a material with high ductility and a large Fracture Process Zone (FPZ). Depending on the initial distances between the two crack tips, one may observe different complex crack paths with in particular a regime where the two cracks repel each other prior to being attracted. We show by strain field analysis how this can be understood according to the principle of local symmetry: the propagation is to the direction where the local shear - mode KII in fracture mechanics language - is zero. Thus the interactions exhibited by the cracks arise from symmetry, from the initial geometry, and from the material properties which induce the FPZ. This complexity makes any long-range prediction of the path(s) impossible.

  15. Use of Polycarbonate Vacuum Vessels in High-Temperature Fusion-Plasma Research

    Energy Technology Data Exchange (ETDEWEB)

    B. Berlinger, A. Brooks, H. Feder, J. Gumbas, T. Franckowiak and S.A. Cohen

    2012-09-27

    Magnetic fusion energy (MFE) research requires ultrahigh-vacuum (UHV) conditions, primarily to reduce plasma contamination by impurities. For radiofrequency (RF)-heated plasmas, a great benefit may accrue from a non-conducting vacuum vessel, allowing external RF antennas which avoids the complications and cost of internal antennas and high-voltage high-current feedthroughs. In this paper we describe these and other criteria, e.g., safety, availability, design flexibility, structural integrity, access, outgassing, transparency, and fabrication techniques that led to the selection and use of 25.4-cm OD, 1.6-cm wall polycarbonate pipe as the main vacuum vessel for an MFE research device whose plasmas are expected to reach keV energies for durations exceeding 0.1 s

  16. Path (un)predictability of two interacting cracks in polycarbonate sheets using Digital Image Correlation.

    Science.gov (United States)

    Koivisto, J; Dalbe, M-J; Alava, M J; Santucci, S

    2016-01-01

    Crack propagation is tracked here with Digital Image Correlation analysis in the test case of two cracks propagating in opposite directions in polycarbonate, a material with high ductility and a large Fracture Process Zone (FPZ). Depending on the initial distances between the two crack tips, one may observe different complex crack paths with in particular a regime where the two cracks repel each other prior to being attracted. We show by strain field analysis how this can be understood according to the principle of local symmetry: the propagation is to the direction where the local shear - mode KII in fracture mechanics language - is zero. Thus the interactions exhibited by the cracks arise from symmetry, from the initial geometry, and from the material properties which induce the FPZ. This complexity makes any long-range prediction of the path(s) impossible.

  17. Facile preparation and magnetic properties of Ni nanotubes in polycarbonate ion-track templates

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.H., E-mail: yhchen@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Duan, J.L.; Yao, H.J.; Mo, D. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, T.Q. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, T.S. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Hou, M.D.; Sun, Y.M. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, J., E-mail: j.liu@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-05-15

    Ni nanotubes, with an inner diameter of about 100 nm and different wall thicknesses (approximately 20, 50, 80 and 110 nm), were successfully fabricated in porous polycarbonate (PC) ion-track templates by a novel method including two-step ion-track etching, two-step electrochemical deposition and one-step electrolysis. In our experiment, wall thickness of Ni nanotubes can be effectively controlled through the etching time of templates. The morphologies and crystal structures of the nanotubes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The magnetic hysteresis loops measured via vibrating sample magnetometry (VSM) indicate that Ni nanotubes with thinner wall thickness possess larger squareness and coercivity value when magnetic field applied parallel to the nanotube's axis, which can be attributed to the shape anisotropy and the formation of multi-domain structure.

  18. Polycarbonate crowns for primary teeth revisited: restorative options, technique and case reports.

    Science.gov (United States)

    Venkataraghavan, Karthik; Chan, John; Karthik, Sandhya

    2014-01-01

    Esthetics by definition is the science of beauty - that particular detail of an animate or inanimate object that makes it appealing to the eye. In the modern, civilized, and cosmetically conscious world, well-contoured and well-aligned white teeth set the standard for beauty. Such teeth are not only considered attractive but are also indicative of nutritional health, self esteem, hygienic pride, and economic status. Numerous treatment approaches have been proposed to address the esthetics and retention of restorations in primary teeth. Even though researchers have claimed that certain restorations are better than the others, particularly owing to the issues mentioned above, the search for the ideal esthetic restoration for the primary teeth continues. This paper revisits and attempts to reintroduce the full coverage restoration, namely, polycarbonate crown, for use in primary anterior teeth.

  19. Effect of Organoclay on Compatibilization, Thermal and Mechanical Properties of Polycarbonate/Polystyrene Blends

    CERN Document Server

    Singh, A K

    2014-01-01

    Pristine and organoclay modified polycarbonate/polystyrene (PC/PS) blends are prepared using melt-mixing technique. These blends are characterized for their morphology, structural, thermal and mechanical properties. Though our FTIR and XRD results show weak interactions between PC and PS phases, however, DSC and morphological study reveals that pristine PC/PS blends are immiscible. On other hand, introduction of organoclay results compatibilization of two polymer phases which is supported by significant shift in glass transition temperatures of the component phases and a distinct morphology having no phase segregation on sub-micron scale. Intercalation of polymers inside the clay gallery is achieved and is supported by XRD studies. A better thermal stability and higher value of modulus of the compatibilized blends compared to pristine PC/PS blends also support the reinforcement effect of organoclay to the PC/PS blend matrix.

  20. MODIFICATION OF SURFACE MECHANICAL PROPERTIES OF POLYCARBONATE BY B+ AND O+ IONS IMPLANTATION

    Institute of Scientific and Technical Information of China (English)

    S.D.Yao; C.Sun; S.Q.Zhou; C.C.Sun; Y.H.Lu; L.Huang; A.Vantomme; Q.Zhao; G.Langouche

    2002-01-01

    By implanting B+ and O+ ions respectively into polycarbonate (PC) plates, the sur-face mechanical properties of PC have been improved. Measurement by Nano IndenterⅡ showed that the hardness of samples increased 7-25 times than that before implan-tation; and the modulus of elasticity raised 2-5 times. The wear-resistance was testedby ball crusher; the width and depth of the wear-streak decreased by 1/3-1/2 or evenmore. The structure, deformation and appearance were analyzed by using Micro-FTIR Spectra, ESCA method and the steps instrument. These analyses showed thatthe structure of PC had been modified: a series of new cross-linking yielded, it de-pends on the Linear Energy Transition (LET) of implanted ions in the high polymercompounds.

  1. Pulsed laser deposition of tin-doped indium oxide (ITO) on polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Yong, T.K. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Tou, T.Y. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)]. E-mail: tytou@mmu.edu.my; Teo, B.S. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)

    2005-07-30

    Indium tin oxide (ITO) films were deposited on polycarbonate (PC) substrates in oxygen at room temperature by pulsed laser deposition (PLD) using a Nd:YAG laser with 355 and 532 nm wavelengths. The ITO films were analyzed by the four-point probe technique, atomic force microscopy (AFM) and UV-visible-Near IR spectrophotometry for electrical conductivity, surface morphological and optical transmission properties, respectively. The main plume species were identified by using a fiber optic spectrometer, which showed that the emission intensity produced by the 355 nm laser wavelength was considerably stronger than that produced by the 532 nm laser wavelength. The ITO film resistivity was an order of magnitude higher than that achieved by a KrF excimer laser, but comparable to ITO-coated substrates prepared by the sputtering method.

  2. Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS.

    Science.gov (United States)

    Antonakou, E V; Kalogiannis, K G; Stephanidis, S D; Triantafyllidis, K S; Lappas, A A; Achilias, D S

    2014-12-01

    Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.

  3. Mechanical and thermomechanical properties of polycarbonate-based polyurethane-silica nanocomposites

    Directory of Open Access Journals (Sweden)

    Rafał Poręba

    2011-09-01

    Full Text Available In this work aliphatic polycarbonate-based polyurethane-silica nanocomposites were synthesized and characterized. The influence of the type and of the concentration of nanofiller differing in average particle size (7 nm for Aerosil 380 and 40 nm for Nanosilica 999 on mechanical and thermomechanical properties was investigated. DMTA measurements showed that Nanosilica 999, irrespective of its concentration, slightly increased the value of the storage shear modulus G’ but Aerosil 380 brings about a nearly opposite effect, the shear modulus in the rubber region decreases with increasing filler content. Very high elongations at break ranging from 800% to more than 1000%, as well as high tensile strengths illustrate excellent ultimate tensile properties of the prepared samples. The best mechanical and thermomechanical properties were found for the sample filled with 0.5 wt.% of Nanosilica 999.

  4. Hyperbranched polycarbonate-based multimolecular micelle with enhanced stability and loading efficiency.

    Science.gov (United States)

    Su, Wei; Luo, Xiao-Hua; Wang, Hua-Fen; Li, Lei; Feng, Jun; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2011-02-16

    We herein develop a facile catalyst-free method to prepare hyperbranched hydroxyl-enriched aliphatic polycarbonate according to SCROP strategy. PEG-attached multiarm hyperbranched copolymer HEHDO-star-mPEG was further designed. It was found that HEHDO-star-mPEG can self-assemble into supramolecular multimolecular micelles in water. HEHDO-star-mPEG micelle showed excellent stability with respect to micellar size upon dilution, and displayed good cell-biocompatibility. An anticancer drug of doxorubicin with hydrogen-bonding functionality was incorporated into obtained micelles to establish a drug delivery system model. A high drug-loading content as well as sustained release pattern for HEHDO-star-mPEG based delivery system was achieved.

  5. The interfacial polycondensation of tetrabromobisphenol-a polycarbonate. 2--Reactivities and phase distribution of catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Jentau Gu (China Technical Consultants Inc., Miaoli (Taiwan, Province of China). Catalyst Research Center); Chunshan Wang (National Cheng-Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering)

    1993-10-05

    Tetrabromobisphenol-A (TBBPA), a sterically hindered bisphenol, is known to give only low molecular weight polymers using the interfacial process. The low reactivity is attributed to the bulkiness and electron-withdrawing bromine substituents at the ortho positions. The optimum reaction conditions for the interfacial polymerization of TBBPA using pyridine derivatives as a catalyst have been developed. From the two-phase concentration distribution constant (K[sub e]) and p K's values of triethylamine, 4-dimethylaminopyridine (DMAP), and TBBPA, the critical process parameters were obtained. Because of its high nucleophilicity and facile leaving character, the DMAP catalyst system produces a high molecular weight TBBPA-polycarbonate (PC) successfully. The profile of the process was followed to obtain a better understanding of the reaction mechanism.

  6. Thermal degradation kinetics and lifetime estimation for polycarbonate/polymethylphenylsilsesquioxane composite

    Institute of Scientific and Technical Information of China (English)

    Jiangbo WANG; Zhong XIN

    2009-01-01

    The thermal degradation behaviors of poly-carbonate/polymethylphenylsilsesquioxane (FRPC) composites were investigated by thermogravimetric analysis (TGA) under isothermal conditions in nitrogen atmosphere. The isothermal kinetics equation was used to describe the thermal degradation process. The results showed that activation energy (E), in the case of isothermal degradation, was a quick increasing function of conversion (a) for polycarbonate (PC) but was a strong and decreasing function of conversion for FRPC. Under the isothermal condition, the addition of polymethylphenylsilsesquioxane (PMPSQ) retardanted the thermal degradation and enhanced the thermal stability of PC during the early and middle stages of thermal degradation. It also indicated a possible existence of a difference in nucleation, nuclei growth, and gas diffusion mechanism in the thermal degradation process between PC and FRPC. Meanwhile, the addition of PMPSQ influenced the lifetime of PC, but the composite still met the demand in manufacturing and application.

  7. Polycarbonate-based benzo-δ-sultam films for high-dose dosimetry in radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Feizi, Shazad [University of Tehran, Tehran (India). School of Chemistry; Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Application Research School; Ziaie, Farhood [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Application Research School; Ghandi, Mehdi [University of Tehran, Tehran (India). School of Chemistry

    2015-05-01

    In this work characteristics of the polycarbonate films with 20 μm in thickness containing different weight percentage of Benzo-δ-sultam were studied for use as a high dose dosimetry system in radiation processing facilities. The sensitivity of the dosimeters and the linearity of dose-response curves were investigated under {sup 60}Co γ-rays in a dose range of 0-100 kGy, and obtained results were compared with the commercial CTA and FWT film dosimeters. The results show that the absorbance at 348 nm depends linearly on the dose in the investigated dose range. The effects of pre-irradiation (shelf-life) and post-irradiation storage in dark and in indirect sunlight are also discussed. The results show that the dosimeters characteristics are stable within 1% at 25 C, 3 months after the irradiation.

  8. Using polycarbonate dyed with dansyl chloride for dosimetry in radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Feizi, Shazad; Ziaie, Farhood [Nuclear Science and Technology Research Institute, Radiation Application Research School, Tehran (Iran, Islamic Republic of); Ghandi, Mehdi [Univ. Tehran (Iran, Islamic Republic of). School of Chemistry

    2015-07-01

    Preparation and characteristics evaluation of the polycarbonate films 20 μm in thickness containing Dansyl chloride as a routine dosimeter in radiation processing facilities were studied. The sensitivity of these films and the linearity of dose-response curves were investigated under {sup 60}Co γ-rays in a dose range of 0-100 kGy, and the obtained results were compared with the commercial CTA and FWT film dosimeters. The results show that the maximum absorbance appeared at 370 nm in all the investigated dose range. The dyed films were found to be stable enough in mediums with high degrees of humidity and temperature, to be reliably used in radio-applications. The effects of pre-irradiation (shelf-life) and post-irradiation storage in dark and in indirect sunlight were also discussed. The films which were made displayed stable characteristics when stored in dark, within 1% at 25 C, 3 months after irradiation.

  9. Evolution of nanodot morphology on polycarbonate (PC) surfaces by 40 keV Ar{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, Meetika, E-mail: meetika89@gmail.com; Chawla, Mahak; Gupta, Divya; Shekhawat, Nidhi; Sharma, Annu; Aggarwal, Sanjeev [Department of Physics, Kurukshetra University, Kurukshetra - 136119 (India)

    2016-05-06

    In the present paper we have discussed the effect of 40 keV Ar{sup +} ions irradiation on nanoscale surface morphology of Polycarbonate (PC) substrate. Specimens were sputtered at off normal incidences of 30°, 40° and 50° with the fluence of 1 × 10{sup 16} Ar{sup +}cm{sup −2}. The topographical behaviour of specimens was studied by using Atomic Force Microscopy (AFM) technique. AFM study demonstrates the evolution of nano dot morphology on PC specimens on irradiating with 1 × 10{sup 16} Ar{sup +}cm{sup −2}. Average size of dots varied from 37-95 nm in this specified range of incidence while density of dots varied from 0.17-3.0 × 107 dotscm{sup −2}. Such variations in morphological features have been supported by estimation of ion range and sputtering yield through SRIM simulations.

  10. Radial-pattern formation in the polycarbonate substratum of recordable compact disks

    Science.gov (United States)

    Tanimura, M.; Ishikawa, I.; Tachibana, M.; Shinozaki, K.; Kojima, K.

    2001-09-01

    A radial pattern is found to form in the polycarbonate (PC) substratum of a recordable compact disk. Characteristic features of the pattern are that it is composed of about 80 needle-like regions, the shape of which closely resembles a thin film. In addition, white light is found to scatter at the needle-like region/matrix boundaries. This suggests that the PC substratum may have inferior transparency due to the formation of this pattern. Thus, it is important to understand the bifurcation of the radial-pattern formation from the viewpoint of materials science and engineering. Based on the mechanics of the PC viscous fluid, it has been found that the bifurcation of the pattern formation has a Reynolds number of about 10-3.

  11. Irradiation effects in polycarbonate induced by 2.1 GeV Kr ions

    Institute of Scientific and Technical Information of China (English)

    TIAN Hui-Xian; JIN Yun-Fan; ZHU Zhi-Yong; SUN You-Mei; WANG Zhi-Guang

    2003-01-01

    Polycarbonate foil stacks were irradiated with 2.1 GeV Kr ions under vacuum at room temperature.The modifications in chemical structure induced by the irradiation were studied by means of Fourier transform infra-red (FTIR) and ultraviolet visible (UV/VIS) spectroscopies. FTIR measurements reveal that material degradationsthrough bond breaking are the main effects. Alkyne end groups are produced by the irradiation. UV/VIS measure-ments indicate a shifting of the absorption edge from ultraviolet towards visible, and a strong increase of absorbancein the ultraviolet and visible regions. The changes in absorbance induced by the irradiation at wavelengths of 380 nm,450 nm and 500 nm scale well with Sne (Se is electronic energy loss) where the value of n increases from 1.69 to 2.02with increasing of the wavelength. The results are briefly discussed.

  12. Synthesis and characterization of novel biodegradable poly(carbonate ester)s with photolabile protecting groups.

    Science.gov (United States)

    Xie, Zhigang; Hu, Xiuli; Chen, Xuesi; Sun, Jing; Shi, Quan; Jing, Xiabin

    2008-01-01

    Novel biodegradable poly(carbonate ester)s with photolabile protecting groups were synthesized by ring-opening copolymerization of L-lactide (LA) with 5-methyl-5-(2-nitro-benzoxycarbonyl)-1,3-dioxan-2-one (MNC) with diethyl zinc (Et2Zn) as catalyst. The poly(L-lactide-co-5-methyl-5-carboxyl-1,3-dioxan-2-one) (P(LA-co-MCC)) was obtained by UV irradiation of poly(L-lactide acid-co-5-methyl-5-(2-nitro-benzoxycarbonyl)-1,3-dioxan-2-one) (P(LA-co-MNC)) to remove the protective 2-nitrobenzyl group. The free carboxyl groups on the copolymers P(LA-co-MCC) were reacted with paclitaxel, a common antitumor drug. Gel permeation chromatography and NMR studies confirmed the copolymer structures and successful attachment of paclitaxel to the copolymer.

  13. Experimentation and Modeling of the Tension Behavior of Polycarbonate at High Strain Rates

    Directory of Open Access Journals (Sweden)

    Yingjie Xu

    2016-02-01

    Full Text Available A comprehensive understanding of the mechanical behavior of polycarbonate (PC under high-rate loadings is essential for better design of PC products. In this work, the mechanical behavior of PC is studied during tensile loading at high strain rates, using a split Hopkinson tension bar (SHTB. A modified experimental technique based on the SHTB is proposed to perform the tension testing on PC at rates exceeding 1000 s−1. The effect of strain rates on the tension stress–strain law of PC is investigated over a wide range of strain rates (0.0005–4500 s−1. Based on the experiments, a physically based constitutive model is developed to describe the strain rate dependent tensile stress–strain law. The high rate tensile deformation mechanics of PC are further studied via finite element simulations using the LSDYNA code together with the developed constitutive model.

  14. Verification of the dispersive charge transport in a hydrazone:polycarbonate molecularly doped polymer.

    Science.gov (United States)

    Tyutnev, Andrey P; Saenko, Vladimir S; Pozhidaev, Evgenii D; Kolesnikov, Vladislav A

    2009-03-18

    We report results of specially planned experiments intended to verify the dispersive character of the charge carrier transport in polycarbonate molecularly doped with hydrazone at 30 wt% loading, using for this purpose samples specifically featuring a well-defined plateau on a linear-linear plot. For this purpose we propose a new variant of the time-of-flight technique which allows easy changing of the generation zone width from about 0.5 µm (surface excitation) through intermediate values to full sample thickness (bulk excitation). To achieve this, we use electron pulses of 3-50 keV energy rather than traditional light pulses provided by lasers. Experimental results corroborated by numerical calculations uniquely prove that carrier transport in this molecularly doped polymer is dispersive, with the dispersion parameter equal to 0.75. Nevertheless, the mobility field dependence follows the famous Poole-Frenkel law.

  15. Marine ecosystem community carbon and nutrient uptake stoichiometry under varying ocean acidification during the PeECE III experiment

    Directory of Open Access Journals (Sweden)

    R. G. J. Bellerby

    2008-11-01

    Full Text Available Changes to seawater inorganic carbon and nutrient concentrations in response to the deliberate CO2 perturbation of natural plankton assemblages were studied during the 2005 Pelagic Ecosystem CO2 Enrichment (PeECE III experiment. Inverse analysis of the temporal inorganic carbon dioxide system and nutrient variations was used to determine the net community stoichiometric uptake characteristics of a natural pelagic ecosystem perturbed over a range of pCO2 scenarios (350, 700 and 1050 μatm. Nutrient uptake showed no sensitivity to CO2 treatment. There was enhanced carbon production relative to nutrient consumption in the higher CO2 treatments which was positively correlated with the initial CO2 concentration. There was no significant calcification response to changing CO2 in Emiliania huxleyi by the peak of the bloom and all treatments exhibited low particulate inorganic carbon production (~15 μmol kg−1. With insignificant air-sea CO2 exchange across the treatments, the enhanced carbon uptake was due to increase organic carbon production. The inferred cumulative C:N:P stoichiometry of organic production increased with CO2 treatment from 1:6.3:121 to 1:7.1:144 to 1:8.25:168 at the height of the bloom. This study discusses how ocean acidification may incur modification to the stoichiometry of pelagic production and have consequences for ocean biogeochemical cycling.

  16. The waterborne polyurethane dispersions based on polycarbonate diol: Effect of ionic content

    Energy Technology Data Exchange (ETDEWEB)

    Cakić, Suzana M., E-mail: suzana.cakic@yahoo.com [University of Niš, Faculty of Technology, Bulevar oslobodjenja 124, 16000 Leskovac (Serbia); Špírková, Milena [Institute of Macromolecular Chemistry AS CR v.v.i., Heyrovskeho Nam. 2, 16206 Prague (Czech Republic); Ristić, Ivan S.; B-Simendić, Jaroslava K. [University of Novi Sad, Faculty of Technology, Bulevar cara Lazara 1, 21000 Novi Sad (Serbia); M-Cincović, Milena [University of Belgrade, Vinča Institute of Nuclear Science, P.O. Box 522, 11001 Belgrade (Serbia); Poręba, Rafał [Institute of Macromolecular Chemistry AS CR v.v.i., Heyrovskeho Nam. 2, 16206 Prague (Czech Republic)

    2013-02-15

    Three water-based polyurethane dispersions (PUD) were synthesized by modified dispersing procedure using polycarbonate diol (PCD), isophorone diisocyanate (IPDI), dimethylolpropionic acid (DMPA), triethylamine (TEA) and ethylenediamine (EDA). The ionic group content in the polyurethane-ionomer structure was varied by changing the amount of the internal emulsifier, DMPA (4.5, 7.5 and 10 wt.% to the prepolymer weight). The expected structures of obtained materials were confirmed by FTIR spectroscopy. The effect of the DMPA content on the thermal properties of polyurethane films was measured by TGA, DTA, DSC and DMTA methods. Increased DMPA amounts result in the higher hard segment contents and in the increase of the weight loss corresponding to the degradation of the hard segments. The reduction of hard segment content led to the elevated temperature of decomposition and to the decrease of the glass transition temperature and thermoplasticity. The atomic force microscopy (AFM), results indicated that phase separation between hard and soft segment of PUD with higher DMPA content is more significant than of PUD with lower DMPA content. The physico-mechanical properties, such as hardness, adhesion test and gloss of the dried films were also determined considering the effect of DMPA content on coating properties. Highlights: ► Polyurethane dispersions (PUD) were synthesized from polycarbonate diol. ► The effect of the DMPA content on the thermal properties of PUD films was measured. ► The thermal stability of PUD was increased by decreasing the DMPA content. ► T{sub g} values of PUD were increased by increasing ionic content. ► The PUD with the highest content of DMPA showed more significant phase separation confirmed by AFM results.

  17. Effect of PEO coating on bubble behavior within a polycarbonate microchannel array: A model for hemodialysis.

    Science.gov (United States)

    Coblyn, Matthew; Truszkowska, Agnieszka; Mohammadi, Mahshid; Heintz, Keely; McGuire, Joseph; Sharp, Kendra; Jovanovic, Goran

    2016-07-01

    Obstruction of fluid flow by stationary bubbles in a microchannel hemodialyzer decreases filtration performance and increases damage to blood cells through flow maldistribution. A polyethylene oxide (PEO)-polybutadiene (PB)-polyethylene oxide surface modification, previously shown to reduce protein fouling and water/air contact angle in polycarbonate microchannel hemodialyzers, can improve microchannel wettability and may reduce bubble stagnation by lessening the resistive forces that compete with fluid flow. In this study, the effect of the PEO-PB-PEO coating on bubble retention in a microchannel array was investigated. Polycarbonate microchannel surfaces were coated with PEO-PB-PEO triblock polymer via radiolytic grafting. Channel obstruction was measured for coated and uncoated microchannels after injecting a short stream of air bubbles into the device under average nominal water velocities of 0.9 to 7.2 cm/s in the channels. The presence of the PEO coating reduced obstruction of microchannels by stationary bubbles within the range of 1.8 to 3.6 cm/s, average nominal velocity. Numerical simulations based on the lattice Boltzmann method indicate that beneficial effects may be due to the maintenance of a lubricating, thin liquid film around the bubble. The determined effective range of the PEO coating for bubble management serves as an important design constraint. These findings serve to validate the multiutility of the PEO-PB-PEO coating (bubble lubrication, biocompatibility, and therapeutic loading). © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 941-948, 2016.

  18. Enzymatic surface erosion of high tensile strength polycarbonates based on natural phenols.

    Science.gov (United States)

    Sommerfeld, Sven D; Zhang, Zheng; Costache, Marius C; Vega, Sebastián L; Kohn, Joachim

    2014-03-10

    Surface erosion has been recognized as a valuable design tool for resorbable biomaterials within the context of drug delivery devices, surface coatings, and when precise control of strength retention is critical. Here we report on high tensile strength, aromatic-aliphatic polycarbonates based on natural phenols, tyrosol (Ty) and homovanillyl alcohol (Hva), that exhibit enzymatic surface erosion by lipase. The Young's moduli of the polymers for dry and fully hydrated samples are 1.0 to 1.2 GPa and 0.8 to 1.2 GPa, respectively. Typical characteristics of enzymatic surface erosion were confirmed for poly(tyrosol carbonate) films with concomitant mass-loss and thickness-loss at linear rates of 0.14 ± 0.01 mg cm(-2) d(-1) and 3.0 ± 0.8 μm d(-1), respectively. The molecular weight and the mechanical properties of the residual films remained constant. Changing the ratio of Ty and Hva provided control over the glass transition temperature (T(g)) and the enzymatic surface erosion: increasing the Hva content in the polymers resulted in higher T(g) and lower enzymatic erosion rate. Polymers with more than 50 mol % Hva were stable at 37 °C in enzyme solution. Analysis on thin films using quartz crystal microbalance with dissipation (QCM-D) demonstrated that the onset temperature of the enzymatic erosion was approximately 20 °C lower than the wet T(g) for all tested polymers. This new finding demonstrates that relatively high tensile strength polycarbonates can undergo enzymatic surface erosion. Moreover, it also sheds light on the connection between T(g) and enzymatic degradation and explains why few of the high strength polymers follow an enzyme-meditated degradation pathway.

  19. Grafting of phosphorylcholine functional groups on polycarbonate urethane surface for resisting platelet adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Bin [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@hotmail.com [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Weijin Road 92, 300072 Tianjin (China); Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Lu, Jian; Zhang, Li; Zhao, Miao; Shi, Changcan; Khan, Musammir [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Guo, Jintang [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Weijin Road 92, 300072 Tianjin (China)

    2013-07-01

    In order to improve the resistance of platelet adhesion on material surface, 2-methacryloyloxyethyl phosphorylcholine (MPC) was grafted onto polycarbonate urethane (PCU) surface via Michael reaction to create biomimetic structure. After introducing primary amine groups via coupling tris(2-aminoethyl)amine (TAEA) onto the polymer surface, the double bond of MPC reacted with the amino group to obtain MPC modified PCU. The modified surface was characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The results verified that MPC was grafted onto PCU surface by Michael reaction method. The MPC grafted PCU surface had a low water contact angle and a high water uptake. This means that the hydrophilic PC functional groups improved the surface hydrophilicity significantly. In addition, surface morphology of MPC grafted PCU film was imaged by atomic force microscope (AFM). The results showed that the grafted surface was rougher than the blank PCU surface. In addition, platelet adhesion study was evaluated by scanning electron microscopy (SEM) observation. The PCU films after treated with platelet-rich plasma demonstrated that much fewer platelets adhered to the MPC-grafted PCU surface than to the blank PCU surface. The antithrombogenicity of the MPC-grafted PCU surface was determined by the activated partial thromboplastin time (APTT). The result suggested that the MPC modified PCU may have potential application as biomaterials in blood-contacting and some subcutaneously implanted devices. - Highlights: • MPC was successfully grafted onto polycarbonate urethane surface via Michael reaction. • High concentration of PC functional groups on the surface via TAEA molecule • Biomimetic surface modification • The modified surface showed high hydrophilicity and anti-platelet adhesion.

  20. XMASS detector

    CERN Document Server

    Abe, K; Hiraide, K; Hirano, S; Kishimoto, Y; Kobayashi, K; Moriyama, S; Nakagawa, K; Nakahata, M; Nishiie, H; Ogawa, H; Oka, N; Sekiya, H; Shinozaki, A; Suzuki, Y; Takeda, A; Takachio, O; Ueshima, K; Umemoto, D; Yamashita, M; Yang, B S; Tasaka, S; Liu, J; Martens, K; Hosokawa, K; Miuchi, K; Murata, A; Onishi, Y; Otsuka, Y; Takeuchi, Y; Kim, Y H; Lee, K B; Lee, M K; Lee, J S; Fukuda, Y; Itow, Y; Nishitani, Y; Masuda, K; Takiya, H; Uchida, H; Kim, N Y; Kim, Y D; Kusaba, F; Motoki, D; Nishijima, K; Fujii, K; Murayama, I; Nakamura, S

    2013-01-01

    The XMASS project aims to detect dark matter, pp and $^{7}$Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  1. XMASS detector

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hieda, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Hiraide, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hirano, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kishimoto, Y.; Kobayashi, K.; Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nakagawa, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Ogawa, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); and others

    2013-07-11

    The XMASS project aims to detect dark matter, pp and {sup 7}Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  2. Influence of substrate on the performances of semi-insulating GaAs detectors

    CERN Document Server

    Baldini, R; Nava, F; Canali, C; Lanzieri, C

    2000-01-01

    A study of the carrier transport mechanism, the charge collection efficiency and the energy resolution has been carried out on semi-insulating GaAs X-ray detectors realised on substrates with concentrations of acceptor dopants N sub a , varying from 10 sup 1 sup 4 to 10 sup 1 sup 7 cm sup - sup 3. The electron collection efficiency (ECE) and the reverse current were found to decrease with increasing N sub a , while the resistivity of the material was found to increase. At room temperature, the best collection efficiency (95%) and the best energy resolution (13.7 keV FWHM) for 59.5 keV X-rays of the sup 2 sup 4 sup 1 Am source, have been achieved with the less doped detectors (N sub a approx 10 sup 1 sup 4 cm sup - sup 3). The concentrations of ionised EL2 sup + , determined by optical measurements in IR regions, was shown to increase with N sub a and to be quasi-inversely proportional to the ECE values. This behaviour strongly supports the hypothesis that the EL2 defects play a main role in the compensation o...

  3. Semiconductor Detectors; Detectores de Semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, E.

    2007-07-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  4. 基于坡度和ECE法规的制动力分配研究%Research on Braking Force Distribution Based on Gradient and ECE Regulations

    Institute of Scientific and Technical Information of China (English)

    冯强; 张晓龙; 吴涛; 陈奇

    2015-01-01

    为了使汽车在上、下坡制动时前后制动力分配能够满足ECE法规的要求。通过对汽车在上、下坡制动时进行受力分析,得到汽车上、下坡制动时前、后轴的利用附着系数,根据ECE法规和汽车在上、下坡及平直路面上制动时前、后轴利用附着系数的大小关系进行前、后制动力分配系数设计,最后对分配效果进行验证,结果表明:该方法设计的制动力分配系数在汽车上、下坡制动时可以满足ECE法规的要求。%To make sure the front and back braking force distribution can meet the requirements of ECE regulations when the vehicle brakes uphill and downhill, the front and rear axle utilization adhesion co⁃efficient of the vehicle were obtained by force analysis during braking uphill and downhill, then the braking force distribution coefficients were designed according to ECE regulations and the magnitude relation of the front and rear axle utilization adhesion coefficients during braking uphill, downhill and straight, finally distribution effects were verified. The results show the braking force distribution coeffi⁃cients designed by this method can meet the requirements of ECE regulations when the vehicle brakes uphill and downhill.

