WorldWideScience

Sample records for hugely enhanced electroluminescence

  1. Electroluminescence

    CERN Document Server

    Henisch, H K

    1962-01-01

    Electroluminescence deals with the multiplicity of forms related to electroluminescence phenomena. The book reviews some basic observations of electroluminescence, the Gudden-Pohl and Dechene effects, the electroluminescence phenomena in zinc sulfide phosphors, in silicon carbide, and in compounds composed of elements in groups III and V of the Periodic Table (such as gallium phosphide). The text also explains polarization of free charge carriers, the outline of junction breakdown theory, carrier recombination, and phosphor suspensions. The book describes the growth of zinc sulfide crystals (f

  2. Enhanced electroluminescence from nanocrystallite Si based MOSLED by interfacial Si nanopyramids

    Institute of Scientific and Technical Information of China (English)

    Gong-Ru Lin

    2007-01-01

    The interfacial Si nano-pyramid-enhanced electroluminescence (EL) of an ITO/SiOx/p-Si/Al metal-oxidesemiconductor (MOS) diode with turn-on voltage of 50 V, threshold current of 1.23 mA/cm2, output power of 16 nW, and lifetime of 10 h is reported.

  3. Experimental observation of electroluminescence enhancement on green LEDs mediated by surface plasmons.

    Science.gov (United States)

    Lee, Kwang-Geol; Choi, Ki-Young; Kim, Jin-Ha; Song, Seok Ho

    2014-08-25

    We experimentally demonstrate the 1.5-fold enhancement of the electroluminescence (EL) of surface-plasmon (SP)-mediated green LEDs. On the p-clad surface of InGaN/GaN multi-quantum well LEDs, a 2-dimensional, second-order grating structure is textured and coated with an Ag electrode. With this setup, a larger EL enhancement factor is obtained at a higher injected current, which suggests that SP-LEDs can be a possible solution to efficiency droop, which is one of the main problems in developing high-power LEDs. Details regarding the implementation of our device are discussed.

  4. Enhanced Electroluminescent Efficiency Based on Functionalized Europium Complexes in Polymer Light-Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong; WANG Lei; LI Chun; ZENG Wen-Jin; SHI Hua-Hong; CAO Yong

    2007-01-01

    Efficient red polymer light-emitting diodes are fabricated with the single active layer from the blends of poly (Nvinylcarbazole) (PVK) in the presence of 30wt.% electron-transporting compound 2-(4-biphenylyl)-5-(p-tertbutylphenyl)-1,3,4-oxadiazole (PBD) and europium complexes. The polyphenylene functionalized europium complex shows an enhanced electroluminescent efficiency due to the large site-isolation effect. For the polyphenylene functionalized europium complex, the maximum external quantum efficiency of 1.90% and luminous efficiency of 2.01 cd A-1 are achieved with emission peak at 612nm. The maximum brightness is more than 300cd m-2.

  5. Enhanced electroluminescence of organic light-emitting diodes by using halloysite nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mondragón, Margarita, E-mail: mmondragon@ipn.mx [Instituto Politécnico Nacional, ESIME Azcapotzalco, Av. de las Granjas 682, 02250 México D.F. (Mexico); Moggio, Ivana; León, Arxel de; Arias, Eduardo [Centro de Investigación en Química Aplicada, CIQA, Blvd. Enrique Reyna 140, 25253 Saltillo, Coahuila (Mexico)

    2013-12-15

    The effect of halloysite clay nanotubes (HNTs) on the optical and electronic properties of poly(2-methoxy-5-[2′-ethylhexyloxy]-1,4-phenylenevinylene) (MEH-PPV) have been investigated. The UV–vis absorption band of the conjugated polymer remains unchanged upon the incorporation of halloysite nanotubes (HNTs). Photoluminescence (PL) measurements reveal a decreased quantum yield in the MEH-PPV/HNTs nanocomposites, compared with bulk MEH-PPV. Improvement of the electroluminescence of organic light-emitting diodes (OLEDs) was achieved by incorporating high contents of HNTs. The nanotubes act to enhanced polymer aggregates, as revealed by AFM analysis, thus increasing charge transport and therefore electroluminescence but also decreasing PL quantum yield. -- Highlights: • Thin films of nanocomposites of MEH-PPV/HNTs were prepared by spin coating. • Quantum yield in the nanocomposites was decreased compared with bulk MEH-PPV. • Improvement of the EL of OLEDs was achieved by incorporating high contents of HNTs. • The HNTs act to enhanced polymer aggregates, as revealed by AFM.

  6. Electroluminescence and photoluminescence of conjugated polymer films prepared by plasma enhanced chemical vapor deposition of naphthalene

    CERN Document Server

    Rajabi, Mojtaaba; Firouzjah, Marzieh Abbasi; Hosseini, Seyed Iman; Shokri, Babak

    2012-01-01

    Polymer light-emitting devices were fabricated utilizing plasma polymerized thin films as emissive layers. These conjugated polymer films were prepared by RF Plasma Enhanced Chemical Vapor Deposition (PECVD) using naphthalene as monomer. The effect of different applied powers on the chemical structure and optical properties of the conjugated polymers was investigated. The fabricated devices with structure of ITO/PEDOT:PSS/ plasma polymerized Naphthalene/Alq3/Al showed broadband Electroluminescence (EL) emission peaks with center at 535-550 nm. Using different structural and optical tests, connection between polymers chemical structure and optical properties under different plasma powers has been studied. Fourier transform infrared (FTIR) and Raman spectroscopies confirmed that a conjugated polymer film with a 3-D cross-linked network was developed. By increasing the power, products tended to form as highly cross-linked polymer films. Photoluminescence (PL) spectra of plasma polymers showed different excimerc ...

  7. Electroluminescence of Zn{sub 2}GeO{sub 4}:Mn through SiC whisker electric field enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Wagstaff, Brandon, E-mail: wagstabj@mcmaster.ca [McMaster University, Department of Engineering Physics, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada); Kitai, Adrian, E-mail: kitaia@mcmaster.ca [McMaster University, Department of Engineering Physics, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada); McMaster University, Department of Materials Science and Engineering, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada)

    2015-11-15

    Alternating current (AC) electroluminescence of thin film oxide phosphors is well known. However in this work electroluminescence of bulk oxide powder phosphors is achieved. A new type of AC Electroluminescent (ACEL) device has been created and developed by integrating SiC whiskers into a phosphor matrix composed of manganese-activated zinc germanate (Zn{sub 2}GeO{sub 4}:Mn{sup 2+}). The conductive SiC whiskers enhance the average electric field in specific regions of the phosphor such that localized breakdown of the phosphor occurs, thus emitting green light. This field enhancement allows light emission to occur in thick film oxide powder phosphors and is notably the first time that bright and reasonably efficient electroluminescence of zinc germanate has been observed without using expensive thin film deposition techniques. Light emission has been achieved in thick pressed pellets using surface-deposited electrodes and the brightness-voltage characteristics of light emission are shown to be consistent with field emission of carriers from the embedded whiskers. - Highlights: • A new electroluminescent phosphor, Zn{sub 2}GeO{sub 4}Mn{sup 2+}+SiC whiskers, is proposed. • A procedure is described to fabricate a solid sample of this composite material. • Under an AC voltage, green light is emitted only in samples containing the SiC whiskers. • A brightness of 25 Cd/m{sup 2} and efficiency of 0.25 Lm/W is observed 9.6×10{sup 6} V/m. • This is notably the first time that ACEL has been observed in bulk Zn{sub 2}GeO{sub 4}Mn{sup 2+}.

  8. Organic electroluminescence

    CERN Document Server

    Kafafi, Zakya H

    2005-01-01

    Organic light-emitting diode(OLED) technology has achieved significant penetration in the commercial market for small, low-voltage and inexpensive displays. Present and future novel technologies based on OLEDs involve rigid and flexible flat panel displays, solid-state lighting, and lasers. Display applications may range from hand-held devices to large flat panel screens that can be rolled up or hung flat on a wall or a ceiling. Organic Electroluminescence gives an overview of the on-going research in the field of organic light-emitting materials and devices, covering the principles of electroluminescence in organic thin films, as well as recent trends, current applications, and future potential uses. The book begins by giving a background of organic electroluminescence in terms of history and basic principles. It offers details on the mechanism(s) of electroluminescence in thin organic films. It presentsin-depth discussions of the parameters that control the external electroluminescence quantum efficien...

  9. Electroluminescence enhancement of glass/ITO/PEDOT:PSS/MEH-PPV/PEDOT:PSS/Al OLED by thermal annealing

    Science.gov (United States)

    Hewidy, Dina; Gadallah, A.-S.; Fattah, G. Abdel

    2017-02-01

    Manufacturing of glass/ITO/PEDOT:PSS/MEH-PPV/PEDOT:PSS/Al organic light emitting diode (OLED) by depositing PEDOT:PSS/MEH-PPV/PEDOT:PSS using spin coating has been reported. The roles of PEDOT:PSS in the structure have been reported. It allows transportation of holes from ITO to the highest occupied molecular orbit (HOMO) of MEH-PPV. In additions, it allows transportation of electrons from Al to lowest unoccupied molecular orbit (LUMO) of MEH:PPV. Further, it confines electrons in the LUMO of MEH:PPV due to the higher barrier of PEDOT:PSS of LUMO. The effect of thermal annealing on the current-voltage curve as well as on the electroluminescence intensity has been reported. The results show that the current increased from 25 mA to 52 mA at 7 V, when the sample was thermally annealed at 150 °C. Such enhancement in electrical injection leads to enhancement of the electroluminescence to a factor of 4.7 at the peak luminescence wavelength (∼592 nm). Reasons for electroluminescence improvement caused by thermal annealing have been proposed.

  10. Huge thermal conductivity enhancement in boron nitride – ethylene glycol nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Żyła, Gaweł, E-mail: gzyla@prz.edu.pl [Department of Physics and Medical Engineering, Rzeszow University of Technology, Rzeszow, 35-905 (Poland); Fal, Jacek; Traciak, Julian [Department of Physics and Medical Engineering, Rzeszow University of Technology, Rzeszow, 35-905 (Poland); Gizowska, Magdalena; Perkowski, Krzysztof [Department of Nanotechnology, Institute of Ceramics and Building Materials, Warsaw, 02-676 (Poland)

    2016-09-01

    Paper presents the results of experimental studies on thermophysical properties of boron nitride (BN) plate-like shaped particles in ethylene glycol (EG). Essentially, the studies were focused on the thermal conductivity of suspensions of these particles. Nanofluids were obtained with two-step method (by dispersing BN particles in ethylene glycol) and its’ thermal conductivity was analyzed at various mass concentrations, up to 20 wt. %. Thermal conductivity was measured in temperature range from 293.15 K to 338.15 K with 15 K step. The measurements of thermal conductivity of nanofluids were performed in the system based on a device using the transient line heat source method. Studies have shown that nanofluids’ thermal conductivity increases with increasing fraction of nanoparticles. The results of studies also presented that the thermal conductivity of nanofluids changes very slightly with the increase of temperature. - Highlights: • Huge thermal conductivity enhancement in BN-EG nanofluid was reported. • Thermal conductivity increase very slightly with increasing of the temperature. • Thermal conductivity increase linearly with volume concentration of particles.

  11. Performance enhancement of ZnS:Mn thin film electroluminescent devices by combination of laser and thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Koutsogeorgis, Demosthenes C., E-mail: demosthenes.koutsogeorgis@ntu.ac.u [School of Science and Technology, Displays Research Group, Nottingham Trent University, Nottingham NG11 8NS (United Kingdom); Cranton, Wayne M.; Ranson, Robert M.; Thomas, Clive B. [School of Science and Technology, Displays Research Group, Nottingham Trent University, Nottingham NG11 8NS (United Kingdom)

    2009-08-26

    The combination of laser and thermal annealing was investigated as a post-deposition process for enhancing the luminescent properties of RF-magnetron sputtered ZnS:Mn thin film electroluminescent devices (TFEL). Laser annealing of the uncoated phosphor layer was performed using KrF excimer 248 nm laser pulses of 20 ns under an argon overpressure of 10 bar to limit laser ablation. Single, double and triple irradiation was applied at 1.4 J/cm{sup 2}. Thermal annealing was performed in vacuum at 500 deg. C and 550 deg. C for 1 h. In this paper we are reporting the brightness-voltage characteristics of devices that have been subjected to all combinations of the two annealing techniques (i.e. laser, thermal, laser + thermal, thermal + laser and finally non-annealed devices). Also, a simple lifetime comparison is made between the best performing device (laser + thermal) and the industrial standard (thermal). The lifetime (time to half brightness) and brightness of the best performing device is found to be more than double compared to the industrial standard.

  12. Spectra of surface plasmon polariton enhanced electroluminescence from electroformed Al-Al{sub 2}O{sub 3}-Ag diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hickmott, T. W. [Department of Physics, State University of New York at Albany, Albany, New York 12222 (United States)

    2015-03-07

    Narrow band-pass filters have been used to measure the spectral distribution of electroluminescent photons with energies between 1.8 eV and 3.0 eV from electroformed Al-Al{sub 2}O{sub 3}-Ag diodes with anodic Al{sub 2}O{sub 3} thicknesses between 12 nm and 18 nm. Electroforming of metal-insulator-metal (MIM) diodes is a non-destructive dielectric breakdown that results in a conducting channel in the insulator and changes the initial high resistance of the MIM diode to a low resistance state. It is a critical step in the development of resistive-switching memories that utilize MIM diodes as the active element. Electroforming of Al-Al{sub 2}O{sub 3}-Ag diodes in vacuum results in voltage-controlled negative resistance (VCNR) in the current-voltage (I-V) characteristics. Electroluminescence (EL) and electron emission into vacuum (EM) develop simultaneously with the current increase that results in VCNR in the I-V characteristics. EL is due to recombination of electrons injected at the Al-Al{sub 2}O{sub 3} interface with radiative defect centers in Al{sub 2}O{sub 3}. Measurements of EL photons between 1.8 eV and 3.0 eV using a wide band-pass filter showed that EL intensity is exponentially dependent on Al{sub 2}O{sub 3} thickness for Al-Al{sub 2}O{sub 3}-Ag diodes between 12 nm and 20 nm thick. Enhanced El intensity in the thinnest diodes is attributed to an increase in the spontaneous emission rate of recombination centers due to high electromagnetic fields generated in Al{sub 2}O{sub 3} when EL photons interact with electrons in Ag or Al to form surface plasmon polaritons at the Al{sub 2}O{sub 3}-Ag or Al{sub 2}O{sub 3}-Al interface. El intensity is a maximum at 2.0–2.2 eV for Al-Al{sub 2}O{sub 3}-Ag diodes with Al{sub 2}O{sub 3} thicknesses between 12 nm and 18 nm. EL in diodes with 12 nm or 14 nm of Al{sub 2}O{sub 3} is enhanced by factors of 8–10 over EL from a diode with 18 nm of Al{sub 2}O{sub 3}. The extent of EL enhancement in

  13. White-Light Electroluminescence with Tetraphenylethylene as Emitting Layer of Aggregation-Induced Emissions Enhancement

    Institute of Scientific and Technical Information of China (English)

    罗建芳; 王晓宏; 王筱梅; 苏文明; 陶绪堂; 陈志刚

    2012-01-01

    Tetraphenylethylene (TPE) based molecules with easy synthesis, good thermal stability, and especially their aggregation-induced emissions enhancement (AIEE) effect recently become attractive organic emitting materials due to their potentially practical application in OLEDs. Herein, the AIEE behaviors of tetraphenylethylene dyes (TMTPE and TBTPE) were investigated. Fabricated luminesent device using TMTPE dye as emitting layer displays two strong emitting bands: the blue emission coming from the first-step aggregation and the yellow emission attrib- uted to the second-step aggregation. Thus, it can be utilized to fabricate the white-light OLEDs (WOLEDs) of the single-emitting-component. A three-layer device with the brightness of 1200 cd·m^-2 and current efficiency of 0.78 cd·A^-1 emits the close to white light with the CIE coordinates of x=0.333 and y=0.358, when applied voltage from 8-13 V, verifying that the TPE-based dyes of AIEE effect can be effectively applied in single-emitting- component WOLEDs fabrication.