  5. Recycling of engineering plastics from waste electrical and electronic equipments: influence of virgin polycarbonate and impact modifier on the final performance of blends.

    Science.gov (United States)

    Ramesh, V; Biswal, Manoranjan; Mohanty, Smita; Nayak, Sanjay K

    2014-05-01

    This study is focused on the recovery and recycling of plastics waste, primarily polycarbonate, poly(acrylonitrile-butadiene-styrene) and high impact polystyrene, from end-of-life waste electrical and electronic equipments. Recycling of used polycarbonate, acrylonitrile-butadiene-styrene, polycarbonate/acrylonitrile-butadiene-styrene and acrylonitrile-butadiene-styrene/high impact polystrene material was carried out using material recycling through a melt blending process. An optimized blend composition was formulated to achieve desired properties from different plastics present in the waste electrical and electronic equipments. The toughness of blended plastics was improved with the addition of 10 wt% of virgin polycarbonate and impact modifier (ethylene-acrylic ester-glycidyl methacrylate). The mechanical, thermal, dynamic-mechanical and morphological properties of recycled blend were investigated. Improved properties of blended plastics indicate better miscibility in the presence of a compatibilizer suitable for high-end application.

  6. Effects of CO2 on particle size distribution and phytoplankton abundance during a mesocosm bloom experiment (PeECE II

    Directory of Open Access Journals (Sweden)

    M. Schartau

    2008-04-01

    Full Text Available The influence of seawater carbon dioxide (CO2 concentration on the size distribution of suspended particles (2–60 μm and on phytoplankton abundance was investigated during a mesocosm experiment at the large scale facility (LFS in Bergen, Norway, in the frame of the Pelagic Ecosystem CO2 Enrichment study (PeECE II. In nine outdoor enclosures the partial pressure of CO2 in seawater was modified by an aeration system to simulate past (~190 μatm CO2, present (~370 μatm CO2 and future (~700 μatm CO2 CO2 conditions in triplicates. Due to the initial addition of inorganic nutrients, phytoplankton blooms developed in all mesocosms and were monitored over a period of 19 days. Seawater samples were collected daily for analysing the abundance of suspended particles and phytoplankton with the Coulter Counter and with Flow Cytometry, respectively. During the bloom period, the abundance of small particles (2 levels. At that time, a direct relationship between the total-surface-to-total-volume ratio of suspended particles and DIC concentration was determined for all mesocosms. Significant changes with respect to the CO2 treatment were also observed in the phytoplankton community structure. While some populations such as diatoms seemed to be insensitive to the CO2 treatment, others like Micromonas spp. increased with CO2, or showed maximum abundance at present day CO2 (i.e. Emiliania huxleyi. The strongest response to CO2 was observed in the abundance of small autotrophic nano-plankton that strongly increased during the bloom in the past CO2 mesocosms. Together, changes in particle size distribution and phytoplankton community indicate a complex interplay between the ability of the cells to physiologically respond to changes in CO2 and size selection. Size of cells is of general importance for a variety of processes in marine systems such as diffusion-limited uptake of substrates, resource allocation, predator-prey interaction, and gravitational settling

  7. Totally implantable artificial hearts and left ventricular assist devices: selecting impermeable polycarbonate urethane to manufacture ventricles.

    Science.gov (United States)

    Yang, M; Zhang, Z; Hahn, C; Laroche, G; King, M W; Guidoin, R

    1999-01-01

    In the development of a new generation of totally implantable artificial hearts and left ventricular assist devices (VADs) for long-term use, the selection of an acceptable material for the fabrication of the ventricles probably represents one of the greatest challenges. Segmented polyether urethanes used to be the material of choice due to their superior flexural performance, acceptable blood compatibility, and ease of processing. However, because they are known to degrade and to be readily permeable to water, they cannot meet the rigorous requirements needed for a new generation of implantable artificial hearts and VADs. Therefore, the objective of the present study was to identify alternative polymeric materials that would be satisfactory for fabricating the ventricles, and in particular, to determine the water permeability through membranes made from four commercial polycarbonate urethanes (Carbothane PC3570A, Chronoflex AR, Corethane 80A, and Corethane 55D) in comparison to those made from two traditional polyether urethanes (Tecoflex EG80A and Tecothane TT-1074A). In addition to determining the rate of water transmission through the six membranes by exposing them to deionized water, saline, and albumin-Krebs solution under pressure and measuring the displacement of liquid by means of a recently developed capillary method, the inherent surface and chemical properties of the six membranes were characterized by SEM, contact angle measurements, FTIR, DSC, and GPC techniques. The results of the study demonstrated that the rate of water transmission through the four polycarbonate urethane membranes was significantly lower than through the two polyether urethanes. In fact the lowest values were recorded with the two Corethane membranes, and the harder type 55D polymer had a lower value (2.7 x 10(-7) g/s cm2) than the softer 80A version (3.3 x 10(-7) g/s cm2). This level of water vapor permeability, which appears to be controlled primarily by a Fickian diffusion

  8. Synthesis and characterization of polycarbonates by melt phase interchange reactions of alkylene and arylene diacetates with alkylene and arylene diphenyl dicarbonates.

    Science.gov (United States)

    Sweileh, Bassam A; Al-Hiari, Yusuf M; Kailani, Mohammad H; Mohammad, Hani A

    2010-05-18

    This work presents a new synthetic approach to aromatic and aliphatic polycarbonates by melt polycondensation of bisphenol A diacetates with alkylene- and arylenediphenyl dicarbonates. The diphenyl dicarbonates were prepared from phenyl chloroformate and the corresponding dihydroxy compounds. The process involved a precondensation step under a slow stream of dry argon with the elimination of phenyl acetate, followed by melt polycondensation at high temperature and under vacuum. The potential of this reaction is demonstrated by the successful synthesis of a series of aromatic-aromatic and aromatic-aliphatic polycarbonates having inherent viscosities from 0.19 to 0.43 dL/g. Thus low to intermediate molecular mass polymers were obtained. The (13)C-NMR spectra of the carbon of the carbonate group showed that the formed polycarbonates contain partial random sequence distribution of monomer residues in their chains. The polycarbonates were characterized by inherent viscosity, FTIR, (1)H-NMR and (13)C-NMR spectroscopy. The glass transition temperatures, measured by DSC, of the polycarbonates were in the range 13-108 degrees C. The thermogravimetric curves of showed that these polymers have good thermal stability up to 250 degrees C. The present approach may open the door for novel polycarbonates containing other organic functional groups.

  9. DIGITAL IMAGE ANALYSIS OF PHASE STRUCTURE IN THE BLEND OF POLY(BUTYLENE TEREPHTHALATE-COCAPROLACTONE) WITH POLYCARBONATE

    Institute of Scientific and Technical Information of China (English)

    MA Dezhu; HE Liling; ZOU Yingfang; LUO Xiaolie; Takafumi Hayashi; Toshio Nishi

    1992-01-01

    The digital image processing technique was used for the extraction of physical information from the temporal image of phase structure in the process of phase separation in the blend of poly (butylene terephthalate-co-caprolactone )with polycarbonate. The power spectrum images of the two-dimensional Fourier transformation (2DFT) of the temporal image of phase structure reflect the change of the phase size with time.

  10. UV-VIS Spectroscopy Study of Polycarbonate Irradiated by 2.1 GeV Kr Ions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The polycarbonate(Pc)film used in this study is a commercial film of about 21μm in thickness.The films were cut to an area of approximately 18 mm×18 mm and piled up to make a stack of thickness slightly larger than the calculated ion projected range.PC stacks were irradiated under vacuum and at room temperature

  11. Modification of epoxy resins with thermoplastic segmented polycarbonate-based polyurethanes

    Directory of Open Access Journals (Sweden)

    Pavličević Jelena

    2014-01-01

    Full Text Available In this work, epoxy hybrid materials were synthesized by addition of thermoplastic segmented aliphatic polyurethanes with good elastic properties. The modified epoxy samples were obtained by curing of previously homogenized mixture of prepared polyurethane melts, epoxy resin and crosslinking agent Jeffamine D-2000. The influence of different weight content of polyurethanes (5, 10 and 15 wt. % compared to pure epoxy resin as well the influence of different hard segments of elastomers (20, 25 and 30 wt. % on the curing of modified epoxy systems was studied. The curing was followed by differential scanning calorimetry (DSC, in dynamic regime from 30 to 300°C, at three heating rates (5, 10 and 20°C/min. With the increase of hard segments content of polyurethanes added in higher concentration (10 and 15 wt. % into epoxy matrix, the temperature of maximum ratio of curing was shifted to lower values (from 205 to 179°C. Obtained DSC data were analyzed using two integral methods (Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose and one differential kinetic model (Friedman. The significant differences were observed in the second part of the epoxy curing (for the reaction degrees higher than 60 %, where the values of activation energies remarkably increase. The addition of polyurethane elastomers retarded the curing process due to decreased mobility of reactant molecules caused by higher viscosity of reaction mixture. By detailed analysis of determined kinetic parameters, it is concluded that the influence of slow diffusion is more pronounced in the presence of thermoplastic polycarbonate-based polyurethanes, which confirmed their effect on the mechanism of epoxy curing. The highest tensile strength and hardness showed the DGEBA modified with the polyurethane with highest hard segment content. Increasing the hard segment content of polyurethane and its concentration in matrix, the tensile strength of modified epoxy was increased. The elongation at break of

  12. Broad-Spectrum Antimicrobial Star Polycarbonates Functionalized with Mannose for Targeting Bacteria Residing inside Immune Cells.

    Science.gov (United States)

    Yang, Chuan; Krishnamurthy, Sangeetha; Liu, Jie; Liu, Shaoqiong; Lu, Xiaohua; Coady, Daniel J; Cheng, Wei; De Libero, Gennaro; Singhal, Amit; Hedrick, James L; Yang, Yi Yan

    2016-06-01

    In this study, a series of star-shaped polycarbonates are synthesized by metal-free organocatalytic ring-opening polymerization of benzyl chloride (BnCl) and mannose-functionalized cyclic carbonate monomers (MTC-BnCl and MTC-ipman) with heptakis-(2,3-di-O-acetyl)-β-cyclodextrin (DA-β-CD) as macroinitiator. The distributions and compositions of pendent benzyl chloride and protected mannose group (ipman) units are facilely modulated by varying the polymerization sequence and feed ratio of the monomers, allowing precise control over the molecular composition, and the resulting polymers have narrow molecular weight distribution. After deprotection of ipman groups and quaternization with various N,N-dimethylalkylamines, these star polymers with optimized compositions of cationic and mannose groups in block and random forms exhibit strong bactericidal activity and low hemolysis. Furthermore, the optimal mannose-functionalized polymer demonstrates mannose receptor-mediated intracellular bactericidal activity against BCG mycobacteria without inducing cytotoxicity on mammalian cells at the effective dose. Taken together, the materials designed in this study have potential use as antimicrobial agents against diseases such as tuberculosis, which is caused by intracellular bacteria.

  13. Flame Retardancy of Polysiloxane Solid Powder Combined with Organophosphate in Polycarbonate

    Directory of Open Access Journals (Sweden)

    Zhou Wenjun

    2016-01-01

    Full Text Available The synergistic effects of methylphenyl-polsiloxane solid powder and organophosphate flame retardant for polycarbonate (PC were investigated by limiting oxygen index(LOI, and cone calorimeter. It was found that the LOI of the flame-retarded PC (FR-PC with polysiloxane and organophosphate binary flame retardants didn’t increase in comparison with that of FR-PC containing a single species flame retardant. The cone calorimeter results show that the heat release rate (HRR of the PC/polysiloxane/organophosphate(PX230 composition is approximately 50% lower than that of the PC/polysiloxane or the PC/PX230. Total heat release (THR of PC/polysiloxane/PX230 also significantly reduce in comparison with that of PC/polysiloxane and PC/PX230 binary composites, which indicates a clear synergistic effect of the polysiloxane and PX230 in the PC flame retardant composites. The CO production rate of the PC/polysiloxane/PX230 during combustion is slightly lower than that of the virgin PC. So the combination of the polysiloxane with PX230 used in PC could synergic inhibit the combustion heat release, and achieve environmental friendly fire-retardant effect.

  14. On crystallization of bisphenol-A polycarbonate thin films upon annealing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chunhong; Li, Qichao; Mao, Wenfeng; Wang, Peng; He, Chunqing, E-mail: hecq@whu.edu.cn

    2015-10-16

    Crystallization of polycarbonate (PC) films as a function of annealing time has been investigated by various methods. A distinct diffraction peak at 17.56°, a sharp decrease of film thickness, an increase of refractive index and branch-type structures on the surface are found merely for the film after crystallization. Interestingly, positron annihilation parameters demonstrate fractional free-volumes in PC films vary significantly not only before crystallization but also at the early stage of annealing, which are not found by other methods. The results show that free-volumes in PC film must be increased remarkably before crystallization, which enables the occurrence of molecule rearrangement. - Highlights: • Fractional free-volume in PC film decreased of early stage of annealing. • Crystallization of PC film on Si substrate occurred after annealed for ∼48 hours. • Fractional free-volume in PC film increased remarkably before crystallization. • Positron diffusion length and S parameter revealed the variation of free volumes.

  15. Metal nanoparticle-doped coloured films on glass and polycarbonate substrates

    Indian Academy of Sciences (India)

    S K Medda; M Mitra; S De; S Pal; G De

    2005-11-01

    In a program on the development of metal (e.g. Au, Ag, Cu and their alloy) nanoparticles in sol{gel derived films, attempts were made to synthesize different coloured coatings on glasses and plastics. The absorption position of surface plasmon resonance (SPR) band arising from the embedded metal nanoparticles was tailored by controlling the refractive index of the matrix for the development of different colours. Thus different coloured (pink to blue) coatings on ordinary sheet glasses were prepared by generating Au nanoparticles in mixed SiO2-TiO2 matrices having refractive index values ranging from about 1.41 to 1.93. In another development, in situ generation of Ag nanoparticles in the inorganic{organic hybrid host leads to the formation of different abrasion resistant coloured coatings (yellow to pink) on polycarbonate substrates after curing. As expected, the SPR peak of Ag or Au is gradually red-shifted due to the increase of refractive index of the coating matrices causing a systematic change of colour.

  16. Surface evolution of polycarbonate/polyethylene terephthalate blends induced by thermal treatments

    Energy Technology Data Exchange (ETDEWEB)

    Licciardello, A.; Auditore, A.; Samperi, F.; Puglisi, C

    2003-01-15

    Bisphenol-A polycarbonate (PC) and polyethyleneterephthalate (PET) blends are known to undergo, upon thermal treatment (melt mixing), exchange reactions leading to the formation of copolymers having a final structure that is also affected by consecutive reactions involving CO{sub 2} and ethylene carbonate losses. In this work we followed the evolution of the surface composition of this system during the melt mixing at 270 deg. C, both with and without catalysts, by means of time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The static SIMS spectra obtained at different treatment times show the appearance of peaks related to newly formed structures and also the modification of the relative intensities of peaks characteristic of both the initial constituents of the blend. From the variation of the relative intensities of peaks related to the bisphenol-A unit of PC and to the phthalate structure of PET, it is shown that after the first stages of melt mixing the surface is PC enriched and that with the progressive formation of a random copolymer the phthalate units increase their concentration at the surface of the system. Hence, as final result of the melt mixing process, the surface composition tends to reflect the relative amount of the repeating units in the bulk.

  17. Surface evolution of polycarbonate/polyethylene terephthalate blends induced by thermal treatments

    Science.gov (United States)

    Licciardello, A.; Auditore, A.; Samperi, F.; Puglisi, C.

    2003-01-01

    Bisphenol-A polycarbonate (PC) and polyethyleneterephthalate (PET) blends are known to undergo, upon thermal treatment (melt mixing), exchange reactions leading to the formation of copolymers having a final structure that is also affected by consecutive reactions involving CO 2 and ethylene carbonate losses. In this work we followed the evolution of the surface composition of this system during the melt mixing at 270 °C, both with and without catalysts, by means of time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The static SIMS spectra obtained at different treatment times show the appearance of peaks related to newly formed structures and also the modification of the relative intensities of peaks characteristic of both the initial constituents of the blend. From the variation of the relative intensities of peaks related to the bisphenol-A unit of PC and to the phthalate structure of PET, it is shown that after the first stages of melt mixing the surface is PC enriched and that with the progressive formation of a random copolymer the phthalate units increase their concentration at the surface of the system. Hence, as final result of the melt mixing process, the surface composition tends to reflect the relative amount of the repeating units in the bulk.

  18. Antibacterial properties of Au doped polycarbonate synthesized by gamma radiation assisted diffusion method

    Science.gov (United States)

    Hareesh, K.; Deore, Avinash V.; Dahiwale, S. S.; Sanjeev, Ganesh; Kanjilal, D.; Ojha, Sunil; Dhole, N. A.; Kodam, K. M.; Bhoraskar, V. N.; Dhole, S. D.

    2015-07-01

    Gold (Au)-Polycarbonate (PC) matrix was prepared by gamma radiation assisted diffusion of Au nanoparticles in PC matrix. UV-Visible spectroscopy showed the surface plasmon resonance around 550 nm which corresponds to Au and this peak shift towards lower wavelength i.e. blue shift indicating the decrease in particle size of Au. Rutherford Backscattering (RBS) experiment confirmed the diffusion of Au in PC and depth of diffusion is found to be around 0.85 μm. X-ray Diffractogram (XRD) results also revealed the diffusion of Au in PC where the peak observed at 2θ∼38.29° which correspond to the FCC structure. Scanning Electron Microscope (SEM) images showed the hexagonal shaped Au nanoparticles and average particle size is found to be around 110 nm. These samples also showed anti-bacterial properties with both gram positive and gram negative bacteria's and revealed the inhibition of the overall growth of the bacteria with gamma dose.

  19. Micro-structuring of polycarbonate-urethane surfaces in order to reduce platelet activation and adhesion.

    Science.gov (United States)

    Clauser, Johanna; Gester, Kathrin; Roggenkamp, Jan; Mager, Ilona; Maas, Judith; Jansen, Sebastian V; Steinseifer, Ulrich

    2014-01-01

    In the development of new hemocompatible biomaterials, surface modification appears to be a suitable method in order to reduce the thrombogenetic potential of such materials. In this study, polycarbonate-urethane (PCU) tubes with different surface microstructures to be used for aortic heart valve models were investigated with regard to the thrombogenicity. The surface structures were produced by using a centrifugal casting process for manufacturing PCU tubes with defined casting mold surfaces which are conferred to the PCU surface during the process. Tubes with different structures defined by altering groove widths were cut into films and investigated under dynamic flow conditions in contact with porcine blood. The analysis was carried out by laser scanning microscopy which allowed for counting various morphological types of platelets with regard to the grade of activation. The comparison between plain and shaped PCU samples showed that the surface topography led to a decline of the activation of the coagulation cascade and thus to the reduction of the fibrin synthesis. Comparing different types of structures revealed that smooth structures with a small groove width (d ~ 3 μm) showed less platelet activation as well as less adhesion in contrast to a distinct wave structure (d ~ 90 μm). These results prove surface modification of polymer biomaterials to be a suitable method for reducing thrombogenicity and hence give reason for further alterations and improvements.

  20. Treatment of polycarbonate by dielectric barrier discharge (DBD) at atmospheric pressure

    Science.gov (United States)

    Kostov, K. G.; Hamia, Y. A. A.; Mota, R. P.; dos Santos, A. L. R.; Nascente, P. A. P.

    2014-05-01

    Generally most plastic materials are intrinsically hydrophobic, low surface energy materials, and thus do not adhere well to other substances. Surface treatment of polymers by discharge plasmas is of great and increasing industrial application because it can uniformly modify the surface of sample without changing the material bulk properties and is environmentally friendly. The plasma processes that can be conducted under ambient pressure and temperature conditions have attracted special attention because of their easy implementation in industrial processing. Present work deals with surface modification of polycarbonate (PC) by a dielectric barrier discharge (DBD) at atmospheric pressure. The treatment was performed in a parallel plate reactor driven by a 60Hz power supply. The DBD plasmas at atmospheric pressure were generated in air and nitrogen. Material characterization was carried out by contact angle measurements, and X-ray photoelectron spectroscopy (XPS). The surface energy of the polymer surface was calculated from contact angle data by Owens-Wendt method using distilled water and diiodomethane as test liquids. The plasma-induced chemical modifications are associated with incorporation of polar oxygen and nitrogen containing groups on the polymer surface. Due to these surface modifications the DBD-treated polymers become more hydrophilic. Aging behavior of the treated samples revealed that the polymer surfaces were prone to hydrophobic recovery although they did not completely recover their original wetting properties.

  1. Heavy ion tracks in polycarbonate. Comparison with a heavy ion irradiated model compound (diphenyl carbonate)

    Science.gov (United States)

    Ferain, E.; Legras, R.

    1993-09-01

    The chemical modifications induced by energetic heavy ion irradiation of polycarbonate (PC) film are determined by GPC, HPLC, ESR, TGA, IR and UV spectrophotometry. The main results of the irradiation are creation of radicals, chain scission, cross-linking and appearance of new chemical groups in the main polymer chain. As far as the creation of new groups is concerned, they are determined by means of a model compound of PC: the diphenyl carbonate (DPC). The following compounds are identified after energetic heavy ion irradiation of DPC: salicylic acid, phenol, 4,4'-biphenol, 2,4'-biphenol, 2,2'-biphenol, 4-phenoxyphenol, 2-phenoxyphenol, phenyl ether, phenyl benzoate, phenyl salicylate, 2-phenylphenol and 2-phenoxyphenyl benzoate. A similarity between the heavy ion irradiation and a heat treatment has also been established with DPC. On the basis of these results, we try to give an explanation of the preferential attack along the tracks of the irradiated film. Also, an explanation of the well-known beneficial effect of an UV exposition of the irradiated film on the selectivity of this preferential chemical attack is suggested.

  2. Formulation and photoirradiation parameters that influenced photoresponsive drug delivery using alkoxylphenacyl-based polycarbonates.

    Science.gov (United States)

    Wehrung, Daniel; Chamsaz, Elaheh A; Joy, Abraham; Oyewumi, Moses O

    2014-11-01

    Recently, we reported the synthesis and biocompatibility of alkoxylphenacyl-based polycarbonates (APP); a promising new class of polymers that undergo photo-induced chain scission. In the current study, nanoparticles (NPs) were prepared from the APP polymer (APP-NPs) and loaded with doxorubicin (DOX) (DOX-APP-NPs) in order to identify and evaluate formulation and photoirradiation parameters that influence photoresponsive efficacy. Stable and spherical APP-NPs were prepared with diameters between 70-80nm depending on APP concentration (10-40mg/mL). There was a direct relationship between APP concentration and resultant particle size. Drug release studies indicated that exposure to the photo-trigger was capable of altering the rate and extent of DOX released. Photoresponsive DOX release was markedly influenced by the frequency of photoirradiation while the effect of APP concentration was most likely propagated through NP size. DOX released by photoactivation retained its efficacy as assessed by cytotoxicity studies in human lung adenocarcinoma (A549) cells. Studies in BALB/c mice indicated that DOX-APP-NPs induce less cardiotoxicity than DOX alone and that DOX-APP-NPs are not susceptible to dose dumping after photoirradiation.

  3. Mechanistic investigations of lipase-catalyzed degradation of polycarbonate in organic solvents.

    Science.gov (United States)

    Artham, Trishul; Mohanalakshmi, N; Paragi-Vedanthi, Padma Priya; Doble, Mukesh

    2011-01-05

    The biodegradation of an engineering thermoplastic, poly (bisphenol-A carbonate) (BPAPC), was carried out using three different lipases from Candida antarctica (CAL), Candida rugosa (CRL) and porcine pancreas (PPL) in water-miscible (tetrahydrofuran) and water-immiscible (chloroform) solvents for 10 days. The degradation was monitored by gel permeation chromatography and Fourier transform infrared spectroscopy. Maximum degradation (ca. 60% reduction in M(n)) of BPAPC was observed in THF with PPL when compared to the control without the enzyme. The degradation products in all the experiments were bisphenol-A and 4-α-cumyl phenol suggesting that the lipases act through an end-chain scission on the polymer. The degradation of BPAPC in THF was in the order of PPL>CAL>CRL, while in CHCl(3) it was CRL>CAL>PPL. To understand this disparity, and to probe the mechanistic aspects of degradation, molecular dynamics investigations were performed on the lipases with model BPAPC in both the solvents. The results also suggested that catalytic triad (Ser, His, Asp/Glu) was involved in the hydrolysis of carbonate bond leading to release of bisphenol-A. These data provide us the basic understanding of the degradation mechanism and a novel methodology for degrading polycarbonate.

  4. Environmental stress cracking in gamma-irradiated polycarbonate - A diffusion approach

    Science.gov (United States)

    Silva, Pietro Paolo J. C. de O.; Araújo, Patricia L. B.; da Silveira, Leopoldo B. B.; Araújo, Elmo S.

    2017-01-01

    Polycarbonate (PC) is an engineering polymer which presents interesting properties. This material has been also used in medical devices, which is frequently exposed to gamma radiosterilization and to chemical agents. This may produce significant changes in polymer structure, leading to failure in service. The present work brings about a new approach on environmental stress cracking (ESC) processes elucidation in 100 kGy gamma-irradiated PC, by evaluating the diffusion process of methanol or 2-propanol in test specimens and determining the diffusion parameters on solvent-irradiated polymer systems. A comparison of diffusion parameters for both solvents indicated that methanol has a considerable ESC action on PC, with diffusion parameter of 7.5×10-14±1% m2 s-1 for non-irradiated PC and 7.8×10-14±2.8% m2 s-1 for PC irradiated at 100 kGy. In contrast, 2-propanol did not act as an ESC agent, as it did promote neither swelling nor cracks in the test specimens. These results were confirmed by visual analysis and optical microscopy. Unexpectedly, structural damages evidenced in tensile strength tests suggested that 2-propanol is as aggressive as methanol chemical for PC. Moreover, although some manufacturers indicate the use of 2-propanol as a cleaning product for PC artifacts, such use should be avoided in parts under mechanical stress.

  5. Evaluation of the potential health risks of substances migrating from polycarbonate replacement baby bottles.

    Science.gov (United States)

    Mertens, Birgit; Van Hoeck, Els; Blaude, Marie-Noëlle; Simon, Coraline; Onghena, Matthias; Vandermarken, Tara; Van Langenhove, Kersten; Demaegdt, Heidi; Vandermeiren, Karin; Covaci, Adrian; Scippo, Marie-Louise; Elskens, Marc; Van Loco, Joris

    2016-11-01

    Since the European Commission prohibited the use of bisphenol A in the production of polycarbonate (PC) baby bottles, many other materials have replaced PC for the manufacture of this type of food contact materials. In the present study, the potential migration risks associated with these alternative materials were investigated. First, all substances were evaluated for endocrine disruptive (ED) activity by using different existing lists of (suspected) ED chemicals. Next, the potential non-ED risks were assessed. A distinction was made between migrants listed in Annex I of European Regulation 10/2011 and the unlisted substances (e.g. non-intentionally added substances). For the listed substances, concentrations in the migration solutions were compared to their respective specific migration limits (SML) (when applicable). Migration of all substances was shown to be below their SML. The unlisted substances were evaluated using toxicological information from previous evaluations, or if not available, by applying the Threshold of Toxicological Concern (TTC) approach. In case the estimated exposure to the unlisted substance exceeded the human exposure TTC value, a more indepth risk assessment was performed. Based on the results of both parts of the study, four baby bottles were considered of high concern because of the potential toxicity of migrating compounds.

  6. Preparation of Indium Tin Oxide Films on Polycarbonate substrates by Radio-frequency Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    LIU Jing; GONG Jian; GU Zhen'an

    2005-01-01

    Indium tin oxide ( ITO ) thin films ( 100 ± 10 nm) were deposited on PC ( polycarbonate ) and glass substrates by rf( radio-frequency ) magnetron sputtering. The oxygen content of the ITO films was changed by variation of the sputtering gas composition. All the other deposition parameters were kept constant. The sheet resistance, optical transmittance and microstructure of ITO films were investigated using a four-point probe, spectrophotometer, X- ray diffractometer( XRD ) and atomic force microscope ( AFM ). Sheet resistances for the ITO films with optical transmittance more than 75% on PC substrates varied from 40 Ω/ cm2 to more than 104 Ω/cm2 with increasing oxygen partial pressure from 0 to about 2% . The same tendency of sheet resistances increasing with increasing oxygen partial pressure was observed on glass substrates. The X-ray diffraction data indicated polycrystalline films with grain orientations predominantly along (440) and (422) directions. The intensities of (440) and (422) peaks increased slightly with the increase of oxygen partial pressure both on PC and glass substrates. The AFM images show that the ITO films on PC substrates were dense and uniform. The average grain size of the films was about 40nm.

  7. Texture Analysis of Hydrophobic Polycarbonate and Polydimethylsiloxane Surfaces via Persistent Homology

    Directory of Open Access Journals (Sweden)

    Ali Nabi Duman

    2017-09-01

    Full Text Available Due to recent climate change-triggered, regular dust storms in the Middle East, dust mitigation has become the critical issue for solar energy harvesting devices. One of the methods to minimize and prevent dust adhesion and create self-cleaning abilities is to generate hydrophobic characteristics on surfaces. The purpose of this study is to explore the topological features of hydrophobic surfaces. We use non-standard techniques from topological data analysis to extract morphological features from the AFM images. Our method recovers most of the previous qualitative observations in a robust and quantitative way. Persistence diagrams, which is a summary of topological structures, witness quantitatively that the crystallized polycarbonate (PC surface possesses spherulites, voids, and fibrils, and the texture height and spherulite concentration increases with the increased immersion period. The approach also shows that the polydimethylsiloxane (PDMS exactly copied the structures at the PC surface but 80 to 90 percent of the nanofibrils were not copied at PDMS surface. We next extract a feature vector from each persistence diagram to show which experiments hold features with similar variance using principal component analysis (PCA. The K-means clustering algorithm is applied to the matrix of feature vectors to support the PCA result, grouping experiments with similar features.

  8. Superposition approach for description of electrical conductivity in sheared MWNT/polycarbonate melts

    Directory of Open Access Journals (Sweden)

    M. Saphiannikova

    2012-06-01

    Full Text Available The theoretical description of electrical properties of polymer melts, filled with attractively interacting conductive particles, represents a great challenge. Such filler particles tend to build a network-like structure which is very fragile and can be easily broken in a shear flow with shear rates of about 1 s–1. In this study, measured shear-induced changes in electrical conductivity of polymer composites are described using a superposition approach, in which the filler particles are separated into a highly conductive percolating and low conductive non-percolating phases. The latter is represented by separated well-dispersed filler particles. It is assumed that these phases determine the effective electrical properties of composites through a type of mixing rule involving the phase volume fractions. The conductivity of the percolating phase is described with the help of classical percolation theory, while the conductivity of non-percolating phase is given by the matrix conductivity enhanced by the presence of separate filler particles. The percolation theory is coupled with a kinetic equation for a scalar structural parameter which describes the current state of filler network under particular flow conditions. The superposition approach is applied to transient shear experiments carried out on polycarbonate composites filled with multi-wall carbon nanotubes.