  14. Nanoparticle-on-mirror cavity modes for huge and/or tunable plasmonic field enhancement

    Science.gov (United States)

    Huang, Yu; Ma, Lingwei; Li, Jianghao; Zhang, Zhengjun

    2017-03-01

    We present a careful numerical study of nanoparticle (NP) faceting, highlighting the great influence of small morphological changes of NP-mirror cavities on near-field enhancement in the nanoparticle-on-mirror (NPOM) system. Using a 3D finite element method (FEM) plasmon mapping method, the active transverse cavity modes can be confirmed. For the dominant mode, we have found that, by increasing the facet width, the resonance can be tuned linearly to the red with little decrease of the peak near-field intensity. It is further demonstrated that by increasing the NP size, the near-field intensity can be strongly enhanced. Understanding of such extreme optics benefits significantly both the optimized design of potential plasmonic devices and the fundamental understanding of nano-optics. Collaborative experimental considerations are expected with the rapid development of nanotechnology.

  15. Huge Differences in the Kinetics of Swelling Enhancement and De-enhancement of Permanently Charged Polyelectrolyte Brushes.

    Science.gov (United States)

    Chu, Xiao; Yang, Jingfa; Zhao, Jiang

    2016-10-06

    As demonstrated previously (X. Chu et al., Soft Matter 2014, 10, 5568), permanently charged polyelectrolyte brushes can experience an enhancement of swelling by exposure to an external monovalent salt solution in moderate concentrations. Beyond the previous static measurements, the kinetics of the swelling enhancement and de-enhancement were investigated in the current study by using a quartz crystal microbalance with dissipation (QCM-D). By developing an effective approach to quantify the response in QCM-D, a vast difference in swelling enhancement and de-enhancement of a model permanently charged polyelectrolyte brush (sodium polystyrene sulfonate, NaPSS) was discovered. The results indicate new physics of the charged brushes: the difference in the attachment and detachment of counterions to the polyelectrolyte chains.

  16. Magnetic field enhanced electroluminescence in organic light emitting diodes based on electron donor-acceptor exciplex blends

    Science.gov (United States)

    Baniya, Sangita; Basel, Tek; Sun, Dali; McLaughlin, Ryan; Vardeny, Zeev Valy

    2016-03-01

    A useful process for light harvesting from injected electron-hole pairs in organic light emitting diodes (OLED) is the transfer from triplet excitons (T) to singlet excitons (S) via reverse intersystem crossing (RISC). This process adds a delayed electro-luminescence (EL) emission component that is known as thermally activated delayed fluorescence (TADF). We have studied electron donor (D)/acceptor(A) blends that form an exciplex manifold in which the energy difference, ΔEST between the lowest singlet (S1) and triplet (T1) levels is relatively small (field of 50 mT at ambient. Moreover the MEL response is activated with activation energy similar that of the EL emission. This suggests that the large magneto-EL originates from an additional spin-mixing channel between singlet and triplet states of the generated exciplexes, which is due to TADF. We will report on the MEL dependencies on the temperature, bias voltage, and D-A materials for optimum OLED performance. Supported by SAMSUNG Global Research Outreach (GRO) program, and also by the NSF-Material Science & Engineering Center (MRSEC) program at the University of Utah (DMR-1121252).

  17. Enhanced DC-operated electroluminescence of forwardly aligned p/MQW/n InGaN nanorod LEDs via DC offset-AC dielectrophoresis.

    Science.gov (United States)

    Eo, Yun Jae; Yoo, Gang Yeol; Kang, Hyelim; Lee, Youngki; Kim, Chan Sik; Oh, Ji Hye; Lee, Keyong Nam; Kim, Woong; Do, Young Rag

    2017-10-11

    We introduce orientation-controlled alignment process of p-GaN/InGaN multi quantum-well/n-GaN (p/MQW/n InGaN) nanorod light-emitting diodes (LEDs) by applying direct-current (DC) offset alternating-current (AC) or pulsed DC electric fields across interdigitated metal electrodes. The as-forwardly aligned p/MQW/n InGaN nanorod LEDs by a pulsed DC dielectrophoresis (DEP) assembly process improve the electroluminescence (EL) intensities by 1.8 times compared to the conventional AC DEP assembly process under DC electric field operation and exhibit an enhanced applied current and EL brightness in the current-voltage and EL intensity-voltage curves that can be directly used as fundamental data to construct DC-operated nanorod LED devices, such as LED areal surface lightings, scalable lightings (micrometers to inches) and formable surface lightings. The enhancement of the applied current, the improved EL intensity, and the increased number of forwardly aligned p/MQW/n InGaN nanorods in panchromatic cathodoluminescence (CL) images confirm the considerable enhancement of forwardly aligned 1D nanorod LEDs between two opposite electrodes using DC offset-AC or a pulsed DC electric field DEP assembly process. These DC offset-AC or pulsed DC electric field DEP assembly process suggests that designing for these types of interactions could yield new ways to control the orientation of asymmetric p/MQW/n InGaN diode-type LED nanorods with a relatively low aspect ratio.

  18. Hybrid electroluminescent devices

    Science.gov (United States)

    Shiang, Joseph John; Duggal, Anil Raj; Michael, Joseph Darryl

    2010-08-03

    A hybrid electroluminescent (EL) device comprises at least one inorganic diode element and at least one organic EL element that are electrically connected in series. The absolute value of the breakdown voltage of the inorganic diode element is greater than the absolute value of the maximum reverse bias voltage across the series. The inorganic diode element can be a power diode, a Schottky barrier diode, or a light-emitting diode.

  19. Materials for Powder-Based AC-Electroluminescence

    Directory of Open Access Journals (Sweden)

    Hubert Schulze Dieckhoff

    2010-02-01

    Full Text Available At present, thick film (powder based alternating current electroluminescence (AC-EL is the only technology available for the fabrication of large area, laterally structured and coloured light sources by simple printing techniques. Substrates for printing may be based on flexible polymers or glass, so the final devices can take up a huge variety of shapes. After an introduction of the underlying physics and chemistry, the review highlights the technical progress behind this development, concentrating on luminescent and dielectric materials used. Limitations of the available materials as well as room for further improvement are also discussed.

  20. MANAGEMENT OF HUGE ENCEPHALOCELE

    Directory of Open Access Journals (Sweden)

    Rajeev

    2015-11-01

    Full Text Available Among all neural tube defects, encephalocele incidents are 1 in 5000 live births. (1 Newborn with encephalocele may be associated with other congenital malformations. Encephalocele patient’s management pose many challenge to neurosurgeon due to other associated anomalies that may present like ventriculocele, Dandy Walker and Arnold-Chiari malformation, and difficult positioning airway management to anaesthesiologist. We discuss a case of huge encephalocele and its management

  1. Fabrication of Green Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    高德青; 黄春辉; 奎热西; 刘凤琴

    2002-01-01

    A gadolinium ternary complex, tris(1-phenyl-3-methyl-4-isobutyryl-5-pyrazolone) (2, 2′-dipyridyl) gadolinium Gd(PMIP)3(Bipy) was synthesized and used as a light emitting material in the organic electroluminescent devices. The devices exhibited the green electroluminescent (EL) emission peaking at 513 nm, originating from the Gd(PMIP)3(Bipy). By improving the configuration, the device with a structure of ITO/poly(N-vinylcarbazole) (PVK) (40 nm)/Gd(PMIP)3(Bipy) (40 nm)/tris (8-hydroxyquinoline) aluminum (ALQ) (40 nm)/Mg∶Ag(200 nm)/Ag(100 nm) showed higher performance and a maximum luminance of 340 cd*m-2 at 18 V.

  2. Enhanced ultraviolet electroluminescence and spectral narrowing from ZnO quantum dots/GaN heterojunction diodes by using high-k HfO{sub 2} electron blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Xiaoming; Long, Hao; Wang, Haoning; Chen, Zhao; Wan, Jiawei; Liu, Yuping; Fang, Guojia, E-mail: gjfang@whu.edu.cn [Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Li, Songzhan [Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); School of Electronic and Electrical Engineering, Wuhan Textile University, Wuhan 430073 (China); Feng, Yamin [Department of Physics, Institute of Nanoscience and Nanotechnology, Central China Normal University, Wuhan 430079 (China); Ouyang, Yifang [College of Physical Science and Technology, Guangxi University, Nanning, Guangxi 530004 (China)

    2014-08-11

    We demonstrated the capability of realizing enhanced ZnO-related UV emissions by using the low-cost and solution-processable ZnO quantum dots (QDs) with the help of a high-k HfO{sub 2} electron blocking layer (EBL) for the ZnO QDs/p-GaN light-emitting diodes (LEDs). Full-width at half maximum of the LED devices was greatly decreased from ∼110 to ∼54 nm, and recombinations related to nonradiative centers were significantly suppressed with inserting HfO{sub 2} EBL. The electroluminescence of the ZnO QDs/HfO{sub 2}/p-GaN LEDs demonstrated an interesting spectral narrowing effect with increasing HfO{sub 2} thickness. The Gaussian fitting revealed that the great enhancement of the Zn{sub i}-related emission at ∼414 nm whereas the deep suppression of the interfacial recombination at ∼477 nm should be the main reason for the spectral narrowing effect.

  3. Electron Injection Enhancement by Diamond-Like Carbon Film in Polymer Electroluminescence Devices%聚合物电致发光器件中用类金刚石碳膜增强电子注入

    Institute of Scientific and Technical Information of China (English)

    李宏建; 闫玲玲; 黄伯云; 易丹青; 胡锦; 何英旋; 彭景翠

    2006-01-01

    A diamond-like carbon (DLC) film is deposited as an electron injection layer between the polymer light-emitting layer (MEH-PPV) and aluminum (Al) cathode electrode in polymer electroluminescence devices (PLEDs) using a radio frequency plasma deposition system. The source material of the DLC is n-butylamine. The devices consist of indium tin oxide (ITO)/MEH-PPV/DLC/Al. Electron injection properties are investigated through I-V characteristics, and the mechanism of electron injection enhancement due to a thin DLC layer has been studied. It is found that: (1) a DLC layer thinner than 1. 0nm leads to a higher turn-on voltage and decreased electroluminescent (EL) efficiency; (2) a 5.0nm DLC layer significantly enhances the electron injection and re sults in the lowest turn-on voltage and the highest EL efficiency; (3) DLC layer that exceeds 5.0nm results in poor device performance; and(4) EL emission can hardly be detected when the layer exceeds 10.0nm. The properties ofITO/MEH-PPV/DLC/Al and ITO/MEH-PPV/LiF/Al are investigated comparatively.%用正丁胺作碳源,采用射频辉光等离子系统制备类金刚石碳膜(DLC),沉积在聚合物发光器件中的发光层(MEH-PPV)和铝(Al)阴极间作电子注入层.制备了结构为ITO/MEH-PPV/DLC/Al的不同DLC厚度的器件,测量了器件的I-V特性、亮度及效率,研究了DLC层对器件电子注入性能影响的机制.结果表明:当DLC厚度小于1.0nm时,其器件有较ITO/MEH-PPV/Al高的启动电压和低的发光效率;当DLC厚度在1.0~5.0nm之间时,器件的性能随着DLC厚度增加而变好;当DLC厚度为5.0nm时,器件具有最低的启动电压与最高的发光效率;当DLC厚度继续增加时,器件的性能随着DLC厚度增加而变差.并对ITO/MEH-PPV/DLC/Al和ITO/MEH-PPV/LiF/Al的器件性能进行了比较研究.

  4. Photoluminescence and electroluminescence from Ge/strained GeSn/Ge quantum wells

    Science.gov (United States)

    Lin, Chung-Yi; Huang, Chih-Hsiung; Huang, Shih-Hsien; Chang, Chih-Chiang; Liu, C. W.; Huang, Yi-Chiau; Chung, Hua; Chang, Chorng-Ping

    2016-08-01

    Ge/strained GeSn/Ge quantum wells are grown on a 300 mm Si substrate by chemical vapor deposition. The direct bandgap emission from strained GeSn is observed in the photoluminescence spectra and is enhanced by Al2O3/SiO2 passivation due to the field effect. The electroluminescence of the direct bandgap emission of strained GeSn is also observed from the Ni/Al2O3/GeSn metal-insulator-semiconductor tunneling diodes. Electroluminescence is a good indicator of GeSn material quality, since defects in GeSn layers degrade the electroluminescence intensity significantly. At the accumulation bias, the holes in the Ni gate electrode tunnel to the strained n-type GeSn layer through the ultrathin Al2O3 and recombine radiatively with electrons. The emission wavelength of photoluminescence and electroluminescence can be tuned by the Sn content.

  5. A multilayer organic electroluminescent device using an organic dye salt

    Science.gov (United States)

    Feng, Xueyuan; Gu, Yongdi; Zhang, Jiayu; Cui, Yiping

    2005-01-01

    Organic electroluminescent devices have received considerable attention due to their application in flat-panel displays. To achieve full-color displays, it is necessary to obtain organic layers emitting red, green, and blue light, but it is still a challenge to obtain efficient and stable organic layer emitting red light so far. Recently, we found that an organic salt, trans-4-[p-[N-ethyl-N-(hydroxyethyl)amino]styryl]-N-methylphridinium tetraphenylborate (ASPT), exhibits efficient red-light emission. In this paper, we report a multilayer electrolumicescent device incorporating a hole-transport layer, an ASPT layer, and an electron-transport layer. The dependence of the carrier transport and the luminescence on the device structure is investigated in detail. Compared to the monolayer device, the balance between hole and electron injections is significantly improved for the multilayer device, and thus the electroluminescent efficiency and intensity are enhanced.

  6. Yellow-green electroluminescence of samarium complexes of 8-hydroxyquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Behzad, Sara Karimi; Najafi, Ezzatollah [Department of Chemistry Shahid Beheshti University G.C., Tehran 1983963113 (Iran, Islamic Republic of); Amini, Mostafa M., E-mail: m-pouramini@sbu.ac.ir [Department of Chemistry Shahid Beheshti University G.C., Tehran 1983963113 (Iran, Islamic Republic of); Janghouri, Mohammad; Mohajerani, Ezeddin [Laser Research Institute Shahid Beheshti University G.C., Tehran 1983963113 (Iran, Islamic Republic of); Ng, Seik Weng [Department of Chemistry, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-12-15

    Four novel samarium complexes were prepared by reacting samarium(III) nitrate with 8-hydroxyquinoline, 2-methyl-8-hydroxyquinoline, and 1,10-phenanthroline and utilized as emitting materials in the electroluminescence device. All complexes were characterized by elemental analysis, infrared, UV–vis and {sup 1}H NMR spectroscopes and the molecular structure of a representative complex, [Sm{sub 2}(Me-HQ){sub 4}(NO{sub 3}){sub 6}] (1), was determined by single-crystal X-ray diffraction. Utilization of a π-conjugated (phenanthroline) ligand as a second ligand in the structure of the samarium complexes resulted in red shifts in both absorption and fluorescence spectra of complexes and moderately enhanced the photoluminescence intensity and the fluorescence quantum yield. The maximum emission peaks showed that a good correlation exists between the nature of the substituent group on the 8-hydroxyquinoline and the addition of the π-conjugated ligand in the structure of samarium complexes and emission wavelength. Devices with samarium(III) complexes with structure of ITO/PEDOT:PSS (90 nm)/PVK:PBD:Sm(III) complexes (75 nm)/Al (180 nm) were fabricated. In the electroluminescence (EL) spectra of the devices, a strong ligand-centered emission and narrow bands arising from the {sup 4}G{sub 5/2}→{sup 6}H{sub J} transitions (J=7/2, 9/2, and 11/2) of the samarium ion were observed for the complexes. The electroluminescent spectra of the samarium complexes were red-shifted as compared with the PVK:PBD blend. We believe that the electroluminescence performance of OLED devices based on samarium complexes relies on overlaps between the absorption of the samarium compounds and the emission of PVK:PBD. This revealed that it is possible to evaluate the electroluminescence performance of the samarium compounds-doped OLED devices based on the emission of PVK:PBD and the absorption of the dopants. - Highlights: • Four novel photoluminescence samarium complexes have been synthesized.