  9. Ammonia modification for flotation separation of polycarbonate and polystyrene waste plastics.

    Science.gov (United States)

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Lin, Qing-quan; Zhang, Ling-ling; Huang, Luo-luo; Zhao, Jun-yao

    2016-05-01

    A promising method, ammonia modification, was developed for flotation separation of polycarbonate (PC) and polystyrene (PS) waste plastics. Ammonia modification has little effect on flotation behavior of PS, while it changes significantly that of PC. The PC recovery in the floated product drops from 100% to 3.17% when modification time is 13min and then rises to 100% after longer modification. The mechanism of ammonia modification was studied by contact angle, and Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) measurements. Contact angle of PC indicates the decline of PC recovery in the floated product is ascribed to an increase in surface wettability. FT-IR and XPS spectra suggest that ammonia modification causes chemical reactions occurred on PC surface. Flotation behavior of ammonia-modified PC and PS was investigated with respect to flotation time, frother concentration and particle sizes. Flotation separation of PC and PS waste plastics was conducted based on the flotation behavior of single plastic. PC and PS mixtures with different particle sizes are separated efficiently, implying that the technology possesses superior applicability to particle sizes of plastics. The purity of PS and PC is up to 99.53% and 98.21%, respectively, and the recovery of PS and PC is larger than 92.06%. A reliable, cheap and effective process is proposed for separation of PC and PS waste plastics.

  10. Polycarbonate surface cell's adhesion examination after Nd:YAG laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ramazani, S.A. Ahmad, E-mail: Ramazani@sharif.ir [Polymer Group, Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Mousavi, Seyyed Abbas, E-mail: Musavi@che.sharif.ir [Department of Chemistry, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Seyedjafari, Ehsan [Department of Biotechnology, University College of Science, University of Tehran (Iran, Islamic Republic of); Poursalehi, Reza [Department of Physics, University of Shahed, Tehran (Iran, Islamic Republic of); Sareh, Shohreh [Research Center of Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Silakhori, Kaveh [Laser Research Center, Atomic Energy Organization, Tehran (Iran, Islamic Republic of); Poorfatollah, Ali Akbar [Research Center of Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Shamkhali, Amir Nasser [Department of Chemistry, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2009-05-05

    Nd:YAG laser treatment was used in order to increase surface cell adhesion aspects of polycarbonate (PC) films prepared via melt process. The treatment was carried out under different wavelengths and beam diameters. ATR-FTIR and UV spectra obtained from different samples before and after laser treatment in air showed that laser irradiation has induced some chemical and physical changes in surface properties. The irradiated films were also characterized using scanning electron microscopy (SEM) and contact angle measurements. Effect of pulse numbers on the surface properties was also investigated. Cell culture test was used to evaluate cell adhesion property on the PC films before and after treatment. The results obtained from this test showed that after laser treatment, the cells were attached and proliferated extensively on the Nd:YAG laser treated films in comparison with the unmodified PC. Moreover, it was revealed that a decrease in the laser beam diameter and an increase in the irradiated pulse numbers increased surface wettability and caused a better cell attachment on the polymer surface. The obtained results also showed that a decrease in the laser beam diameter and an increase in the irradiated pulse numbers increased surface wettability and caused a better cell attachment on the polymer surface.

  11. Vertically aligned zinc oxide nanowires electrodeposited within porous polycarbonate templates for vibrational energy harvesting

    Science.gov (United States)

    Boughey, Francesca L.; Davies, Timothy; Datta, Anuja; Whiter, Richard A.; Sahonta, Suman-Lata; Kar-Narayan, Sohini

    2016-07-01

    A piezoelectric nanogenerator has been fabricated using a simple, fast and scalable template-assisted electrodeposition process, by which vertically aligned zinc oxide (ZnO) nanowires were directly grown within a nanoporous polycarbonate (PC) template. The nanowires, having average diameter 184 nm and length 12 μm, are polycrystalline and have a preferred orientation of the [100] axis parallel to the long axis. The output power density of a nanogenerator fabricated from the as-grown ZnO nanowires still embedded within the PC template was found to be 151 ± 25 mW m-3 at an impedance-matched load, when subjected to a low-level periodic (5 Hz) impacting force akin to gentle finger tapping. An energy conversion efficiency of ˜4.2% was evaluated for the electrodeposited ZnO nanowires, and the ZnO-PC composite nanogenerator was found to maintain good energy harvesting performance through 24 h of continuous fatigue testing. This is particularly significant given that ZnO-based nanostructures typically suffer from mechanical and/or environmental degradation that otherwise limits their applicability in vibrational energy harvesting. Our template-assisted synthesis of ZnO nanowires embedded within a protective polymer matrix through a single growth process is thus attractive for the fabrication of low-cost, robust and stable nanogenerators.

  12. UV-curable low surface energy fluorinated polycarbonate-based polyurethane dispersion.

    Science.gov (United States)

    Hwang, Hyeon-Deuk; Kim, Hyun-Joong

    2011-10-15

    UV-curable low surface energy fluorinated polycarbonate-based polyurethane dispersions were synthesized by incorporating a hydroxy-terminated perfluoropolyether (PFPE) into the soft segment of polyurethane. The effects of the PFPE content on the UV-curing behavior, physical, surface, thermal properties and refractive index were investigated. The UV-curing behavior was analyzed by photo-differential scanning calorimetry. The surface free energy of the UV-cured film, which is related to the water or oil repellency, was calculated from contact angle measurements using the Lewis acid-base three liquids method. The surface free energy decreased significantly with increasing fluorine concentration because PFPE in the soft segment was tailored to the surface and produced a UV-cured film with a hydrophobic fluorine enriched surface, as confirmed by X-ray photoelectron spectroscopy. With increasing the fluorine content, the refractive indices of UV-cured films decreased. However, the UV-curing rate and final conversion was decreased with increasing contents of PFPE, which resulted in the decrease of the glass transition temperature (T(g)), crosslink density, tensile strength and surface hardness.

  13. Electrically Conductive Compounds of Polycarbonate, Liquid Crystalline Polymer, and Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Penwisa Pisitsak

    2012-01-01

    Full Text Available A thermotropic liquid crystalline polymer (LCP was blended with polycarbonate (PC and multiwalled carbon nanotube (CNT with the goal of improving electrical conductivity and mechanical properties over PC. The LCP was anticipated to produce fibrillar domains in PC and help improve the mechanical properties. The study was carried out using two grades of LCP—Vectra A950 (VA950 and Vectra V400P (V400P. The compounds contained 20 wt% LCP and 0.5 to 15 wt% CNT. The compounds were prepared by melt-blending in a twin-screw minicompounder and then injection molded using a mini-injection molder. The fibrillar domains of LCP were found only in the case of PC/VA950 blend. However, these fibrils turned into droplets in the presence of CNT. It was found that CNT preferentially remained inside the LCP domains as predicted from the value of spreading coefficient. The electrical conductivity showed the following order with the numbers in parenthesis representing the electrical percolation threshold of the compounds: PC/CNT (1% > PC/VA950P/CNT (1% > PC/V400P/CNT (3%. The storage modulus showed improvements with the addition of CNT and VA950.

  14. Investigation of thermally stimulated properties of SHI beam irradiated polycarbonate/polystyrene double layered samples

    Science.gov (United States)

    Rathore, Bhupendra Singh; Gaur, Mulayam Singh; Singh, Kripa Shanker

    2011-12-01

    The double layered samples of polycarbonate/polystyrene (PC/PS) have been prepared by solvent casting method and irradiated with 55 MeV C 5+ beam at different ion fluences range from 1 × 10 11 to 1 × 10 13 ion/cm 2. The effect of swift heavy ion (SHI) beam in interfacial phenomena, phase change, dielectric relaxation, degradation temperature, stability, charge storage and transport mechanism of PC/PS pristine and irradiated double layered samples have been investigated by thermally stimulated discharge current (TSDC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). TSDC show α, β-relaxation peaks shifted to the lower temperatures side with increase of fluence. The activation energy and relaxation time decrease, while the depolarization current and charge released increase with increase in the ion fluences. DSC curve show the glass transition temperature ( T g) and heat capacity decreases with increase in the ion fluences. The TGA characteristics represent the thermal stability, which is found to be decreased with increase in the ion fluences.

  15. Surface modification of carbon black for the reinforcement of polycarbonate/acrylonitrile–butadiene–styrene blends

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B.B. [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); Chen, Y. [School of materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002 (China); Wang, F. [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); Hong, R.Y., E-mail: rhong@suda.edu.cn [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); College of Chemistry, Chemical Engineering and Materials Science & Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China)

    2015-10-01

    Highlights: • CB was modified through the method of oxygen plasma treatment. • Surface modified CB applied in PC/ABS blends. • The treated CB showed better compatibility in PC/ABS blends. • PC/ABS blends with treated CB showed better mechanical and thermal properties. - Abstract: The surface of carbon black was modified by oxygen plasma treatment for different times (10, 20 and 30 min). In order to increase the applicability of carbon black (CB), functional groups were grafted on the generally inert surface of CB using oxygen plasma. The surface compositional and structural changes that occurred on CB were investigated by SEM, FT-IR, Raman spectroscopy, XRD and BET. Subsequently, CB reinforced polycarbonate (PC)/acrylonitrile-butadiene-styrene (ABS) composites were prepared by internal batch mixing with the addition of different content of CB (3, 6, 9, 12 wt%). The morphology of PC/ABS/CB (7/3/6 wt%) nanocomposites was studied through scanning electron microscopy. Observations of SEM images showed that the plasma-treated CB had a better dispersion in the blend matrix. Moreover, the mechanical tests showed that the tensile strength and impact strength were improved by 32.4% and 22.5%, respectively, with the addition of plasma-treated CB. In addition, the thermal stability was improved and glass transition temperatures of both PC and ABS increased as shown by TGA and DSC, respectively.

  16. Wear rate evaluation of a novel polycarbonate-urethane cushion form bearing for artificial hip joints.

    Science.gov (United States)

    Elsner, Jonathan J; Mezape, Yoav; Hakshur, Keren; Shemesh, Maoz; Linder-Ganz, Eran; Shterling, Avi; Eliaz, Noam

    2010-12-01

    There is growing interest in the use of compliant materials as an alternative to hard bearing materials such as polyethylene, metal and ceramics in artificial joints. Cushion form bearings based on polycarbonate-urethane (PCU) mimic the natural synovial joint more closely by promoting fluid-film lubrication. In the current study, we used a physiological simulator to evaluate the wear characteristics of a compliant PCU acetabular buffer, coupled against a cobalt-chrome femoral head. The wear rate was evaluated over 8 million cycles gravimetrically, as well as by wear particle isolation using filtration and bio-ferrography (BF). The gravimetric and BF methods showed a wear rate of 9.9-12.5mg per million cycles, whereas filtration resulted in a lower wear rate of 5.8mg per million cycles. Bio-ferrography was proven to be an effective method for the determination of wear characteristics of the PCU acetabular buffer. Specifically, it was found to be more sensitive towards the detection of wear particles compared to the conventional filtration method, and less prone to environmental fluctuations than the gravimetric method. PCU demonstrated a low particle generation rate (1-5×10⁶ particles per million cycles), with the majority (96.6%) of wear particle mass lying above the biologically active range, 0.2-10μm. Thus, PCU offers a substantial advantage over traditional bearing materials, not only in its low wear rate, but also in its osteolytic potential.

  17. Confinement of phonon propagation in laser deposited tungsten/polycarbonate multilayers

    Science.gov (United States)

    Döring, Florian; Ulrichs, Henning; Pagel, Sinja; Müller, Markus; Mansurova, Maria; Müller, Matthias; Eberl, Christian; Erichsen, Torben; Huebner, Dennis; Vana, Philipp; Mann, Klaus; Münzenberg, Markus; Krebs, Hans-Ulrich

    2016-09-01

    Nanoscale multilayer thin films of W and PC (Polycarbonate) show, due to the great difference of the components’ characteristics, fascinating properties for a variety of possible applications and provide an interesting research field, but are hard to fabricate with low layer thicknesses. Because of the great acoustic mismatch between the two materials, such nanoscale structures are promising candidates for new phononic materials, where phonon propagation is strongly reduced. In this article we show for the first time that W/PC-multilayers can indeed be grown with high quality by pulsed laser deposition. We analyzed the polymer properties depending on the laser fluence used for deposition, which enabled us to find best experimental conditions for the fabrication of high-acoustic-mismatch W/PC multilayers. The multilayers were analyzed by fs pump-probe spectroscopy showing that phonon dynamics on the ps time-scale can strongly be tailored by structural design. While already periodic multilayers exhibit strong phonon localization, especially aperiodic structures present outstandingly low phonon propagation properties making such 1D-layered W/PC nano-structures interesting for new phononic applications.

  18. The efficiency of night insulation using aerogel-filled polycarbonate panels during the heating season

    Science.gov (United States)

    Adelsberger, Kathleen

    Energy is the basis for modern life. All modern technology from a simple coffee maker to massive industrial facilities is powered by energy. While the demand for energy is increasing, our planet is suffering from the consequences of using fossil fuels to generate electricity. Therefore, the world is looking at clean energy and solar power to minimize this effect on our environment. However, saving energy is extremely important even for clean energy. The more we save the less we have to generate. Heat retention in buildings is one step towards achieving passive heating. Therefore, efforts are made to prevent heat from escaping buildings through the glass during cold nights. Movable insulation is a way to increase the insulation value of the glass to reduce heat loss towards the outdoor. This thesis examines the performance of the aerogel-filled polycarbonate movable panels in the Ecohawks building, a building located on the west campus of The University of Kansas. Onsite tests were performed using air and surface temperature sensors to determine the effectiveness of the system. Computer simulations were run by Therm 7.2 simulation software to explore alternative design options. A cost analysis was also performed to evaluate the feasibility of utilizing movable insulation to reduce the heating bills during winter. Results showed that sealed movable insulation reduces heat loss through the glazing by 67.5%. Replacing aerogel with XPS panels reduces this percentage to 64.3%. However, it reduces the cost of the insulation material by 98%.

  19. Charge carrier transport in molecularly doped polycarbonate as a test case for the dipolar glass model.

    Science.gov (United States)

    Novikov, S V; Tyutnev, A P

    2013-03-14

    We present the results of Monte Carlo simulations of the charge carrier transport in a disordered molecular system containing spatial and energetic disorders using the dipolar glass model. Model parameters of the material were chosen to fit a typical polar organic photoconductor polycarbonate doped with 30% of aromatic hydrazone, whose transport properties are well documented in literature. Simulated carrier mobility demonstrates a usual Poole-Frenkel field dependence and its slope is very close to the experimental value without using any adjustable parameter. At room temperature transients are universal with respect to the electric field and transport layer thickness. At the same time, carrier mobility does not depend on the layer thickness and transients develop a well-defined plateau where the current does not depend on time, thus demonstrating a non-dispersive transport regime. Tails of the transients decay as power law with the exponent close to -2. This particular feature indicates that transients are close to the boundary between dispersive and non-dispersive transport regimes. Shapes of the simulated transients are in very good agreement with the experimental ones. In summary, we provide a first verification of a self-consistency of the dipolar glass transport model, where major transport parameters, extracted from the experimental transport data, are then used in the transport simulation, and the resulting mobility field dependence and transients are in very good agreement with the initial experimental data.

  20. Post Magnetron Sputter And Reactive Sputter Coating Of Contoured Glass, Acrylic And Polycarbonate Substrates

    Science.gov (United States)

    Wright, Michael P.

    1985-12-01

    A Post Magnetron Sputter concept employing a cylindrical internally cooled target (cathode) is described. The use of an internal, rotating, permanent magnetic field resulting in 360° utilisation of the target material is outlined. Computer controlled horizontal and vertical movement of the cathode assembly facilitates the coating of contoured substrates which may be glass, acrylic or polycarbonate. Deposition of different metals is easily achieved by changing the cathode or covering it with a suitable sheath material. The design of the cathode results in economic utilisation of the target material, which is particularly important when sputtering expensive metals such as gold. In addition to the deposition of metallic films, such as stainless steel or chrome, reactive sputtering may be undertaken by the introduction of a reactive gas into the vacuum chamber. In this way metal oxide, sulphide or nitride layers may be deposited according to the requirements of the layer structure. Specific optically-active oxides such as indium tin oxide are easily deposited in a uniform film and the formation of multilayer coatings for sun protective and heat rejecting applications is practicable. Indeed, a complete process may be undertaken without removing the substrate from the chamber; merely by adding or changing the reactive gas present.

  1. Measurement of photoneutron dose produced by wedge filters of a high energy linac using polycarbonate films.

    Science.gov (United States)

    Hashemi, Seyed Mehdi; Hashemi-Malayeri, Bijan; Raisali, Gholamreza; Shokrani, Parvaneh; Sharafi, Ali Akbar; Torkzadeh, Falamarz

    2008-05-01

    Radiotherapy represents the most widely spread technique to control and treat cancer. To increase the treatment efficiency, high energy linacs are used. However, applying high energy photon beams leads to a non-negligible dose of neutrons contaminating therapeutic beams. In addition, using conventional linacs necessitates applying wedge filters in some clinical conditions. However, there is not enough information on the effect of these filters on the photoneutrons produced. The aim of this study was to investigate the change of photoneutron dose equivalent due to the use of linac wedge filters. A high energy (18 MV) linear accelerator (Elekta SL 75/25) was studied. Polycarbonate films were used to measure the dose equivalent of photoneutrons. After electrochemical etching of the films, the neutron dose equivalent was calculated using Hp(10) factor, and its variation on the patient plane at 0, 5, 10, 50 and 100 cm from the center of the X-ray beam was determined. By increasing the distance from the center of the X-ray beam towards the periphery, the photoneutron dose equivalent decreased rapidly for the open and wedged fields. Increasing of the field size increased the photoneutron dose equivalent. The use of wedge filter increased the proportion of the neutron dose equivalent. The increase can be accounted for by the selective absorption of the high energy photons by the wedge filter.

  2. Radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Taleyarkhan, Rusi P.

    2017-06-27

    Alpha particle detecting devices are disclosed that have a chamber that can hold a fluid in a tensioned metastable state. The chamber is tuned with a suitable fluid and tension such that alpha emitting materials such as radon and one or more of its decay products can be detected. The devices can be portable and can be placed in areas, such as rooms in dwellings or laboratories and used to measure radon in these areas, in situ and in real time. The disclosed detectors can detect radon at and below 4 pCi/L in air; also, at and below 4,000 pCi/L or 300 pCi/L in water.

  3. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  4. Pixel Vertex Detectors

    OpenAIRE

    Wermes, Norbert

    2006-01-01

    Pixel vertex detectors are THE instrument of choice for the tracking of charged particles close to the interaction point at the LHC. Hybrid pixel detectors, in which sensor and read-out IC are separate entities, constitute the present state of the art in detector technology. Three of the LHC detectors use vertex detectors based on this technology. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as ...

  5. Effects of Phase Separation Behavior on Morphology and Performance of Polycarbonate Membranes

    Directory of Open Access Journals (Sweden)

    Alamin Idris

    2017-04-01

    Full Text Available The phase separation behavior of bisphenol-A-polycarbonate (PC, dissolved in N-methyl-2-pyrrolidone and dichloromethane solvents in coagulant water, was studied by the cloud point method. The respective cloud point data were determined by titration against water at room temperature and the characteristic binodal curves for the ternary systems were plotted. Further, the physical properties such as viscosity, refractive index, and density of the solution were measured. The critical polymer concentrations were determined from the viscosity measurements. PC/NMP and PC/DCM membranes were fabricated by the dry-wet phase inversion technique and characterized for their morphology, structure, and thermal stability using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis, respectively. The membranes’ performances were tested for their permeance to CO2, CH4, and N2 gases at 24 ± 0.5 °C with varying feed pressures from 2 to 10 bar. The PC/DCM membranes appeared to be asymmetric dense membrane types with appreciable thermal stability, whereas the PC/NMP membranes were observed to be asymmetric with porous structures exhibiting 4.18% and 9.17% decrease in the initial and maximum degradation temperatures, respectively. The ideal CO2/N2 and CO2/CH4 selectivities of the PC/NMP membrane decreased with the increase in feed pressures, while for the PC/DCM membrane, the average ideal CO2/N2 and CO2/CH4 selectivities were found to be 25.1 ± 0.8 and 21.1 ± 0.6, respectively. Therefore, the PC/DCM membranes with dense morphologies are appropriate for gas separation applications.

  6. High fidelity computational characterization of the mechanical response of thermally aged polycarbonate

    Science.gov (United States)

    Zhang, Zesheng; Zhang, Lili; Jasa, John; Li, Wenlong; Gazonas, George; Negahban, Mehrdad

    2017-07-01

    A representative all-atom molecular dynamics (MD) system of polycarbonate (PC) is built and conditioned to capture and predict the behaviours of PC in response to a broad range of thermo-mechanical loadings for various thermal aging. The PC system is constructed to have a distribution of molecular weights comparable to a widely used commercial PC (LEXAN 9034), and thermally conditioned to produce models for aged and unaged PC. The MD responses of these models are evaluated through comparisons to existing experimental results carried out at much lower loading rates, but done over a broad range of temperatures and loading modes. These experiments include monotonic extension/compression/shear, unilaterally and bilaterally confined compression, and load-reversal during shear. It is shown that the MD simulations show both qualitative and quantitative similarity with the experimental response. The quantitative similarity is evaluated by comparing the dilatational response under bilaterally confined compression, the shear flow viscosity and the equivalent yield stress. The consistency of the in silico response to real laboratory experiments strongly suggests that the current PC models are physically and mechanically relevant and potentially can be used to investigate thermo-mechanical response to loading conditions that would not easily be possible. These MD models may provide valuable insight into the molecular sources of certain observations, and could possibly offer new perspectives on how to develop constitutive models that are based on better understanding the response of PC under complex loadings. To this latter end, the models are used to predict the response of PC to complex loading modes that would normally be difficult to do or that include characteristics that would be difficult to measure. These include the responses of unaged and aged PC to unilaterally confined extension/compression, cyclic uniaxial/shear loadings, and saw-tooth extension/compression/shear.

  7. Isolation of methylene dianiline and aqueous-soluble biodegradation products from polycarbonate-polyurethanes.

    Science.gov (United States)

    Tang, Y W; Labow, R S; Santerre, J P

    2003-08-01

    Polycarbonate-polyurethanes (PCNUs) have provided the medical device industry with practical alternatives to oxidation-sensitive polyether-urethanes (PEUs). To date, many studies have focused on PCNUs synthesized with 4,4'-methylene diphenyl-diisocyanate (MDI). The relative hydrolytic stability of this class of polyurethanes is actually quite surprising given the inherent hydrolytic potential of the aliphatic carbonate group. Yet, there has been little information reporting on the rationale for the material's demonstrated hydrolytic stability. Recent work has shown that PCNU materials have a strong sensitivity towards hydrolysis when changes are made to their hard segment content and/or chemistry. However, knowledge is specifically lacking in regards of the identification of cleavage sites and the specific nature of the biodegradation products. Using high-performance liquid chromatography, radiolabel tracers and mass spectrometry, the current study provides insight into the distribution of biodegradation products from the enzyme-catalyzed hydrolysis of five different PCNUs. The hydrolytic sensitivity of the materials is shown to be related to the distribution of products, which itself is a direct consequence of unique micro-structures formed within the different materials. While an MDI-based polymer was shown to be the most hydrolytically stable material, it was the only PCNU that produced its diamine analog, in this case 4,4'-methylene dianiline (MDA), as a degradation product. Given the concern over aromatic diamine toxicity, this finding is important and highlights the fact that relative biostability is a distinct issue from that of degradation product toxicity, and that both must be considered separately when assessing the impact of biodegradation on biomaterial in vivo compatibility.

  8. Short Term Evaluation of an Anatomically Shaped Polycarbonate Urethane Total Meniscus Replacement in a Goat Model.

    Directory of Open Access Journals (Sweden)

    A C T Vrancken

    Full Text Available Since the treatment options for symptomatic total meniscectomy patients are still limited, an anatomically shaped, polycarbonate urethane (PCU, total meniscus replacement was developed. This study evaluates the in vivo performance of the implant in a goat model, with a specific focus on the implant location in the joint, geometrical integrity of the implant and the effect of the implant on synovial membrane and articular cartilage histopathological condition.The right medial meniscus of seven Saanen goats was replaced by the implant. Sham surgery (transection of the MCL, arthrotomy and MCL suturing was performed in six animals. The contralateral knee joints of both groups served as control groups. After three months follow-up the following aspects of implant performance were evaluated: implant position, implant deformation and the histopathological condition of the synovium and cartilage.Implant geometry was well maintained during the three month implantation period. No signs of PCU wear were found and the implant did not induce an inflammatory response in the knee joint. In all animals, implant fixation was compromised due to suture breakage, wear or elongation, likely causing the increase in extrusion observed in the implant group. Both the femoral cartilage and tibial cartilage in direct contact with the implant showed increased damage compared to the sham and sham-control groups.This study demonstrates that the novel, anatomically shaped PCU total meniscal replacement is biocompatible and resistant to three months of physiological loading. Failure of the fixation sutures may have increased implant mobility, which probably induced implant extrusion and potentially stimulated cartilage degeneration. Evidently, redesigning the fixation method is necessary. Future animal studies should evaluate the improved fixation method and compare implant performance to current treatment standards, such as allografts.

  9. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  10. The influence of hard segment content on mechanical and thermal properties of polycarbonate-based polyurethane materials

    Directory of Open Access Journals (Sweden)

    Budinski-Simendić Jaroslava

    2012-01-01

    Full Text Available Aliphatic segmented polyurethanes were prepared by one-step procedure in catalytic reaction between polycarbonate diol, hexamethylene-diisocyanate and 1,4-butandiol (as chain extender. The hard segment content TS was varied (17, 24, 30 and 42 wt. % by changing the ratio of starting compounds. The soft segment is made from flexible aliphatic polycarbonate diol, while hard segments consist of chain extender and diisocyanate component. In order to study the hydrogen bonding formation and phase separation, Fourier transform infrared spectroscopy (FT-IR was used. Wide angle X-ray scattering (WAXS was performed to determine a degree of crystallinity and to investigate the phase behavior of prepared elastomers. The effect of TS content on mechanical properties (tensile strength, elongation at break and hardness was tested. Thermal behavior of prepared novel polycarbonate-based polyurethanes was investigated using differential scanning callorimetry (DSC. It was determined that the elastomer which contains the highest amount of urethane groups in its structure (TS content of 42 wt. % exhibits the most pronounced phase separation and the highest degree of crystallinity. All prepared polyurethanes exhibit high elongation at break (over 700%. The glass transition temperature Tg of prepared samples was in the temperature region from −39 to −36°C, and it was found to be slightly influenced by the soft segment content. The enthalpy of chain segments relaxation in diffused region between hard and soft domains (detected in the temperature range from 35 to 55 °C was decreased with the increase of hard segment content. The multiple melting of hard segments (connected with the dissruption of physical crosslinks appeared above 100 °C. It was found that the melting enthalpy linearly increases with the increase of urethane group content. Sample with 42 wt. % of TS has the highest value of melting enthalpy (41.5 J/g.

  11. Safety and efficacy of electrospun polycarbonate-urethane vascular graft for early hemodialysis access: first clinical results in man.

    Science.gov (United States)

    Wijeyaratne, Serosha M; Kannangara, Lushanthi

    2011-01-01

    The purpose of this study was to assess the safety and efficacy of an electrospun multilayered, self-sealing polycarbonate-urethane graft for early hemodialysis access in patients. Seventeen eligible consenting patients had a polycarbonate-urethane graft (AVflo™) implanted and followed up prospectively for 12 months or to the end of secondary patency. Performance measures included graft patency, complications, time to first cannulation, and hemostasis times after needle withdrawal. All patients were of Asian origin (mean age 57 years, range 29-78). Diabetes mellitus was the most common cause of renal failure (52.9%). There were no systemic or local reactions to the graft. Five patients (29.4%) died due to medical complications unrelated to the device. There was 1 pseudoaneurysm, 3 infected grafts that subsequently thrombosed, and 1 primary thrombosis associated with thrombophilia. One venous stenosis needed balloon angioplasty. Primary and secondary patency rates at 6 months were 72.7% and 81.8%, and at 12 months, 54.5% and 72.7%, respectively. Postimplantation vascular access needs were met entirely by the graft in every instance and prevented the need for venous catheters. Fifty-six percent were accessed within 8 days, the earliest being 48 hours. Finally, all arterial punctures and 98% of venous punctures had sealed in less than 5 minutes, with two thirds sealing off within 3 minutes of needle withdrawal. The electrospun polycarbonate-urethane graft is safe in humans, permits early access obviating the need for venous catheters, and has equivalent patency to other prosthetic grafts at 1 year.

  12. pH-responsive biodegradable micelles based on acid-labile polycarbonate hydrophobe: synthesis and triggered drug release.

    Science.gov (United States)

    Chen, Wei; Meng, Fenghua; Li, Feng; Ji, Shun-Jun; Zhong, Zhiyuan

    2009-07-13

    pH-responsive biodegradable micelles were prepared from block copolymers comprising of a novel acid-labile polycarbonate hydrophobe and poly(ethylene glycol) (PEG). Two new cyclic aliphatic carbonate monomers, mono-2,4,6-trimethoxybenzylidene-pentaerythritol carbonate (TMBPEC, 2a) and mono-4-methoxybenzylidene-pentaerythritol carbonate (MBPEC, 2b) were designed and successfully synthesized via a two-step procedure. The ring-opening polymerization of 2a or 2b in the presence of methoxy PEG in dichloromethane at 50 °C using zinc bis[bis(trimethylsilyl)amide] as a catalyst yielded the corresponding block copolymers PEG-PTMBPEC (3a) or PEG-PMBPEC (3b) with low polydispersities (PDI 1.03-1.04). The copolymerization of D,L-lactide (DLLA) and 2a under otherwise the same conditions could also proceed smoothly to afford PEG-P(TMBPEC-co-DLLA) (3c) block copolymer. These block copolymers readily formed micelles in water with sizes of about 120 nm as determined by dynamic light scattering (DLS). The hydrolysis of the acetals of the polycarbonate was investigated using UV/vis spectroscopy. The results showed that the acetals of micelles 3a, while stable at pH 7.4 are prone to rapid hydrolysis at mildly acidic pH of 4.0 and 5.0, with a half-life of 1 and 6.5 h, respectively. The acetal hydrolysis resulted in significant swelling of micelles, as a result of change of hydrophobic polycarbonate to hydrophilic polycarbonate. In comparison, the acetals of PMBPEC of micelles 3b displayed obviously slower hydrolysis at the same pH. Both paclitaxel and doxorubicin could be efficiently encapsulated into micelles 3a achieving high drug loading content (13.0 and 11.7 wt %, respectively). The in vitro release studies showed clearly a pH dependent release behavior, that is, significantly faster drug release at mildly acidic pH of 4.0 and 5.0 compared to physiological pH. These pH-responsive biodegradable micelles are promising as smart nanovehicles for targeted delivery of anticancer drugs.

  13. Performance comparison of four kinds of flat nonimaging Fresnel lenses made of polycarbonates and polymethyl methacrylate for concentrated photovoltaics.

    Science.gov (United States)

    Languy, Fabian; Habraken, Serge

    2011-07-15

    Solar concentrators made of a single refractive primary optics are limited to a concentration ratio of about 1000× [Opt. Express 19, A280 (2011)], due only to longitudinal chromatic aberration, while mirrors are limited to ∼46,000× by the angular size of the Sun. To reduce the chromatic aberration while keeping cost-effective systems for concentrated photovoltaics, a study of four different kinds of flat Fresnel doublets made of polycarbonates and polymethyl methacrylate is presented. It reveals that Fresnel doublets may have fewer optical losses than non-Fresnel doublets, with a lower lateral chromatic split allowing for even higher concentration ratio.

  14. Growth of silicone-immobilized bacteria on polycarbonate membrane filters, a technique to study microcolony formation under anaerobic conditions

    DEFF Research Database (Denmark)

    Højberg, Ole; Binnerup, S. J.; Sørensen, Jan

    1997-01-01

    A technique was developed to study microcolony formation by silicone- immobilized bacteria on polycarbonate membrane filters under anaerobic conditions. A sudden shift to anaerobiosis was obtained by submerging the filters in medium which was depleted for oxygen by a pure culture of bacteria....... The technique was used to demonstrate that preinduction of nitrate reductase under low-oxygen conditions was necessary for nonfermenting, nitrate-respiring bacteria, e.g., Pseudomonas spp., to cope with a sudden lack of oxygen. In contrast, nitrate-respiring, fermenting bacteria, e.g., Bacillus and Escherichia...

  15. Anticipation on the Development of Polycarbonate Production Technology by Using Ester-interchange Method in China

    Institute of Scientific and Technical Information of China (English)

    Cai Shengquan; Shen Ji

    2004-01-01

    Polycarbonate (hereinafter referred to as "PC ") is the sole product having good transparency among the 5 major engineering plastics. In 2000, the worldwide PC production capacity was reached up to 2,800,000 tons of several hundreds of brands of various grades. It is estimated that the global PC production capacity will exceed 3,500,000 tons in 2005. The global demand for PC was 1,900,000 tons in 2000, which will reach to 2,600,000 tons and more than 3,000,000 tons in 2003 and 2005 respectively according to relevant estimations. The total production capacity of PC of the whole country reached to 3000-4000 tons in 2003. PC imported to China in 2003 was up to 534,000 tons and the apparent amount of consumption of that year was 447,000 tons.The scientific and technical personnel of Chenguang Chemical Research Institute engaged in the research and development of PC production technologies have been advancing wave upon wave with a combatant spirit and the spirit of "Storming the gate" for more than 40 years, having made important breakthroughs in a continuous PC manufacturing process by using ester-interchange method and in project amplification techniques. We consider that favorable conditions are now already available in China for building up PC production plants (each has an annual production capacity of 10,000 tons or above) by using ester- interchange method.In the recent 2 years, the growth rate of domestic annual PC consumption was up to more than 30 %, almost all of which relied on imports from foreign countries. Consequently, the development of domestically made PC has become a task, which brooks no delay. At present, conditions for building up domestic large-scale PC production plants are already available. It should be noted that PC production technologies are matured, PC products have a huge market potential and the returns on investment are optimistic. Therefore, building PC production plants, each with an annual production capacity of 10,000 tons ( approx

  16. The role of polycarbonate monomer bisphenol-A in insulin resistance

    Directory of Open Access Journals (Sweden)

    Milos Pjanic

    2017-09-01

    Full Text Available Bisphenol A (BPA is a synthetic unit of polycarbonate polymers and epoxy resins, the types of plastics that could be found in essentially every human population and incorporated into almost every aspect of the modern human society. BPA polymers appear in a wide range of products, from liquid storages (plastic bottles, can and glass linings, water pipes and tanks and food storages (plastics wraps and containers, to medical and dental devices. BPA polymers could be hydrolyzed spontaneously or in a photo- or temperature-catalyzed process, providing widespread environmental distribution and chronic exposure to the BPA monomer in contemporary human populations. Bisphenol A is also a xenoestrogen, an endocrine-disrupting chemical (EDC that interferes with the endocrine system mimicking the effects of an estrogen and could potentially keep our endocrine system in a constant perturbation that parallels endocrine disruption arising during pregnancy, such as insulin resistance (IR. Gestational insulin resistance represents a natural biological phenomenon of higher insulin resistance in peripheral tissues of the pregnant females, when nutrients are increasingly being directed to the embryo instead of being stored in peripheral tissues. Gestational diabetes mellitus may appear in healthy non-diabetic females, due to gestational insulin resistance that leads to increased blood sugar levels and hyperinsulinemia (increased insulin production from the pancreatic beta cells. The hypothesis states that unnoticed and constant exposure to this environmental chemical might potentially lead to the formation of chronic low-level endocrine disruptive state that resembles gestational insulin resistance, which might contribute to the development of diabetes. The increasing body of evidence supports the major premises of this hypothesis, as exemplified by the numerous publications examining the association of BPA and insulin resistance, both epidemiological and

  17. Independent control of adhesive and bulk properties of hybrid silica coatings on polycarbonate.

    Science.gov (United States)

    Lionti, Krystelle; Cui, Linying; Volksen, Willi; Dauskardt, Reinhold; Dubois, Geraud; Toury, Berangere

    2013-11-13

    Transparent polymers are widely used in many applications ranging from automotive windows to microelectronics packaging. However, their intrinsic characteristics, in particular their mechanical properties, are significantly degraded with exposure to different weather conditions. For instance, under humid environment or UV-irradiation, polycarbonate (PC) undergoes depolymerization, leading to the release of Bisphenol A, a molecule presumed to be a hormonal disruptor, potentially causing health problems. This is a serious concern and the new REACH (Registration, Evaluation, Authorization and Restriction of Chemical substances ) program dictates that materials releasing Bisphenol A should be removed from the market by January 1st, 2015 (2012-1442 law). Manufacturers have tried to satisfy this new regulation by depositing atop the PC a dense oxide-like protective coating that would act as a barrier layer. While high hardness, modulus, and density can be achieved by this approach, these coatings suffer from poor adhesion to the PC as evidenced by the numerous delamination events occurring under low scratch constraints. Here, we show that the combination of a N2/H2-plasma treatment of PC before depositing a hybrid organic-inorganic solution leads to a coating displaying elevated hardness, modulus, and density, along with a very high adherence to PC (> 20 J/m(2) as measured by double cantilever beam test). In this study, the sol-gel coatings were composed of hybrid O/I silica (based on organoalkoxysilanes and colloidal silica) and designed to favor covalent bonding between the hybrid network and the surface treated PC, hence increasing the contribution of the plastic deformation from the substrate. Interestingly, double-cantilever beam (DCB) tests showed that the coating's adhesion to PC was the same irrespective of the organoalkoxysilanes/colloidal silica ratio. The versatility of the sol-gel deposition techniques (dip-coating, spray-coating, etc.), together with the

  18. Controlling alpha tracks registration in Makrofol DE 1-1 detector

    Science.gov (United States)

    Hassan, N. M.; Hanafy, M. S.; Naguib, A.; El-Saftawy, A. A.

    2017-09-01

    Makrofol DE 1-1 is a recent type of solid state nuclear track detectors could be used to measure radon concentration in the environment throughout the detection of α-particles emitted from radon decay. Thus, studying the physical parameters that control the formation of alpha tracks is vital for environmental radiation protection. Makrofol DE 1-1 polycarbonate detector was irradiated by α-particles of energies varied from 2 to 5 MeV emitted from the 241Am source of α-particle energy of 5.5 MeV. Then, the detector was etched in an optimum etching solution of mixed ethyl alcohol in KOH aqueous solution of (85% (Vol.) of 6 M KOH + 15% (Vol.) C2H5OH) at 50 °C for 3 h. Afterward, the bulk etch rate, etching sensitivity, and the registration efficiency of the detector, which control the tracks registration, were measured. The bulk etch rate of Makrofol detector was found to be 3.71 ± 0.71 μm h-1. The etching sensitivity and the detector registration efficiency were decreased exponentially with α-particles' energies following Bragg curve. A precise registration of α-particle was presented in this study. Therefore, Makrofol DE 1-1 can be applied as a radiation dosimeter as well as radon and thoron monitors.

  19. Carbon nanotubes with silver nanoparticle decoration and conductive polymer coating for improving the electrical conductivity of polycarbonate composites

    KAUST Repository

    Patole, Archana S.

    2015-01-01

    We proposed a strategy to enhance the conductivity of polycarbonate by using three-phase hybrid metallic/non-metallic fillers. Ethylene diamine (EDA) functionalized multiwalled carbon nanotubes (MWCNT-EDA) are first decorated with silver nanoparticles. These Ag/ MWCNT-EDA fillers are then coated with a conductive layer of ethylene glycol treated PEDOT: PSS (poly [3,4-ethylenedioxythiophene]: poly [styrenesulfonate]) (EP). In such an approach, the MWCNT backbone is covered by a highly conductive coating made of Ag nanoparticles surrounded by EP. To understand how Ag and EP form a highly conductive coating, the effect of different wt% of Ag nanoparticles on EP was studied. Ag nanoparticles around the size of 128 ± 28 nmeffectively lowered the volume resistivity of bulk EP, resulting in a highly conducting Ag/EP blend. We found that in the final Ag/MWCNT-EDA/EP assembly, the EP coating enhances the electrical conductivity in two ways: (1) it is an efficient dispersing agent that helps in achieving a uniform dispersion of the Ag/MWCNT-EDA and (2) it acts as a conductive bridge between particles (Ag and MWCNT-EDA), reducing the particle to particle resistivity. When inserted into polycarbonate, this three-phase blend successfully reduced the volume resistivity of the polymer by two orders of magnitude compared with previous approaches.

  20. The MINOS Detectors

    CERN Document Server

    Grashorn, A H E W

    2005-01-01

    The Main Injector Neutrino Oscillation Search (MINOS) experiment's primary goal is the precision measurement of the neutrino oscillation parameters in the atmospheric neutrino sector. This long-baseline experiment uses Fermilab's NuMI beam, measured with a Near Detector at Fermilab, and again 735 km later using a Far Detector in the Soudan Mine Underground Lab in northern Minnesota. The detectors are magnetized iron/scintillator calorimeters. The Far Detector has been operational for cosmic ray and atmospheric neutrino data from July of 2003, the Near Detector from September 2004, and the NuMI beam started in early 2005. This poster presents details of the two detectors.

  1. GADRAS Detector Response Function.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

    2014-11-01

    The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

  2. The TALE Tower Detector

    Science.gov (United States)

    Bergman, D. R.

    The TA Low Energy Extension will include a Tower FluorescenceDetector. Extensive air showers at the lowest usful energies for fluorescence detectors will in general be close to the detector. This requires viewing all elevation angles to be able to reconstruct showers. The TALE Tower Detector, operating in conjunction with other TALE detectors will view elevation angles up to above 70 degrees, with an azimuthal coverage of about 90 degrees. Results from a prototype mirror operated in conjunction with the HiRes detector will also be presented.

  3. Drift Chambers detectors; Detectores de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Martinez laso, L.

    1989-07-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs.

  4. Identification and quantification of bisphenol A and bisphenol B in polyvinylchloride and polycarbonate medical devices by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Gimeno, Pascal; Spinau, Coline; Lassu, Nelly; Maggio, Annie-Françoise; Brenier, Charlotte; Lempereur, Laurent

    2015-11-01

    A gas chromatography with mass spectrometry method has already been developed and published for the identification and quantification of 14 phthalates and five nonphthalate plasticizers in polyvinylchloride medical devices. In order to assay, in addition to plasticizers, bisphenols A and B possibly present in polyvinylchloride samples, this previous method was extended to the assay of these additional potential endocrine disruptors. Furthermore, as bisphenol A could also be present in polycarbonate samples, the method used for the polyvinylchloride sample was tested and validated for the assay of bisphenols A and B in polycarbonate medical devices. The separation of all compounds, including bisphenols A and B, is obtained on a cross-linked 5%-phenyl/95%-dimethylpolysiloxane capillary column using a temperature gradient. For both plastics, samples are dissolved in tetrahydrofuran followed by a precipitation of the plastic by addition of ethanol. Results obtained point out residual bisphenol A amounts for polycarbonate samples ranging from 0.6 to 0.8% and for polyvinylchloride samples less or equal to 5 ppm. No bisphenol B was detected in the samples tested. For bisphenols A and B, mean recoveries obtained on spiked polyvinylchloride or polycarbonate sample preparations ranged from 87 to 108% in accordance with in-house specification (80-110%). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Influence of flavour absorption by food-packaging materials (low-density polyethylene, polycarbonate and polyethylene terephthalate) on taste perception of a model solution and orange juice

    NARCIS (Netherlands)

    Willige, van R.W.G.; Linssen, J.P.H.; Legger, A.; Voragen, A.G.J.

    2003-01-01

    The influence of flavour absorption by low-density polyethylene (LDPE), polycarbonate (PC) and polyethylene terephthalate (PET) on taste perception of a model solution containing seven flavour compounds and orange juice in glass bottles was studied with and without pieces of the respective plastic

  6. 脂肪族聚碳酸酯及其在医学中的应用%Progress of Aliphatic Polycarbonates and their Applications in the Biomedical Field

    Institute of Scientific and Technical Information of China (English)

    周瑜; 刘芝兰; 陈红祥

    2011-01-01

    During the past decade,aliphatic polycarbonates have been widely studied and used in the biomedical field,because they are biocompatible,biodegradable and able to functionalization.In this article,combining with the authors' work and referring to the research status about biodegradable aliphatic polycarbonates at home and abroad,aliphatic polycarbonates were sorted according to the structure of polymer chains and also introduced briefly.Their synthetic methods and applications in the biomedical field were reviewed.In addition,the future development of aliphatic polycarbonates was also put forward.%脂肪族聚碳酸酯具有优良的生物降解性、生物相容性和可功能化性等特点,近十几年来在生物医学领域得到了迅速发展。结合本实验室对生物可降解脂肪族聚碳酸酯的研究工作以及国内外研究现状,根据高分子链的几何形状对脂肪族聚碳酸酯进行了分类介绍,综述了它们的合成方法及其在生物医学领域中的应用,同时展望了脂肪族聚碳酸酯的未来发展趋势。

  7. Influence of flavour absorption by food-packaging materials (low-density polyethylene, polycarbonate and polyethylene terephthalate) on taste perception of a model solution and orange juice

    NARCIS (Netherlands)

    Willige, van R.W.G.; Linssen, J.P.H.; Legger, A.; Voragen, A.G.J.

    2003-01-01

    The influence of flavour absorption by low-density polyethylene (LDPE), polycarbonate (PC) and polyethylene terephthalate (PET) on taste perception of a model solution containing seven flavour compounds and orange juice in glass bottles was studied with and without pieces of the respective plastic f

  8. Novel routes in flame retardancy of bisphenol A polycarbonate/impact modifier/aryl phosphate blends

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzyn, Eliza

    2013-07-01

    The massive use of electronic engineering products accompanied by high demands on fire safety has led to increasing interest in environmentally friendly flame retardancy of bisphenol A polycarbonate (PC) based materials. In this work, novel routes for enhancing the flame retardancy of PC/Impact Modifier/Aryl phosphate were studied with respect to pyrolysis (TG, TG-FTIR, ATR-FTIR, NMR), flammability (LOI and UL 94) and fire behavior (cone calorimeter at different irradiations). To improve charring of PC/ABS{sub PTFE}+Aryl phosphate, the exchange of bisphenol A bis(diphenyl phosphate) (BDP) with novel aryl phosphates was proposed. Two novel flame retardants were synthesized: 3,3,5-trimethylcyclohexylbisphenol-bis(diphenyl phosphate) (TMC-BDP) and bisphenol A-bis(diethylphosphate) (BEP). TMC-BDP was more stable than BDP, thus gave a potential to increase the chemical reactions between the components of the PC/ABS{sub PTFE}+Aryl phosphate, whereas more reactive BEP was expected to increase the cross linking activity with the polymer matrix. Nevertheless, the corresponding blends did not enhance the flame retardancy compared to PC/ABS{sub PTFE}+BDP. BEP in PC/ABS{sub PTFE} preferred to cross-link with itself instead of with PC, thus it showed poor fire protection performance. TMC-BDP gave as good results as BDP in PC/ABS PTFE material. The results delivered evidence that BDP possesses a high degree of optimization in PC/ABS{sub PTFE} system. To provide a novel impact modifier improving not only mechanical properties but also the fire retardancy of PC/BDP material, the replacement of highly flammable acrylonitrile-butadiene-styrene (ABS) with silicon acrylate rubber (SiR) with high content of polydimethylsiloxane (PDMS) was studied. In PC/SiR{sub PTFE}/BDP the replacement of ABS is beneficial, but PDMS worsened the BDP gas phase and condensed phase action. PDMS reacted also with PC during combustion. PDMS-PC and PDMS-BDP interactions led to silicon dioxide. In fact, the

  9. Thermal kinetic inductance detector

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, Thomas; Gades, Lisa; Miceli, Antonio; Quaranta, Orlando

    2016-12-20

    A microcalorimeter for radiation detection that uses superconducting kinetic inductance resonators as the thermometers. The detector is frequency-multiplexed which enables detector systems with a large number of pixels.

  10. Forward tracking detectors

    Indian Academy of Sciences (India)

    Klaus Mönig

    2007-11-01

    Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  11. The OSMOND detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Dalgliesh, R. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Duxbury, D.M., E-mail: dom.duxbury@stfc.ac.uk [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Holt, S.A.; Kinane, C.J. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Marsh, A.S. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Rhodes, N.J.; Schooneveld, E.M. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Spill, E.J.; Stephenson, R. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom)

    2013-01-11

    The development and testing of the Off Specular MicrOstrip Neutron Detector (OSMOND) is described. Based on a microstrip gas chamber the aim of the project was to produce a high counting rate detector capable of replacing the existing rate limited scintillator detectors currently in use on the CRISP reflectometer for off specular reflectometry experiments. The detector system is described together with results of neutron beam tests carried out at the ISIS spallation neutron source.

  12. A New Numerical Approach to Evaluate Variation of Electric Field Strength at the End of Particle Trajectory in Nuclear Track Detectors

    Institute of Scientific and Technical Information of China (English)

    SUN Xiu-Dong; Ali Mostofizadeh; HOU Chun-Feng; M.Reza Kardan

    2008-01-01

    A geometrical model for an electrochemical etching(ECE)track in a dielectric detector is defined and a primary programme is written to generate the track.The generated track is transformed to an M×N matrix of primary voltages.Using a numerical method,the matrix of final voltages is computed,and using another numerical approach.the electric field strengths in the elements of detector volume are computed.The final field strength at the end of particle trajectory is obtained.The results of our numerical computation show that there are exact correlations between the field strength at the end of particle trajectory and the parameters of track under ECE.It is found that although two traditional models of Mason and Smythe in dielectrics can be partly applied for short we find that there is an expressive relationship between the field strength and the incidence angle of impacted particle.while the mentioned traditional models are not able to explain this effect.

  13. The CAPRICE RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

    1995-09-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

  14. Electroactive, Near Infrared Absorbing Nickel Bis(dithiolene) Complex Polycarbonates and Polyurethanes

    Science.gov (United States)

    1991-04-12

    Waters 840 GPC system with UV (300 nm) and refractive index detector accessories. TGA and DSC were carried out on a DuPont 9900 Thermal Analysis 16...REPOR-, 7t DECLASSIF IA O o.rRADirG SCHEDU 4PER;ORMING ORCANIZATION REPORT tNjv BER S, T,7 EOflRirZ p(- At, iz AT lor. -E POR7T N~uvbE R S, 6a NA ME OF...films can be cast from solution. Gel permeation chromatographic analysis on these polymers indicates hydrodynamic volumes comparable to polystyrene

  15. Fabrication and characterization of polycarbonate microstructured polymer optical fibers for high-temperature-resistant fiber Bragg grating strain sensors

    DEFF Research Database (Denmark)

    Fasano, Andrea; Woyessa, Getinet; Stajanca, Pavol;

    2016-01-01

    Here we present the fabrication of a solid-core microstructured polymer optical fiber (mPOF) made of polycarbonate (PC), and report the first experimental demonstration of a fiber Bragg grating (FBG) written in a PC optical fiber. The PC used in this work has a glass transition temperature of 145°C....... We also characterize the mPOF optically and mechanically, and further test the sensitivity of the PC FBG to strain and temperature. We demonstrate that the PC FBG can bear temperatures as high as 125°C without malfunctioning. In contrast, polymethyl methacrylate-based FBG technology is generally...

  16. Specific features of direct formation of graphite-like microstructures in polycarbonate samples by single femtosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Ganin, D V; Lapshin, K E; Obidin, A Z; Vartapetov, S K [Physics Instrumentation Center, A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Troitsk, Moscow Region (Russian Federation)

    2015-11-30

    We present the result of the experiments on producing graphite-like cylindrical microstructures by focusing single femtosecond laser pulses into the bulk of a transparent polymer (polycarbonate). The microstructures are embedded in a cladding with a modified refractive index, possessing waveguide properties. In the experiments with nontransparent screens and diaphragms, placed in the laser beam in front of the entrance pupil of the objective with a large numerical aperture, we have found that the paraxial rays are blocked by the peripheral ones, which reduces the length of the destruction region in the pre-focal zone. In the experiments with transparent screens and diaphragms, introducing optical delays τ{sub d} between the paraxial and peripheral rays, the quantitative dependence of the destruction region length in the pre-focal zone on the value of τ{sub d} is determined. (interaction of laser radiation with matter. laser plasma)

  17. Effect of chain extenders on mechanical and thermal properties of recycled poly (ethylene terephthalate) and polycarbonate blends

    Science.gov (United States)

    Srithep, Y.; Pholharn, D.; Dassakorn, A.; Morris, J.

    2017-06-01

    Poly(ethylene terephthalate) (PET) based thermoplastics are common, particularly in packaging. Due to both thermal and hydrolytic degradation, recycled PET (rPET) shows poor mechanical properties. The effect of adding 30% polycarbonate (PC) and chain extender (CE) on mechanical, thermal and morphological properties was investigated. rPET with PC and CE was melt blended in a single screw extruder, which was then tensile test specimens were formed by injection molding rPET and PC compatibility was improved via chain extending reactions which in turn improved the rPET and PC blend mechanical properties. With the addition of 30%PC the tensile modulus of rPET increased by 18% and it increased by 223% when 2%CE was added to rPET and 30%PC blends. Also, the CE reaction affected crystallization, monitored by differential scanning calorimetry: the melting enthalpy ofblends was lowered by increased CE content.

  18. Lithium-Assisted Copolymerization of CO 2 /Cyclohexene Oxide: A Novel and Straightforward Route to Polycarbonates and Related Block Copolymers

    KAUST Repository

    Zhang, Dongyue

    2016-03-23

    A facile route toward alternating polycarbonates by anionic copolymerization of carbon dioxide (CO2) and cyclohexene oxide (CHO), using lithium halide or alkoxide as initiators and triisobutylaluminum (TiBA) as activator, is reported. α,ω-Heterobifunctional and α,ω-dihydroxypoly(cyclohexene carbonate)s (PCHC) as well as poly(CHC-co-CHO) copolymers with different carbonate composition could also be easily synthesized by adjusting the amount of TiBA or by adding inert lithium salts. The value of this initiating system also resides in the easy access to PSt-b-PCHC (PSt: polystyrene) and PI-b-PCHC (PI: polyisoprene) block copolymers which can be derived by mere one-pot sequential addition of styrene or dienes first and then of CO2 and CHO under the same experimental conditions. © 2016 American Chemical Society.

  19. Settlement of planulae of the Moon jellyfish Aurelia aurita onto hydrophilic polycarbonate plates modified by atmospheric plasma treatment.

    Science.gov (United States)

    Tomaru, Akiko; Sasaki, Ryota; Miyahara, Hidekazu; Okino, Akitoshi; Ogawa, Nobuhiro; Hamasaki, Koji

    2014-01-01

    It has been reported that planula larvae of some jellyfish prefer artificial substrates for settlement. This research focused on the relationship between the settlement of planulae and the wettability of artificial substrate surfaces. We used atmospheric plasmas to change the wettability of the surfaces of polycarbonate (PC) plates because plasma treatment has no chemical side effects. The treatment made the surfaces hydrophilic, as evidenced by the decrease of contact angle from 85° to 35°. X-ray photoelectron spectroscopy revealed that the change of wettability of the PC plates could be attributed to N2, which was probably ionized in the air above the plates. Scanning electron microscopy revealed no difference in the surface morphology of the plates before and after plasma treatment. Results of bioassays using treated PC plates showed that planulae tended to preferentially settle on hydrophobic surfaces.

  20. Effect of the focal plane position on CO2 laser beam cutting of injection molded polycarbonate sheets

    Science.gov (United States)

    Moradi, Mahmoud; Mehrabi, Omid; Azdast, Taher; Benyounis, Khaled Y.

    2016-11-01

    In the present research, the effect of laser beam focal plane position (FPP) on the kerf quality of the polycarbonate laser cutting is investigated. Low power CO2 laser is used as the heat source of the cutting runs. In the experiments, FPP is varied from 0 to -4mm while other processing parameters (i.e. laser power, cutting speed and gas pressure) are considered constant. Upper and lower kerf width, kerf taper, upper heat affected zone and surface roughness of the kerf wall are also considered as the responses. Observations signified that reducing the position of the laser beam focal point from zero to - 3mm reduces the upper and lower kerf width. However reducing FPP below -3mm leads to an increase in the kerf width. Results also reveals that upper heat affected zone value reduces by reduction in FPP. Moreover the best kerf wall surface roughness occurred at FPP= -3mm.

  1. Polycarbonate/Polypropylene-Graft-Maleic Anhydride and Nano-Zeolite-Based Nanocomposite Membrane: Mechanical and Gas Separation Performance

    Directory of Open Access Journals (Sweden)

    Kausar A.

    2016-12-01

    Full Text Available In this effort, blend membrane of polycarbonate (PC and polypropylene-graft-maleic anhydride (PPMA was fabricated via phase inversion technique. The nano-zeolite (NZ was employed as nanofiller. Morphology of PC/PPMA/NZ membrane revealed unique inter-connected branched microstructure. Tensile strength and Young’s Modulus of PC/PPMA/NZ 0.1-5 were in the range of 59.9-74.5 MPa and 111.4-155.2 MPa respectively. The nano-zeolite filler was also effective in enhancing the permselectivity αCO2/N2 (23.5 to 38.5 relative to blend membrane (20.3. The permeability PCO2 of PC/PPMA/NZ 5 membrane was found as 106.2 Barrer. Filler loading enhanced gas diffusivity, however filler content did not significantly influence CO2 and N2 solubility.

  2. Settlement of planulae of the Moon jellyfish Aurelia aurita onto hydrophilic polycarbonate plates modified by atmospheric plasma treatment.

    Directory of Open Access Journals (Sweden)

    Akiko Tomaru

    Full Text Available It has been reported that planula larvae of some jellyfish prefer artificial substrates for settlement. This research focused on the relationship between the settlement of planulae and the wettability of artificial substrate surfaces. We used atmospheric plasmas to change the wettability of the surfaces of polycarbonate (PC plates because plasma treatment has no chemical side effects. The treatment made the surfaces hydrophilic, as evidenced by the decrease of contact angle from 85° to 35°. X-ray photoelectron spectroscopy revealed that the change of wettability of the PC plates could be attributed to N2, which was probably ionized in the air above the plates. Scanning electron microscopy revealed no difference in the surface morphology of the plates before and after plasma treatment. Results of bioassays using treated PC plates showed that planulae tended to preferentially settle on hydrophobic surfaces.

  3. Migration of bisphenol A from polycarbonate baby bottles purchased in the Spanish market by liquid chromatography and fluorescence detection.

    Science.gov (United States)

    Santillana, M I; Ruiz, E; Nieto, M T; Bustos, J; Maia, J; Sendón, R; Sánchez, J J

    2011-11-01

    During the last decade the safety of bisphenol A (BPA) monomer in polycarbonate baby bottles has drawn the attention of both the public and the scientific community. This paper presents the results of BPA migration from polycarbonate baby bottles bought in the Spanish market, into simulant B (3% acetic acid), 50% ethanol and into real food (reconstituted infant formula). Furthermore, it was also the objective of this study to assess the suitability of 50% ethanol as a simulant for infant formula. BPA was analysed by a multi-analyte liquid chromatography method with fluorescence detection and mass spectrometry confirmation. The method was in-house validated and accredited by the national accreditation body. The validation results for this analyte in the previous mentioned matrices were: LOD = 0.004-0.007 mg kg(-1); LOQ (validated) = 0.03 mg kg(-1); RSD% = 3.4-5.8; and recovery = 106.6-118.2%. A collection of 72 different baby bottle samples from 12 different brands were analysed. Baby bottle material was identified by FTIR. The migration test conditions used were those recommended for baby bottles in the Guidelines on testing conditions for articles in contact with foodstuffs (with a focus on kitchenware), prepared by the European network of laboratories for food-contact materials. In most of the migration assays the results were below the LOD. In four of the commercial brands there was detectable migration into the simulant 50% ethanol and BPA was detected in only two samples of infant formula (0.01 mg kg(-1)). Migration results obtained were in compliance with European Union regulations.

  4. Bisphenol-A and residual monomer leaching from orthodontic adhesive resins and polycarbonate brackets: a systematic review.

    Science.gov (United States)

    Kloukos, Dimitrios; Pandis, Nikolaos; Eliades, Theodore

    2013-04-01

    The objective of this systematic review was to assess the short- and long-term release of components of orthodontic adhesives and polycarbonate brackets in the oral environment. Electronic database searches of published and unpublished literature were performed. The following electronic databases with no language and publication date restrictions were searched: MEDLINE (via Ovid and PubMed), EMBASE (via Ovid), Cochrane Oral Health Group's Trials Register, and CENTRAL. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. The reference lists of all eligible studies were checked for additional studies. Two review authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion or the involvement of an arbiter. No randomized controlled trial was identified. In the absence of randomized controlled trials, observational studies were included. Eleven studies met the inclusion criteria. All were observational studies conducted in vivo or in vitro. The bisphenol-A release from orthodontic bonding resins was found to be between 0.85 and 20.88 ng per milliliter in vivo, and from traces to 65.67 ppm in vitro. Polycarbonate brackets released amounts of 22.24 μg per gram in ethanol solution and 697 μg per gram after 40 months in water. Bis-GMA and TEGDMA leaching in vitro reached levels of 64 and 174 mg per 10 μL, respectively. Because of the heterogeneity in methodologies and reporting, only qualitative synthesis was performed. The available evidence on this topic derived from observational in-vivo and in-vitro studies that represent a moderate level of evidence. The variety of setups and the different units allied to the diversity of reporting among studies did not allow calculation of pooled estimates. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  5. Equalized near maximum likelihood detector

    OpenAIRE

    2012-01-01

    This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.