  7. Electroluminescence in BaFCl single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Somaiah, K.; Paracchini, C.

    1987-06-01

    A study of electroluminescence in BaFCl single crystals as a function of temperature is reported. At an excitation voltage of 5 kV, electroluminescent intensity, which is feeble at room temperature, is shown to increase with decreasing temperature. The increase is rapid between 250 K and 175 K and levels off as 80 K is approached. A tentative explanation, in the light of x-ray induced luminescence, is offered. (U.K.).

  8. Electroluminescence of Si Nanocrystal-Doped SiO2

    Institute of Scientific and Technical Information of China (English)

    CHEN Dan; XIE Zhi-Qiang; WU Qian; ZHAO You-Yuan; LU Ming

    2007-01-01

    @@ We perform a comparative study on the electroluminescence (EL) and photoluminescence (PL) of Si nanocrystaldoped SiO2 (nc-Si:SiO2) and SiO2, and clarify whether the contribution from Si nanocrystals in the EL of nc-Si:SiO2 truly exists. The results unambiguously indicate the presence of EL of Si nanocrystals. The difference of peak positions between the EL and PL spectra are discussed. It is found that the normal method of passivation to enhance the PL of Si nanocrystals is not equally effective for the EL, hence new methods need to be explored to promote the EL of Si nanocrystals.

  9. Novel Mechano-Luminescent Sensors Based on Piezoelectric/Electroluminescent Composites

    Directory of Open Access Journals (Sweden)

    Yunzhang Fang

    2011-04-01

    Full Text Available A high-sensitivity mechano-luminescent sensor was fabricated on the basis of piezoelectric/electroluminescent composites. The working principle of this mechano-luminescent sensor was elucidated by analyzing the relationship between the piezoelectric-induced charges and the electroluminescent effects. When a stress is applied on the piezoelectric layer, electrical charges will be induced at both the top and bottom sides of the piezoelectric layer. The induced electrical charges will lead to a light output from the electroluminescent layer, thus producing a mechano-luminescence effect. By increasing the vibration strength or frequency applied, the mechano-luminescence output can be obviously enhanced. Mechano-luminescence sensors have potential in smart stress-to-light devices, such as foot-stress-distribution-diagnosis systems and dynamic-load-monitors for bridge hanging cables.

  10. Preparation of CdSe nanocrystals in organic system and electroluminescence characteristics of the devices

    Institute of Scientific and Technical Information of China (English)

    TANG Ai-wei; TENG Feng; GAO Yin-hao; LI Dan; LIANG Chun-jun; WANG Yong-sheng

    2006-01-01

    CdSe nanocrystals were prepared by a colloidal chemical approach using CdO and Se powder as precursors in an organic system of TOPO/TOP,and a multilayered electroluminescence device was fabricated with CdSe as emitting layer.The results show that the photoluminescence spectra of the CdSe nanocrystals almost cover the whole visible region and the full width at half maximum (FWHM) is appropriately 200 nm.The electroluminescence spectrum of the multilayered device at different voltages was investigated.The electroluminescence intensity is enhanced with increasing operating voltage,and the CIE coordinates of the device change from (0.34,0.37) at 6 V to (0.44,0.46)at 20 V as the operating voltage increases,which indicates that the colors of the device could be tuned by the operating voltage.

  11. Organic electroluminescent devices having improved light extraction

    Science.gov (United States)

    Shiang, Joseph John

    2007-07-17

    Organic electroluminescent devices having improved light extraction include a light-scattering medium disposed adjacent thereto. The light-scattering medium has a light scattering anisotropy parameter g in the range from greater than zero to about 0.99, and a scatterance parameter S less than about 0.22 or greater than about 3.

  12. A Stable Blue Organic Electroluminescent Material

    Institute of Scientific and Technical Information of China (English)

    郑新友; 吴有智; 等

    2002-01-01

    In order to compare two kinds of blue electroluminescent materials,we have investigated two kinds of blue OLEDs with the similar structure ITO/CuPc/NPB/JBEM:perylene/Alq/Mg:Ag[device(J)] and ITO/CuPc/NPB/DPVBi:perylene/Alq/Mg:Ag[device(D)].The difference of luminance and efficiency was not obvious for the two devices,However,there was remarkable difference for their lifetime.The device(J) achieved longer half lifetime of 1035h at initial luminance of 100 cd/m2,and that of device(D) was only255h,According to their energy level diagrams,the differentce of their stability may originate from different host materials in the two devices.It may be attributed to the better thermal stability of JBEM molecues than that of DPVBi.It is shown that JBEM may be a promising blue organic electroluminescent material with great stability.

  13. Organic Electroluminescent Sensor for Pressure Measurement

    Directory of Open Access Journals (Sweden)

    Tomohide Niimi

    2012-10-01

    Full Text Available We have proposed a novel concept of a pressure sensor called electroluminescent pressure sensor (ELPS based on oxygen quenching of electroluminescence. The sensor was fabricated as an organic light-emitting device (OLED with phosphorescent dyes whose phosphorescence can be quenched by oxygenmolecules, and with a polymer electrode which permeates oxygen molecules. The sensor was a single-layer OLED with Platinum (II octaethylporphine (PtOEP doped into poly(vinylcarbazole (PVK as an oxygen sensitive emissive layer and poly(3,4-ethylenedioxythiophene mixed with poly(styrenesulfonate (PEDOT:PSS as an oxygen permeating polymer anode. The pressure sensitivity of the fabricated ELPS sample was equivalent to that of the sensor excited by an illumination light source. Moreover, the pressure sensitivity of the sensor is equivalent to that of conventional pressure-sensitive paint (PSP, which is an optical pressure sensor based on photoluminescence.

  14. Electroluminescence of Copolyfluorenes in the Visible Range of the Spectrum

    Science.gov (United States)

    Kopylova, T. N.; Nikonova, E. N.; Nikonov, S. Yu.; Gadirov, R. M.; Telminov, E. N.; Degtyarenko, K. M.; Odod, A. V.; Yakimanskii, A. V.; Il'gach, D. M.

    2016-04-01

    Results of spectral-luminescent and electroluminescent investigations of organic semiconductor polyfluorenebased copolymers in diode devices emitting dark blue, green, red, and white light are presented.

  15. AC Electroluminescent Processes in Pr3+-Activated (Ba0.4Ca0.6TiO3 Diphase Polycrystals

    Directory of Open Access Journals (Sweden)

    Nan Gao

    2017-05-01

    Full Text Available We investigated the properties of alternating current (AC-driven electroluminescence from (Ba0.4Ca0.6TiO3:Pr3+ diphase polycrystal-based device. The results of crystal phases and micrographs, and the symmetrical dual emissions in one AC cycle, indicate the spontaneous formation of a dielectric/phosphor/dielectric sandwich microstructure in (Ba0.4Ca0.6TiO3:Pr3+. The electroluminescent device emits a red light of 617 nm, which is attributed to the 1D2-3H4 transition of Pr3+ in the phosphor phase. At a fixed AC frequency, the intensity of electroluminescence exhibits a steep enhancement when applying an increased driving electric field that is beyond a threshold. In a fixed driving electric field, the intensity of electroluminescence shows a rapid rise at low frequencies, but reaches saturation at high frequencies. Based on a double-injection model, we discussed systematically the electroluminescent processes in a whole cycle of AC electric field, which matched well with the experimental data. Our investigation is expected to expand our understanding of such a diphase electroluminescent device, thereby promoting their applications in lighting and displays.

  16. A rare clinic entity: Huge trichobezoar.

    Science.gov (United States)

    Hamidi, Hidayatullah; Muhammadi, Marzia; Saberi, Bismillah; Sarwari, Mohammad Arif

    2016-01-01

    Trichobezoar is a rare clinical entity in which a ball of hair amasses within the alimentary tract. It can either be found as isolated mass in the stomach or may extend into the intestine. Trichobezoars mostly occur in young females with psychiatric disorders such as trichophagia and trichotillomania. Authors present a giant trichobezoar in an 18year old female presented with complaints of upper abdominal mass, epigastric area pain, anorexia and weight loss. The patient underwent trans-abdominal ultrasonography (USG), Computed tomography (CT), upper gastrointestinal endoscopy and subsequently laparotomy. USG was inconclusive due to non-specific findings. It revealed a thick echogenic layer with posterior dirty shadowing extending from the left sub-diaphragmatic area to the right sub hepatic region obscuring the adjacent structures. Abdominal CT images revealed a huge, well defined, multi-layered, heterogeneous, solid appearing, non-enhancing mass lesion in the gastric lumen extending from the gastric fundus to the pyloric canal. An endoscopic attempt was performed for removal of this intraluminal mass, but due to its large size, and hard nature, the endoscopic removal was unsuccessful. Finally the large trichobezoar was removed with open laparotomy. Trichobezoars should be suspected in young females with long standing upper abdominal masses; as the possibility of malignancy is not very common in this age group. While USG is inconclusive, trichobezoar can be accurately diagnosed with CT. In patient with huge trichobezoar, laparotomy can be performed firstly because of big size and location of mass, and psychiatric recommendation should be made to prevent relapse of this entity. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Intelligent Classification in Huge Heterogeneous Data Sets

    Science.gov (United States)

    2015-06-01

    INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS JUNE 2015 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...To) JUL 2013 – APR 2015 4. TITLE AND SUBTITLE INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT...signals and through data dimension reduction, and to develop and tailor algorithms for the extraction of intelligence from several huge heterogeneous

  18. Imaging of huge lingual thyroid gland with goitre

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.C.; Chen, C.Y.; Chen, F.H.; Lee, G.W.; Hsiao, H.S. [Nat. Defense Medical Centre, Taipei (Taiwan, Province of China). Dept. of Diagnostic Radiol.; Zimmermann, R.A. [Department of Radiology, The Children`s Hospital of Philadelphia, 34th St. and Civic Blvd., Philadelphia, PA 19014 (United States)

    1998-05-01

    We present the CT and MRI findings in a 75-year-old woman with a huge pathologically proven lingual thyroid which underwent goitrous degeneration. CT and MRI showed a midline, tongue-based, exophytic mass with areas of necrosis and heterogeneous contrast enhancement, as seen in large goitres in the normal thyroid gland. (orig.) With 1 fig., 7 refs.

  19. Synthesis and Electroluminescence Characterization of Cadmium Complex

    Directory of Open Access Journals (Sweden)

    Rahulkumar

    2011-01-01

    Full Text Available We have synthesized and characterized a new electroluminescence material,Cadmium [(2-(2-hydroxyphenylbenzoxazole(8-hydoxyquinoline] Cd(HPBq. The absorption spectra of this material show maxima at 378 nm. It may be attributed due to π° – π* transition. The photoluminescence showed peak at 520 nm. TGA data of the material shows stability up to 370 °C .Organic light emitting diode have been fabricated with this material and the fundamental structures of the device is ITO/α-NPD/ Cd(HPBq/BCP/Alq3/LiF/Al exhibited a luminescence peak at 550 nm. The maximum luminescence of the device was 295 cd/m2 with current density of 6687 A/m2 at 20 V. The maximum current efficiency of OLED was 1.01 cd/A at 17 V and power efficiency was 1.01 lm/w at 17 V.

  20. Liquid crystalline networks for electroluminescent displays

    CERN Document Server

    Contoret, A E A

    2001-01-01

    This work presents the first low molar mass organic electroluminescent (EL) material to form a nematic glass and then emit plane-polarised light from the vitrified state on application of an electric field. Photocrosslinkable molecules are also discussed which form insoluble films on illumination with ultra-violet light. This approach combines the ease of deposition of small molecules with the robustness and stability of polymers, allowing simple fabrication of multi-layer EL devices and photo-patterning. A range of conjugated low molar-mass molecules are considered, containing the anthracene, perylene and fluorene cores, with the aims of producing a general recipe for efficient EL, based on ordered, stable nematics at room temperature. Many physical properties are compared and molecular mechanics modeling is used to represent molecular geometries. An acrylate and several diene photo-polymerisable derivatives of the fluorenes undergo photo-crosslinking. Infrared and photoluminescence spectroscopy is used to e...

  1. FIrpic: archetypal blue phosphorescent emitter for electroluminescence.

    Science.gov (United States)

    Baranoff, Etienne; Curchod, Basile F E

    2015-05-14

    FIrpic is the most investigated bis-cyclometallated iridium complex in particular in the context of organic light emitting diodes (OLEDs) because of its attractive sky-blue emission, high emission efficiency, and suitable energy levels. In this Perspective we review the synthesis, structural characterisations, and key properties of this emitter. We also survey the theoretical studies and summarise a series of selected monochromatic electroluminescent devices using FIrpic as the emitting dopant. Finally we highlight important shortcomings of FIrpic as an emitter for OLEDs. Despite the large body of work dedicated to this material, it is manifest that the understanding of photophysical and electrochemical processes are only broadly understood mainly because of the different environment in which these properties are measured, i.e., isolated molecules in solvent vs. device.

  2. Synthesis and electroluminescence properties of benzothiazole derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Fu Huiying [Department of Materials Science, Fudan University, Shanghai 200433 (China); Gao Xindong [State Key Laboratory of Applied Surface Physics, Fudan University, Shanghai 200433 (China); Zhong Gaoyu; Zhong Zhiyang [Department of Materials Science, Fudan University, Shanghai 200433 (China); Xiao Fei, E-mail: feixiao@fudan.edu.c [Department of Materials Science, Fudan University, Shanghai 200433 (China); Shao Bingxian [Department of Materials Science, Fudan University, Shanghai 200433 (China)

    2009-10-15

    Benzothiazole-based blue fluorescent materials N-(4-(benzo[d]thiazol-2-yl)phenyl)-N-phenylbenzenamine (BPPA) and N-(4-(benzo[d]thiazol-2-yl)phenyl)-N-phenylnaphthalen-1-amine (BPNA) were synthesized for use in organic light-emitting diodes (OLEDs). Electroluminescent device with a configuration of ITO/NPB/BPPA/BCP/Alq{sub 3}/LiF/Al showed a maximum brightness of 3760 cd/m{sup 2} at 14.4 V with the CIE coordinates of (0.16, 0.16). A current efficiency of 3.01 cd/A and an external quantum efficiency of 2.37% at 20 mA/cm{sup 2} were obtained from this device. Molecules derived from BPPA and BPNA with incorporated dicyanomethylidene, which is a functional group for most red fluorescent molecules, were designed, synthesized and characterized to study the red fluorescence properties of the benzothiazole derivatives.

  3. Huge ascending aortic aneurysm with an intraluminal thrombus in an embolic event-free patient.

    Science.gov (United States)

    Parato, Vito Maurizio; Prifti, Edvin; Pezzuoli, Franco; Labanti, Benedetto; Baboci, Arben

    2015-03-01

    We present a case of an 87-year-old male patient with a huge ascending aortic aneurysm, filled by a huge thrombus most probably due to previous dissection. This finding was detected by two-dimensional transthoracic echocardiography and contrast-enhanced computed tomography (CT) angiography scan. The patient refused surgical treatment and was medically treated. Despite the huge and mobile intraluminal thrombus, the patient remained embolic event-free up to 6 years later, and this makes the case unique.