  6. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  7. The DØ detector

    Science.gov (United States)

    Abachi, S.; Abolins, M.; Acharya, B. S.; Adam, I.; Ahn, S.; Aihara, H.; Alvarez, G.; Alves, G. A.; Amos, N.; Anderson, W.; Antipov, Yu.; Aronson, S. H.; Astur, R.; Avery, R. E.; Baden, A.; Balderston, J.; Baldin, B.; Bantly, J.; Barasch, E.; Bartlett, J. F.; Bazizi, K.; Behnke, T.; Bezzubov, V.; Bhat, P. C.; Blazey, G.; Blessing, S.; Boehnlein, A.; Borcherding, F.; Borders, J.; Bozko, N.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoy, V.; Butler, J. M.; Callot, O.; Chakraborty, D.; Chekulaev, S.; Chen, J.; Chen, L.-P.; Chen, W.; Choudhary, B. C.; Christenson, J. H.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M.; Cutts, D.; Dahl, O. I.; Daniels, B.; De, K.; Demarteau, M.; Denisenko, K.; Denisenko, N.; Denisov, D.; Denisov, S.; Dharmaratna, W.; Diehl, H. T.; Diesburg, M.; Dixon, R.; Draper, P.; Ducros, Y.; Durston-Johnson, S.; Eartly, D.; Eberhard, P. H.; Edmunds, D.; Efimov, A.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eroshin, O.; Evdokimov, V.; Fahey, S.; Fanourakis, G.; Fatyga, M.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finley, D.; Finocchiaro, G.; Fisk, H. E.; Flattum, E.; Forden, G. E.; Fortner, M.; Franzini, P.; Fuess, S.; Gallas, E.; Gao, C. S.; Geld, T. L.; Genser, K.; Gerber, C. E.; Gibbard, B.; Glebov, V.; Glicenstein, J. F.; Gobbi, B.; Goforth, M.; Good, M. L.; Goozen, F.; Gordon, H.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Grossman, N.; Grudberg, P.; Guida, J. A.; Guida, J. M.; Guryn, W.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hansen, S.; Hauptman, J.; Hedin, D.; Heinson, A. P.; Heintz, U.; Heuring, T.; Hirosky, R.; Hodel, K.; Hoftun, J. S.; Hubbard, J. R.; Huehn, T.; Huson, R.; Igarashi, S.; Ito, A. S.; James, E.; Jiang, J.; Johns, K.; Johnson, C. R.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jung, C. K.; Kahn, S.; Kanekal, S.; Kernan, A.; Kerth, L.; Kirunin, A.; Klatchko, A.; Klima, B.; Klochkov, B.; Klopfenstein, C.; Klyukhin, V.; Kochetkov, V.; Kohli, J. M.; Kononenko, W.; Kotcher, J.; Kotov, I.; Kourlas, J.; Kozelov, A.; Kozlovsky, E.; Krafczyk, G.; Krempetz, K.; Krishnaswamy, M. R.; Kroon, P.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Landsberg, G.; Lanou, R. E.; Laurens, P.; Lee-Franzini, J.; Li, J.; Li, R.; Li-Demarteau, Q. Z.; Lima, J. G. R.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y.-C.; Lloyd-Owen, D.; Lobkowicz, F.; Loken, S. C.; Lokos, S.; Lueking, L.; Maciel, A. K. A.; Madaras, R. J.; Madden, R.; Malamud, E.; Mangeot, Ph.; Manning, I.; Mansoulié, B.; Manzella, V.; Mao, H.-S.; Marcin, M.; Markosky, L.; Marshall, T.; Martin, H. J.; Martin, M. I.; Martin, P. S.; Marx, M.; May, B.; Mayorov, A.; McCarthy, R.; McKinley, J.; Mendoza, D.; Meng, X.-C.; Merritt, K. W.; Milder, A.; Mincer, A.; Mondal, N. K.; Montag, M.; Mooney, P.; Mudan, M.; Mulholland, G. T.; Murphy, C.; Murphy, C. T.; Nang, F.; Narain, M.; Narasimham, V. S.; Neal, H. A.; Nemethy, P.; Nešić, D.; Ng, K. K.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Pang, M.; Para, A.; Park, C. H.; Partridge, R.; Paterno, M.; Peryshkin, A.; Peters, M.; Pi, B.; Piekarz, H.; Pischalnikov, Yu.; Pizzuto, D.; Pluquet, A.; Podstavkov, V.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Que, Y.-K.; Quintas, P. Z.; Rahal-Callot, G.; Raja, R.; Rajagopalan, S.; Rao, M. V. S.; Rasmussen, L.; Read, A. L.; Regan, T.; Repond, S.; Riadovikov, V.; Rijssenbeek, M.; Roe, N. A.; Rubinov, P.; Rutherfoord, J.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Sculli, J.; Selove, W.; Shea, M.; Shkurenkov, A.; Shupe, M.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, A.; Smith, D.; Smith, R. P.; Snow, G. R.; Snyder, S.; Sosebee, M.; Souza, M.; Spadafora, A. L.; Stampke, S.; Stephens, R.; Stevenson, M. L.; Stewart, D.; Stocker, F.; Stoyanova, D.; Stredde, H.; Streets, K.; Strovink, M.; Suhanov, A.; Taketani, A.; Tartaglia, M.; Taylor, J. D.; Teiger, J.; Theodosiou, G.; Thompson, J.; Tisserant, S.; Trippe, T. G.; Tuts, P. M.; Van Berg, R.; Vaz, M.; Vishwanath, P. R.; Volkov, A.; Vorobiev, A.; Wahl, H. D.; Wang, D.-C.; Wang, L.-Z.; Weerts, H.; Wenzel, W. A.; White, A.; White, J. T.; Wightman, J.; Willis, S.; Wimpenny, S. J.; Wolf, Z.; Womersley, J.; Wood, D. R.; Xia, Y.; Xiao, D.; Xie, P.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yang, M.-J.; Yoshikawa, C.; Youssef, S.; Yu, J.; Zeller, R.; Zhang, S.; Zhou, Y. H.; Zhu, Q.; Zhu, Y.-S.; Zieminska, D.; Zieminski, A.; Zinchenko, A.; Zylberstejn, A.; DØ Collaboration

    1994-01-01

    The DØ detector is a large general purpose detector for the study of short-distance phenomena in high energy antiproton-proton collisions, now in operation at the Fermilab Tevatron collider. The detector focusses upon the detection of electrons, muons, jets and missing transverse momentum. We describe the design and performance of the major elements of the detector, including the tracking chambers, transition radiation detector, liquid argon calorimetry and muon detection. The associated electronics, triggering systems and data acquisition systems are presented. The global mechanical, high voltage, and experiment monitoring and control systems which support the detector are described. We also discuss the design and implementation of software and software support systems that are specific to DØ.

  8. Noble Gas Detectors

    CERN Document Server

    Aprile, Elena; Bolozdynya, Alexander I; Doke, Tadayoshi

    2006-01-01

    This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc.The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentation

  9. ATLAS inner detector performance

    CERN Document Server

    Gadomski, S

    2001-01-01

    The ATLAS Inner Detector consists of three subsystems using different tracking detector technologies: silicon pixels, silicon strips and straw tubes. The combination gives ATLAS a robust, hermetic and efficient tracking system, able to reconstruct tracks at the highest foreseen LHC luminosities. The inner detector provides vertex and momentum measurements, electron identification and some $K/\\pi$ separation. Since last year the beam pipe of ATLAS was changed, causing a redesign of the first tracking layer and a deterioration of the impact parameter resolutions.

  10. LHCb Detector Performance

    CERN Document Server

    AUTHOR|(CDS)2075808; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Pessina, Gianluigi; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2015-01-01

    The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are described, using data taken from 2010 to 2012. It is shown that the design criteria of the experiment have been met. The excellent performance of the detector has allowed the LHCb collaboration to publish a wide range of physics results, demonstrating LHCb's unique role, both as a heavy flavour experiment and as a general purpose detector in the forward region.

  11. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  12. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  13. Photocapacitive MIS infrared detectors

    Science.gov (United States)

    Sher, A.; Lu, S. S.-M.; Moriarty, J. A.; Crouch, R. K.; Miller, W. E.

    1978-01-01

    A new class of room-temperature infrared detectors has been developed through use of metal-insulator-semiconductor (MIS) or metal-insulator-semiconductor-insulator-metal (MISIM) slabs. The detectors, which have been fabricated from Si, Ge and GaAs, rely for operation on the electrical capacitance variations induced by modulated incident radiation. The peak detectivity for a 1000-A Si MISIM detector is comparable to that of a conventional Si detector functioning in the photovoltaic mode. Optimization of the photocapacitive-mode detection sensitivity is discussed.

  14. 聚碳酸酯纳米药物的制备与性能%Synthesis and properties of polycarbonate nanoparticles drugs

    Institute of Scientific and Technical Information of China (English)

    鄢国平; 邵春桃; 韩林; 邹头君; 刘凡; 龚晓芸; 常秀鹏

    2013-01-01

    采用可生物降解高分子材料链接或包埋抗癌药物制备高分子纳米或微米药物,不仅可以提高药物的抗癌功效而且能减小药物对正常组织的毒副作用.以9-苯基-2,4,8,10-四氧螺[5,5]十一烷-3-酮与2,2-二甲基二亚甲基合成的羟基化的碳酸酯共聚物P (PTC-co-DTC)为载体,将肿瘤靶向基团叶酸通过化学反应键连在聚碳酸酯的侧链,从而制备肿瘤靶向性高分子载体,并进行了傅立叶红外光谱、核磁共振氢谱、紫外-可见光谱等结构表征.再将靶向高分子载体与5-氟尿嘧啶复合,采用高压电场喷雾法与透析法分别制得两种肿瘤靶向聚碳酸酯纳米抗癌药物,并初步研究了纳米抗癌药物的体外药物控制释放性能.研究结果表明碳酸酯纳米药物具有较好的药物释放性能,且高压电场喷雾法制备的纳米药物比透析法制备的纳米药物释放药物速率快.%The polymer nanoparticles and microspheres are usually prepared by the entrapment and attachment of the anticancer drugs using biodegradable polymer materials as the carriers.These drug delivery systems can not only increase anticancer efficacy,but also reduce the toxicity of drugs to normal tissues.In this work,the tumer-targeting polycarbonates were prepared by the incorporation of folic acid(FA) as a tumer-targeting group into the partly deprodected polycarbonate P(DTC-co-PTC)containing hydroxyl group.Sequently,the tumer-targeting polycarbonate anticancer nanoparticles and microspheres were prepared by the high-voltage electrostatic field-assisted atomization and dialysis methods using 5-fluorouracil(5-Fu) as an anticancer drug model and the tumer-targeting polycarbonates containing FA groups as polymer carriers.These polycarbonates anticancer nanoparticles and microspheres were further characterized and their properties in vitro were also evaluated.The drug release tests indicate that these polycarbonates anticancer nanoparticles and

  15. A comparative study of track registration response of Makrofol-(KG, KL and N) polycarbonate to sup 4 sup 0 Ar ions

    CERN Document Server

    Kumar, A

    1999-01-01

    In the present work a comparative study of track registration response of sup 4 sup 0 Ar ions in different types of Makrofol polycarbonates viz. Makrofol-KG, KL and N have been done. The etched track parameters viz. bulk etch rate, track etch rate, etch rate ratio, cone angle and etching efficiency were calculated. The variation of etching rates with temperature were found to be exponential and follow the Arrhenius equation. The values of activation energy for bulk and track etching were also calculated. Maximum etchable track length/range were also obtained and compared with the theoretical values obtained from computer program RANGE. From the results it is found that the polycarbonates having same chemical composition manufactured by different chemical processes have slightly different behavior

  16. Capability of 19-L polycarbonate plastic water cooler containers for efficient solar water disinfection (SODIS): Field case studies in India, Bahrain and Spain

    OpenAIRE

    Mathur, Chandana

    2015-01-01

    The small treated volume (typically ~2 L) associated with polyethylene terephthalate (PET) bottles that are most frequently used in solar water disinfection (SODIS), is a major obstacle to uptake of this water treatment technology in resource-poor environments. In order to address this problem we have conducted a series of experiments in Spain, Bahrain and India, to assess the efficacy of large volume (19 L) transparent plastic (polycarbonate) water cooler/dispenser containers (WDCs)...

  17. Capability of 19-litre polycarbonate plastic water cooler containers for efficient solar water disinfection (SODIS): field case studies in India, Bahrain and Spain.

    OpenAIRE

    Keogh, Michael B; Castro-Alférez, M; Polo-López, M I; Calderero, I Fernández; Al-Eryani, Y A; Joseph-Titus, C; Sawant, B; R Dhodapkar; Mathur, C; McGuigan, Kevin G; Fernández-Ibáñez, P.

    2015-01-01

    The small treated volume (typically ~2 litres) associated with polyethylene terephthalate (PET) bottles that are most frequently used in solar water disinfection (SODIS), is a major obstacle to uptake of this water treatment technology in the developing world. In order to address this problem we have conducted a series of experiments in Spain, Bahrain and India, to assess the efficacy of large volume (19 litres) transparent plastic (polycarbonate) water cooler/dispenser containers (WDCs) as S...

  18. High-optical-quality blends of anionic polymethine salts and polycarbonate with enhanced third-order non-linearities for silicon-organic hybrid devices.

    Science.gov (United States)

    Li, Zhong'an; Liu, Yang; Kim, Hyeongeu; Hales, Joel M; Jang, Sei-Hum; Luo, Jingdong; Baehr-Jones, Tom; Hochberg, Michael; Marder, Seth R; Perry, Joseph W; Jen, Alex K-Y

    2012-11-20

    A series of anionic polymethine dyes with different aromatic counterions are prepared to improve their compatibility as guests in an amorphous polycarbonate host. When they are used as the cladding material for silicon hybrid slot waveguides, four-wave mixing wavelength conversion and two-photon absorption-based optical-power modulation are observed. Such guest-host materials may be attractive candidates for all-optical signal-processing applications.

  19. SYNTHESIS AND CHARACTERIZATION OF LIQUID CRYSTALLINE MULTI-BLOCK COPOLYMERS,POLY[1,6-BIS(4-OXYBENZOYL-OXY)HEXANE TEREPHTHALATE]-b-BISPHENOL A POLYCARBONATE

    Institute of Scientific and Technical Information of China (English)

    Hui-qing Zhang; Xiong-yan Zhao; De-shan Liu; Qi-xiang Zhou

    1999-01-01

    A series of liquid crystalline multi-block copolymers poly[1,6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segment lengths were synthesized in tetrachloroethane by solution polycondensation in which hydroxyl terminated PC and acyl chloride terminated PHTH-6 were used. It is found that block copolymers with high molecular weight and welldefined structures were obtained. All the block copolymers exhibit a nematic liquid crystalline texture.

  20. Thermal energy harvesting for large-scale applications using MWCNT-grafted glass fibers and polycarbonate-MWCNT nanocomposites

    Science.gov (United States)

    Tzounis, L.; Liebscher, M.; Mäder, E.; Pötschke, P.; Stamm, M.; Logothetidis, S.

    2015-02-01

    The thermoelectric properties of multi-wall carbon nanotube (MWCNT) -grafted glass fiber yarns (GF-CNT) and their epoxy model composites, as well as of polymer nanocomposites consisting of a polycarbonate (PC) matrix filled with differently functionalized MWCNTs have been examined. The GF-CNT hierarchical multi-scale structures were prepared by dip coating glass fiber yarns in a solution of carbonyl chloride modified MWCNTs; MWCNT-COCl (at a concentration of 0.5 mg/ml) under Ar atmosphere. The resulting GF-CNT exhibited high electrical conductivity (σ= 2.1×103 S/m) due to the dense MWCNT deposited networks. The fiber surface morphology was investigated by scanning electron microscopy (SEM). The GF-CNT showed Seebeck coefficient (S); S = 16.8 μV/K, and power factor (P.F); P.F = 0.59 μW/mK-2. The high electrical conductivity of the GF-CNT is a key parameter for an optimum thermoelectric performance, since it can facilitate the flow of the thermally induced charge carriers upon being exposed to a temperature gradient. Polycarbonate/MWCNT nanocomposites were prepared by small-scale melt-mixing process using a microcompounder. Unfunctionalized, carboxyl (-COOH) and hydroxyl (-OH) modified MWCNTs were incorporated in PC at a constant amount of 2.5 wt.%, concentration above the electrical percolation threshold. The amount of MWCNTs was kept low to understand the fundamental aspects of their physical properties and their correlation to the composite morphology, as revealed by transmission electron microscopy (TEM). It was found that different functional groups can affect the thermoelectric performance and the conductivity of the nanocomposites. Namely, the highest Seebeck coefficient (S) was found for the composite containing carboxyl functionalized MWCNTs (11.3 μV/K), due to the highest oxygen content of MWCNTs proven by X-Ray Photoelectron spectroscopy (XPS). It is believed that MWCNT-grafted glass fibers as reinforcements in composite structural materials and PC

  1. Thermal energy harvesting for large-scale applications using MWCNT-grafted glass fibers and polycarbonate-MWCNT nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Tzounis, L., E-mail: ltzounis@physics.auth.gr [Leibniz-Institut für Polymerforschung Dresden e.V., IPF, Hohe Str. 6, D-01069 Dresden (Germany); Technische Universität Dresden, Helmholtzstraße 10, 01069 Dresden (Germany); Laboratory for Thin Films-Nanosystems and Nanometrolo (Greece); Liebscher, M.; Stamm, M. [Leibniz-Institut für Polymerforschung Dresden e.V., IPF, Hohe Str. 6, D-01069 Dresden, Germany and Technische Universität Dresden, Helmholtzstraße 10, 01069 Dresden (Germany); Mäder, E.; Pötschke, P. [Leibniz-Institut für Polymerforschung Dresden e.V., IPF, Hohe Str. 6, D-01069 Dresden (Germany); Logothetidis, S., E-mail: logot@auth.gr [Laboratory for Thin Films-Nanosystems and Nanometrology (LTFN), Physics Department, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2015-02-17

    The thermoelectric properties of multi-wall carbon nanotube (MWCNT) -grafted glass fiber yarns (GF-CNT) and their epoxy model composites, as well as of polymer nanocomposites consisting of a polycarbonate (PC) matrix filled with differently functionalized MWCNTs have been examined. The GF-CNT hierarchical multi-scale structures were prepared by dip coating glass fiber yarns in a solution of carbonyl chloride modified MWCNTs; MWCNT-COCl (at a concentration of 0.5 mg/ml) under Ar atmosphere. The resulting GF-CNT exhibited high electrical conductivity (σ = 2.1×10{sup 3} S/m) due to the dense MWCNT deposited networks. The fiber surface morphology was investigated by scanning electron microscopy (SEM). The GF-CNT showed Seebeck coefficient (S); S = 16.8 μV/K, and power factor (P.F); P.F = 0.59 μW/mK−2. The high electrical conductivity of the GF-CNT is a key parameter for an optimum thermoelectric performance, since it can facilitate the flow of the thermally induced charge carriers upon being exposed to a temperature gradient. Polycarbonate/MWCNT nanocomposites were prepared by small-scale melt-mixing process using a microcompounder. Unfunctionalized, carboxyl (-COOH) and hydroxyl (-OH) modified MWCNTs were incorporated in PC at a constant amount of 2.5 wt.%, concentration above the electrical percolation threshold. The amount of MWCNTs was kept low to understand the fundamental aspects of their physical properties and their correlation to the composite morphology, as revealed by transmission electron microscopy (TEM). It was found that different functional groups can affect the thermoelectric performance and the conductivity of the nanocomposites. Namely, the highest Seebeck coefficient (S) was found for the composite containing carboxyl functionalized MWCNTs (11.3 μV/K), due to the highest oxygen content of MWCNTs proven by X-Ray Photoelectron spectroscopy (XPS). It is believed that MWCNT-grafted glass fibers as reinforcements in composite structural

  2. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  3. Detector Systems at CLIC

    CERN Document Server

    Simon, Frank

    2011-01-01

    The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detector concepts for the ILC, ILD and SID, were adapted for CLIC using calorimeters with dense absorbers limiting leakage through increased compactness, as well as modified forward and vertex detector geometries and precise time stamping to cope with increased background levels. The overall detector concepts for CLIC are presented, with particular emphasis on the main detector and engineering challenges, such as: the ultra-thi...

  4. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  5. CMS Detector Posters

    CERN Multimedia

    2016-01-01

    CMS Detector posters (produced in 2000): CMS installation CMS collaboration From the Big Bang to Stars LHC Magnetic Field Magnet System Trackering System Tracker Electronics Calorimetry Eletromagnetic Calorimeter Hadronic Calorimeter Muon System Muon Detectors Trigger and data aquisition (DAQ) ECAL posters (produced in 2010, FR & EN): CMS ECAL CMS ECAL-Supermodule cooling and mechatronics CMS ECAL-Supermodule assembly

  6. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  7. The LDC detector concept

    Indian Academy of Sciences (India)

    Ties Behnke; LDC Concept Group

    2007-11-01

    In preparation of the experimental program at the international linear collider (ILC), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design force behind the LDC is the particle flow concept.

  8. Introduction to detectors

    CERN Document Server

    Walenta, Albert H

    1995-01-01

    Concepts for momentum measurements,particle identification and energy measurements (calorimeters) as well for imaging applications in medecine, biology and industry (non destructive testing) will be put into relation to the specific detection princip In particular the resolution for position, time, energy and intensity measurement and the efficiency will be discussed. Signal extraction,electronic signal processing and principles of information capture will close the logic circle to the input : the radiation properties.The lecture will provide some sources for data tables and small demonstration computer programs f The basic detector physics as interaction of radiation with matter, information transport via free charges,photons and phonons and the signal formation will be presented in some depth with emphasis on the influence on specific parameters for detector The lecture will cover the most popular detector principles, gas detectors (ion chambers,MPWC's and MSGC's), semiconductor detectors scintillators and ...

  9. Nanomechanical resonance detector

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, Jeffrey C; Zettl, Alexander K

    2013-10-29

    An embodiment of a nanomechanical frequency detector includes a support structure and a plurality of elongated nanostructures coupled to the support structure. Each of the elongated nanostructures has a particular resonant frequency. The plurality of elongated nanostructures has a range of resonant frequencies. An embodiment of a method of identifying an object includes introducing the object to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the object. An embodiment of a method of identifying a molecular species of the present invention includes introducing the molecular species to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the molecular species.

  10. The PERDaix detector

    Energy Technology Data Exchange (ETDEWEB)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Kirn, Thomas, E-mail: kirn@physik.rwth-aachen.de [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhoever, Jens [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany)

    2012-12-11

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246 Multiplication-Sign 400 Multiplication-Sign 859 mm{sup 3}, a geometrical acceptance of 32 cm{sup 2}sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  11. The PERDaix detector

    Science.gov (United States)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman; Kirn, Thomas; Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhöver, Jens

    2012-12-01

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246×400×859 mm3, a geometrical acceptance of 32 cm2sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  12. ATLAS ITk Pixel detector

    CERN Document Server

    Gemme, Claudia; The ATLAS collaboration

    2016-01-01

    The high luminosity upgrade of the LHC (HL-LHC) in 2026 will provide new challenge to the ATLAS tracker. The current inner detector will be replaced with a whole silicon tracker which will consist of a five barrel layer Pixel detector surrounded by a four barrel layer Strip detector. The expected high radiation level are requiring the development of upgraded silicon sensors as well as new a front-end chip. The dense tracking environment will require finer granularity detectors. The data rates will require new technologies for high bandwidth data transmission and handling. The current status of the HL-LHC ATLA Pixel detector developments as well as the various layout options will be reviewed.

  13. Investigaciones sobre la Entrevista Conductual Estructurada (ECE) en la Selección de Personal en la Administración General del País Vasco: Meta-análisis de la Fiabilidad

    OpenAIRE

    JESUS F. SALGADO; SILVIA MOSCOSO; MIKEL GORRITI

    2004-01-01

    Este artículo tiene por objetivos: (1) presentar las entrevistas conductuales estructuradas (ECE) como una técnica apropiada para la selección de personal en las organizaciones tanto privadas como públicas; (2) describir el proceso de implementación de las entrevistas conductuales estructuradas en la Administración General del País Vasco (AGPV) y mostrar cómo instrumentos desarrollados inicialmente en el ámbito de las organizaciones privadas pueden utilizarse sin merma de calidad ni de garant...

  14. Reclamation of post-consumer plastics for development of polycarbonate and acrylonitrile butadiene styrene based nanocomposites with nanoclay

    Science.gov (United States)

    Zicans, Janis; Meri, Remo Merijs; Ivanova, Tatjana; Berzina, Rita; Saldabola, Ruuta; Maksimov, Robert

    2016-05-01

    Suitability of recycled acrylonitrile-butadiene-styrene (R-ABS) and recycled polycarbonate (R-PC) for the development of polymer matrix nanocomposites with organically modified nanoclay (OMMT) is evaluated in comparison to virgin polymers (V-ABS and V-PC) based systems. The influence of OMMT content on the structure as well as calorimetric, mechanical and thermal properties of virgin and recycled polymers containing systems is revealed. Increase in stiffness and strength of virgin and recycled polymers based systems is observed along with rising nanoclay content. However, it is observed that reinforcing efficiency of clays on the R-ABS containing systems is reduced to certain extent in comparison to those, based on virgin polymers. It is shown, that in the presence of OMMT approximation of glass transition temperatures of both polymeric components is observed, which can testify about certain improvement of compatibility between PC and ABS. Increment of the modulus of elasticity and yield strength of the nanocomposites is associated with anisodiametric shape of OMMT, as well as with intercalation of polymer within the interlaminar space of the clay nanoparticles. It is also demonstrated that addition of nanoclay improves thermogravimetric behavior of the investigated compositions. Consequently, it is suggested that nanoclays can be used as promising functional additives and replace halogenated flame-retardants, without reducing mechanical properties of the composites.

  15. Surface modification of polycarbonate and polyethylene naphtalate foils by UV-ozone treatment and μPlasma printing

    Science.gov (United States)

    Verkuijlen, R. O. F.; van Dongen, M. H. A.; Stevens, A. A. E.; van Geldrop, J.; Bernards, J. P. C.

    2014-01-01

    In this study, we investigated the effect of UV-ozone and μPlasma printing on surface modification of polycarbonate (PC) and polyethylene naphthalate (PEN). The effects on the wetting behaviour was studied, in terms of surface energy and chemical modification of the treated substrate, by analysis of attenuated total reflectance-Fourier transform infrared spectrometry (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Both UV-ozone and μPlasma printing are effective ways to modify the wettability of both polymer substrates, substantially increasing the wetting envelope after a short treatment period. This increase is primarily due to an increase of the polar part of the surface energy. This is confirmed by ATR-FTIR and XPS, which show the formation of oxygen containing groups as well as a decrease in the aromatic Csbnd C bonds on the surface of the substrate due to the treatment. For both types of surface treatment, prolonged exposure showed no further increase in wettability, although continuous change in chemical composition of the surface was measured. This effect is more evident for UV-ozone treatment, as a larger increase in O/C ratio of the surface was measured as compared to μPlasma printing. It can be concluded that μPlasma printing results in a more chemically selective modification as compared to UV-ozone. In the case that chemical selectivity and treatment time are considered important, μPlasma printing is favourable over UV-ozone.

  16. Rheological Behavior of a Novel Organic-Inorganic Hybrid: Micro/Nano-Tin Fluorophosphate Glass-Polycarbonate.

    Science.gov (United States)

    Yang, Jing; Liu, Huiwen; Yu, Honglin; Zou, Xiaoxuan; Jing, Bo; Dai, Wenli

    2016-03-01

    The rheological behavior of a novel, binary organic-inorganic hybrid consisting of an ultra-low Tg tin fluorophosphate glass (Pglass) and polycarbonate (PC) was investigated using oscillatory rheometry. It was found that the complex viscosity of the hybrid showed Pglass content dependence. Under low Pglass content (10-30%), the complex viscosity of the hybrid was lower than that of pure PC. While the complex viscosity was dramatically increased and higher than that of pure PC with the content of Pglass above 30%. This phenomenon was particularly remarkable at low frequencies. Besides, with the addition of Pglass the hybrid material exhibited shear-thinning behavior and the shear-thinning characteristics became more obvious with the enhancement of the Pglass content, indicating the presence of nonlinear chemical and physical interactions between the hybrid components. Differential scanning calorimetry (DSC) measurements revealed that increasing the content of Pglass caused a decrease of the glass transition temperature (Tg) of the hybrids, suggesting that Pglass was acting as a macromolecular plasticizer for the PC. The microstructure of the Pglass in the hybrid material was characterized by scanning electron microscopy (SEM). The results showed that the Pglass were dispersed as micro- and nano-bead in the continuous phase of PC and the Pglass appeared aggregation partly with the increase of the Pglass content. This contribution was anticipated to be a guideline for the processing of this promising new class of hybrid materials.

  17. Self-assembly by multi-drop evaporation of carbon-nanotube droplets on a polycarbonate substrate

    Science.gov (United States)

    Machrafi, H.; Minetti, C.; Dauby, P. C.; Iorio, C. S.

    2017-01-01

    Carbon nanotubes are allowed to self-assemble by depositing a droplet of a water dispersion thereof and letting it evaporate on a polycarbonate substrate. The effect of the number of droplets, evaporated on the same deposition spot, on the self-assembly density is assessed to be more than proportional for the first five depositions. The obtained nanoporous nanostructures are further tested for their electrical resistance and wettability. Two concentrations are used. It is found that a higher concentration and more importantly a higher number of droplet depositions causes the electrical resistance to decrease up to four orders of magnitude and the static contact angle to decrease more than three times. The contact angle hysteresis also increases due to an increasing advancing contact angle and a decreasing receding one. This is explained by the degree of coverage of the substrate by the carbon nanotubes as is also shown by scanning electron microscope images. A better coverage is suggested to cause more pinning for an advancing droplet and a higher capillary force for a receding droplet.

  18. Laser-assisted direct joining of AISI304 stainless steel with polycarbonate sheets: Thermal analysis, mechanical characterization, and bonds morphology

    Science.gov (United States)

    Lambiase, F.; Genna, S.

    2017-02-01

    Laser-Assisted Metal and Plastic bonding (LAMP) of AISI304 sheets with polycarbonate sheets is investigated in this work. The process was performed by means of a high power diode laser with a maximum power of 200 W. The study introduces an integrated experimental approach aimed at understanding how the main process conditions (laser power and scanning speed) influence the direct-bonds quality, dimensions and presence of defects. To this end, the bonds dimension, shear strength, formation and dimension of bubbles in the bonded region were related to the temperature measurements and process parameters. According to the achieved results, the processing window that enables a good adhesion of the two materials is relatively small; this is due the activation of the adhesion phenomena that require overcoming an energy threshold. However, excessive energy levels reduce the bonds strength due to the increase in defects (bubbles) dimension that may combine (coalescence) leading to the formation of a central tunnel where the two substrates are completely detached.

  19. Evidence of blocking effects on 3-keV Ne7+ ions guided through nanocapillaries in polycarbonate

    Science.gov (United States)

    Stolterfoht, N.; Hellhammer, R.; Sulik, B.; Juhász, Z.; Bayer, V.; Trautmann, C.; Bodewits, E.; Hoekstra, R.

    2011-06-01

    We studied the dynamic properties of ion guiding through nanocapillaries etched in insulating polycarbonate (PC). Capillaries with diameters of 95 and 165 nm and a length of 10 μm were used. In a further sample, the capillaries had a diameter of 175 nm and a length of 30 μm. A few additional measurements were made using capillaries in polyethylene terephthalate (PET). The temporal evolution of the intensity and the angular distribution of the transmitted ions were studied by measuring transmission profiles as a function of the charge deposited on the sample surface. The tilt angle of the capillary axis was varied from 0° to 5°. The mean emission angle of the transmission profiles exhibit pronounced oscillations, similarly as in previous measurements using PET. However, for PC, nearly an order of magnitude more charge needs to be inserted into the capillaries to accomplish the oscillations. In contrast to PET, with PC, we observed a strong decrease of the profile intensities with irradiation time. This observation provides evidence of blocking effects on the ions, which are likely to be due to a repulsive field produced by significant charge deposition inside the PC capillaries.

  20. Transparent, Adherent, and Photocatalytic SiO2-TiO2 Coatings on Polycarbonate for Self-Cleaning Applications

    Directory of Open Access Journals (Sweden)

    Sanjay S. Latthe

    2014-07-01

    Full Text Available Photocatalytic TiO2 coatings are famously known for their excellent self-cleaning behavior, where very thin water layer formed on the superhydrophilic surface can easily wash-off the dirt particles while flowing. Here we report the preparation of the optically transparent, adherent, highly wettable towards water and photocatalytic SiO2-TiO2 coatings on polycarbonate (PC substrate for self-cleaning applications. The silica barrier layer was applied on UV-treated PC substrate before spin coating the SiO2-TiO2 coatings. The effect of different vol% of SiO2 in TiO2 and its influence on the surface morphology, mechanical stability, wettability, and photocatalytic properties of the coatings were studied in detail. The coatings prepared from 7 vol% of SiO2 in TiO2 showed smooth, crack-free surface morphology and low surface roughness compared to the coatings prepared from the higher vol% of SiO2 in TiO2. The water drops on this coating acquires a contact angle less than 10° after UV irradiation for 30 min. All the coatings prepared from different vol% (7 to 20 of SiO2 in TiO2 showed high transparency in the visible range.

  1. Investigating the Inter-Tube Conduction Mechanism in Polycarbonate Nanocomposites Prepared with Conductive Polymer-Coated Carbon Nanotubes.

    Science.gov (United States)

    Ventura, Isaac Aguilar; Zhou, Jian; Lubineau, Gilles

    2015-12-01

    A well-known strategy to improve the electrical conductivity of polymers is to dope them with high-aspect-ratio and conductive nanoparticles such as carbon nanotubes (CNTs). However, these nanocomposites also exhibit undesirable properties such as damage-sensitive and history-dependent conductivity because their macroscopic electrical conductivity is largely determined by the tunneling effect at the tube/tube interface. To reduce these issues, new nanocomposites have been developed with CNTs that have been coated with a conductive layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS). It has been posited that the insulating region between the CNTs is replaced by a conductive polymer bridge; this has not been proven up to now. We propose here to investigate in-depth how the macroscopic conductivity of these materials is changing when (1) varying the frequency of the electrical loading (impedance spectroscopy), (2) varying the mechanical hydrostatic pressure, and (3) varying the voltage of the electrical loading. The response is systematically compared to the one of conventional carbon nanotube/polycarbonate (CNT/PC) nanocomposites so we can clarify how efficiently the tunneling effect is suppressed from these composites. The objective is to elucidate further the mechanism for conduction in such material formulations.

  2. Enteric polymer based on pH-responsive aliphatic polycarbonate functionalized with vitamin E to facilitate oral delivery of tacrolimus.

    Science.gov (United States)

    Wang, Menglin; Sun, Jin; Zhai, Yinglei; Lian, He; Luo, Cong; Li, Lin; Du, Yuqian; Zhang, Dong; Ding, Wenya; Qiu, Shuhong; Liu, Yuhai; Kou, Longfa; Han, Xiangfei; Xiang, Rongwu; Wang, Yongjun; He, Zhonggui

    2015-04-13

    To improve the bioavailability of orally administered drugs, we synthesized a pH-sensitive polymer (poly(ethylene glycol)-poly(2-methyl-2-carboxyl-propylene carbonate)-vitamin E, mPEG-PCC-VE) attempting to integrate the advantages of enteric coating and P-glycoprotein (P-gp) inhibition. The aliphatic polycarbonate chain was functionalized with carboxyl groups and vitamin E via postpolymerization modification. Optimized by comparison and central composite design, mPEG113-PCC32-VE4 exhibited low critical micelle concentration of 1.7 × 10(-6) mg/mL and high drug loading ability for tacrolimus (21.2% ± 2.7%, w/w). The pH-responsive profile was demonstrated by pH-dependent swelling and in vitro drug release. Less than 4.0% tacrolimus was released under simulated gastric fluid after 2.5 h, whereas an immediate release was observed under simulated intestinal fluid. The mPEG113-PCC32-VE4 micelles significantly increased the absorption of P-gp substrate tacrolimus in the whole intestine. The oral bioavailability of tacrolimus micelles was 6-fold higher than that of tacrolimus solution in rats. This enteric polymer therefore has the potential to become a useful nanoscale carrier for oral delivery of drugs.

  3. Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by froth flotation combined with ammonia pretreatment.

    Science.gov (United States)

    Wang, Chong-Qing; Wang, Hui; Liu, Qun; Fu, Jian-Gang; Liu, You-Nian

    2014-12-01

    The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Preparation of TiO₂ nanowires/nanotubes using polycarbonate membranes and their uses in dye-sensitized solar cells.

    Science.gov (United States)

    Roh, Dong Kyu; Patel, Rajkumar; Ahn, Sung Hoon; Kim, Dong Jun; Kim, Jong Hak

    2011-10-05

    Track-etched polycarbonate (PC) membranes were used as a soft template to synthesize mesoporous TiO(2) for use in dye-sensitized solar cells (DSSCs). The Ti precursor infiltrated into the cylindrical confined spaces of PC membranes. Upon calcination at 500 °C, TiO(2) nanowires (15TNW) were obtained from PC with a 15 nm pore diameter, whereas TiO(2) nanotubes (50TNT and 100TNT) were generated from PC with 50 and 100 nm diameter pores, respectively. TNW and TNT were used as photoelectrodes in DSSCs employing a polymer electrolyte. The ranking of the cell efficiencies of the 200 nm thick TiO(2) films was 50TNT (1.1%) > 15TNW (0.8%) ≅ 100TNT (0.7%), which was mostly attributed to different amounts of dye adsorption due to different surface areas. These TNW and TNT films were further coated with the graft copolymer-directed mesoporous TiO(2) and were used as interfacial layers between the FTO glass and the 4 μm thick nanocrystalline TiO(2) film. As a result, the order of energy conversion efficiency was 15TNW (5.0%) ≅ 50TNT (4.8%) > 100TNT (4.1%). The improved performance of 15TNW was due to a higher transmittance through the electrode and a longer electron lifetime for recombination. The DSSC performance was systematically investigated in terms of interfacial resistance and charge recombination using electrochemical impedance spectroscopy.

  5. Surface modification of polycarbonate and polyethylene naphtalate foils by UV-ozone treatment and μPlasma printing

    Energy Technology Data Exchange (ETDEWEB)

    Verkuijlen, R.O.F. [Expertise Centre Thin Films and Functional Materials, Fontys University of Applied Sciences, 5600 AH Eindhoven (Netherlands); Dongen, M.H.A. van, E-mail: mha.vandongen@fontys.nl [Expertise Centre Thin Films and Functional Materials, Fontys University of Applied Sciences, 5600 AH Eindhoven (Netherlands); Stevens, A.A.E. [InnoPhysicsB.V., 5627 JM Eindhoven (Netherlands); Geldrop, J. van; Bernards, J.P.C. [Expertise Centre Thin Films and Functional Materials, Fontys University of Applied Sciences, 5600 AH Eindhoven (Netherlands)

    2014-01-30

    In this study, we investigated the effect of UV-ozone and μPlasma printing on surface modification of polycarbonate (PC) and polyethylene naphthalate (PEN). The effects on the wetting behaviour was studied, in terms of surface energy and chemical modification of the treated substrate, by analysis of attenuated total reflectance-Fourier transform infrared spectrometry (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Both UV-ozone and μPlasma printing are effective ways to modify the wettability of both polymer substrates, substantially increasing the wetting envelope after a short treatment period. This increase is primarily due to an increase of the polar part of the surface energy. This is confirmed by ATR-FTIR and XPS, which show the formation of oxygen containing groups as well as a decrease in the aromatic C-C bonds on the surface of the substrate due to the treatment. For both types of surface treatment, prolonged exposure showed no further increase in wettability, although continuous change in chemical composition of the surface was measured. This effect is more evident for UV-ozone treatment, as a larger increase in O/C ratio of the surface was measured as compared to μPlasma printing. It can be concluded that μPlasma printing results in a more chemically selective modification as compared to UV-ozone. In the case that chemical selectivity and treatment time are considered important, μPlasma printing is favourable over UV-ozone.

  6. Investigating the Inter-Tube Conduction Mechanism in Polycarbonate Nanocomposites Prepared with Conductive Polymer-Coated Carbon Nanotubes

    KAUST Repository

    Ventura, Isaac Aguilar

    2015-12-16

    A well-known strategy to improve the electrical conductivity of polymers is to dope them with high-aspect-ratio and conductive nanoparticles such as carbon nanotubes (CNTs). However, these nanocomposites also exhibit undesirable properties such as damage-sensitive and history-dependent conductivity because their macroscopic electrical conductivity is largely determined by the tunneling effect at the tube/tube interface. To reduce these issues, new nanocomposites have been developed with CNTs that have been coated with a conductive layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS). It has been posited that the insulating region between the CNTs is replaced by a conductive polymer bridge; this has not been proven up to now. We propose here to investigate in-depth how the macroscopic conductivity of these materials is changing when (1) varying the frequency of the electrical loading (impedance spectroscopy), (2) varying the mechanical hydrostatic pressure, and (3) varying the voltage of the electrical loading. The response is systematically compared to the one of conventional carbon nanotube/polycarbonate (CNT/PC) nanocomposites so we can clarify how efficiently the tunneling effect is suppressed from these composites. The objective is to elucidate further the mechanism for conduction in such material formulations.

  7. Exposure Hazard to Bisphenol A for Labor and Particle Size Dis-tribution at Polycarbonate Molding Plants

    Directory of Open Access Journals (Sweden)

    Yuchan CHAO

    2015-10-01

    Full Text Available Background: This research provides an insight into exposure information and particle size distributions of Bisphenol A (BPA, a common environmental hormone, at polycarbonate (PC molding plants in southern Taiwan.Methods: The inhalable dust sampler as IOM and the micro-orifice uniform deposition impactor (MOUDI were used for samples collection to evaluate the level and particle size distribution of BPA in PC molding plants. All col-lected samples were analyzed by high performance liquid chromatography (HPLC for BPA concentrations.Results: BPA concentrations detected from the plant using optical grade PC material ranged from 32.28 to 44.97 μg/m3, which were significantly higher than BPA concentrations (16.16 to 19.39 μg/m3 detected from the plant using food grade PC material. Under working environment, the particle size distribution showed a single mode distribution, with a MMAD of 0.84μm and a GSD of 1.97. Emission of BPA increased during heating process and most of BPA particles deposited in the nasal cavity (63.37%, following by alveolus (30.7%, and trachea-bronchus (5.93%.Discussion: It is of importance that proper personal protection should be taken upon the BPA particulates released during the molding process at PC molding plants.

  8. 7th annual report 1998. UN ECE convention on long-range transboundary air pollution. International cooperative programme on integrated monitoring of air pollution effects on ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kleemola, S.; Forsius, M. [eds.

    1998-11-01

    The Integrated Monitoring Programme (ICP IM) is part of the Effects Monitoring Strategy under the UN ECE Long-Range Transboundary Air Pollution Convention. The main aim of ICP IM is to provide a framework to observe and understand the complex changes occurring in the external environment. The monitoring and prediction of complex ecosystem effects on undisturbed reference areas require a continuous effort to improve the collection and assessment of data on the international scale. At the 1997 Task Force meeting it was decided that future annual reports from ICP IM would have a more technical character. The report could include some scientific material but also short technical descriptions of recent national activities and publications. Scientific articles should preferably be published in recognised scientific journals. The responsibility for producing annual reports would still lie on the Programme Centre, but more contributions from National Focal Points were welcomed. The content of the present Annual Report reflects the decisions of the Task Force meeting. The report gives a general overview of the ICP IM activities, the present content of the ICP IM database, and presents results from assessment activities carried out by several collaborating institutes and the ICP IM Programme Centre during the programme year 1997/98. The resources of the Programme Centre have been targeted to the revision of the Programme Manual and the EU/LIFE-project `Development of Assessment and Monitoring Techniques at Integrated Monitoring Sites in Europe`, which has limited the possibilities to carry out additional evaluations of ICP IM data. Section 1 is a short status report of the ICP IM activities, content of the IM database, including the contents of the GIS database, and the present geographical coverage of the monitoring network. Section 2 contains a report on multivariate gradient analysis applied to relate chemical and biological observations (prepared by D. de Zwart, RIVM

  9. Surprising radiation detectors

    CERN Document Server

    Fleischer, Robert

    2003-01-01

    Radiation doses received by the human body can be measured indirectly and retrospectively by counting the tracks left by particles in ordinary objects like pair of spectacles, glassware, compact disks...This method has been successfully applied to determine neutron radiation doses received 50 years ago on the Hiroshima site. Neutrons themselves do not leave tracks in bulk matter but glass contains atoms of uranium that may fission when hurt by a neutron, the recoil of the fission fragments generates a track that is detectable. The most difficult is to find adequate glass items and to evaluate the radiation shield they benefited at their initial place. The same method has been used to determine the radiation dose due to the pile-up of radon in houses. In that case the tracks left by alpha particles due to the radioactive decay of polonium-210 have been counted on the superficial layer of the window panes. Other materials like polycarbonate plastics have been used to determine the radiation dose due to heavy io...

  10. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Aschenauer, E.C. [DESY, Zeuthen (Germany); Belostotski, S. [B.P. Konstantinov Petersburg Nuclear Physics Insitute, Gatchina (Russian Federation)] [and others; Collaboration: HERMES Recoil Detector Group

    2013-02-15

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  11. Detectors for Tomorrow's Instruments

    Science.gov (United States)

    Moseley, Harvey

    2009-01-01

    Cryogenically cooled superconducting detectors have become essential tools for a wide range of measurement applications, ranging from quantum limited heterodyne detection in the millimeter range to direct searches for dark matter with superconducting phonon detectors operating at 20 mK. Superconducting detectors have several fundamental and practical advantages which have resulted in their rapid adoption by experimenters. Their excellent performance arises in part from reductions in noise resulting from their low operating temperatures, but unique superconducting properties provide a wide range of mechanisms for detection. For example, the steep dependence of resistance with temperature on the superconductor/normal transition provides a sensitive thermometer for calorimetric and bolometric applications. Parametric changes in the properties of superconducting resonators provides a mechanism for high sensitivity detection of submillimeter photons. From a practical point of view, the use of superconducting detectors has grown rapidly because many of these devices couple well to SQUID amplifiers, which are easily integrated with the detectors. These SQUID-based amplifiers and multiplexers have matured with the detectors; they are convenient to use, and have excellent noise performance. The first generation of fully integrated large scale superconducting detection systems are now being deployed. I will discuss the prospects for a new generation of instruments designed to take full advantage of the revolution in detector technology.

  12. The Belle II Detector

    Science.gov (United States)

    Piilonen, Leo; Belle Collaboration, II

    2017-01-01

    The Belle II detector is now under construction at the KEK laboratory in Japan. This project represents a substantial upgrade of the Belle detector (and the KEKB accelerator). The Belle II experiment will record 50 ab-1 of data, a factor of 50 more than that recorded by Belle. This large data set, combined with the low backgrounds and high trigger efficiencies characteristic of an e+e- experiment, should provide unprecedented sensitivity to new physics signatures in B and D meson decays, and in τ lepton decays. The detector comprises many forefront subsystems. The vertex detector consists of two inner layers of silicon DEPFET pixels and four outer layers of double-sided silicon strips. These layers surround a beryllium beam pipe having a radius of only 10 mm. Outside of the vertex detector is a large-radius, small-cell drift chamber, an ``imaging time-of-propagation'' detector based on Cerenkov radiation for particle identification, and scintillating fibers and resistive plate chambers used to identify muons. The detector will begin commissioning in 2017.

  13. ATLAS Detector Interface Group

    CERN Multimedia

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  14. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France)

    1998-04-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X {yields} e{sup -} converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the {sup 3}He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  15. 不同链结构的双酚A聚碳酸酯对脂肪族聚碳酸酯结晶行为的影响%EFFECT OF BISPHENOL A POLYCARBONATE WITH DIFFERENT CHAIN STRUCTURE ON THE CRYSTALLIZATION BEHAVIOR OF ALIPHATIC POLYCARBONATE

    Institute of Scientific and Technical Information of China (English)

    宁炜; 刘琛阳; 朱文祥; 李春成; 王笃金

    2012-01-01

    脂肪族聚碳酸酯(APC)是一类可降解的高分子材料,因其生产工艺可固定温室气体的主要成分二氧化碳,这种可降解塑料得到了越来越多的关注.作为半结晶高分子材料,脂肪族聚碳酸酯的结晶性能和结晶结构对成型加工、力学性能和降解性能具有重要的影响.借助热分析(示差扫描量热仪DSC)和形态学观察(偏光显微镜POM)两种方法研究了不同链结构的双酚A型聚碳酸酯对半结晶脂肪族聚碳酸酯——聚碳酸1,4-丁二醇酯结晶动力学行为的影响.实验发现质量分数1%的双酚A聚碳酸酯的加入促进了聚碳酸1,4-丁二醇酯的成核,但不同链结构的双酚A聚碳酸酯对其晶体生长具有相反的作用,线形双酚A聚碳酸酯(PC-L)能够促进晶体生长,而支化双酚A聚碳酸酯(PC-B)则抑制晶体生长.用原子力显微镜在轻敲模式下研究了两种双酚A聚碳酸酯与APC共混物熔融状态下的相结构,发现熔体结构的不同是导致两种共混物与纯的APC相比,结晶速率呈现相反变化趋势的主要原因.%In the present investigation, the effect of the chain structure and aggregation state of bisphenol A polycarbonate ( PC) on the crystallization kinetics and morphology of the poly ( butylene carbonate) has been studied by DSC and POM. It was found that the addition of bisphenol A polycarbonate A promoted the nucleation of the poly( butylene carbonate) , while the chain structure of PC had the opposite influence on the crystal growth rate of the poly ( butylene carbonate). The linear bisphenol A polycarbonate polycarbonate accelerates the crystal growth rate of poly ( butylene carbonate) , while the long chain-branched bisphenol A polycarbonate decelerates it. The phase images of the blends of aliphatic polycarbonates and bisphenol A polycarbonate were obtained under the tapping mode by atomic force microscopy ( AFM). The linear bisphenol A polycarbonate shows isolated irregular

  16. The HOTWAXS detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E.; Derbyshire, G.E. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Diakun, G. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Duxbury, D.M. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom)], E-mail: d.m.duxbury@rl.ac.uk; Fairclough, J.P.A. [Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF (United Kingdom); Harvey, I.; Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Lipp, J.D.; Marsh, A.S.; Salisbury, J. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Sankar, G. [Royal Institution of GB, 21 Albemarle Street, London W1S 4BS (United Kingdom); Spill, E.J.; Stephenson, R. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Terrill, N.J. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2007-10-11

    The development and testing of the HOTWAXS position-sensitive X-ray detector for Synchrotron Radiation Sources is described. Funded from a facility development grant, the aim of the project was to produce a high counting rate, parallax-free photon counting detector to be used in the combined studies of X-ray absorption fine structure and X-ray diffraction (XAFS/XRD), and also in the technique of small angle and wide angle X-ray scattering (SAXS/WAXS). The detector system is described together with results of experiments carried out at the Daresbury Laboratory Synchrotron Radiation Source.

  17. Performance of GLD detector

    Indian Academy of Sciences (India)

    T Yoshioka

    2007-12-01

    Most of the important physics processes to be studied in the international linear collider (ILC) experiment have multi-jets in the final state. In order to achieve better jet energy resolution, the so-called particle flow algorithm (PFA) will be employed and there is a general consensus that PFA derives overall ILC detector design. Four detector concepts for the ILC experiment have been proposed so far in the world; the GLD detector that has a large inner calorimeter radius, which is considered to have an advantage for a PFA, is one of them. In this paper, general scheme and performance of the GLD-PFA will be presented.

  18. Microfluidic Scintillation Detectors

    CERN Multimedia

    Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.

  19. The Silicon Cube detector

    Energy Technology Data Exchange (ETDEWEB)

    Matea, I.; Adimi, N. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Blank, B. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France)], E-mail: blank@cenbg.in2p3.fr; Canchel, G.; Giovinazzo, J. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Borge, M.J.G.; Dominguez-Reyes, R.; Tengblad, O. [Insto. Estructura de la Materia, CSIC, Serrano 113bis, E-28006 Madrid (Spain); Thomas, J.-C. [GANIL, CEA/DSM - CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France)

    2009-08-21

    A new experimental device, the Silicon Cube detector, consisting of six double-sided silicon strip detectors placed in a compact geometry was developed at CENBG. Having a very good angular coverage and high granularity, it allows simultaneous measurements of energy and angular distributions of charged particles emitted from unbound nuclear states. In addition, large-volume Germanium detectors can be placed close to the collection point of the radioactive species to be studied. The setup is ideally suited for isotope separation on-line (ISOL)-type experiments to study multi-particle emitters and was tested during an experiment at the low-energy beam line of SPIRAL at GANIL.

  20. ATLAS Inner Detector Alignment

    CERN Document Server

    Bocci, A

    2008-01-01

    The ATLAS experiment is a multi-purpose particle detector that will study high-energy particle collisions produced by the Large Hadron Collider at CERN. In order to achieve its physics goals, the ATLAS tracking requires that the positions of the silicon detector elements have to be known to a precision better than 10 μm. Several track-based alignment algorithms have been developed for the Inner Detector. An extensive validation has been performed with simulated events and real data coming from the ATLAS. Results from such validation are reported in this paper.

  1. Directional radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, Jonathan L.

    2017-09-12

    Directional radiation detectors and systems, methods, and computer-readable media for using directional radiation detectors to locate a radiation source are provided herein. A directional radiation detector includes a radiation sensor. A radiation attenuator partially surrounds the radiation sensor and defines an aperture through which incident radiation is received by the radiation sensor. The aperture is positioned such that when incident radiation is received directly through the aperture and by the radiation sensor, a source of the incident radiation is located within a solid angle defined by the aperture. The radiation sensor senses at least one of alpha particles, beta particles, gamma particles, or neutrons.

  2. Protein-ECE MEtallopincer Hybrids

    NARCIS (Netherlands)

    Kruithof, C.A.

    2007-01-01

    Modification of proteins with metal complexes is a promising and a relatively new field which conceals many challenges and potential applications. The field is a balance of contributions from the biological (protein engineering, bioconjugation) and chemical sciences (organic, inorganic and organomet

  3. A model-based, multichannel, real-time capable sawtooth crash detector

    Science.gov (United States)

    van den Brand, H.; de Baar, M. R.; van Berkel, M.; Blanken, T. C.; Felici, F.; Westerhof, E.; Willensdorfer, M.; The ASDEX Upgrade Team; The EUROfusion MST1 Team

    2016-07-01

    Control of the time between sawtooth crashes, necessary for ITER and DEMO, requires real-time detection of the moment of the sawtooth crash. In this paper, estimation of sawtooth crash times is demonstrated using the model-based interacting multiple model (IMM) estimator, based on simplified models for the sawtooth crash. In contrast to previous detectors, this detector uses the spatial extent of the sawtooth crash as detection characteristic. The IMM estimator is tuned and applied to multiple ECE channels at once. A model for the sawtooth crash is introduced, which is used in the IMM algorithm. The IMM algorithm is applied to seven datasets from the ASDEX Upgrade tokamak. Five crash models with different mixing radii are used. All sawtooth crashes that have been identified beforehand by visual inspection of the data, are detected by the algorithm. A few additional detections are made, which upon closer inspection are seen to be sawtooth crashes, which show a partial reconnection. A closer inspection of the detected normal crashes shows that about 42% are not well fitted by any of the full reconnection models and show some characteristics of a partial reconnection. In some case, the measurement time is during the sawtooth crashes, which also results in an incorrect estimate of the mixing radius. For data provided at a sampling rate of 1 kHz, the run time of the IMM estimator is below 1 ms, thereby fulfilling real-time requirements.

  4. Novel Photo-Detectors and Photo-Detector Systems

    OpenAIRE

    Danilov, M.

    2008-01-01

    Recent developments in photo-detectors and photo-detector systems are reviewed. The main emphasis is made on Silicon Photo-Multipliers (SiPM) - novel and very attractive photo-detectors. Their main features are described. Properties of detectors manufactured by different producers are compared. Different applications are discussed including calorimeters, muon detection, tracking, Cherenkov light detection, and time of flight measurements.

  5. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  6. ALICE Forward Multiplicity Detector

    CERN Multimedia

    Christensen, C

    2013-01-01

    The Forward Multiplicity Detector (FMD) extends the coverage for multiplicity of charge particles into the forward regions - giving ALICE the widest coverage of the 4 LHC experiments for these measurements.

  7. OPAL detector electromagnetic calorimeter

    CERN Multimedia

    1988-01-01

    Half of the electromagnetic calorimeter of the OPAL detector is seen in this photo. This calorimeter consists of 4720 blocks of lead glass. It was used to detect and measure the energy of photons, electrons and positrons by absorbing them.

  8. The LUX Prototype Detector

    CERN Document Server

    Akerib, D S; Bedikian, S; Bernstein, A; Bolozdynya, A; Bradley, A; Cahn, S; Carr, D; Chapman, J J; Clark, K; Classen, T; Curioni, A; Dahl, C E; Dazeley, S; deViveiros, L; Dragowsky, M; Druszkiewicz, E; Fiorucci, S; Gaitskell, R J; Hall, C; Faham, C; Holbrook, B; Kastens, L; Kazkaz, K; Kwong, J; Lander, R; Leonard, D; Malling, D; Mannino, R; McKinsey, D N; Mei, D; Mock, J; Morii, M; Nikkel, J; Phelps, P; Shutt, T; Skulski, W; Sorensen, P; Spaans, J; Steigler, T; Svoboda, R; Sweany, M; Thomson, J; Tripathi, M; Walsh, N; Webb, R; White, J; Wolfs, F L H; Woods, M; Zhang, C

    2012-01-01

    The LUX (Large Underground Xenon) detector is a two-phase xenon Time Projection Chamber (TPC) designed to search for WIMP-nucleon dark matter interactions. As with all noble element detectors, continuous purification of the detector medium is essential to produce a large ($>$1ms) electron lifetime; this is necessary for efficient measurement of the electron signal which in turn is essential for achieving robust discrimination of signal from background events. In this paper we describe the development of a novel purification system deployed in a prototype detector. The results from the operation of this prototype indicated heat exchange with an efficiency above 94% up to a flow rate of 42 slpm, allowing for an electron drift length greater than 1 meter to be achieved in approximately two days and sustained for the duration of the testing period.

  9. The CLIC Detector Concept

    CERN Document Server

    Pitters, Florian Michael

    2016-01-01

    CLIC is a concept for a future linear collider that would provide e+e- collisions at up to 3 TeV. The physics aims require a detector system with excellent jet energy and track momentum resolution, highly efficient flavour-tagging and lepton identification capabilities, full geometrical coverage extending to low polar angles and timing information in the order of nanoseconds to reject beam-induced background. To deal with those requirements, an extensive R&D programme is in place to overcome current technological limits. The CLIC detector concept includes a low-mass all-silicon vertex and tracking detector system and fine-grained calorimeters designed for particle flow analysis techniques, surrounded by a 4 T solenoid magnet. An overview of the requirements and design optimisations for the CLIC detector concept is presented.

  10. Hybrid photon detectors

    CERN Document Server

    D'Ambrosio, C

    2003-01-01

    Hybrid photon detectors detect light via vacuum photocathodes and accelerate the emitted photoelectrons by an electric field towards inversely polarized silicon anodes, where they are absorbed, thus producing electron-hole pairs. These, in turn, are collected and generate electronic signals on their ohmic contacts. This review first describes the characteristic properties of the main components of hybrid photon detectors: light entrance windows, photocathodes, and silicon anodes. Then, essential relations describing the trajectories of photoelectrons in electric and magnetic fields and their backscattering from the silicon anodes are derived. Depending on their anode configurations, three families of hybrid photon detectors are presented: hybrid photomultiplier tubes with single anodes for photon counting with high sensitivity and for gamma spectroscopy; multi-anode photon detector tubes with anodes subdivided into square or hexagonal pads for position-sensitive photon detection; imaging silicon pixel array t...

  11. GRAVITY detector systems

    Science.gov (United States)

    Mehrgan, Leander H.; Finger, Gert; Eisenhauer, Frank; Panduro, Johana

    2016-08-01

    GRAVITY is a second generation instrument for the VLT Interferometer, designed for high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the K-band. It will combine the AO corrected beams of the four VLT telescopes. In total, the GRAVITY instrument uses five eAPD detectors four for the infrared wavefront sensors of each telescope and one for the fringe tracker. In addition two Hawaii2RG arrays are installed, one for the acquisition camera and one for the spectrometer. The SAPHIRA eAPD array is a newly developed near-infrared detector with sub-electron noise performance at frame rates > 1Kfps. For all seven detectors the ESO common controller, NGC, is used. This paper presents an overview and comparison of GRAVITY detector systems and their final performances at the telescope

  12. Pocked surface neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

    2003-04-08

    The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

  13. Europe plans megaton detector

    CERN Multimedia

    Cartlidge, Edwin

    2004-01-01

    A group of French and Italian particle physicists hopes to carry on the long tradition of building large underground detectors by constructing a device deep under the Alps containing a million tonnes of extremely pure water.

  14. The pixelated detector

    CERN Multimedia

    Sutton, C

    1990-01-01

    "Collecting data as patterns of light or subatomic particles is vitally important in all the sciences. The new generation of solid-state detectors called pixel devices could transform experimental research at all levels" (4 pages).

  15. Improved CO [lidar detector

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, P.L.; Busch, G.E.; Thompson, D.C.; Remelius, D.K.; Wells, F.D.

    1999-07-18

    A high sensitivity, CO{sub 2} lidar detector, based on recent advances in ultra-low noise, readout integrated circuits (ROIC), is being developed. This detector will combine a high speed, low noise focal plane array (FPA) with a dispersive grating spectrometer. The spectrometer will filter the large background flux, thereby reducing the limiting background photon shot noise. In order to achieve the desired low noise levels, the HgCdTe FPA will be cooled to {approximately}50K. High speed, short pulse operation of the lidar system should enable the detector to operate with the order of a few noise electrons in the combined detector/ ROIC output. Current receiver design concepts will be presented, along with their expected noise performance.

  16. Analysis on the Residual Braking Performance of Multi-axle Vehicles Based on ECE Regulation%基于ECE法规的多轴汽车剩余制动性能分析

    Institute of Scientific and Technical Information of China (English)

    童成前; 何仁; 周燕; 高树新

    2011-01-01

    根据ECE制动法规对行车制动失效条件下的多轴汽车剩余制动性能的要求,提出基于ECE制动法规的多轴汽车剩余制动性能分析方法,包括理论分析和试验验证.在理论分析中,最大减速度采用作图分析方法求得.最后,通过实例来说明本方法的分析过程.结果表明:该方法简单、实用.%According to the requirements of residual braking performance of multi-axle vehicles in the event of service braking failure specified in ECE regulation, an analysis method of residual braking performance of multi-axle vehicles based on ECE regulation is proposed, including theoretical analysis and test verification. In theoretical analysis,the maximum deceleration is evaluated by mapping. Finally,the method is illustrated by an analysis on a real case. The results indicate that the method is simple and practical.

  17. Detector Control System for the ATLAS Forward Proton detector

    CERN Document Server

    Czekierda, Sabina; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) is a forward detector using a Roman Pot technique, recently installed in the LHC tunnel. It is aiming at registering protons that were diffractively or electromagnetically scattered in soft and hard processes. Infrastructure of the detector consists of hardware placed both in the tunnel and in the control room USA15 (about 330 meters from the Roman Pots). AFP detector, like the other detectors of the ATLAS experiment, uses the Detector Control System (DCS) to supervise the detector and to ensure its safe and coherent operation, since the incorrect detector performance may influence the physics results. The DCS continuously monitors the detector parameters, subset of which is stored in data bases. Crucial parameters are guarded by alarm system. A detector representation as a hierarchical tree-like structure of well-defined subsystems built with the use of the Finite State Machine (FSM) toolkit allows for overall detector operation and visualization. Every node in the hierarchy is...

  18. The AMANDA Neutrino Detector

    Energy Technology Data Exchange (ETDEWEB)

    Wischnewski, R.; Andres, E.; Askebjer, P.; Barwick, S.; Bay, R.; Bergstroem, L.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Carius, S.; Carlson, M.; Chinowsky, W.; Chirkin, D.; Cowen, D.; Costa, C.; Dalberg, E.; Deyoung, T.; Edsjo, J.; Ekstroem, P.; Goobar, A.; Gray, L.; Hallgren, A.; Halzen, F.; Hardtke, R.; He, Y.; Hill, G.; Hulth, P.; Hundertmark, S.; Jacobsen, J.; Kandhadai, V.; Karle, A.; Kim, J.; Leich, H.; Leuthold, M.; Lindahl, P.; Liss, T.; Liubarsky, I.; Loaiza, P.; LOwder, D.; Marciniewski, P.; Miller, T.; Miocinovic, P.; Mock, P.; Morse, R.; Newcomer, M.; Niessen, P.; Nygren, D.; Perez de los Heros, C.; Porrata, R.; Price, P.; Przybylski, G.; Rhode, W.; Richter, S.; Rodriguez, J.; Romenesko, P.; Ross, D.; Rubinstein, H.; Schmidt, T.; Schneider, E.; Schwarz, R.; Schwendicke, U.; Smoot, G.; Solarz, M.; Sorin, V.; Spiering, C.; Steffen, P.; Stokstad, R.; Streicher, O.; Thollander, L.; Thon, T.; Tilav, S.; Walck, C.; Wiebusch, C.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S

    1999-03-01

    The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B with an expected effective area for TeV neutrinos of {approx} 10{sup 4} m{sup 2}, has been taking data since 1997. Progress with calibration, investigation of ice properties, as well as muon and neutrino data analysis are described. The next stage 20-string detector AMANDA-II with {approx}800 PMTs will be completed in spring 2000.

  19. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  20. Phi factory detector requirements

    Energy Technology Data Exchange (ETDEWEB)

    Arisaka, K.; Atac, M.; Berg, R.; Buchanan, C.; Calvette, M.; Khazin, B.; Kinoshita, K.; Muller, T.; Ohshima, T.; Olsen, S.; Park, J.; Santoni, C.; Shirai, J.; Solodov, E.; Thompson, J.; Triggiani, G.; Ueno, K.; Yamamoto, H.; Detector and Simulation Working Group

    1991-08-01

    We identify the experimental problems and the conditions required for successful phi-factory operation, and show the range of detector parameters which, in conjunction with different machine designs, may meet these conditions. We started by considering, comparing and criticizing the Italian and Novosibirsk designs. With this discussion as a background, we defined the apparent experimental problems and detector constraints. In this article we summarize our understanding. (orig./HSI).