  4. Outcome of Hepatectomy for Huge Hepatocellular Carcinoma.

    Science.gov (United States)

    Jo, Sungho

    2011-05-01

    In spite of the recent improved results of hepatectomy for huge hepatocellular carcinomas (HCC), the prognosis of patients with huge HCCs is still poor compared to that of patients with small HCCs. This study was performed to compare the results of hepatectomy between patients with huge HCCs and those with small HCCs, to identify the prognostic factors in patients with huge HCCs, and to determine the preoperative selection criteria. We retrospectively analyzed 51 patients who underwent hepatectomy, between July 1994 and February 2009 at Dankook University Hospital. Patients with HCC≥10 cm were classified in large (L) group and others were classified in small (S) group. The clinicopathological features, operative procedures, and postoperative outcome were compared between both groups and various prognostic factors were investigated in group L. Eleven patients were classified in group L. Tumor size, vascular invasion, and tumor stage were higher in group L. Postoperative morbidity was higher in group L, but mortality was not different between the groups. Disease-free survivals were significantly lower in group L than in group S (36.4%, and 24.2% vs. 72.0%, and 44.0% for 1- and 3-year), but overall survival rates were similar in both groups (45.5%, and 15.2% in group L vs. 60.3%, and 41.3% in group S for 3- and 5-year). Presence of satellite nodules was the only prognostic factor in multivariate analysis after surgery for huge HCC. Regardless of tumor size, huge HCCs deserve consideration for surgery in patients with preserved liver function. Furthermore, the effect of surgery could be maximized with appropriate selection criteria, such as huge HCC without satellite nodules.

  5. Connecting slow earthquakes to huge earthquakes.

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes.

  6. Connecting slow earthquakes to huge earthquakes

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-01

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes.

  7. Treatment strategies for huge central neurocytomas.

    Science.gov (United States)

    Xiong, Zhong-wei; Zhang, Jian-jian; Zhang, Ting-bao; Sun, Shou-jia; Wu, Xiao-lin; Wang, Hao; You, Chao; Wang, Yu; Zhang, Hua-qiu; Chen, Jin-cao

    2015-02-01

    Central neurocytomas (CNs), initially asymptomatic, sometimes become huge before detection. We described and analyzed the clinical, radiological, operational and outcome data of 13 cases of huge intraventricular CNs, and discussed the treatment strategies in this study. All huge CNs (n=13) in our study were located in bilateral lateral ventricle with diameter ≥5.0 cm and had a broad-based attachment to at least one side of the ventricle wall. All patients received craniotomy to remove the tumor through transcallosal or transcortical approach and CNs were of typical histologic and immunohistochemical features. Adjuvant therapies including conventional radiation therapy (RT) or gamma knife radiosurgery (GKRS) were also performed postoperatively. Transcallosal and transcortical approaches were used in 8 and 5 patients, respectively. Two patients died within one month after operation and 3 patients with gross total resection (GTR) were additionally given a decompressive craniectomy (DC) and/or ventriculoperitoneal shunt (VPS) as the salvage therapy. Six patients received GTR(+RT) and 7 patients received subtotal resection (STR)(+GKRS). Eight patients suffered serious complications such as hydrocephalus, paralysis and seizure after operation, and patients who underwent GTR showed worse functional outcome [less Karnofsky performance scale (KPS) scores] than those having STR(+GKRS) during the follow-up period. The clinical outcome of huge CNs seemed not to be favorable as that described in previous reports. Surgical resection for huge CNs should be meticulously considered to guarantee the maximum safety. Better results were achieved in STR(+GKRS) compared with GTR(+RT) for huge CNs, suggesting that STR(+GKRS) may be a better treatment choice. The recurrent or residual tumor can be treated with GKRS effectively.

  8. Analysis of power supply circuits for electroluminescent panels

    Science.gov (United States)

    Drumea, Andrei; Dobre, Robert Alexandru

    2016-12-01

    The electroluminescent panel is a light emitting device that requires for normal operations alternative voltages with peak to peak amplitudes in 100V… 300V range and frequencies in 100Hz … 2 kHz range. Its advantages, when compared with standard light sources like incandescent lamps, gas-discharge lamps or light emitting diodes (LEDs), are lower power consumption, flexible substrate and uniform light without observable luminous points. One disadvantage of electroluminescent panels is the complex power supply required to drive them, but the continuous improvement in passive and active integrated devices for switched mode power supplies will eventually solve this issue. The present paper studies different topologies for these power supplies and the effect of the electric parameters like the amplitude, frequency, waveform of the supplying voltage on the light emission and on power consumption for electroluminescent panels with different size and colors.

  9. Electroluminescent, polycrystalline cadmium selenide nanowire arrays.

    Science.gov (United States)

    Ayvazian, Talin; van der Veer, Wytze E; Xing, Wendong; Yan, Wenbo; Penner, Reginald M

    2013-10-22

    Electroluminescence (EL) from nanocrystalline CdSe (nc-CdSe) nanowire arrays is reported. The n-type, nc-CdSe nanowires, 400-450 nm in width and 60 nm in thickness, were synthesized using lithographically patterned nanowire electrodeposition, and metal-semiconductor-metal (M-S-M) devices were prepared by the evaporation of two gold contacts spaced by either 0.6 or 5 μm. These M-S-M devices showed symmetrical current voltage curves characterized by currents that increased exponentially with applied voltage bias. As the applied biased was increased, an increasing number of nanowires within the array "turned on", culminating in EL emission from 30 to 50% of these nanowires at applied voltages of 25-30 V. The spectrum of the emitted light was broad and centered at 770 nm, close to the 1.74 eV (712 nm) band gap of CdSe. EL light emission occurred with an external quantum efficiency of 4 × 10(-6) for devices with a 0.60 μm gap between the gold contacts and 0.5 × 10(-6) for a 5 μm gap-values similar to those reported for M-S-M devices constructed from single-crystalline CdSe nanowires. Kelvin probe force microscopy of 5 μm nc-CdSe nanowire arrays showed pronounced electric fields at the gold electrical contacts, coinciding with the location of strongest EL light emission in these devices. This electric field is implicated in the Poole-Frenkel minority carrier emission and recombination mechanism proposed to account for EL light emission in most of the devices that were investigated.

  10. Progress and Prospects in Stretchable Electroluminescent Devices

    Science.gov (United States)

    Wang, Jiangxin; Lee, Pooi See

    2017-03-01

    Stretchable electroluminescent (EL) devices are a new form of mechanically deformable electronics that are gaining increasing interests and believed to be one of the essential technologies for next generation lighting and display applications. Apart from the simple bending capability in flexible EL devices, the stretchable EL devices are required to withstand larger mechanical deformations and accommodate stretching strain beyond 10%. The excellent mechanical conformability in these devices enables their applications in rigorous mechanical conditions such as flexing, twisting, stretching, and folding.The stretchable EL devices can be conformably wrapped onto arbitrary curvilinear surface and respond seamlessly to the external or internal forces, leading to unprecedented applications that cannot be addressed with conventional technologies. For example, they are in demand for wide applications in biomedical-related devices or sensors and soft interactive display systems, including activating devices for photosensitive drug, imaging apparatus for internal tissues, electronic skins, interactive input and output devices, robotics, and volumetric displays. With increasingly stringent demand on the mechanical requirements, the fabrication of stretchable EL device is encountering many challenges that are difficult to resolve. In this review, recent progresses in the stretchable EL devices are covered with a focus on the approaches that are adopted to tackle materials and process challenges in stretchable EL devices and delineate the strategies in stretchable electronics. We first introduce the emission mechanisms that have been successfully demonstrated on stretchable EL devices. Limitations and advantages of the different mechanisms for stretchable EL devices are also discussed. Representative reports are reviewed based on different structural and material strategies. Unprecedented applications that have been enabled by the stretchable EL devices are reviewed. Finally, we

  11. Progress and Prospects in Stretchable Electroluminescent Devices

    Directory of Open Access Journals (Sweden)

    Wang Jiangxin

    2017-03-01

    Full Text Available Stretchable electroluminescent (EL devices are a new form of mechanically deformable electronics that are gaining increasing interests and believed to be one of the essential technologies for next generation lighting and display applications. Apart from the simple bending capability in flexible EL devices, the stretchable EL devices are required to withstand larger mechanical deformations and accommodate stretching strain beyond 10%. The excellent mechanical conformability in these devices enables their applications in rigorous mechanical conditions such as flexing, twisting, stretching, and folding.The stretchable EL devices can be conformably wrapped onto arbitrary curvilinear surface and respond seamlessly to the external or internal forces, leading to unprecedented applications that cannot be addressed with conventional technologies. For example, they are in demand for wide applications in biomedical-related devices or sensors and soft interactive display systems, including activating devices for photosensitive drug, imaging apparatus for internal tissues, electronic skins, interactive input and output devices, robotics, and volumetric displays. With increasingly stringent demand on the mechanical requirements, the fabrication of stretchable EL device is encountering many challenges that are difficult to resolve. In this review, recent progresses in the stretchable EL devices are covered with a focus on the approaches that are adopted to tackle materials and process challenges in stretchable EL devices and delineate the strategies in stretchable electronics. We first introduce the emission mechanisms that have been successfully demonstrated on stretchable EL devices. Limitations and advantages of the different mechanisms for stretchable EL devices are also discussed. Representative reports are reviewed based on different structural and material strategies. Unprecedented applications that have been enabled by the stretchable EL devices are

  12. 不同密度银纳米粒子对氧化锌基发光二极管发光的增强%Localized Surface Plasmon Resonance Enhanced Electroluminescence from ZnO-based Light-emitting Diodes via Optimizing The Density of Sliver Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    乔倩; 单崇新; 刘娟意; 陶丽芳; 王瑞; 张存喜; 李炳辉; 申德振

    2015-01-01

    Localized surface plasmon resonance enhanced n-ZnO/i-ZnO/MgO/p-GaN heterostruc-ture light-emitting diodes ( LEDs) with different sliver nanoparticles ( Ag NPs) density were fabrica-ted using molecular-beam epitaxy technique. It is found that the introduction of Ag NPs with suitable density is favorable for the effective resonant coupling between excitons in ZnO and the localized sur-face plasmons of Ag NPs, and thereby significantly improves the electroluminescence ( EL) perform-ance of the device. Note that the enhancement ratio increases firstly with the Ag NPs density and then decreases, and the variation is believed to be resulted from balance between the enhancement caused by the resonant coupling between the excitons in ZnO and the localized surface plasmons of Ag NPs and the extinction of the emitted photons by the Ag NPs.%采用分子束外延法制备不同密度的银纳米粒子( Ag NPs)修饰的局域表面等离子体共振增强n-ZnO/i-ZnO/MgO/p-GaN 异质结发光二极管( LEDs),并对其电学及光学性质进行表征。结果显示:LEDs中引入适当浓度的Ag NPs有利于Ag NPs局域表面等离子体激元与ZnO激子相耦合,可以显著提高器件的电致发光性能;随着Ag NPs浓度的增加,LEDs发光增强倍数先增大后减小,分析认为这是Ag NPs局域表面等离子体共振耦合增强过程和Ag NPs的消光过程两者之间相互博弈而导致的结果。

  13. A Huge Ancient Schwannoma of the Epiglottis.

    Science.gov (United States)

    Lee, Dong Hoon; Kim, Jo Heon; Yoon, Tae Mi; Lee, Joon Kyoo; Lim, Sang Chul

    2016-03-01

    Ancient schwannoma of the epiglottis is extremely rare. The authors report the first case of a patient with a huge ancient schwannoma of the epiglottis. Clinicians should consider the possibility that ancient schwannoma may originate in the epiglottis mimicking the other more frequently observed lesions.

  14. On the spectral difference between electroluminescence and photoluminescence of Si nanocrystals: a mechanism study of electroluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dong-Chen; Chen, Jia-Rong; Zhu, Jiang; Lu, Chen-Tian; Lu, Ming, E-mail: minglu@fudan.ac.cn [Fudan University, Department of Optical Science and Engineering, and Shanghai Ultra-Precision Optical Manufacturing Engineering Center (China)

    2013-11-15

    Spectral shift, especially blueshift, in peak position of electroluminescence (EL) spectrum of Si nanocrystal (Si-nc) with respect to its photoluminescence (PL) counterpart has been often observed. Explanations for the spectral difference are different for different EL mechanisms adopted. To gain a relevant picture of the EL process, in this work, we analyze three EL mechanisms that are mainly applied nowadays, i.e., the model of defect light emission, that of band-filling, and that of Si-nc size selection by the carrier energy. Different Si-nc samples and working conditions are designed and their EL and PL emissions monitored according to the predictions of the three models. It is concluded that the observed EL is mainly of Si-nc-related origin. The experimental results are more consistent with the model of Si-nc size selection.

  15. Automatic Detection of Inactive Solar Cell Cracks in Electroluminescence Images

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    2017-01-01

    We propose an algorithm for automatic determination of the electroluminescence (EL) signal threshold level corresponding to inactive solar cell cracks, resulting from their disconnection from the electrical circuit of the cell. The method enables automatic quantification of the cell crack size...

  16. A huge presacral Tarlov cyst. Case report.

    Science.gov (United States)

    Ishii, Kazuhiko; Yuzurihara, Masahito; Asamoto, Shunji; Doi, Hiroshi; Kubota, Motoo

    2007-08-01

    Perineural cysts have become a common incidental finding during lumbosacral magnetic resonance (MR) imaging. Only some of the symptomatic cysts warrant treatment. The authors describe the successful operative treatment of a patient with, to the best of their knowledge, the largest perineural cyst reported to date. A 29-year-old woman had been suffering from long-standing constipation and low-back pain. During an obstetric investigation for infertility, the clinician discovered a huge presacral cystic mass. Computed tomography myelography showed the lesion to be a huge Tarlov cyst arising from the left S-3 nerve root and compressing the ipsilateral S-2 nerve. The cyst was successfully treated by ligation of the cyst neck together with sectioning of the S-3 nerve root. Postoperative improvement in her symptoms and MR imaging findings were noted. Identification of the nerve root involved by the cyst wall, operative indication, operative procedure, and treatment of multiple cysts are important preoperative considerations.

  17. From tiny microalgae to huge biorefineries

    OpenAIRE

    Gouveia, L.

    2014-01-01

    Microalgae are an emerging research field due to their high potential as a source of several biofuels in addition to the fact that they have a high-nutritional value and contain compounds that have health benefits. They are also highly used for water stream bioremediation and carbon dioxide mitigation. Therefore, the tiny microalgae could lead to a huge source of compounds and products, giving a good example of a real biorefinery approach. This work shows and presents examples of experimental...

  18. A rare clinic entity: Huge trichobezoar

    Directory of Open Access Journals (Sweden)

    Hidayatullah Hamidi, Dr, MD

    2016-01-01

    Conclusion: Trichobezoars should be suspected in young females with long standing upper abdominal masses; as the possibility of malignancy is not very common in this age group. While USG is inconclusive, trichobezoar can be accurately diagnosed with CT. In patient with huge trichobezoar, laparotomy can be performed firstly because of big size and location of mass, and psychiatric recommendation should be made to prevent relapse of this entity.

  19. Laparoscopic Management of Huge Cervical Myoma.

    Science.gov (United States)

    Peker, Nuri; Gündoğan, Savaş; Şendağ, Fatih

    To demonstrate the feasibility of laparoscopic management of a huge cervical myoma. Step-by-step video demonstration of the surgical procedure (Canadian Task Force classification III-C). Uterine myoma is the most common benign neoplasm of the female reproductive tract, with an estimated incidence of 25% to 30% at reproductive age [1,2]. Patients generally have no symptoms; however, those with such symptoms as severe pelvic pain, heavy uterine bleeding, or infertility may be candidates for surgery. The traditional management is surgery; however, uterine artery embolization or hormonal therapy using a gonadotropin-releasing hormone agonist or a selective estrogen receptor modulator should be preferred as the medical approach. Surgical management should be performed via laparoscopy or laparotomy; however, the use of laparoscopic myomectomy is being debated for patients with huge myomas. Difficulties in the excision, removal, and repair of myometrial defects, increased operative time, and blood loss are factors keeping physicians away from laparoscopic myomectomy [1,2]. A 40-year-old gravida 0, para 0 woman was admitted to our clinic with complaints of chronic pelvic pain, dyspareunia, and infertility. Her health history was unremarkable. Ultrasonographic examination revealed a 14 × 10-cm myoma in the cervical region. On bimanual examination, an immobile solid mass originating from the uterine cervix and filling the pouch of Douglas was palpated. The patient was informed of the findings, and laparoscopic myomectomy was recommended because of her desire to preserve her fertility. Abdominopelvic examination revealed a huge myoma filling and enlarging the cervix. Myomectomy was performed using standard technique as described elsewhere. A transverse incision was made using a harmonic scalpel. The myoma was fixed with a corkscrew manipulator and enucleated. Once bleeding was controlled, the myoma bed was filled with Spongostan to prevent possible bleeding from leakage

  20. Huge music archives on mobile devices

    DEFF Research Database (Denmark)

    Blume, H.; Bischl, B.; Botteck, M.