  1. Modelling semiconductor pixel detectors

    CERN Document Server

    Mathieson, K

    2001-01-01

    expected after 200 ps in most cases. The effect of reducing the charge carrier lifetime and examining the charge collection efficiency has been utilised to explore how these detectors would respond in a harsh radiation environment. It is predicted that over critical carrier lifetimes (10 ps to 0.1 ns) an improvement of 40 % over conventional detectors can be expected. This also has positive implications for fabricating detectors, in this geometry, from materials which might otherwise be considered substandard. An analysis of charge transport in CdZnTe pixel detectors has been performed. The analysis starts with simulation studies into the formation of contacts and their influence on the internal electric field of planar detectors. The models include a number of well known defect states and these are balanced to give an agreement with a typical experimental I-V curve. The charge transport study extends to the development of a method for studying the effect of charge sharing in highly pixellated detectors. The ...

  2. Gamma ray detector modules

    Science.gov (United States)

    Capote, M. Albert (Inventor); Lenos, Howard A. (Inventor)

    2009-01-01

    A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C. An encapsulant is disposed between the interposer circuit card first surface and the semiconductor detector array substrate first surface, encapsulating the solder columns, the encapsulant curing at a temperature no greater than 120 degrees C.

  3. ATLAS Inner Detector (Pixel Detector and Silicon Tracker)

    CERN Multimedia

    ATLAS Outreach

    2006-01-01

    To raise awareness of the basic functions of the Pixel Detector and Silicon Tracker in the ATLAS detector on the LHC at CERN. This colorful 3D animation is an excerpt from the film "ATLAS-Episode II, The Particles Strike Back." Shot with a bug's eye view of the inside of the detector. The viewer is taken on a tour of the inner workings of the detector, seeing critical pieces of the detector and hearing short explanations of how each works.

  4. Formation of various crystalline structures in a polypropylene/polycarbonate in situ microfibrillar blend during the melt second flow.

    Science.gov (United States)

    Xia, Xiao-Chao; Yang, Wei; He, Shan; Xie, Dan-Dan; Zhang, Rui-Yan; Tian, Feng; Yang, Ming-Bo

    2016-05-18

    A strong shear flow was imposed on the melt of polycarbonate (PC) microfibrils with β-nucleation agent reinforced isotactic polypropylene (iPP) during the melt second flow process, i.e. gas-assisted injection molding (GAIM). A special shell-core structure was formed in the iPP/PC microfibrils with β-nucleation agent (PP/PC/β-NA) composites. A lot of β-transcrystalline and α-transcrystalline superstructures were observed in the skin and sub-skin regions, whereas β-spherulite structures were formed in the gas channel region. There is no doubt that the distinct hierarchical structure has great potential to significantly improve the mechanical performance of the composites, and the experimental results verify this. The results of the mechanical performance testing show that the yield strength of the PP/PC/β-NA composites reached 61.9 MPa, which is 19.7 MPa higher than that of the iPP parts molded by GAIM (G-iPP) (42.2 MPa). The tensile modulus of the PP/PC/β-NA composites (3.3 GPa) increased by 135%, compared to that of G-iPP (1.4 GPa). The high content of β-crystals improved the elongation at break of the composites compared to the iPP/PC microfibril (PP/PC) composites; the elongation at break of the PP/PC/β-NA composites (13%) is over 3 times greater than that of the PP/PC composites (4%).

  5. Toward Plastic Smart Windows: Optimization of Indium Tin Oxide Electrodes for the Synthesis of Electrochromic Devices on Polycarbonate Substrates.

    Science.gov (United States)

    Laurenti, Marco; Bianco, Stefano; Castellino, Micaela; Garino, Nadia; Virga, Alessandro; Pirri, Candido F; Mandracci, Pietro

    2016-03-01

    Plastic smart windows are becoming one of the key elements in view of the fabrication of inexpensive, lightweight electrochromic (EC) devices to be integrated in the new generation of high-energy-efficiency buildings and automotive applications. However, fabricating electrochromic devices on polymer substrates requires a reduction of process temperature, so in this work we focus on the development of a completely room-temperature deposition process aimed at the preparation of ITO-coated polycarbonate (PC) structures acting as transparent and conductive plastic supports. Without providing any substrate heating or surface activation pretreatments of the polymer, different deposition conditions are used for growing indium tin oxide (ITO) thin films by the radiofrequency magnetron sputtering technique. According to the characterization results, the set of optimal deposition parameters is selected to deposit ITO electrodes having high optical transmittance in the visible range (∼90%) together with low sheet resistance (∼8 ohm/sq). The as-prepared ITO/PC structures are then successfully tested as conductive supports for the fabrication of plastic smart windows. To this purpose, tungsten trioxide thin films are deposited by the reactive sputtering technique on the ITO/PC structures, and the resulting single electrode EC devices are characterized by chronoamperometric experiments and cyclic voltammetry. The fast switching response between colored and bleached states, together with the stability and reversibility of their electrochromic behavior after several cycling tests, are considered to be representative of the high quality of the EC film but especially of the ITO electrode. Indeed, even if no adhesion promoters, additional surface activation pretreatments, or substrate heating were used to promote the mechanical adhesion among the electrode and the PC surface, the observed EC response confirmed that the developed materials can be successfully employed for the

  6. Synthesis and Characterization of Novel Polycarbonate Based Polyurethane/Polymer Wrapped Hydroxyapatite Nanocomposites: Mechanical Properties, Osteoconductivity and Biocompatibility.

    Science.gov (United States)

    Selvakumar, M; Jaganathan, Saravana Kumar; Nando, Golok B; Chattopadhyay, Santanu

    2015-02-01

    The present investigation reports the preparation of two types of 2D rod-like nano-hydroxyapatite (nHA) (unmodified and Polypropylene glycol (PPG) wrapped) of varying high-aspect ratios, by modified co-precipitation methods, without any templates. These nHA were successfully introduced into novel synthesized Thermoplastic Polyurethane (TPU) matrices based on polycarbonate soft segments, by both in-situ and ex-situ techniques. Physico-mechanical properties of the in-situ prepared TPU/nHA nanocomposites were found to be superior compared to the ex-situ counterparts, and pristine nHA reinforced TPU. Improved biocompatibility of the prepared nanocomposites was confirmed by MTT assays using osteoblast-like MG63 cells. Cell proliferation was evident over an extended period. Osteoconductivity of the nanocomposites was observed by successful formation of an apatite layer on the surface of the samples, after immersion into simulated body fluid (SBF). Prothrombin time (PT) and activated partial thromboplastin time (APTT), as calculated from coagulation assays, displayed an increase in the clotting time, particularly for the PPG-wrapped nHA nanocomposites, prepared through the in-situ technique. Only 0.3% of hemolysis was observed for the in-situ prepared nanocomposites, which establishes the antithrombotic property of the material. The key parameters for enhancing the technical properties and biocompatibility of the nanocomposites are: the interfacial adhesion parameter (B(σy)), the polymer-filler affinity, the aspect ratio of filler and non-covalent modifications, and the state of dispersion. Thus, the novel TPU/polymer wrapped nHA nanocomposites have great potential for biomedical applications, in particular for vascular prostheses, cardiovascular implants, scaffolds, and soft and hard tissues implants.

  7. Assessment of polycarbonate filter in a molecular analytical system for the microbiological quality monitoring of recycled waters onboard ISS.

    Science.gov (United States)

    Bechy-Loizeau, Anne-Laure; Flandrois, Jean-Pierre; Abaibou, Hafid

    2015-07-01

    On the ISS, as on Earth, water is an essential element for life and its quality control on a regular basis allows to ensure the health of the crew and the integrity of equipment. Currently, microbial water analysis onboard ISS still relies on the traditional culture-based microbiology methods. Molecular methods based on the amplification of nucleic acids for microbiological analysis of water quality show enormous potential and are considered as the best alternative to culture-based methods. For this reason, the Midass, a fully integrated and automated prototype was designed conjointly by ESA and bioMérieux for a rapid monitoring of the microbiological quality of air. The prototype allows air sampling, sample processing and the amplification/detection of nucleic acids. We describe herein the proof of principle of an analytical approach based on molecular biology that could fulfill the ESA's need for a rapid monitoring of the microbiological quality of recycled water onboard ISS. Both concentration and recovery of microorganisms are the main critical steps when the microfiltration technology is used for water analysis. Among filters recommended standards for monitoring the microbiological quality of the water, the polycarbonate filter was fully in line with the requirements of the ISO 7704-1985 standard in terms of efficacy of capture and recovery of bacteria. Moreover, this filter does not retain nucleic acids on the surface and has no inhibitory effect on their downstream processing steps such as purification and amplification/detection. Although the Midass system was designed for the treatment of air samples, the first results on the integration of PC filters were encouraging. Nevertheless, system modifications are needed to better adapt the Midass system for the monitoring of the microbiological water quality.

  8. PEGylated and Functionalized Aliphatic Polycarbonate Polyplex Nanoparticles for Intravenous Administration of HDAC5 siRNA in Cancer Therapy.

    Science.gov (United States)

    Frère, Antoine; Baroni, Alexandra; Hendrick, Elodie; Delvigne, Anne-Sophie; Orange, François; Peulen, Olivier; Dakwar, George R; Diricq, Jérôme; Dubois, Philippe; Evrard, Brigitte; Remaut, Katrien; Braeckmans, Kevin; De Smedt, Stefaan C; Laloy, Julie; Dogné, Jean-Michel; Feller, Georges; Mespouille, Laetitia; Mottet, Denis; Piel, Géraldine

    2017-01-25

    Guanidine and morpholine functionalized aliphatic polycarbonate polymers are able to deliver efficiently histone deacetylase 5 (HDAC5) siRNA into the cytoplasm of cancer cells in vitro leading to a decrease of cell proliferation were previously developed. To allow these biodegradable and biocompatible polyplex nanoparticles to overcome the extracellular barriers and be effective in vivo after an intravenous injection, polyethylene glycol chains (PEG750 or PEG2000) were grafted on the polymer structure. These nanoparticles showed an average size of about 150 nm and a slightly positive ζ-potential with complete siRNA complexation. Behavior of PEGylated and non-PEGylated polyplexes were investigated in the presence of serum, in terms of siRNA complexation (fluorescence correlation spectroscopy), size (dynamic light scattering and single-particle tracking), interaction with proteins (isothermal titration calorimetry) and cellular uptake. Surprisingly, both PEGylated and non-PEGylated formulations presented relatively good behavior in the presence of fetal bovine serum (FBS). Hemocompatibility tests showed no effect of these polyplexes on hemolysis and coagulation. In vivo biodistribution in mice was performed and showed a better siRNA accumulation at the tumor site for PEGylated polyplexes. However, cellular uptake in protein-rich conditions showed that PEGylated polyplex lost their ability to interact with biological membranes and enter into cells, showing the importance to perform in vitro investigations in physiological conditions closed to in vivo situation. In vitro, the efficiency of PEGylated nanoparticles decreases compared to non-PEGylated particles, leading to the loss of the antiproliferative effect on cancer cells.

  9. A high-performance polycarbonate electrophoresis microchip with integrated three-electrode system for end-channel amperometric detection.

    Science.gov (United States)

    Wang, Yurong; Chen, Hengwu; He, Qiaohong; Soper, Steven A

    2008-05-01

    A fully integrated polycarbonate (PC) microchip for CE with end-channel electrochemical detection operated in an amperometric mode (CE-ED) has been developed. The on-chip integrated three-electrode system consisted of a gold working electrode, an Ag/AgCl reference electrode and a platinum counter electrode, which was fabricated by photo-directed electroless plating combined with electroplating. The working electrode was positioned against the separation channel exit to reduce post-channel band broadening. The electrophoresis high-voltage (HV) interference with the amperometric detection was assessed with respect to detection noise and potential shifts at various working-to-reference electrode spacing. It was observed that the electrophoresis HV interference caused by positioning the working electrode against the channel exit could be diminished by using an on-chip integrated reference electrode that was positioned in close proximity (100 microm) to the working electrode. The CE-ED microchip was demonstrated for the separation of model analytes, including dopamine (DA) and catechol (CA). Detection limits of 132 and 164 nM were achieved for DA and CA, respectively, and a theoretical plate number of 2.5x10(4)/m was obtained for DA. Relative standard deviations in peak heights observed for five runs of a standard solution containing the two analytes (0.1 mM for each) were 1.2 and 3.1% for DA and CA, respectively. The chip could be continuously used for more than 8 h without significant deterioration in analytical performance.

  10. Progresses in Research of Aliphatic Polycarbonates%脂肪族聚碳酸酯的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘峰; 翟刚; 李建国; 刘绍英; 杨先贵; 王公应

    2013-01-01

    综述了通过环氧化物与CO2共聚法、脂肪族环状碳酸酯开环聚合法及脂肪族二元醇与碳酸二烃基酯聚合法合成脂肪族聚碳酸酯(APCs)的研究进展,特别是对各种反应体系所采用催化剂的突破性研究成果进行了介绍,并对反应机理进行了分析.讨论了APCs的结构与其生物降解性及热分解性等性能的关系;结合APCs的性质介绍了它在医用材料、陶瓷及橡胶工业等领域的应用.比较了合成APCs的不同途径的特点,并对APCs材料的合成方法及其应用的发展趋势进行了展望.%The catalysts for the synthesis of aliphatic polycarbonates(APCs) were summarized according to three reaction systems,namely the copolymerization of carbon dioxide with epoxides,the ring-opening polymerization of cyclic carbonates and the two-step polycondensation of dialkyl carbonates and aliphatic diols.Particularly,the new research achievements for the catalysts and the mechanism of the reactions were introduced.The relationship between the structures and the performances of APCs,such as biodegradability and thermal decomposition,were discussed.The applications of APCs in medical materials,ceramics,rubber industry and so on were introduced.The synthesis of APCs by different methods were analyzed briefly.The development trend of APCs in future was forecasted.

  11. Applying graphene oxide nano-film over a polycarbonate nanoporous membrane to monitor E. coli by infrared spectroscopy

    Science.gov (United States)

    Singh, Krishna Pal; Dhek, Neeraj Singh; Nehra, Anuj; Ahlawat, Sweeti; Puri, Anu

    2017-01-01

    Nano-biosensors are excellent monitoring tools for rapid, specific, sensitive, inexpensive, in-field, on-line, and/or real-time detection of pathogens in foods, soil, air, and water samples. A variety of nano-materials (metallic, polymeric, and/or carbon-based) were employed to enhance the efficacy, efficiency, and sensitivity of these nano-biosensors, including graphene-based materials, especially graphene oxide (GO)-based materials. GO bears many oxygen-bearing groups, enabling ligand conjugation at the high density critical for sensitive detection. We have fabricated GO-modified nano-porous polycarbonate track-etched (PCTE) membranes that were conjugated to an Escherichia coli-specific antibody (Ab) and used to detect E. coli. The random distribution of nanopores on the PCTE membrane surface and the bright coating of the GO onto the membrane were confirmed by scanning electron microscope. Anti-E. coli β-gal Abs were conjugated to the GO surface via 1-ethyl-3,3-dimethylaminopropyl carbodiimide hydrochloride-N-hydroxysuccinimide chemistry; antibody coating was confirmed by the presence of a characteristic IR peak near 1600 cm- 1. A non-corresponding Ab (anti-Pseudomonas) was used as a negative control under identical conditions. When E. coli interacted anti-E.coli β-gal with Ab-coated GO-nano-biosensor units, we observed a clear shift in the IR peak from 3373.14 to 3315 cm- 1; in contrast, we did not observe any shift in IR peaks when the GO unit was coated with the non-corresponding Ab (anti-Pseudomonas). Therefore, the detection of E. coli using the described GO-nano-sensor unit is highly specific, is highly selective and can be applied for real-time monitoring of E. coli with a detection limit between 100 μg/mL and 10 μg/mL, similar to existing detection systems.

  12. Tyrosine-derived polycarbonate scaffolds for bone regeneration in a rabbit radius critical-size defect model.

    Science.gov (United States)

    Kim, Jinku; McBride, Sean; Donovan, Amy; Darr, Aniq; Magno, Maria Hanshella R; Hollinger, Jeffrey O

    2015-05-08

    The aim of the study was to determine bone regeneration in a rabbit radius critical-size defect (CSD) model using a specific polymer composition (E1001(1k)) from a library of tyrosine-derived polycarbonate scaffolds coated with a calcium phosphate (CP) formulation (E1001(1k) + CP) supplemented with recombinant human bone morphogenetic protein-2 (rhBMP-2). Specific doses of rhBMP-2 (0, 17, and 35 μg/scaffold) were used. E1001(1k) + CP scaffolds were implanted in unilateral segmental defects (15 mm length) in the radial diaphyses of New Zealand White rabbits. At 4 and 8 weeks post-implantation, bone regeneration was determined using micro-computed tomography (µCT), histology, and histomorphometry. The quantitative outcome data suggest that E1001(1k) + CP scaffolds with rhBMP-2 were biocompatible and promoted bone regeneration in segmental bone defects. Histological examination of the implant sites showed that scaffolds made of E1001(1k) + CP did not elicit adverse cellular or tissue responses throughout test periods up to 8 weeks. Noteworthy is that the incorporation of a very small amount of rhBMP-2 into the scaffolds (as low as 17 μg/defect site) promoted significant bone regeneration compared to scaffolds consisting of E1001(1k) + CP alone. This finding indicates that E1001(1k) + CP may be an effective platform for bone regeneration in a critical size rabbit radius segmental defect model, requiring only a minimal dose of rhBMP-2.

  13. 结晶态双酚A型聚碳酸酯固相缩聚的研究%Study on Solid State Polycondensation of Crystalline Bisphenol-A Polycarbonate

    Institute of Scientific and Technical Information of China (English)

    王金; 丁一刚

    2011-01-01

    High molecular weight bisphenol—A polycarbonate (BAPC) was respectively synthesized by solid state polycondensation with crystalline and amorphous bisphenol—A polycarbonate prepolymer in a solid phase reactor. The bisphenol—A polycarbonate was characterized by DSC and FTIR spectroscopy. The results showed that bisphenol—A polycarbonate glass transition temperatures increased after solid state polycondensation, while its thermal stability enhanced. In addition, the polycondensation temperature of crystalline prepoymer was lower than that of amorphous. The polycondensation synthesized by crystalline bisphenol—A polycarbonate was amorphous.%在自制的反应器中将结晶态、无定形两种双酚A型聚碳酸酯(BAPC)预聚体固相缩聚合成了高摩尔质量的双酚A型聚碳酸酯.采用DSC、IR对双酚A型聚碳酸酯(BAPC)的熔融行为和结构进行了表征.结果表明,BAPC在固相缩聚后,玻璃化转变温度升高,热稳定性增强,其中BAPC为结晶态时固相缩聚的温度低于无定形态BAPC的固相缩聚温度,且结晶态BAPC固相缩聚后为无定形态.

  14. Detectors on the drawing board

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Linear collider detector developers inside and outside CERN are tackling the next generation of detector technology. While their focus has centred on high-energy linear collider detectors, their innovative concepts and designs will be applicable to any future detector.   A simulated event display in one of the new generation detectors. “While the LHC experiments remain the pinnacle of detector technology, you may be surprised to realise that the design and expertise behind them is well over 10 years old,” says Lucie Linssen, CERN’s Linear Collider Detector (LCD) project manager whose group is pushing the envelope of detector design. “The next generation of detectors will have to surpass the achievements of the LHC experiments. It’s not an easy task but, by observing detectors currently in operation and exploiting a decade’s worth of technological advancements, we’ve made meaningful progress.” The LCD team is curr...

  15. Use of UV-vis-NIR spectroscopy to monitor label-free interaction between molecular recognition elements and erythropoietin on a gold-coated polycarbonate platform.

    Science.gov (United States)

    Citartan, Marimuthu; Gopinath, Subash C B; Tominaga, Junji; Chen, Yeng; Tang, Thean-Hock

    2014-08-01

    Label-free-based detection is pivotal for real-time monitoring of biomolecular interactions and to eliminate the need for labeling with tags that can occupy important binding sites of biomolecules. One simplest form of label-free-based detection is ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy, which measure changes in reflectivity as a means to monitor immobilization and interaction of biomolecules with their corresponding partners. In biosensor development, the platform used for the biomolecular interaction should be suitable for different molecular recognition elements. In this study, gold (Au)-coated polycarbonate was used as a platform and as a proof-of-concept, erythropoietin (EPO), a doping substance widely abused by the athletes was used as the target. The interaction of EPO with its corresponding molecular recognition elements (anti-EPO monoclonal antibody and anti-EPO DNA aptamer) is monitored by UV-vis-NIR spectroscopy. Prior to this, to show that UV-vis-NIR spectroscopy is a suitable method for measuring biomolecular interaction, the interaction between biotin and streptavidin was demonstrated via this strategy and reflectivity of this interaction decreased by 25%. Subsequent to this, interaction of the EPO with anti-EPO monoclonal antibody and anti-EPO DNA aptamer resulted in the decrease of reflectivity by 5% and 10%, respectively. The results indicated that Au-coated polycarbonate could be an ideal biosensor platform for monitoring biomolecular interactions using UV-vis-NIR spectroscopy. A smaller version of the Au-coated polycarbonate substrates can be derived from the recent set-up, to be applied towards detecting EPO abuse among atheletes.

  16. SELF-ASSEMBLED MICRO-DOMAINS ON THE UPPERMOST SURFACE OF FLUORINATED POLY(CARBONATE URETHANE)S WITH FLUORINATED SIDE CHAIN ATTACHED ON HARD SEGMENTS

    Institute of Scientific and Technical Information of China (English)

    Hong Tan; Min Guo; Jie-hua Li; Xing-yi Xie; Yin-ping Zhong; Qiang Fu

    2004-01-01

    The surface phase separated structure of polyurethanes is always desired due to the advantage of better biocompatibility, compared with the homogeneous one. The key issue is how to control and characterize the surface morphology. In this work, we report the uppermost surface morphology of fluorinated poly(carbonate urethane)s with fluorinated side chains attached to hard segments as studied by AFM, XPS and contact angle measurement. A self-assembled micro-domain with the fluorinated side chain standing up on the uppermost surface has been proposed for polyurethane with higher fluorinated content, based on the result obtained.

  17. Enzymatic Synthesis and Characterization of Novel Polycarbonates Derived from 5-Allyloxy-1,3-dioxan-2-one and 5,5-Dimethyl-1,3-dioxan-2-one

    Institute of Scientific and Technical Information of China (English)

    Yan Ping WANG; Feng HE; Gang LIU; Ren Xi ZHUO

    2006-01-01

    Novel polycarbonates from 5-allyloxy-1, 3-dioxan-2-one (ATMC) with 5, 5-dimethyl1, 3-dioxan-2-one (DTC) were successfully synthesized for the first time using immobilized porcine pancreas lipase (IPPL) as catalyst. The resulting copolymers were characterized by IR,1HNMR, 13C NMR and GPC. The molecular weight (Mn) of the copolymer with molar feed ratio of 10:90 (ATMC:DTC) was 9300 and the polydispersity was 1.31, while the Mn increased to 14300 and polydispersity of 1.25 with the feed ratio of 50:50. Moreover, the composition of the copolymers agreed well with the monomer feed.

  18. One-step preparation and pH-tunable self-aggregation of amphoteric aliphatic polycarbonates bearing plenty of amine and carboxyl groups.

    Science.gov (United States)

    Wang, Hua-Fen; Jia, Hui-Zhen; Zhu, Jing-Yi; Chu, Yan-Feng; Feng, Jun; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2012-12-01

    This paper reports a novel amphoteric aliphatic polycarbonate bearing both amine and carboxyl groups. In the absence of protection-deprotection chemistry, the multi-functionalized copolymer is synthesized by one-step enzymatic copolymerization. The influences of the reaction conditions including monomer feed ratio and polymerization time are explored. The simultaneous incorporation of amine and carboxyl functionalities provides the copolymer with a pH-tunable self-aggregation feature, leading to various aggregation states including precipitated agglomerate, well-dispersed positively or negatively charged nanoparticles in a controlled manner. The copolymer displays minimal cytotoxicity to 293T and HeLa cells.

  19. The ZEUS microvertex detector

    CERN Document Server

    Garfagnini, A

    1999-01-01

    A new vertex detector for the ZEUS experiment at HERA will be installed during the 1999-2000 shutdown, for the high-luminosity runs of HERA. It will allow to reconstruct secondary vertex tracks, coming from the decay of long-lived particles with a lifetime of about 10 sup - sup 1 sup 2 s, and improve the global momentum resolution of the tracking system. The interaction region will be surrounded with single-sided silicon strip detectors, with capacitive charge division: three double layers in the central region (600 detectors), and 4 'wheels' in the forward region (112 silicon planes). Due to the high number of readout channels, 512 readout strips per silicon plane in the barrel region and 480 in the forward part, and the large coverage of the vertex detector (almost 1 m long), the front-end electronics has to be placed on top of the detectors and has to be radiation tolerant since doses up to 2 kGy are expected near the interaction region. The HELIX chip has been chosen as analog chip with a low-noise, charg...

  20. Nonequilibrium superconducting detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Esposito, E.; Lisitskyi, M. P.; Nappi, C.; Pagano, S.; Perez de Lara, D.

    2006-03-01

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  1. Nonequilibrium superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, R [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Ejrnaes, M [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); INFN Sezione di Napoli, 80126 Naples (Italy); Esposito, E [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Lisitskyi, M P [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Nappi, C [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Pagano, S [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Saudi Arabia) (Italy); Perez de Lara, D [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy)

    2006-03-15

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  2. Detectors in Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Blaj, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carini, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carron, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Haller, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hart, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hasi, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Herrmann, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kenney, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Segal, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tomada, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  3. OPERA: Electronic Detector

    CERN Document Server

    Jollet, C

    2010-01-01

    OPERA is an hybrid detector for the ni-tau appearance search in a direct way, and the Electronic Detectors (ED) have the crucial role of triggerring for the neutrino events and of localizing such an interaction inside the target. Another very important task of the ED is to identify the muon since only a correct matching of such a track with a track in the emulsion connected to the vertex of the event allows to reduce the charm background to the desired level. The ED, fully working since 2006, consist of a target tracker (scintillator strips) and a spectrometer (RPC and drift tubes). The different sub-detectors are de- scribed in the poster, as well as their performance both on Monte Carlo (MC) and real data.

  4. Transition Radiation Detectors

    CERN Document Server

    Andronic, A

    2012-01-01

    We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.

  5. The LHCb Detector Upgrade

    CERN Document Server

    Schindler, H

    2013-01-01

    The LHCb collaboration presented a Letter of Intent (LOI) to the LHCC in March 2011 for a major upgrading of the detector during Long Shutdown 2 (2018) and intends to collect a data sample of 50/fb in the LHC and High-Luminosity-LHC eras. The aim is to operate the experiment at an instantaneous luminosity 2.5 times above the present operational luminosity, which has already been pushed to twice the design value. Reading out the detector at 40MHz allows to increase the trigger efficiencies especially for the hadronic decay modes. The physics case and the strategy for the upgrade have been endorsed by the LHCC. This paper presents briefly the physics motivations for the LHCb upgrade and the proposed changes to the detector and trigger.

  6. JSATS Detector Field Manual

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eric Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flory, Adam E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lamarche, Brian L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-06-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) Detector is a software and hardware system that captures JSATS Acoustic Micro Transmitter (AMT) signals. The system uses hydrophones to capture acoustic signals in the water. This analog signal is then amplified and processed by the Analog to Digital Converter (ADC) and Digital Signal Processor (DSP) board in the computer. This board digitizes and processes the acoustic signal to determine if a possible JSATS tag is present. With this detection, the data will be saved to the computer for further analysis. This document details the features and functionality of the JSATS Detector software. The document covers how to install the software, setup and run the detector software. The document will also go over the raw binary waveform file format and CSV files containing RMS values

  7. JSATS Detector Field Manual

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eric Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flory, Adam E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lamarche, Brian L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-06-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) Detector is a software and hardware system that captures JSATS Acoustic Micro Transmitter (AMT) signals. The system uses hydrophones to capture acoustic signals in the water. This analog signal is then amplified and processed by the Analog to Digital Converter (ADC) and Digital Signal Processor (DSP) board in the computer. This board digitizes and processes the acoustic signal to determine if a possible JSATS tag is present. With this detection, the data will be saved to the computer for further analysis. This document details the features and functionality of the JSATS Detector software. The document covers how to install the software, setup and run the detector software. The document will also go over the raw binary waveform file format and CSV files containing RMS values

  8. Cryogenic Tracking Detectors

    CERN Multimedia

    Luukka, P R; Tuominen, E M; Mikuz, M

    2002-01-01

    The recent advances in Si and diamond detector technology give hope of a simple solution to the radiation hardness problem for vertex trackers at the LHC. In particular, we have recently demonstrated that operating a heavily irradiated Si detector at liquid nitrogen (LN$_2$) temperature results in significant recovery of Charge Collection Efficiency (CCE). Among other potential benefits of operation at cryogenic temperatures are the use of large low-resistivity wafers, simple processing, higher and faster electrical signal because of higher mobility and drift velocity of carriers, and lower noise of the readout circuit. A substantial reduction in sensor cost could result The first goal of the approved extension of the RD39 program is to demonstrate that irradiation at low temperature in situ during operation does not affect the results obtained so far by cooling detectors which were irradiated at room temperature. In particular we shall concentrate on processes and materials that could significantly reduce th...

  9. The AFP Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  10. Production of grids in plastic detectors

    CERN Document Server

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

    1972-01-01

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

  11. Deposition of grids on plastic detectors

    CERN Document Server

    Birabeau, J P; Mendola, Onofrio

    1972-01-01

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

  12. ALICE Transition Radiation Detector

    CERN Multimedia

    Pachmayer, Y

    2013-01-01

    The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high Pτ tracks in one single TRD stack.

  13. Edgeless silicon pad detectors

    Science.gov (United States)

    Perea Solano, B.; Abreu, M. C.; Avati, V.; Boccali, T.; Boccone, V.; Bozzo, M.; Capra, R.; Casagrande, L.; Chen, W.; Eggert, K.; Heijne, E.; Klauke, S.; Li, Z.; Mäki, T.; Mirabito, L.; Morelli, A.; Niinikoski, T. O.; Oljemark, F.; Palmieri, V. G.; Rato Mendes, P.; Rodrigues, S.; Siegrist, P.; Silvestris, L.; Sousa, P.; Tapprogge, S.; Trocmé, B.

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in "edgeless" planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5±8 stat..±6 syst.) μm.

  14. Edgeless silicon pad detectors

    Energy Technology Data Exchange (ETDEWEB)

    Perea Solano, B. [CERN, CH-1211 Geneva 23 (Switzerland)]. E-mail: blanca.perea.solano@cern.ch; Abreu, M.C. [LIP and University of Algarve, 8000 Faro (Portugal); Avati, V. [CERN, CH-1211 Geneva 23 (Switzerland); Boccali, T. [INFN Sez. di Pisa and Scuola Normale Superiore, Pisa (Italy); Boccone, V. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Bozzo, M. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Capra, R. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Casagrande, L. [INFN Sez. di Roma 2 and Universita di Roma 2, Rome (Italy); Chen, W. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Eggert, K. [CERN, CH-1211 Geneva 23 (Switzerland); Heijne, E. [CERN, CH-1211 Geneva 23 (Switzerland); Klauke, S. [CERN, CH-1211 Geneva 23 (Switzerland); Li, Z. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Maeki, T. [Helsinki Institute of Physics, Helsinki (Finland); Mirabito, L. [CERN, CH-1211 Geneva 23 (Switzerland); Morelli, A. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Niinikoski, T.O. [CERN, CH-1211 Geneva 23 (Switzerland); Oljemark, F. [Helsinki Institute of Physics, Helsinki (Finland); Palmieri, V.G. [Helsinki Institute of Physics, Helsinki (Finland); Rato Mendes, P. [LIP and University of Algarve, 8000 Faro (Portugal); Rodrigues, S. [LIP and University of Algarve, 8000 Faro (Portugal); Siegrist, P. [CERN, CH-1211 Geneva 23 (Switzerland); Silvestris, L. [INFN Sez. Di Bari, Bari (Italy); Sousa, P. [LIP and University of Algarve, 8000 Faro (Portugal); Tapprogge, S. [Helsinki Institute of Physics, Helsinki (Finland); Trocme, B. [Institut de Physique Nucleaire, Villeurbanne (France)

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in 'edgeless' planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5{+-}8{sub stat.}.{+-}6{sub syst.}) {mu}m.