    2011-01-01

    The availability of huge nonvolatile storage capacities such as flash memory allows large music archives to be maintained even in mobile devices. With the increase in size, manual organization of these archives and manual search for specific music becomes very inconvenient. Automated dynamic...... and difficult to tackle on mobile platforms. Against this background, we provided an overview of algorithms for music classification as well as their computation times and other hardware-related aspects, such as power consumption on various hardware architectures. For mobile platforms such as smartphones...

  1. A New Kind of Blue Hybrid Electroluminescent Device.

    Science.gov (United States)

    Wang, Junling; Li, Zhuan; Liu, Chunmei

    2016-04-01

    Bright blue Electroluminescence come from a ITO/BBOT doped silica (6 x 10(-3) M) made by a sol-gel method/Al driven by AC with 500 Hz at different voltages and Gaussian analysis under 55 V showed that blue emission coincidenced with typical triple emission from BBOT. This kind of device take advantage of organics (BBOT) and inorganics (silica). Electroluminescence from a single-layered sandwiched device consisting of blue fluorescent dye 2,5-bis (5-tert-butyl-2-benzoxazolyl) thiophene (BBOT) doped silica made by sol-gel method was investigated. A number of concentrations of hybrid devices were prepared and the maxium concentration was 6 x 10(-3) M. Blue electroluminescent (EL) always occurred above a threshold field 8.57 x 10(5) V/cm (30 V) at alternating voltage at 500 HZ. The luminance of the devices increased with the concentration of doped BBOT, but electroluminescence characteristics were different from a single molecule's photoluminescence properties of triple peaks. When analyzing in detail direct-current electroluminescence devices of pure BBOT, a single peak centered at 2.82 eV appeared with the driven voltage increase, which is similar to the hybrid devices. Comparing Gaussian decomposition date between two kinds of devices, the triple peak characteristic of BBOT was consistent. It is inferred that BBOT contributed EL of the hybrid devices mainly and silica may account for a very small part. Meanwhile the thermal stability of matrix silica was measured by Thermal Gravity-Mass Spectroscopy (TG-MS). There is 12 percent weight loss from room temperature to 1000 °C and silica has about 95% transmittance. So the matric silica played an important role in thermal stability and optical stability for BBOT. In addition, this kind of blue electroluminescence device can take advantages of organic materials BBOT and inorganic materials silica. This is a promising way to enrich EL devices, especially enriching inorganic EL color at a low cost.

  2. Laparoscopic Management of Huge Myoma Nascendi.

    Science.gov (United States)

    Peker, Nuri; Gündoğan, Savas; Şendağ, Fatih

    To demonstrate the feasibility of laparoscopic management of a huge myoma nascendi. Step-by-step video demonstration of the surgical procedure (Canadian Task Force classification III-C). Uterine myoma is the most common benign neoplasm of the female reproductive tract, with an estimated incidence of 25% to 30% at reproductive age [1,2]. Patients generally have no symptoms; however, those with such symptoms as severe pelvic pain, heavy uterine bleeding, or infertility may be candidates for surgery. The traditional management is surgery; however, uterine artery embolization or hormonal therapy using a gonadotropin-releasing hormone agonist or a selective estrogen receptor modulator should be preferred as the medical approach. Surgical management should be performed via laparoscopy or laparotomy; however, the use of laparoscopic myomectomy is being debated for patients with huge myomas. Difficulties in the excision, removal, and repair of myometrial defects, increased operative time, and blood loss are factors keeping physicians away from laparoscopic myomectomy [1,2]. A 35-year-old woman was admitted to our clinic with complaints of chronic pelvic pain and heavy menstrual bleeding. Her medical history included multiple hospitalizations for blood transfusions, along with a recently measured hemoglobin level of 9.5 g/dL and a hematocrit value of 29%. She had never been married and had no children. Pelvic ultrasonography revealed a 12 × 10-cm uterine myoma located on the posterior side of the corpus uteri and protruding through to the cervical channel. This was a huge intramural submucous myoma in close proximity to the endometrial cavity and spreading through the myometrium. On vaginal examination, the myoma was found to extend into the vagina through the cervical channel. Laparoscopic myomectomy was planned because of the patient's desire for fertility preservation. Abdominopelvic exploration revealed a huge myoma filling the posterior side of the corpus uteri and

  3. Direct observation of bubble-assisted electroluminescence in liquid xenon

    CERN Document Server

    Erdal, E; Chepel, V; Rappaport, M L; Vartsky, D; Breskin, A

    2015-01-01

    Bubble formation in liquid xenon underneath a Thick Gaseous Electron Multiplier (THGEM) electrode immersed in liquid xenon was observed with a CCD camera. With voltage across the THGEM, the appearance of bubbles was correlated with that of electroluminescence signals induced by ionization electrons from alpha-particle tracks. This confirms recent indirect evidence that the observed photons are due to electroluminescence within a xenon vapor layer trapped under the electrode. The bubbles seem to emerge spontaneously due to heat flow from 300K into the liquid, or in a controlled manner, by locally boiling the liquid with resistive wires. Controlled bubble formation resulted in energy resolution of {\\sigma}/E~7.5% for ~6,000 ionization electrons. The phenomenon could pave ways towards the conception of large-volume 'local dual-phase' noble-liquid TPCs.

  4. Liquid Hole Multipliers: bubble-assisted electroluminescence in liquid xenon

    CERN Document Server

    Arazi, L; Coimbra, A E C; Rappaport, M L; Vartsky, D; Chepel, V; Breskin, A

    2015-01-01

    In this work we discuss the mechanism behind the large electroluminescence signals observed at relatively low electric fields in the holes of a Thick Gas Electron Multiplier (THGEM) electrode immersed in liquid xenon. We present strong evidence that the scintillation light is generated in xenon bubbles trapped below the THGEM holes. The process is shown to be remarkably stable over months of operation, providing - under specific thermodynamic conditions - energy resolution similar to that of present dual-phase liquid xenon experiments. The observed mechanism may serve as the basis for the development of Liquid Hole Multipliers (LHMs), capable of producing local charge-induced electroluminescence signals in large-volume single-phase noble-liquid detectors for dark matter and neutrino physics experiments.

  5. Quantifying Solar Cell Cracks in Photovoltaic Modules by Electroluminescence Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso; Glick, Stephen; Kerekes, Tamas; Teodorescu, Remus

    2015-06-14

    This article proposes a method for quantifying the percentage of partially and totally disconnected solar cell cracks by analyzing electroluminescence images of the photovoltaic module taken under high- and low-current forward bias. The method is based on the analysis of the module's electroluminescence intensity distribution, applied at module and cell level. These concepts are demonstrated on a crystalline silicon photovoltaic module that was subjected to several rounds of mechanical loading and humidity-freeze cycling, causing increasing levels of solar cell cracks. The proposed method can be used as a diagnostic tool to rate cell damage or quality of modules after transportation. Moreover, the method can be automated and used in quality control for module manufacturers, installers, or as a diagnostic tool by plant operators and diagnostic service providers.

  6. Passive Matrix Organic Electroluminescent Display for 3G Cellular Phone

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The major features of the display technologies for 3G cellular phone are reviewed. The comparison between their potential candidates for 3G cellular phone is given, and a detailed discussion is made on passive matrix organic electroluminescent display technology. A novel method to improve display contrast ratio is presented. Finally several 3G phone set prototypes with OLED display panels are given as well as the market forecast

  7. Study on electroluminescence from porous silicon light-emitting diode

    Institute of Scientific and Technical Information of China (English)

    Yajun Yang; Qingshan Li; Xianyun Liu

    2006-01-01

    @@ Porous silicon (PS) light-emitting diode (LED) with an ITO/PS/p-Si/Al structure was fabricated by anodic oxidation method. Photoluminescence (PL) of the PS LED was measured with a peak at 593 nm, and electroluminescence (EL) was measured with a peak at 556 nm under the conditions of 7.5-V forward bias and 210-mA current intensity. The spectral width of EL was measured to be about 160 nm.

  8. Huge Tongue Lipoma: A Case Report

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Damghani

    2015-03-01

    Full Text Available Introduction: Lipomas are among the most common tumors of the human body. However, they are uncommon in the oral cavity and are observed as slow growing, painless, and asymptomatic yellowish submucosal masses. Surgical excision is the treatment of choice and recurrence is not expected.    Case Report: The case of a 30-year-old woman with a huge lipoma on the tip of her tongue since 3 years, is presented. She had difficulty with speech and mastication because the tongue tumor was filling the oral cavity. Clinical examination revealed a yellowish lesion, measuring 8 cm in maximum diameter, protruding from the lingual surface. The tumor was surgically excised with restoration of normal tongue function and histopathological examination of the tumor confirmed that it was a lipoma.   Conclusion:  Tongue lipoma is rarely seen and can be a cause of macroglossia. Surgical excision for lipoma is indicated for symptomatic relief and exclusion of associated malignancy.

  9. Galaxies Collide to Create Hot, Huge Galaxy

    Science.gov (United States)

    2009-01-01

    This image of a pair of colliding galaxies called NGC 6240 shows them in a rare, short-lived phase of their evolution just before they merge into a single, larger galaxy. The prolonged, violent collision has drastically altered the appearance of both galaxies and created huge amounts of heat turning NGC 6240 into an 'infrared luminous' active galaxy. A rich variety of active galaxies, with different shapes, luminosities and radiation profiles exist. These galaxies may be related astronomers have suspected that they may represent an evolutionary sequence. By catching different galaxies in different stages of merging, a story emerges as one type of active galaxy changes into another. NGC 6240 provides an important 'missing link' in this process. This image was created from combined data from the infrared array camera of NASA's Spitzer Space Telescope at 3.6 and 8.0 microns (red) and visible light from NASA's Hubble Space Telescope (green and blue).

  10. Quantitative structure-property relationships of electroluminescent materials: Artificial neural networks and support vector machines to predict electroluminescence of organic molecules

    Indian Academy of Sciences (India)

    Alana Fernandes Golin; Ricardo Stefani

    2013-12-01

    Electroluminescent compounds are extensively used as materials for application in OLED. In order to understand the chemical features related to electroluminescence of such compounds, QSPR study based on neural network model and support vector machine was developed on a series of organic compounds commonly used in OLED development. Radial-basis function-SVM model was able to predict the electroluminescence with good accuracy ( = 0.90). Moreover, RMSE of support vector machine model is approximately half of RMSE observed for artificial neural networks model, which is significant from the point of view of model precision, as the dataset is very small. Thus, support vector machine is a good method to build QSPR models to predict the electroluminescence of materials when applied to small datasets. It was observed that descriptors related to chemical bonding and electronic structure are highly correlated with electroluminescence properties. The obtained results can help in understating the structural features related to the electroluminescence, and supporting the development of new electroluminescent materials.

  11. Room temperature direct-bandgap electroluminescence from a horizontal Ge ridge waveguide on Si

    Science.gov (United States)

    He, Chao; Liu, Zhi; Cheng, Bu-Wen

    2016-12-01

    We report a lateral Ge-on-Si ridge waveguide light emitting diode (LED) grown by ultrahigh vacuum chemical vapor deposition (UHV-CVD). Direct-bandgap electroluminescence (EL) of Ge waveguide under continuous current is observed at room temperature. The heat-enhancing luminescence and thermal radiation-induced superlinear increase of edge output optical power are found. The spontaneous emission and thermal radiation based on the generalized Planck radiation law are calculated and fit very well to the experimental results. The Ge waveguides with different lengths are studied and the shorter one shows stronger EL intensity. Project supported by the National Basic Research Program of China (Grant No. 2013CB632103), the National Natural Science Foundation of China (Grant Nos. 61176013 and 61036003), and the Science Fund from Beijing Science and Technology Commission, China (Grant No. Z151100003315019).

  12. Two-phase Cryogenic Avalanche Detector with electroluminescence gap operated in argon doped with nitrogen

    CERN Document Server

    Bondar, A; Dolgov, A; Nosov, V; Shekhtman, L; Shemyakina, E; Sokolov, A

    2016-01-01

    A two-phase Cryogenic Avalanche Detector (CRAD) with electroluminescence (EL) gap, operated in argon doped with a minor (49$\\pm$7 ppm) admixture of nitrogen, has been studied. The EL gap was optically read out using cryogenic PMTs located on the perimeter of the gap. We present the results of the measurements of the N$_2$ content, detector sensitivity to X-ray-induced signals, EL gap yield and electron lifetime in the liquid. The detector sensitivity, at a drift field in liquid Ar of 0.6 kV/cm, was measured to be 9 and 16 photoelectrons recorded at the PMTs per keV of deposited energy at 23 and 88 keV respectively. Such two-phase detectors, with enhanced sensitivity to the S2 (ionization-induced) signal, are relevant in the field of argon detectors for dark matter search and low energy neutrino detection.

  13. Two-phase Cryogenic Avalanche Detector with electroluminescence gap operated in argon doped with nitrogen

    Science.gov (United States)

    Bondar, A.; Buzulutskov, A.; Dolgov, A.; Nosov, V.; Shekhtman, L.; Shemyakina, E.; Sokolov, A.

    2017-02-01

    A two-phase Cryogenic Avalanche Detector (CRAD) with electroluminescence (EL) gap, operated in argon doped with a minor (49±7 ppm) admixture of nitrogen, has been studied. The EL gap was optically read out using cryogenic PMTs located on the perimeter of the gap. We present the results of the measurements of the N2 content, detector sensitivity to X-ray-induced signals, EL gap yield and electron lifetime in the liquid. The detector sensitivity, at a drift field in liquid Ar of 0.6 kV/cm, was measured to be 9 and 16 photoelectrons recorded at the PMTs per keV of deposited energy at 23 and 88 keV respectively. Such two-phase detectors, with enhanced sensitivity to the S2 (ionization-induced) signal, are relevant in the field of argon detectors for dark matter search and low energy neutrino detection.

  14. HUBBLE SPIES HUGE CLUSTERS OF STARS FORMED

    Science.gov (United States)

    2002-01-01

    BY ANCIENT ENCOUNTER This stunningly beautiful image [right] taken with the NASA Hubble Space Telescope shows the heart of the prototypical starburst galaxy M82. The ongoing violent star formation due to an ancient encounter with its large galactic neighbor, M81, gives this galaxy its disturbed appearance. The smaller picture at upper left shows the entire galaxy. The image was taken in December 1994 by the Kitt Peak National Observatory's 0.9-meter telescope. Hubble's view is represented by the white outline in the center. In the Hubble image, taken by the Wide Field and Planetary Camera 2, the huge lanes of dust that crisscross M82's disk are another telltale sign of the flurry of star formation. Below the center and to the right, a strong galactic wind is spewing knotty filaments of hydrogen and nitrogen gas. More than 100 super star clusters -- very bright, compact groupings of about 100,000 stars -- are seen in this detailed Hubble picture as white dots sprinkled throughout M82's central region. The dark region just above the center of the picture is a huge dust cloud. A collaboration of European and American scientists used these clusters to date the ancient interaction between M82 and M81. About 600 million years ago, a region called 'M82 B' (the bright area just below and to the left of the central dust cloud) exploded with new stars. Scientists have discovered that this ancient starburst was triggered by the violent encounter with M81. M82 is a bright (eighth magnitude), nearby (12 million light-years from Earth) galaxy in the constellation Ursa Major (the Great Bear). The Hubble picture was taken Sept. 15, 1997. The natural-color composite was constructed from three Wide Field and Planetary Camera 2 exposures, which were combined in chromatic order: 4,250 seconds through a blue filter (428 nm); 2,800 seconds through a green filter (520 nm); and 2,200 seconds through a red (820 nm) filter. Credits for Hubble image: NASA, ESA, R. de Grijs (Institute of

  15. Electroluminescence and cathodoluminescence from polyethylene and polypropylene films: Spectra reconstruction from elementary components and underlying mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, B. [Université de Toulouse, UPS, INP, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse (France); Teyssedre, G.; Laurent, C. [Université de Toulouse, UPS, INP, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse (France); CNRS, LAPLACE, F-31062 Toulouse (France)

    2016-01-14

    The mechanisms of electroluminescence from large band gap polymers used as insulation in electric components are still under debate. It becomes important to unravel the underlying physics of the emission because of increasing thermo-electric stress and a possible relationship between electroluminescence and field withstand. We report herein on the cathodoluminescence spectra of polyethylene and polypropylene films as a way to uncover the nature of its contributions to electroluminescence emission. It is shown that spectra from the two materials are structured around four elementary components, each of them being associated with a specific process contributing to the overall emission with different weights depending on excitation conditions and on materials. The cathodoluminescence and electroluminescence spectra of each material are reconstructed from the four spectral components and their relative contribution are discussed. It is shown that electroluminescence from polyethylene and polypropylene has the same origin pointing towards generic mechanisms in both.

  16. Electroluminescence and cathodoluminescence from polyethylene and polypropylene films: Spectra reconstruction from elementary components and underlying mechanisms

    Science.gov (United States)

    Qiao, B.; Teyssedre, G.; Laurent, C.

    2016-01-01

    The mechanisms of electroluminescence from large band gap polymers used as insulation in electric components are still under debate. It becomes important to unravel the underlying physics of the emission because of increasing thermo-electric stress and a possible relationship between electroluminescence and field withstand. We report herein on the cathodoluminescence spectra of polyethylene and polypropylene films as a way to uncover the nature of its contributions to electroluminescence emission. It is shown that spectra from the two materials are structured around four elementary components, each of them being associated with a specific process contributing to the overall emission with different weights depending on excitation conditions and on materials. The cathodoluminescence and electroluminescence spectra of each material are reconstructed from the four spectral components and their relative contribution are discussed. It is shown that electroluminescence from polyethylene and polypropylene has the same origin pointing towards generic mechanisms in both.

  17. Electroluminescence of a-Si/c-Si heterojunction solar cells after high energy irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ferrara, Manuela

    2009-11-24

    The crystalline silicon as absorber material will certainly continue to dominate the market for space applications of solar cells. In the contribution under consideration the applicability of a-Si:H/c-Si heterojunction solar cells in space has been tested by the investigation of the cell modification by high energy protons and comparing the results to the degradation of homojunction crystalline silicon reference cells. The investigated solar cells have been irradiated with protons of different energies and doses. For all investigated solar cells the maximum damage happens for an energy of about 1.7 MeV and is mainly due to the decrease of the effective minority carrier diffusion length in the crystalline silicon absorber. Simulations carried out by AFORS-HET, a heterojunction simulation program, also confirmed this result. The main degradation mechanism for all types of devices is the monotonically decreasing charge carrier diffusion length in the p-type monocrystalline silicon absorber layer. For the heterojunction solar cell an enhancement of the photocurrent in the blue wavelength region has been observed but only in the case of heterojunction solar cell with intrinsic a-Si:H buffer layer. Additionally to the traditional characterization techniques the electroluminescence technique used for monitoring the modifications of the heteroluminescence technique used for monitoring the modifications of the heterointerface between amorphous silicon and crystalline silicon in solar cells after proton irradiation. A direct relation between minority carrier diffusion length and electroluminescence quantum efficiency has been observed but also details of the interface modification could be monitored by this technique.

  18. Photoluminescence and Electroluminescence Studies on Tb-Doped Silicon Rich Oxide Materials and Devices

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Photoluminescence (PL) characteristics of Tb-doped silicon rich oxide (SRO) films prepared by DC-sputtering and post-annealing processes were studied. The silicon richness of the SRO film could be controlled by varying the sputtering power and oxygen concentration in the sputtering chamber. PL emission from the as-deposited sample was found to be composed of Tb3+ intra 4f transition-related emission and the silicon nano particle-related broad bandwidth emission. Thermal annealing could significantly improve the material properties as well as the PL signals. PL properties depended strongly upon the annealing scheme and silicon richness. Annealing at high temperatures (900~1050 ℃) enhanced Tb-related emission and suppressed the silicon nano particle-related emission. For samples with different silicon richness, annealing at 950 ℃ was found to produce higher PL signals than at other temperatures. It was attributed more to lifetime quenching than to concentration quenching. Electroluminescent (EL) devices with a capacitor structure were fabricated, the optimized process condition for the EL device was found to be different from that of PL emission. Among the annealing schemes that were used, wet oxidation was found to improve device performance the most, whereas, dry oxidation was found to improve material property the most. Wet oxidation allowed the breakdown electrical field to increase significantly and to reach above 10 mV·cm-1. The EL spectra showed a typical Tb3+ emission, agreeing well with the PL spectra. The I-V measurements indicated that for 100 nm thick film, the Fowler-Nordheim tunneling started at an electrical field of around 6 mV·cm-1 and the light emission became detectable at a current density of around 10-4 A·cm-2 and higher. Strong electroluminescence light emission was detected when the electrical field was close to 10 mV·cm-1.

  19. Electroluminescent device having improved light output

    Energy Technology Data Exchange (ETDEWEB)

    Tyan; Yuan-Sheng (Webster, NY); Preuss, Donald R. (Rochester, NY); Farruggia, Giuseppe (Webster, NY); Kesel, Raymond A. (Avon, NY); Cushman, Thomas R. (Rochester, NY)

    2011-03-22

    An OLED device including a transparent substrate having a first surface and a second surface, a transparent electrode layer disposed over the first surface of the substrate, a short reduction layer disposed over the transparent electrode layer, an organic light-emitting element disposed over the short reduction layer and including at least one light-emitting layer and a charge injection layer disposed over the light emitting layer, a reflective electrode layer disposed over the charge injection layer and a light extraction enhancement structure disposed over the first or second surface of the substrate; wherein the short reduction layer is a transparent film having a through-thickness resistivity of 10.sup.-9 to 10.sup.2 ohm-cm.sup.2; wherein the reflective electrode layer includes Ag or Ag alloy containing more than 80% of Ag; and the total device size is larger than 10 times the substrate thickness.

  20. Umbilicoplasty in children with huge umbilical hernia

    Directory of Open Access Journals (Sweden)

    Akakpo-Numado Gamedzi Komlatsè

    2014-01-01

    Full Text Available Background: Huge umbilical hernias (HUH are voluminous umbilical hernia (UH that are frequent in black African children. Several surgical techniques are used in their treatment for umbilical reconstruction, but techniques using skin flaps provide better aesthetic results. In this study, we presented our technique of umbilicoplasty in HUH, and its results. Patients and Methods: It is a retrospective study on children treated for HUH, from January 2012 to December 2013. The UH was called HUH when its basis diameter (BD exceeds 3 cm. Every HUH was characterised by its height, BD and morphology. Our technique was a two lateral flaps technique; the flaps are symmetrical and drawn so as to reconstitute the different parts of the umbilicus. The results were appreciated with criteria, including the peripheral ring and the central depression of the neo-umbilicus. Results : Twelve children were concerned (7 boys and 5 girls. Their mean age was 5 years and 6 months. The mean BD was 5.6 cm (extremes 3 and 8 cm, and the mean height of the HUH was 7.45 cm (extremes 3 and 9 cm. All underwent umbilicoplasty. In early post-operative period, two children presented a transitory subcutaneous hematoma. Late complications were granulation tissue with two children, and cheloid scar with one. With a mean follow-up of 10 months, we had 10 excellent results and two fair results according to our criteria. Conclusion: Our two lateral flaps umbilicoplasty is well-adapted to HUH in children. It is simple and assures a satisfactory anatomical and cosmetic result.

  1. Dispenser printed electroluminescent lamps on textiles for smart fabric applications

    Science.gov (United States)

    de Vos, Marc; Torah, Russel; Tudor, John

    2016-04-01

    Flexible electroluminescent (EL) lamps are fabricated onto woven textiles using a novel dispenser printing process. Dispenser printing utilizes pressurized air to deposit ink onto a substrate through a syringe and nozzle. This work demonstrates the first use of this technology to fabricate EL lamps. The luminance of the dispenser printed EL lamps is compared to screen-printed EL lamps, both printed on textile, and also commercial EL lamps on polyurethane film. The dispenser printed lamps are shown to have a 1.5 times higher luminance than the best performing commercially available lamp, and have a comparable performance to the screen-printed lamps.

  2. Topographic analysis of silicon nanoparticles-based electroluminescent devices

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Sanchez, A., E-mail: amorales@inaoep.mx [INAOE, Electronics Department, Apartado 51, Puebla 72000 (Mexico); Barreto, J.; Dominguez, C. [Instituto de Microelectronica de Barcelona, IMB-CNM (CSIC), Barcelona (Spain); Aceves, M.; Leyva, K.M. [INAOE, Electronics Department, Apartado 51, Puebla 72000 (Mexico); Luna-Lopez, J.A.; Carrillo, J. [CIDS-BUAP, Apdo. 1651, Puebla 72000 (Mexico); Pedraza, J. [INAOE, Electronics Department, Apartado 51, Puebla 72000 (Mexico)

    2010-10-25

    Electroluminescent properties of silicon nanoparticles embedded in MOS devices have been studied. Silicon rich oxide (SRO) films with 4 at.% of silicon excess were used as active layers. Intense and stable light emission is observed with the naked eye as shining spots at the surface of devices. AFM measurements on these devices exhibit a remarkably granular surface where the EL spots are observed. The EL measurements show a broad visible spectrum with various peaks between 420 and 870 nm. These EL spots are related with charge injection through conductive paths created by adjacent Si-nps within the SRO.

  3. Hepatectomy for huge hepatocellular carcinoma: single institute's experience.

    Science.gov (United States)

    Yang, Lianyue; Xu, Jiangfeng; Ou, Dipeng; Wu, Wei; Zeng, Zhijun

    2013-09-01

    The surgical resection of huge hepatocellular carcinoma (HCC) is still controversial. This study was designed to introduce our experience of liver resection for huge HCC and evaluate the safety and outcomes of hepatectomy for huge HCC. A total of 258 hepatic resections for the patients with huge HCC were analysed retrospectively from December 2002 to December 2011. The operative outcomes were compared with 293 patients with HCC >5.0 cm but huge HCC group and HCC >5.0 cm but huge HCC group has significantly a more longer overall and disease-free survival time than nodular huge HCC (P = 0.026, P = 0.022). Univariate and multivariate analysis revealed that the types of tumour, vascular invasion, and UICC stage were independent prognostic factors for overall survival (P = 0.047, P = 0.037, P = 0.033). Hepatic resection can be performed safely for huge HCC with a low mortality and favorable survival outcomes. Solitary huge HCC has the better surgical outcomes than nodular huge HCC.

  4. High-sensitivity strain visualization using electroluminescence technologies

    Science.gov (United States)

    Xu, Jian; Jo, Hongki

    2016-04-01

    Visualizing mechanical strain/stress changes is an emerging area in structural health monitoring. Several ways are available for strain change visualization through the color/brightness change of the materials subjected to the mechanical stresses, for example, using mechanoluminescence (ML) materials and mechanoresponsive polymers (MRP). However, these approaches were not effectively applicable for civil engineering system yet, due to insufficient sensitivity to low-level strain of typical civil structures and limitation in measuring both static and dynamic strain. In this study, design and validation for high-sensitivity strain visualization using electroluminescence technologies are presented. A high-sensitivity Wheatstone bridge, of which bridge balance is precisely controllable circuits, is used with a gain-adjustable amplifier. The monochrome electroluminescence (EL) technology is employed to convert both static and dynamic strain change into brightness/color change of the EL materials, through either brightness change mode (BCM) or color alternation mode (CAM). A prototype has been made and calibrated in lab, the linearity between strain and brightness change has been investigated.

  5. Hybrid electroluminescent device based on MEH-PPV and ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Hewidy, Dina; Gadallah, A.-S.; Fattah, G. Abdel

    2017-02-15

    Hybrid organic/inorganic electroluminescent device based on the structure of glass/ITO/PEDOT:PSS/MEH-PPV/ZnO/ZnO submicrorods/Al has been manufactured. Spin coating has been used to deposit both PEDOT:PSS and MEH-PPV. Two-step process has been used to synthesis ZnO submicrorods, namely, spin coating and chemical bath deposition. Changing the dimensions of the ZnO submicrorods in this layer structure has been investigated to improve the performance of the organic/inorganic electroluminescence device. Such layer structure provides electroluminescence with narrow emission bands due to a high gain with this structure. X-ray diffraction patterns and scanning electron microscope images show that ZnO submicrorods have hexagon structure. Current-voltage curve for the structure has been reported. Electroluminescence curves (electroluminescence intensity versus wavelength) at different bias voltages have been presented and these results show narrowing in full width at half maximum in the spectra at high current density compared to photoluminescence excitation. The narrowing in the spectrum has been explained. - Highlights: • Manufacturing of MEH-PPV and ZnO electroluminescent device has been reported. • Spin coating and chemical bath deposition have been used for preparation of ZnO. • SEM images and X-ray diffraction of ZnO have been presented. • Current-voltage curves and electroluminescent measurements have been reported.

  6. Comparison of electroluminescence intensity and photocurrent of polymer based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, Ulrich; Swonke, Thomas; Auer, Richard [Bayerisches Zentrum fuer Angewandte Energieforschung e.V., Erlangen (Germany); Pinna, Luigi; Brabec, Christoph J. [Bayerisches Zentrum fuer Angewandte Energieforschung e.V., Erlangen (Germany); I-MEET, University Erlangen (Germany); Stubhan, Tobias; Li, Ning [I-MEET, University Erlangen (Germany)

    2011-11-15

    The reciprocity theorem for solar cell predicts a linear relation between electroluminescence emission and photovoltaic quantum efficiency and an exponential dependence of the electroluminescence signal on the applied voltage. Both dependencies are experimentally verified for polymer based solar cells in this paper. Furthermore it is shown, that electroluminescence imaging of organic solar cells has the potential to visualize the photocurrent distribution significantly faster than standard laser beam induced current mapping (LBIC) techniques. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Optimization of Dynamically Generated SQL Queries for Tiny-Huge, Huge-Tiny Problem

    Directory of Open Access Journals (Sweden)

    Arjun K Sirohi

    2013-03-01

    Full Text Available In most new commercial business software applications like Customer Relationship Management, the datais stored in the database layer which is usually a Relational Database Management System (RDBMS likeOracle, DB2 UDB or SQL Server. To access data from these databases, Structured Query Language (SQLqueries are used that are generated dynamically at run time based on defined business models and businessrules. One such business rule is visibility- the capability of the application to restrict data access based onthe role and responsibility of the user logged in to the application. This is generally achieved by appendingsecurity predicates in the form of sub-queries to the main query based on the roles and responsibility of theuser. In some cases, the outer query may be more restrictive while in other cases, the security predicatesmay be more restrictive. This often results in a dilemma for the cost-based optimizer (CBO of the backenddatabase whether to drive from the outer query or drive from the security predicate sub-queries. Thisdilemma is sometimes called the “Tiny-Huge, Huge-Tiny” problem and results in serious performancedegradation by way of increased response times on the application User Interface (UI. This paperprovides a case study of a new approach to vastly reduce this CBO dilemma by a combination of denormalizedcolumns and re-writing of the security predicates’ sub-queries at run-time, thereby levelling theouter and security sub-queries. This approach results in more stable execution plans in the database andmuch better performance of such SQLs, effectively leading to higher performance and scalability of theapplication.