  15. Radiation Detectors and Art

    Science.gov (United States)

    Denker, Andrea

    The use of radiation detectors in the analysis of art objects represents a very special application in a true interdisciplinary field. Radiation detectors employed in this field detect, e.g., x-rays, γ-rays, β particles, and protons. Analyzed materials range from stones, metals, over porcelain to paintings. The available nondestructive and noninvasive analytical methods cover a broad range of techniques. Hence, for the sake of brevity, this chapter will concentrate on few techniques: Proton Induced X-ray Emission (PIXE) and Proton Induced γ-ray Emission (PIGE).

  16. The Upgraded D0 Detector

    CERN Document Server

    Abazov, V M; Abolins, M; Acharya, B S; Adams, D L; Adams, M; Adams, T; Agelou, M; Agram, J L; Ahmed, S N; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Andeen, T; Anderson, J T; Anderson, S; Andrieu, B; Angstadt, R; Anosov, V; Arnoud, Y; Arov, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Babukhadia, L; Bacon, Trevor C; Badaud, F; Baden, A; Baffioni, S; Bagby, L; Baldin, B; Balm, P W; Banerjee, P; Banerjee, S; Barberis, E; Bardon, O; Barg, W; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bhattacharjee, M; Baturitsky, M A; Bauer, D; Bean, A; Baumbaugh, B; Beauceron, S; Begalli, M; Beaudette, F; Begel, M; Bellavance, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Besson, A; Beuselinck, R; Beutel, D; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Bishoff, A; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Blumenschein, U; Bockenthein, E; Bodyagin, V; Böhnlein, A; Boeriu, O; Bolton, T A; Bonamy, P; Bonifas, D; Borcherding, F; Borissov, G; Bos, K; Bose, T; Boswell, C; Bowden, M; Brandt, A; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Burdin, S; Burke, S; Burnett, T H; Busato, E; Buszello, C P; Butler, D; Butler, J M; Cammin, J; Caron, S; Bystrický, J; Canal, L; Canelli, F; Carvalho, W; Casey, B C K; Casey, D; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Chevalier, L; Chi, E; Chiche, R; Cho, D K; Choate, R; Choi, S; Choudhary, B; Chopra, S; Christenson, J H; Christiansen, T; Christofek, L; Churin, I; Cisko, G; Claes, D; Clark, A R; Clement, B; Clément, C; Coadou, Y; Colling, D J; Coney, L; Connolly, B; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Coss, J; Cothenet, A; Cousinou, M C; Cox, B; Crepe-Renaudin, S; Cristetiu, M; Cummings, M A C; Cutts, D; Da Motta, H; Das, M; Davies, B; Davies, G; Davis, G A; Davis, W; De, K; de Jong, P; De Jong, S J; De La Cruz-Burelo, E; de La Taille, C; De Oliveira Martins, C; Dean, S; Degenhardt, J D; Déliot, F; Delsart, P A; Del Signore, K; De Maat, R; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doets, M; Doidge, M; Dong, H; Doulas, S; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dvornikov, O; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Eltzroth, J T; Elvira, V D; Eno, S; Ermolov, P; Eroshin, O V; Estrada, J; Evans, D; Evans, H; Evdokimov, A; Evdokimov, V N; Fagan, J; Fast, J; Fatakia, S N; Fein, D; Feligioni, L; Ferapontov, A V; Ferbel, T; Ferreira, M J; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fleck, I; Fitzpatrick, T; Flattum, E; Fleuret, F; Flores, R; Foglesong, J; Fortner, M; Fox, H; Franklin, C; Freeman, W; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Gao, M; García, C; García-Bellido, A; Gardner, J; Gavrilov, V; Gay, A; Gay, P; Gelé, D; Gelhaus, R; Genser, K; Gerber, C E; Gershtein, Yu; Gillberg, D; Geurkov, G; Ginther, G; Gobbi, B; Goldmann, K; Golling, T; Gollub, N; Golovtsov, V L; Gómez, B; Gómez, G; Gómez, R; Goodwin, R W; Gornushkin, Y; Gounder, K; Goussiou, A; Graham, D; Graham, G; Grannis, P D; Gray, K; Greder, S; Green, D R; Green, J; Green, J A; Greenlee, H; Greenwood, Z D; Gregores, E M; Grinstein, S; Gris, P; Grivaz, J F; Groer, L; Grünendahl, S; Grünewald, M W; Gu, W; Guglielmo, J; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Haas, A; Hadley, N J; Haggard, E; Haggerty, H; Hagopian, S; Hall, I; Hall, R E; Han, C; Han, L; Hance, R; Hanagaki, K; Hanlet, P; Hansen, S; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, C; Hays, J; Hazen, E; Hebbeker, T; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Hou, S; Houben, P; Hu, Y; Huang, J; Huang, Y; Hynek, V; Huffman, D; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jacquier, Y; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jayanti, R; Jenkins, A; Jesik, R; Jiang, Y; Johns, K; Johnson, M; Johnson, P; Jonckheere, A; Jonsson, P; Jöstlein, H; Jouravlev, N I; Juárez, M; Juste, A; Kaan, A P; Kado, M; Käfer, D; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J; Kalmani, S D; Karmanov, D; Kasper, J; Katsanos, I; Kau, D; Kaur, R; Ke, Z; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A I; Kharzheev, Yu M; Kim, H; Kim, K H; Kim, T J; Kirsch, N; Klima, B; Klute, M; Kohli, J M; Konrath, J P; Komissarov, E V; Kopal, M; Korablev, V M; Kostritskii, A V; Kotcher, J; Kothari, B; Kotwal, A V; Koubarovsky, A; Kozelov, A V; Kozminski, J; Kryemadhi, A; Kuznetsov, O; Krane, J; Kravchuk, N; Krempetz, K; Krider, J; Krishnaswamy, M R; Krzywdzinski, S; Kubantsev, M A; Kubinski, R; Kuchinsky, N; Kuleshov, S; Kulik, Y; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Kuznetsov, V E; Kwarciany, R; Lager, S; Lahrichi, N; Landsberg, G L; Larwill, M; Laurens, P; Lavigne, B; Lazoflores, J; Le Bihan, A C; Le Meur, G; Lebrun, P; Lee, S W; Lee, W M; Leflat, A; Leggett, C; Lehner, F; Leitner, R; Leonidopoulos, C; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Li, X; Lima, J G R; Lincoln, D; Lindenmeyer, C; Linn, S L; Linnemann, J; Lipaev, V V; Lipton, R; Litmaath, M; Lizarazo, J; Lobo, L; Lobodenko, A; Lokajícek, M; Lounis, A; Love, P; Lü, J; Lubatti, H J; Lucotte, A; Lueking, L; Luo, C; Lynker, M; Lyon, A L; Machado, E; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Magnan, A M; Maity, M; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Manakov, V; Mao, H S; Maravin, Y; Markley, D; Markus, M; Marshall, T; Martens, M; Martin, M; Martin-Chassard, G; Mattingly, S E K; Matulik, M; Mayorov, A A; McCarthy, R; McCroskey, R; McKenna, M; McMahon, T; Meder, D; Melanson, H L; Melnitchouk, A S; Mendes, A; Mendoza, D; Mendoza, L; Meng, X; Merekov, Y P; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miao, C; Miettinen, H; Mihalcea, D; Mikhailov, V; Miller, D; Mitrevski, J; Mokhov, N; Molina, J; Mondal, N K; Montgomery, H E; Moore, R W; Moulik, T; Muanza, G S; Mostafa, M; Moua, S; Mulders, M; Mundim, L; Mutaf, Y D; Nagaraj, P; Nagy, E; Naimuddin, M; Nang, F; Narain, M; Narasimhan, V S; Narayanan, A; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neuenschwander, R T; Neustroev, P; Nöding, C; Nomerotski, A; Novaes, S F; Nozdrin, A; Nunnemann, T; Nurczyk, A; Nurse, E; O'Dell, V; O'Neil, D C; Oguri, V; Olis, D; Oliveira, N; Olivier, B; Olsen, J; Oshima, N; Oshinowo, B O; Oteroy-Garzon, G J; Padley, P; Papageorgiou, K; Parashar, N; Park, J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Pérez, E; Peters, O; Petroff, P; Petteni, M; Phaf, L; Piegaia, R; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Pompos, A; Polosov, P; Pope, B G; Popkov, E; Porokhovoy, S; Prado da Silva, W L; Pritchard, W; Prokhorov, I; Prosper, H B; Protopopescu, S D; Przybycien, M B; Qian, J; Quadt, A; Quinn, B; Ramberg, E; Ramirez-Gomez, R; Rani, K J; Ranjan, K; Rao, M V S; Rapidis, P A; Rapisarda, S; Raskowski, J; Ratoff, P N; Ray, R E; Reay, N W; Rechenmacher, R; Reddy, L V; Regan, T; Renardy, J F; Reucroft, S; Rha, J; Ridel, M; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F K; Robinson, S; Rodrigues, R F; Roco, M T; Rotolo, C; Royon, C; Rubinov, P; Ruchti, R; Rucinski, R; Rud, V I; Rusakovich, N; Russo, P; Sabirov, B; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Satyanarayana, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, A D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schukin, A A; Schwartzman, A; Schwienhorst, R; Sen-Gupta, S; Severini, H; Shabalina, E; Shamim, M; Shankar, H C; Shary, V; Shchukin, A A; Sheahan, P; Shephard, W D; Shivpuri, R K; Shishkin, A A; Shpakov, D; Shupe, M; Sidwell, R A; Simák, V; Sirotenko, V I; Skow, D; Skubic, P L; Slattery, P F; Smith, D E; Smith, R P; Smolek, K; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Song, Y; Sonnenschein, L; Sopczak, A; Sorin, V; Sosebee, M; Soustruznik, K; Souza, M; Spartana, N; Spurlock, B; Stanton, N R; Stark, J; Steele, J; Stefanik, A; Steinberg, J L; Steinbruck, G; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tentindo-Repond, S; Tamburello, P; Taylor, W; Telford, P; Temple, J; Terentyev, N K; Teterin, V; Thomas, E; Thompson, J; Thooris, B; Titov, M; Toback, D; Tokmenin, V V; Tolian, C; Tomoto, M; Tompkins, D; Toole, T; Torborg, J; Touze, F; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Trippe, T G; Tsybychev, D; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Utes, M; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; Van den Berg, P J; Van Gemmeren, P; Van Kooten, R; Van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A H; Vasilyev, I A; Vaupel, M; Vaz, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Vigneault, M; Villeneuve-Séguier, F; Vishwanath, P R; Vlimant, J R; Von Törne, E; Vorobyov, A; Vreeswijk, M; Vu-Anh, T; Vysotsky, V S; Wahl, H D; Walker, R; Wallace, N; Wang, L; Wang, Z M; Warchol, J; Warsinsky, M; Watts, G; Wayne, M; Weber, M; Weerts, H; Wegner, M; Wermes, N; Wetstein, M; White, A; White, V; Whiteson, D; Wicke, D; Wijnen, T A M; Wijngaarden, D A; Wilcer, N; Willutzki, H; Wilson, G W; Wimpenny, S J; Wittlin, J; Wlodek, T; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Wu, Z; Xie, Y; Xu, Q; Xuan, N; Yacoob, S; Yamada, R; Yan, M; Yarema, R J; Yasuda, T; Yatsunenko, Y A; Yen, Y; Yip, K; Yoo, H D; Yoffe, F; Youn, S W; Yu, J; Yurkewicz, A; Zabi, A; Zanabria, M; Zatserklyaniy, A; Zdrazil, M; Zeitnitz, C; Zhang, B; Zhang, D; Zhang, X; Zhao, T; Zhao, Z; Zheng, H; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zitoun, R; Zmuda, T; Zutshi, V; Zviagintsev, S; Zverev, E G; Zylberstejn, A

    2005-01-01

    The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.

  17. The Upgraded D0 detector

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, D.L.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahmed, S.N.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G.A.; Anastasoaie, M.; Andeen, T.; Anderson, J.T.; Anderson, S.; /Buenos Aires U. /Rio de Janeiro, CBPF /Sao Paulo, IFT /Alberta U.

    2005-07-01

    The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.

  18. Status of the KEDR detector

    CERN Document Server

    Anashin, V V; Baibusinov, B O; Balashov, V; Baldin, E M; Barkov, L M; Barladyan, A K; Barnyakov, M Y; Baru, S E; Bedny, I; Beilin, D M; Blinov, A E; Blinov, V E; Bondarev, D V; Bondar, A E; Buzykaev, A R; Cantoni, P; Chilingarov, A G; Dneprovsky, L V; Eidelman, S I; Epifanov, D A; Frabetti, P L; Gaidarev, P B; Groshev, V R; Karpov, S V; Kiselev, V A; Klimenko, S G; Kolachev, G M; Kononov, S A; Kozlov, V N; Kravchenko, E A; Kulikov, V F; Kurdadze, L M; Kuzmin, A S; Kuznecov, S A; Lanni, F; Lelchuk, M Y; Leontiev, L A; Levichev, E B; Malyshev, V M; Manfredi, P F; Maslennikov, A L; Minakov, G D; Nagaslaev, V P; Naumenkov, A I; Nikitin, S A; Nomerotski, A; Onuchin, A P; Oreshkin, S B; Ovechkin, R; Palombo, F; Peleganchuk, S V; Petrosyan, S S; Pivovarov, S V; Poluektov, A O; Pospelov, G E; Protopopov, I Ya; Re, V; Romanov, L V; Root, N I; Ruban, A A; Savinov, G A; Shamov, A G; Shatilov, D; Shubin, M A; Shusharo, A I; Shwartz, B A; Sidorov, V A; Skovpen, Y I; Smakhtin, V P; Snopkov, R G; Sokolov, A V; Soukharev, A M; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Y; Usov, Y V; Vorobyev, A I; Yushkov, A N; Zatcepin, A V; Zhilich, V N

    2002-01-01

    KEDR is a general-purpose detector for experiments at the VEPP-4M e sup + e sup - -collider in the energy range 2E=2.0-12 GeV. All detector subsystems (except the aerogel Cherenkov counters) have been installed into the detector at VEPP-4M. Some preliminary data have been taken in the energy region of the J/PSI meson. The tuning of the detector and the VEPP-4M collider is in progress. Preliminary results on the detector performance are presented. The future experimental program for the KEDR detector is discussed.

  19. Status of the KEDR detector

    Energy Technology Data Exchange (ETDEWEB)

    Anashin, V.V.; Aulchenko, V.M.; Baibusinov, B.O.; Balashov, V.; Baldin, E.M.; Barkov, L.M.; Barladyan, A.K.; Barnyakov, M.Yu.; Baru, S.E.; Bedny, I.V.; Beilin, D.M.; Blinov, A.E.; Blinov, V.E.; Bondarev, D.V.; Bondar, A.E.; Buzykaev, A.R.; Cantoni, P.; Chilingarov, A.G.; Dneprovsky, L.V.; Eidelman, S.I.; Epifanov, D.A.; Frabetti, P.L.; Gaidarev, P.B.; Groshev, V.R.; Karpov, S.V.; Kiselev, V.A.; Klimenko, S.G.; Kolachev, G.M.; Kononov, S.A.; Kozlov, V.N.; Kravchenko, E.A.; Kulikov, V.F.; Kurdadze, L.M.; Kuzmin, A.S.; Kuznecov, S.A.; Lanni, F.; Lelchuk, M.Yu.; Leontiev, L.A.; Levichev, E.B.; Malyshev, V.M.; Manfredi, P.F.; Maslennikov, A.L.; Minakov, G.D.; Nagaslaev, V.P.; Naumenkov, A.; Nikitin, S.A.; Nomerotsky, A.; Onuchin, A.P.; Oreshkin, S.B.; Ovechkin, R.; Palombo, F.; Peleganchuk, S.V.; Petrosyan, S.S.; Pivovarov, S.V.; Poluektov, A.O.; Pospelov, G.E.; Protopopov, I.Ya.; Re, V.; Romanov, L.V.; Root, N.I.; Ruban, A.A.; Savinov, G.A.; Shamov, A.G.; Shatilov, D.; Shubin, M.A.; Shusharo, A.I.; Shwartz, B.A.; Sidorov, V.A.; Skovpen, Yu.I.; Smakhtin, V.P.; Snopkov, R.G.; Sokolov, A.V.; Soukharev, A.M.; Talyshev, A.A.; Tayursky, V.A.; Telnov, V.I.; Tikhonov, Yu.A. E-mail: tikhonov@cppm.in2p3.fr; Todyshev, K.Yu.; Usov, Yu.V.; Vorobyev, A.I.; Yushkov, A.N.; Zatcepin, A.V.; Zhilich, V.N

    2002-02-01

    KEDR is a general-purpose detector for experiments at the VEPP-4M e{sup +}e{sup -}-collider in the energy range 2E=2.0-12 GeV. All detector subsystems (except the aerogel Cherenkov counters) have been installed into the detector at VEPP-4M. Some preliminary data have been taken in the energy region of the J/{psi} meson. The tuning of the detector and the VEPP-4M collider is in progress. Preliminary results on the detector performance are presented. The future experimental program for the KEDR detector is discussed.

  20. Applying graphene oxide nano-film over a polycarbonate nanoporous membrane to monitor E. coli by infrared spectroscopy.

    Science.gov (United States)

    Singh, Krishna Pal; Dhek, Neeraj Singh; Nehra, Anuj; Ahlawat, Sweeti; Puri, Anu

    2017-01-05

    Nano-biosensors are excellent monitoring tools for rapid, specific, sensitive, inexpensive, in-field, on-line, and/or real-time detection of pathogens in foods, soil, air, and water samples. A variety of nano-materials (metallic, polymeric, and/or carbon-based) were employed to enhance the efficacy, efficiency, and sensitivity of these nano-biosensors, including graphene-based materials, especially graphene oxide (GO)-based materials. GO bears many oxygen-bearing groups, enabling ligand conjugation at the high density critical for sensitive detection. We have fabricated GO-modified nano-porous polycarbonate track-etched (PCTE) membranes that were conjugated to an Escherichia coli-specific antibody (Ab) and used to detect E. coli. The random distribution of nanopores on the PCTE membrane surface and the bright coating of the GO onto the membrane were confirmed by scanning electron microscope. Anti-E. coli β-gal Abs were conjugated to the GO surface via 1-ethyl-3,3-dimethylaminopropyl carbodiimide hydrochloride-N-hydroxysuccinimide chemistry; antibody coating was confirmed by the presence of a characteristic IR peak near 1600cm(-1). A non-corresponding Ab (anti-Pseudomonas) was used as a negative control under identical conditions. When E. coli interacted anti-E.coli β-gal with Ab-coated GO-nano-biosensor units, we observed a clear shift in the IR peak from 3373.14 to 3315cm(-1); in contrast, we did not observe any shift in IR peaks when the GO unit was coated with the non-corresponding Ab (anti-Pseudomonas). Therefore, the detection of E. coli using the described GO-nano-sensor unit is highly specific, is highly selective and can be applied for real-time monitoring of E. coli with a detection limit between 100μg/mL and 10μg/mL, similar to existing detection systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Fabrication of a gold microelectrode for amperometric detection on a polycarbonate electrophoresis chip by photodirected electroless plating.

    Science.gov (United States)

    Kong, Yong; Chen, Hengwu; Wang, Yurong; Soper, Steven A

    2006-07-01

    A novel method of photoresist-free micropatterning coupled with electroless gold plating is described for the fabrication of an integrated gold electrode for electrochemical detection (ED) on a polycarbonate (PC) electrophoresis microchip. The microelectrode layout was photochemically patterned onto the surface of a PC plate by selective exposure of the surface coated without photoresist to 254 nm UV light through a chromium/quartz photomask. Thus, the PC plate was selectively sensitized by formation of reactive chemical moieties in the exposed areas. After a series of wet chemistry reactions, the UV-exposed area was activated with a layer of gold nanoparticles that served as a seed to catalyze the electroless plating. The gold microelectrode was then selectively plated onto the activated area by using an electroless gold plating bath. Nonselective gold deposition on the unwanted areas was eliminated by sonication of the activated PC plate in a KSCN solution before electroless plating, and the adhesion of the plated electrodes to the PC surface was strengthened with thermal annealing. Compared with the previously reported electroless plating technique for fabrication of microelectrodes on a microchip, the present method avoided the use of a membrane stencil with an electrode pattern to restrict the area to be wet-chemically sensitized. The CE with integrated ED (CE-ED) microchip was assembled by thermal bonding an electrode-plated PC cover plate to a microchannel-embossed PC substrate. The novel method allows one to fabricate low-cost, electrode-integrated, complete PC CE-ED chips with no need of a clean room. The fabricated CE-ED microchip was demonstrated for separation and detection of model analytes, including dopamine (DA) and catechol (CA). Detection limits of 0.65 and 1.03 microM were achieved for DA and CA, respectively, and theoretical plate number of 1.4 x 10(4) was obtained for DA. The plated gold electrode can be used for about 4 h, bearing usually more

  2. PHASE STRUCTURE AND THERMAL BEHAVIOR OF LIQUID CRYSTALLINE MULTI-BLOCK COPOLYMERS,POLY[1,6-BIS(4-OXYBENZOYL-OXY)HEXANE TEREPHTHALATE]-b-BISPHENOL A POLYCARBONATE

    Institute of Scientific and Technical Information of China (English)

    Hui-qing Zhang; Xiong-yan Zhao; De-shan Liu; Qi-xiang Zhou

    1999-01-01

    Liquid crystalline multi-block copolymers poly[1,6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segments of polycarbonate (PC) and thermotropic polyester PHTH-6 were synthesized in tetrachloroethane at 144~146℃. The influence of segment length on the resulting phase structure and thermal behavior of block copolymers was also discussed. It is demonstrated by TEM and DMA that the resulting block copolymers show a considerable microphase separation. The degree of phase separation and the thermal behavior of the block copolymers are strongly dependent on the molecular weight of the segments incorporated.

  3. Reactive Flash Simulation of the Continuous Melt Transesterification Process of Polycarbonate%聚碳酸酯连续熔融酯交换过程的反应闪蒸模拟

    Institute of Scientific and Technical Information of China (English)

    秦吉臣; 谢小莉; 曹贤武; 瞿金平

    2007-01-01

    A model of the continuous melt transesterification process of bisphenol-A and diphenyl carbonate in a continuous stirred tank reactor to produce polycarbonate is presented. The model is developed by using the molecular species model of polycarbonate melt polycondensation and the modeling method of reactive flash. Liquid phase is treated as perfect mixed flow and the vapor phase is assumed following the ideal gas law. With this model,the continuous melt transesterification process of bisphenol-A and diphenyl carbonate is examined with respect to different process parameters.

  4. Fast Detector Simulation Using Lelaps, Detector Descriptions in GODL

    Energy Technology Data Exchange (ETDEWEB)

    Langeveld, Willy; /SLAC

    2005-07-06

    Lelaps is a fast detector simulation program which reads StdHep generator files and produces SIO or LCIO output files. It swims particles through detectors taking into account magnetic fields, multiple scattering and dE/dx energy loss. It simulates parameterized showers in EM and hadronic calorimeters and supports gamma conversions and decays. In addition to three built-in detector configurations, detector descriptions can also be read from files in the new GODL file format.

  5. 肾透析发展趋势与创新材料%Bayer MaterialSicence Innovative Polycarbonates for Kidney Disease Dialysis

    Institute of Scientific and Technical Information of China (English)

    王良文; 郑家胜

    2014-01-01

    拜耳材料科技开发出一系列的医用级聚碳酸酯(P C)材料,多年来已广泛应用于全球众多医疗元器件及设备制造商。本文说明肾病医疗透析器壳体材料的特性要求以提高透析疗程安全性,再探讨为透析器无氧包装而开发的新一代聚碳酸酯(P C)材料-模克隆® Rx2440的材料性能。%Bayer MaterialScience developed a series of medical polycarbonate resins which are widely used by global medical device components and device manufacturers for years. This article explains the special material requirement to enhance safety of dialysis treatment, and further discusses the new polycarbonate grade-Makrolon® Rx 2440 fulifl ing the gamma sterilization trend of dialyzer packed in oxygen-free condition.

  6. Mechanical, Electromagnetic, and X-ray Shielding Characterization of a 3D Printable Tungsten-Polycarbonate Polymer Matrix Composite for Space-Based Applications

    Science.gov (United States)

    Shemelya, Corey M.; Rivera, Armando; Perez, Angel Torrado; Rocha, Carmen; Liang, Min; Yu, Xiaoju; Kief, Craig; Alexander, David; Stegeman, James; Xin, Hao; Wicker, Ryan B.; MacDonald, Eric; Roberson, David A.

    2015-08-01

    Material-extrusion three-dimensional (3D) printing has recently attracted much interest because of its process flexibility, rapid response to design alterations, and ability to create structures "on-the-go". For this reason, 3D printing has possible applications in rapid creation of space-based devices, for example cube satellites (CubeSat). This work focused on fabrication and characterization of tungsten-doped polycarbonate polymer matrix composites specifically designed for x-ray radiation-shielding applications. The polycarbonate-tungsten polymer composite obtained intentionally utilizes low loading levels to provide x-ray shielding while limiting effects on other properties of the material, for example weight, electromagnetic functionality, and mechanical strength. The fabrication process, from tungsten functionalization to filament extrusion and material characterization, is described, including printability, determination of x-ray attenuation, tensile strength, impact resistance, and gigahertz permittivity, and failure analysis. The proposed materials are uniquely advantageous when implemented in 3D printed structures, because even a small volume fraction of tungsten has been shown to substantially alter the properties of the resulting composite.

  7. Probing the role of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) -coated multiwalled carbon nanotubes in the thermal and mechanical properties of polycarbonate nanocomposites

    KAUST Repository

    Zhou, Jian

    2014-03-05

    The role played by multiwalled carbon nanotubes (MWCNTs) coated with poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) in the thermal and mechanical properties of polycarbonate (PC) nanocomposites was analyzed. We used differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) to demonstrate that the glass transition temperature of polycarbonate nanocomposites decreased whereas the storage modulus of the samples increased by including PEDOT/PSS-coated MWCNTs. These results indicated that PEDOT/PSS acts as an antiplasticizer. We attributed the enhancement of the storage modulus to the strong hydrogen bonding between PSS and the PC matrix and the reduction of the free volume in the PC matrix due to the shrinkage of PEDOT/PSS upon heating. We also investigated changes in the thermal conductivity and thermal degradation behavior of the nanocomposites. The results indicated that PEDOT/PSS did not play a significant role in improving the thermal conductivity and thermal stability of PC nanocomposites. The relative improvements in the conductivity and thermal stability of the samples that contained PEDOT/PSS were attributed to the better dispersion of the MWCNTs in the PC matrix. © 2014 American Chemical Society.

  8. Pixel detector insertion

    CERN Multimedia

    CMS

    2015-01-01

    Insertion of the Pixel Tracker, the 66-million-channel device used to pinpoint the vertex of each colliding proton pair, located at the heart of the detector. The geometry of CMS is a cylinder lying on its side (22 meters long and 15 meters high in dia

  9. Sensitive hydrogen leak detector

    Science.gov (United States)

    Myneni, Ganapati Rao

    1999-01-01

    A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

  10. B-factory detectors

    CERN Document Server

    Marlow, D R

    2002-01-01

    The designs of the recently commissioned BaBar and Belle B-Factory detectors are described. The discussion is organized around the methods and instruments used to detect the so-called gold-plated-mode B sup 0->J/PSI K sub S decays and related modes.

  11. The BABAR Detector

    CERN Document Server

    CERN. Geneva

    2002-01-01

    BABAR, the detector for the SLAC PEP-II asymmetric e+e- B Factory operating at the upsilon 4S resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

  12. CALIBRATION OF PHOSWICH DETECTORS

    NARCIS (Netherlands)

    LEEGTE, HKW; KOLDENHOF, EE; BOONSTRA, AL; WILSCHUT, HW

    1992-01-01

    Two important aspects for the calibration of phoswich detector arrays have been investigated. It is shown that common gate ADCs can be used: The loss in particle identification due to fluctuations in the gate timing in multi-hit events can be corrected for by a simple procedure using the measured ti

  13. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

    The RPC system is operating with a very high uptime, an average chamber efficiency of about 95% and an average cluster size around 1.8. The average number of active channels is 97.7%. Eight chambers are disconnected and forty are working in single-gap mode due to high-voltage problems. The total luminosity lost due to RPCs in 2012 is 88.46 pb–1. One of the main goals of 2012 was to improve the stability of the endcap trigger that is strongly correlated to the performances of the detector, due to the 3-out-3 trigger logic. At beginning of 2011 the instability of the detector efficiency was about 10%. Detailed studies found that this was mainly due to the strong correlation between the performance of the detector and the atmospheric pressure (P). Figure XXY shows the linear correlation between the average cluster size of the endcap chamber versus P. This effect is expected for gaseous detectors and can be reduced by correcting the applied high-voltage working point (HVapp) according to the followi...

  14. Ionic smoke detectors

    CERN Document Server

    2002-01-01

    Ionic smoke detectors are products incorporating radioactive material. This article summarises the process for their commercialization and marketing, and how the activity is controlled, according to regulations establishing strict design and production requisites to guarantee the absence of radiological risk associated both with their use and their final handling as conventional waste. (Author)

  15. ALICE Silicon Pixel Detector

    CERN Multimedia

    Manzari, V

    2013-01-01

    The Silicon Pixel Detector (SPD) forms the innermost two layers of the 6-layer barrel Inner Tracking System (ITS). The SPD plays a key role in the determination of the position of the primary collision and in the reconstruction of the secondary vertices from particle decays.

  16. The CLIC Vertex Detector

    CERN Document Server

    Dannheim, D

    2015-01-01

    The precision physics needs at TeV-scale linear electron-positron colliders (ILC and CLIC) require a vertex-detector system with excellent flavour-tagging capabilities through a meas- urement of displaced vertices. This is essential, for example, for an explicit measurement of the Higgs decays to pairs of b-quarks, c-quarks and gluons. Efficient identification of top quarks in the decay t → W b will give access to the ttH-coupling measurement. In addition to those requirements driven by physics arguments, the CLIC bunch structure calls for hit tim- ing at the few-ns level. As a result, the CLIC vertex-detector system needs to have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low material budget, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations challenge current technological limits. A detector concept based on hybrid pixel-detector technology is under development for the CLIC ver- tex det...

  17. First ALICE detectors installed!

    CERN Multimedia

    2006-01-01

    Detectors to track down penetrating muon particles are the first to be placed in their final position in the ALICE cavern. The Alice muon spectrometer: in the foreground the trigger chamber is positioned in front of the muon wall, with the dipole magnet in the background. After the impressive transport of its dipole magnet, ALICE has begun to fill the spectrometer with detectors. In mid-July, the ALICE muon spectrometer team achieved important milestones with the installation of the trigger and the tracking chambers of the muon spectrometer. They are the first detectors to be installed in their final position in the cavern. All of the eight half planes of the RPCs (resistive plate chambers) have been installed in their final position behind the muon filter. The role of the trigger detector is to select events containing a muon pair coming, for instance, from the decay of J/ or Y resonances. The selection is made on the transverse momentum of the two individual muons. The internal parts of the RPCs, made o...

  18. Superconducting Single Photon Detectors

    NARCIS (Netherlands)

    Dorenbos, S.N.

    2011-01-01

    This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and fluoresc

  19. The BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G

    2001-05-18

    BABAR, the detector for the SLAC PEP-II asymmetric e{sup +}e{sup -} B Factory operating at the {Upsilon}(4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

  20. High-resolution ionization detector and array of such detectors

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S. (Ypsilanti, MI); Rojeski, Ronald A. (Pleasanton, CA)

    2001-01-16

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.