  8. Quantitative description of electroluminescence images of polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Seeland, Marco; Roesch, Roland; Hoppe, Harald [Institute of Physics, Ilmenau University of Technology, Ilmenau (Germany)

    2011-07-01

    We present a quantitative description of electroluminescence images obtained on organic solar cells, which is based on a device modeling employing a network of interconnected microdiodes. The equivalent circuit network model takes interface and bulk resistances as well as the sheet resistance of the transparent electrode into account. The application of this model allows direct calculation of the lateral current and voltage distribution as well as determination of internal resistances and the sheet resistance of the higher resistive electrode. Furthermore, we have extended the microdiode-model to also describe and predict current voltage characteristics for devices under illumination. Finally the local nature of this description enables important conclusions concerning the geometry dependent performance of thin film solar cells.

  9. Highly stretchable electroluminescent skin for optical signaling and tactile sensing.

    Science.gov (United States)

    Larson, C; Peele, B; Li, S; Robinson, S; Totaro, M; Beccai, L; Mazzolai, B; Shepherd, R

    2016-03-04

    Cephalopods such as octopuses have a combination of a stretchable skin and color-tuning organs to control both posture and color for visual communication and disguise. We present an electroluminescent material that is capable of large uniaxial stretching and surface area changes while actively emitting light. Layers of transparent hydrogel electrodes sandwich a ZnS phosphor-doped dielectric elastomer layer, creating thin rubber sheets that change illuminance and capacitance under deformation. Arrays of individually controllable pixels in thin rubber sheets were fabricated using replica molding and were subjected to stretching, folding, and rolling to demonstrate their use as stretchable displays. These sheets were then integrated into the skin of a soft robot, providing it with dynamic coloration and sensory feedback from external and internal stimuli.

  10. Kinetics of transient electroluminescence in organic light emitting diodes

    Science.gov (United States)

    Shukla, Manju; Kumar, Pankaj; Chand, Suresh; Brahme, Nameeta; Kher, R. S.; Khokhar, M. S. K.

    2008-08-01

    Mathematical simulation on the rise and decay kinetics of transient electroluminescence (EL) in organic light emitting diodes (OLEDs) is presented. The transient EL is studied with respect to a step voltage pulse. While rising, for lower values of time, the EL intensity shows a quadratic dependence on (t - tdel), where tdel is the time delay observed in the onset of EL, and finally attains saturation at a sufficiently large time. When the applied voltage is switched off, the initial EL decay shows an exponential dependence on (t - tdec), where tdec is the time when the voltage is switched off. The simulated results are compared with the transient EL performance of a bilayer OLED based on small molecular bis(2-methyl 8-hydroxyquinoline)(triphenyl siloxy) aluminium (SAlq). Transient EL studies have been carried out at different voltage pulse amplitudes. The simulated results show good agreement with experimental data. Using these simulated results the lifetime of the excitons in SAlq has also been calculated.

  11. Electroluminescence Spectrum Shift with Switching Behaviour of Diamond Thin Films

    Institute of Scientific and Technical Information of China (English)

    王小平; 王丽军; 张启仁; 姚宁; 张兵临

    2003-01-01

    We report a special phenomenon on switching behaviour and the electroluminescence (EL) spectrum shift of doped diamond thin films. Nitrogen and cerium doped diamond thin films were deposited on a silicon substrate by microwave plasma-assisted chemical vapour deposition system and other special techniques. An EL device with a three-layer structure of nitrogen doped diamond/cerium doped diamond/SiO2 thin films was made. The EL device was driven by a direct-current power supply. Its EL character has been investigated, and a switching behaviour was observed. The EL light emission colour of diamond films changes from yellow (590nm) to blue (454 nm) while the switching behaviour appears.

  12. Electroluminescence Gray Scale Display Driving Method and Circuit

    Institute of Scientific and Technical Information of China (English)

    KANG Hao; LI Rong-yu; YANG Xin

    2007-01-01

    The increasing use of color terminals for personal computers has raised a demand for video graphic adapter(VGA)-format panel displays. Since only monochrome(ZnS∶Mn) electroluminescence(EL) displays of suitable size and speed are available, lack of colors has to be replaced by grayscale in the first place. There are two basic driving methods to achieve grayscale in thin-film EL displays: pulse amplitude modulation(PAM) method and pulse width modulation(PWM) method. But there are serious disadvantages of the two traditional methods. For the former method, the high voltage PAM ICs are too expensive to produce the grayscale EL display in bulks and the driver integrated circuit(IC) is complex. Though the PWM method has good grayscale display quality, the hardware implementation is too complex. A new driving method with which the width and the amplitude of the pulse can be modulated and simultaneously the challenge can be solved efficaciously is presented.

  13. Design of efficient electroluminescent lanthanide(III) complexes

    CERN Document Server

    You, B R; Park, N G; Kim, Y S

    2001-01-01

    The lanthanide complexes have been anticipated to exhibit high efficiency along with a narrow emission spectrum. Photoluminescence for the lanthanide complex is characterized by a high efficiency since both single and triplet excitons are involved in the luminescence process. However, the maximum external electroluminescence quantum efficiencies have exhibited values around 1% due to triplet-triplet annihilation at high current. Here, we proposed a new energy transfer mechanism to overcome triplet-triplet annihilation by the Eu complex doped into phosphorescent materials with triplet levels that were higher than single levels of the Eu complex. In order to show the feasibility of the proposed energy transfer mechanism and to obtain the optimal ligands and host material, we have calculated the effect depending on ligands as a factor that controls emission intensity in lanthanide complexes. The calculation shows that triplet state as well as singlet state of anion ligand affects on absorption efficiency indirec...

  14. Electroluminescent Polymers and Carbon Nanotubes for Flat Panel Displays

    Institute of Scientific and Technical Information of China (English)

    Liming Dai; Limin Dong; Mei Gao; Shaoming Huang; Oddvar Johansen; Albert W.H.Mau,Zoran Vasic; Berthold Winkler; Yongyuang Yang

    2000-01-01

    polymeric light-emitting diodes(LEDs) with sufficient brightness. efficiencies, low driving voltages, and various interesting features have been reported. The relatively short device lifetime, however, still remains as a major problem to be solved before any commercial applications will be realized. In this regard,carbon nanotubes have recently been proposed as more robust electron field emitters for flat panel displays. We have synthesised large arrays of vertically aligned carbon nanotubes, from which micropatterns of the aligned nanotubes suitable for flat panel displays were fabricated on various substrates. In this paper, we summarise our work on the synthesis and microfabrication of electroluminescent polymers and carbon nanotubes for flat panel displays with reference to other complementary work as appropriate.

  15. Frequency Response of Modulated Electroluminescence of Light-Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    FENG Lie-Feng; LI Yang; LI Ding; WANG Cun-Da; ZHANG Guo-Yi; YAO Dong-Sheng; LIU Wei-Fang; XING Peng-Fei

    2011-01-01

    Frequency responses of modulated electroluminescence (EL) of light-emitting diodes were measured using a testing setup.With increasing frequency of the ac signal,the relative light intensity (RLI) clearly decreases.Furthermore,a peculiar asynchrony between the RLI and ac small-signal is observed.At frequencies higher than 10kHz,the RLI clearly lags behind the ac signal and the absolute value of the lagging angle is nearly proportional to the signal frequency.Using the classical recombination model of light-emitting diodes under ac small-signal modulation,these abnormal characteristics of modulated EL can be clearly explained.High-power light-emitting diodes (LEDs) have received great attention recently owing to their applications in energy-saving lights,display items and many other fields;therefore,the optical and electrical characteristics of LEDs at forward bias hold significant potential for research.[1-4] However,for a new kind of light emission device,the general research on its performance focuses on the light emission and dc currentvoltage (I-V) characteristics.%Frequency responses of modulated electroluminescence (EL) of light-emitting diodes were measured using a testing setup. With increasing frequency of the ac signal, the relative light intensity (RLI) clearly decreases. Furthermore, a peculiar asynchrony between the RLI and ac small-signal is observed. At frequencies higher than 10kHz, the RLI clearly lags behind the ac signal and the absolute value of the lagging angle is nearly proportional to the signal frequency. Using the classical recombination model of light-emitting diodes under ac small-signal modulation, these abnormal characteristics of modulated EL can be clearly explained.

  16. Structural, morphological and electroluminescence studies of Zno:Co nanophosphor

    Science.gov (United States)

    Singh, Anju; Vishwakarma, H. L.

    2016-09-01

    The nanoparticles of zinc oxide (ZnO) doped with various concentrations of cobalt (Co) were synthesized by chemical precipitation method in the presence of capping agent polyvinylpyrrolidone (PVP). The effect of doping concentration on structural and morphological properties has been studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). Cell volume, bond length, texture coefficient, lattice constants and dislocation density are also studied. Here, we also compared the interplaner spacing and relative peak intensities from their standard values with different angles. Crystallite sizes have been calculated by Debye-Scherrer's formula whose values are decreasing with increase in cobalt content up to 3 %. It has been seen that the growth orientation of the prepared ZnO nanorods was (101). The XRD analysis also ensures that ZnO has a hexagonal (wurtzite) crystal structure. The electroluminescence (EL) cells were prepared by placing pure and cobalt-doped ZnO nanoparticles between ITO-coated conducting glass plate and aluminium foil. Alternating voltage of various frequencies was applied, and EL brightness at different voltages was measured and corresponding current was also recorded. The voltage dependence of electroluminescence (EL) brightness of the ZnO:Co shows exponential increase. The linear voltage-current characteristic indicates ohmic nature. The EL brightness at a particular voltage is found to increase by increasing Co doping, but for higher percentage of Co the EL brightness is reduced. It is also seen that Co does not influence the threshold voltage. The brightness is also affected by increasing the frequency of AC signal.

  17. Organic electroluminescent materials and devices emitting in UV and NIR regions

    Science.gov (United States)

    Pushkarev, A. P.; Bochkarev, M. N.

    2016-12-01

    Literature data on organic materials capable of generating electroluminescence in the UV (200–400 nm) and near-IR (700–2000 nm) spectral ranges are summarized and systematized. Organic, organometallic and coordination compounds are considered. Comparative analysis of materials is performed, and the composition and operating characteristics of light-emitting diodes based on them and possible mechanisms of electroluminescence generation are discussed. The bibliography includes 173 references.

  18. Magneto-electroluminescence of organic heterostructures: Analytical theory and spectrally resolved measurements

    OpenAIRE

    Liu,Feilong; Kelley, Megan R.; Crooker, Scott A.; Nie, Wanyi; Mohite, Aditya D.; Ruden, P. Paul; Smith, Darryl L.

    2014-01-01

    The effect of a magnetic field on the electroluminescence of organic light emitting devices originates from the hyperfine interaction between the electron/hole polarons and the hydrogen nuclei of the host molecules. In this paper, we present an analytical theory of magneto-electroluminescence for organic semiconductors. To be specific, we focus on bilayer heterostructure devices. In the case we are considering, light generation at the interface of the donor and acceptor layers results from th...

  19. Scarless surgery for a huge liver cyst: A case report.

    Science.gov (United States)

    Kashiwagi, Hiroyuki; Kawachi, Jun; Isogai, Naoko; Ishii, Masanori; Miyake, Katsunori; Shimoyama, Rai; Fukai, Ryota; Ogino, Hidemitsu

    2017-09-01

    Symptomatic or complicated liver cysts sometimes require surgical intervention and laparoscopic fenestration is the definitive treatment for these cysts. We performed minimally invasive surgery, hybrid natural orifice transluminal endoscopic surgery (NOTES) without scarring, for a huge liver cyst. An 82-year-old female presented with a month-long history of right upper abdominal pain. We diagnosed her condition as a huge liver cyst by morphological studies. She denied any history of abdominal trauma. Her serum CEA and CA19-9 were normal and a serum echinococcus serologic test was negative. Laparoscopic fenestration, using a hybrid NOTES procedure via a transvaginal approach, was performed for a huge liver cyst because we anticipated difficulty with an umbilical approach, such as single incision laparoscopic surgery (SILS). Her post-operative course was uneventful and she was discharged from our hospital three days after surgery. Pain killers were not required during and after hospitalization. No recurrence of the liver cyst or bulging was detected by clinical examination two years later. A recent trend of laparoscopic procedure has been towards minimizing the number of incisions to achieve less invasiveness. This hybrid NOTES, with a small incision for abdominal access, along with vaginal access, enabled painless operation for a huge liver cyst. We report a huge liver cyst treated by hybrid NOTES. This approach is safe, less invasive, and may be the first choice for a huge liver cyst. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Efficient Visible Electroluminescence from Porous Silicon Diodes Passivated by Carbon Films

    Institute of Scientific and Technical Information of China (English)

    李宏建; 彭景翠; 瞿述; 颜永红; 许雪梅; 赵楚军

    2002-01-01

    By using n-butylamine as a carbon resource, carbon film is deposited on the p-n porous silicon (PS) surface with aradio-frequency glow discharge plasma system. Raman spectra and infrared reflection (IR) spectra of the carbonfilms indicate that there are amine-group and hydrogen atoms therein. The IR spectra of the passivated PSsamples exhibit that the PS surfaces are mainly covered with Si-C, Si-N and Si-O bonds. Electroluminescence(EL) spectra show that the EL intensity of the passivated PS diodes increases greatly and the blueshift of theEL peak occurs compared with the diodes without treatment. Both of these are stable while the passivateddiodes are exposed to the air indoors. The I-V characteristics reveal that the passivated diodes have a smallerseries resistance and a lower onset voltage. The influence of the carbon film passivation on EL properties of PShas also been discussed. The results have proven that carbon film passivation is a good way to enhance the PSluminescent intensity and stability.

  1. Temperature and current dependent electroluminescence measurements on colour-coded multiple quantum well light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Bergbauer, Werner [OSRAM Opto Semiconductors GmbH, Regensburg (Germany); FH Deggendorf (Germany); Laubsch, Ansgar; Peter, Matthias; Mayer, Tobias; Bader, Stefan; Oberschmid, Raimund; Hahn, Berthold [OSRAM Opto Semiconductors GmbH, Regensburg (Germany); Benstetter, Guenther [FH Deggendorf (Germany)

    2008-07-01

    As the efficiency and the luminous flux have been increased enormously in the last few years, today Light Emitting Diodes (LEDs) are even pushed to applications like general lighting and Home Cinema Projection. Still, InGaN/GaN heterostructure based LEDs suffer from loss-mechanisms like non-radiative defect and Auger recombination, carrier leakage and piezo-field induced carrier separation. To optimize the high current efficiency we evaluated the benefit of Multiple Quantum Well (MQW) compared to Single Quantum Well (SQW) LEDs. Temperature dependent electroluminescence of colour-coded structures with different Indium content in certain Quantum Wells was measured. The experiments demonstrated a strong temperature and current dependence of the MQW operation. The comparison between different LED structures showed effectively the increased LED performance of those structures which operate with a well adjusted MQW active area. Due to the enhanced carrier distribution in the high current range, these LEDs show a higher light output and additionally a reduced wavelength shift.

  2. Stochastic Huge-Resonance Caused by Coupling for a Globally Coupled Linear System

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui

    2009-01-01

    In the paper, we investigate a globally coupled linear system with finite subunits subject to temporal periodic force and with multiplicative dichotomous noise.It is shown that, the global coupling among the subunits can hugely enhance the phenomenon of SR for the amplitude of the average mean field as the functions of the transition rate of the noise and that as the function of the frequency of the signal respectively.

  3. Solid state carbon nanotube device for controllable trion electroluminescence emission

    Science.gov (United States)

    Liang, Shuang; Ma, Ze; Wei, Nan; Liu, Huaping; Wang, Sheng; Peng, Lian-Mao

    2016-03-01

    Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ~5 × 10-4 photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for gradually increasing bias were also investigated. The realization of electrically induced pure trion emission opens up a new opportunity for CNT film-based optoelectronic devices, providing a new degree of freedom in controlling the devices to extend potential applications in spin or magnetic optoelectronics fields.Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ~5 × 10-4 photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for

  4. Tentative anatomy of ZnS-type electroluminescence

    Science.gov (United States)

    Bringuier, E.

    1994-05-01

    The paper reviews the electrical and optical mechanisms at work in sulfide-based thin-film electroluminescence display devices within the framework of general semiconductor physics. The electrical problem is twofold: (i) charge carriers are sourced at high electric field in a nominally insulating material, the carrier density increasing by almost eight orders of magnitude; (ii) the carriers are transported at high field, with an average energy largely exceeding the thermal one. (i) Carrier sourcing is best understood from direct-current-driven ZnS films, and is ascribed to partly filled deep donors transferring electrons to the conduction band by Fowler-Nordheim tunneling. The deep donors also act as carrier sinkers, and evidence for space charge is afforded by small-signal impedance analysis disclosing a markedly inductive behavior. The conduction picture obtained from dc-driven films is then used to clarify the operation of alternating-current electroluminescence structures where the sulfide is sandwiched between two blocking oxide layers. The electrostatics of the ac structure is investigated in detail including space charge and field nonuniformity, and external observables are related to internal quantities. The simple model of interfacial carrier sourcing and sinking is examined. (ii) High-field electronic transport is controlled by the electron-phonon interaction, and the modeling resorts to numerical simulations or the lucky-drift concept. At low electron energies the interaction with phonons is predominantly polar, while at optical energies it proceeds via deformation potential scattering. In spite of the uncertainties in transport models in that range, it is likely that ˜50% of the electrons overtake 2 eV at the usual operating fields in ZnS. Light emission is associated with impurity luminescence centers embedded in the sulfide host. They are excited while current is flowing, and the ensuing relaxation is partly radiative. We describe the two ways in

  5. MRI Verification of a Case of Huge Infantile Rhabdomyoma

    Science.gov (United States)

    Ramadani, Naser; Kreshnike, Kreshnike Dedushi; Muçaj, Sefedin; Kabashi, Serbeze; Hoxhaj, Astrit; Jerliu, Naim; Bejiçi, Ramush

    2016-01-01

    Introduction: Cardiac rhabdomyoma is type of benign myocardial tumor that is the most common fetal cardiac tumor. Cardiac rhabdomyomas are usually detected before birth or during the first year of life. They account for over 60% of all primary cardiac tumors. Case report: A 6 month old child with coughing and obstruction in breathing, was hospitalized in the Pediatric Clinic in UCCK, Pristine. The difficulty of breathing was heard and the pathological noise of the heart was noticed from the pediatrician. In the echo of the heart at the posterior and apico-lateral part of the left ventricle a tumoral mass was presented with the dimensions of 56 × 54 mm that forwarded the contractions of the left ventricle, the mass involved also the left ventricle wall and was not vascularized. The right ventricle was deformed and with the shifting of the SIV on the right the contractility was preserved. Aorta, the left arch and AP were normal with laminar circulation. The pericard was presented free. Radiography of thoracic organs was made; it resulted on cardiomegaly and significant bronchovascular drawing. It was completed with an MRI and it resulted on: Cardiomegaly due to large tumoral mass lesion (60×34 mm) involving lateral wall of left ventricle. It was isointense to the muscle on T1W images, markedly hyperintense on T2W images. There were a few septa or bant like hypointensities within lesion. On postcontrast study it showed avid enhancement. The left ventricle volume was decreased. Mild pericardial effusion was also noted. Surgical intervention was performed and it resulted on the histopathological aspect as a huge infantile rhadbomyoma. Conclusion: In most cases no treatment is required and these lesions regress spontaneously. Patients with left ventricular outflow tract obstruction or refractory arrhythmias respond well to surgical excision. Rhabdomyomas are frequently diagnosed by means of fetal echocardiography during the prenatal period. PMID:27147810

  6. Synthesis and characterization of thin film electroluminescent devices all-prepared by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez, E.B. [Universidad Autónoma de la Ciudad de México, Calle Prolongación San Isidro Núm. 151, Col. San Lorenzo Tezonco, Iztapalapa 09790, D. F., México (Mexico); Bizarro, M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán 04510, Distrito Federal, México (Mexico); Alonso, J.C., E-mail: alonso@unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán 04510, Distrito Federal, México (Mexico)

    2013-12-02

    Alternating current thin film electroluminescent devices have been fabricated using aluminum-doped zinc oxide (ZnO:Al) as transparent conducting layer, aluminum oxide (Al{sub 2}O{sub 3}) as insulating layers, and manganese-doped zinc sulfide (ZnS:Mn) as electroluminescent layer. All these films were deposited by the ultrasonic spray pyrolysis technique at the same temperature (450°) on glass substrates, forming a standard MISIM (metal–insulator–semiconductor–insulator–metal) configuration. The electroluminescence of MISIM devices with a total thickness of ∼ 1330 nm was investigated by applying a sinusoidal voltage with a frequency of 10 kHz. The devices showed orange-emission spectra centered at approximately 570 nm, characteristic of {sup 4}T{sub 1} → {sup 6}A{sub 1} radiative transitions of Mn{sup 2+} ions in the ZnS host, with a sharp intensity increase upon increasing the root mean square voltage above a threshold of 25 V and a rapid saturation for voltages higher than 38 V. The electroluminescent emission of these MISIM structures can be observed with the naked eye under ambient illumination. - Highlights: • Thin film electroluminescent devices were fabricated by ultrasonic spray pyrolysis at 450 °C. • The electroluminescent devices were fabricated on glass substrates. • ZnO:Al was used as transparent conductive layer. • ZnS:Mn and Al{sub 2}O{sub 3} were used as phosphor and insulating layers, respectively. • The electroluminescent devices have a low threshold operation voltage.

  7. Effect of gold nanorods and nanocubes on electroluminescent performances in organic light-emitting diodes and its working mechanism

    Directory of Open Access Journals (Sweden)

    Ying Xu

    2015-06-01

    Full Text Available In this manuscript we investigated the influence of Au nanoparticles on electrical and electroluminescent (EL performances in organic light-emitting diodes (OLEDs via doping as-synthesized Au nanorods (NRs or nanocubes (NCs into hole transport layer (HTL. Through accurately controlling the distance between the Au NRs and the emitting layer, altering the guest emitter’s lifetime, and replacing Au NRs with Au NCs to satisfy a better spectrum overlap with the emission guest, we got a conclusion that doping Au NRs or NCs into HTL has no significant influence on the device’s electrical and EL performances, although we observed an increase in the spontaneous emission rate in a fluorescent material by the exciton-surface plasmon-coupling. Our results suggest that a further research on emission mechanism in surface plasmon-enhanced OLEDs is still in process.

  8. Design and Synthesis of a Highly Stable Six-hydrogen-bonded Self-assembly Yellowish Green Electroluminescent Molecular Duplex

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper describes the design, synthesis and characterization of a hydrogen-bonded molecular duplex with 1,8-naphthalimide fluorescent pendants. The two oligoamide molecular strands, with complementary hydrogen bond sequences of DDADAA and AADADD, caa form an ultra stable self-assembly duplex. Its molecular structure was confirmed by 1H NMR and ESI-MS, and its photoluminescence properties were determined. The resulting duplex exhibited a dramatically enhanced photoluminescence (PL) quantum efficiency of 63.7% compared to the corresponding 1,8-naphthalimide segment (32.4%), suggesting that the formation of the duplex with larger molecular weight could successfully inhibit the quenching of the fluorescent pendant.This novel duplex is a prospective candidate for new electroluminescent emitter.

  9. PHOTO- AND ELECTRO-LUMINESCENCE FROM HYDROGENATED AMORPHOUS SILICON CARBIDE FILMS PREPARED BY USING ORGANIC CARBON SOURCE

    Institute of Scientific and Technical Information of China (English)

    Xu Jun; Ma Tian-fu; Li Wei; Chen Kun-ji; Li Zhi-feng; Lu Wei

    2000-01-01

    Hydrogenated amorphous silicon carbide (a-SiC:H) films were grown byusing an organic source, xylene (C8H{10), instead of methane(CH4) in a conventional plasma enhanced chemical vapor depositionsystem. The optical band gap of these samples was increased gradually bychanging the gas ratio of C8H10 to SiH4. The film with highoptical band gap was soft and polymer-like and intense photoluminescencewere obtained. Room temperature electro-luminescence was also achievedwith peak energy at 2.05 eV (600 nm) for the a-SiC:H film withoptical band gap of 3.2 eV.1.8mm

  10. Characteristics of electroluminescence phenomenon in virgin and thermally aged LDPE

    Science.gov (United States)

    Bani, N. A.; Abdul-Malek, Z.; Ahmad, H.; Muhammad-Sukki, F.; Mas'ud, A. A.

    2015-08-01

    High voltage cable requires a good insulating material such as low density polyethylene (LDPE) to be able to operate efficiently in high voltage stresses and high temperature environment. However, any polymeric material will experience degradation after prolonged application of high electrical stresses or other extreme conditions. The continuous degradation will shorten the life of a cable therefore further understanding on the behaviour of the aged high voltage cable needs to be undertaken. This may be observed through electroluminescence (EL) measurement. EL occurs when a solid-state material is subjected to a high electrical field stress and associated with the generation of charge carriers within the polymeric material and that these charges can be produced by injection, de-trapping and field-dissociation at the metal-polymer interface. The behaviour of EL emission can be affected by applied field, applied frequency, ageing time, ageing temperature and types of materials, among others. This paper focuses on the measurement of EL emission of additive-free LDPE thermally aged at different temperature subjected to varying electric stresses at 50Hz. It can be observed that EL emission increases as voltage applied is increased. However, EL emission decreases as ageing temperature is increased for varying applied voltage.

  11. A New Conducting Polymer Electrode for Organic Electroluminescence Devices

    Institute of Scientific and Technical Information of China (English)

    QU Shu; PENG Jing-Cui

    2008-01-01

    @@ Conducting polymer polydimethylsiloxane (PDMS) is studied for the high performance electrode of organic electroluminescence devices. A method to prepare the electrode consisting of a SiC thin film and PDMS is investigated. By using ultra thin SiC films with different thicknesses, the organic electroluminescenee devices are obtained in an ultra vacuum system with the model device PDMS/SiC/PPV/Alq3, where PPV is poly para-phenylene vinylene and Alq3 is tris(8-hydroxyquinoline) aluminium. The capacitance-voltage (C-V), capacitance-frequency (C-F), current-voltage (I- V), radiation intensity-voltage (R- V) and luminance efficiency-voltage (E-V) measurements are systematically studied to investigate the conductivity, Fermi align-ment and devices properties in organic semiconductors. Scanning Kelvin probe measurement shows that the work function of PDMS/SiC anode with a 2.5-nm SiC over layer can be increased by as much as 0.28eV, compared to the conventional ITO anode. The result is attributed to the charge transfer effect and ohmic contacts at the interface.

  12. Kinetics of transient electroluminescence in organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Manju; Brahme, Nameeta [School of Studies in Physics, Pt. Ravishanker Shukla University, Raipur (Congo, The Democratic Republic of the) 492010 (India); Kumar, Pankaj; Chand, Suresh [Center for Organic Electronics, National Physical Laboratory, Dr K S Krishnan Road, New Delhi-110012 (India); Kher, R S [Department of Physics, Government Science PG College, Bilaspur (Congo, The Democratic Republic of the) 495006 (India); Khokhar, M S K [Department of Rural Technology, GuruGhasidas University Bilaspur (Congo, The Democratic Republic of the) 495009 (India)], E-mail: manjushukla2003@gmail.com

    2008-08-21

    Mathematical simulation on the rise and decay kinetics of transient electroluminescence (EL) in organic light emitting diodes (OLEDs) is presented. The transient EL is studied with respect to a step voltage pulse. While rising, for lower values of time, the EL intensity shows a quadratic dependence on (t - t{sub del}), where t{sub del} is the time delay observed in the onset of EL, and finally attains saturation at a sufficiently large time. When the applied voltage is switched off, the initial EL decay shows an exponential dependence on (t - t{sub dec}), where t{sub dec} is the time when the voltage is switched off. The simulated results are compared with the transient EL performance of a bilayer OLED based on small molecular bis(2-methyl 8-hydroxyquinoline)(triphenyl siloxy) aluminium (SAlq). Transient EL studies have been carried out at different voltage pulse amplitudes. The simulated results show good agreement with experimental data. Using these simulated results the lifetime of the excitons in SAlq has also been calculated.

  13. Solid state carbon nanotube device for controllable trion electroluminescence emission.

    Science.gov (United States)

    Liang, Shuang; Ma, Ze; Wei, Nan; Liu, Huaping; Wang, Sheng; Peng, Lian-Mao

    2016-03-28

    Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ∼5 × 10(-4) photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for gradually increasing bias were also investigated. The realization of electrically induced pure trion emission opens up a new opportunity for CNT film-based optoelectronic devices, providing a new degree of freedom in controlling the devices to extend potential applications in spin or magnetic optoelectronics fields.

  14. Pattern Visual Evoked Potentials Elicited by Organic Electroluminescence Screen

    Directory of Open Access Journals (Sweden)

    Celso Soiti Matsumoto

    2014-01-01

    Full Text Available Purpose. To determine whether organic electroluminescence (OLED screens can be used as visual stimulators to elicit pattern-reversal visual evoked potentials (p-VEPs. Method. Checkerboard patterns were generated on a conventional cathode-ray tube (S710, Compaq Computer Co., USA screen and on an OLED (17 inches, 320 × 230 mm, PVM-1741, Sony, Tokyo, Japan screen. The time course of the luminance changes of each monitor was measured with a photodiode. The p-VEPs elicited by these two screens were recorded from 15 eyes of 9 healthy volunteers (22.0 ± 0.8 years. Results. The OLED screen had a constant time delay from the onset of the trigger signal to the start of the luminescence change. The delay during the reversal phase from black to white for the pattern was 1.0 msec on the cathode-ray tube (CRT screen and 0.5 msec on the OLED screen. No significant differences in the amplitudes of P100 and the implicit times of N75 and P100 were observed in the p-VEPs elicited by the CRT and the OLED screens. Conclusion. The OLED screen can be used as a visual stimulator to elicit p-VEPs; however the time delay and the specific properties in the luminance change must be taken into account.

  15. Nanoscale dynamic inhomogeneities in electroluminescence of conjugated polymers

    Science.gov (United States)

    Hatano, Tatsuhiko; Nozue, Shuho; Habuchi, Satoshi; Vacha, Martin

    2011-09-01

    We report the observation and characterization of dynamic spatial heterogeneities in the electroluminescence (EL) of conjugated polymer organic light-emitting diodes via high-sensitivity fluorescence microscopy. The active layers of the single-layer devices are polymers of the poly(phenylene vinylene) family, i.e., poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylene vinylene] and a commercially available copolymer, Super Yellow. The devices are prepared directly on a microscope coverslip, making it possible to use high numerical aperture oil-immersion objective lenses with a diffraction-limited resolution of a few hundred nanometers for microscopic EL imaging. Detection via high-sensitivity CCD camera allows the measurement of EL dynamics with millisecond time resolution for a wide range of applied voltages. We found spatial heterogeneities in the form of high EL intensity sites in all devices studied. The EL from these sites is strongly fluctuating in time, and the dynamics is bias voltage dependent. At the same time, there is no difference in the local microscopic EL spectra between the high- and low-intensity sites. The results are interpreted in terms of a changing charge balance and local structural changes in the active film layer.

  16. A case of a huge gastroepiploic arterial aneurysm.

    Science.gov (United States)

    Ikeda, Hirokuni; Takeo, Masahiko; Mikami, Ryuuichi; Yamamoto, Mistuo

    2015-08-05

    An 85-year-old man complaining of vague abdominal discomfort was admitted to our hospital. A pulsatile 8 × 7-cm mass in the right upper abdomen was noticed on clinical examination. Computed tomography of the abdomen showed a huge arterial aneurysm in the right gastroepiploic artery, and the left gastroepiploic artery was meandering and expanding. An image diagnosis of gastroepiploic arterial aneurysm (GEAA) was made. Because of the huge size of the aneurysm and the predicted high risk of perforation, surgical intervention was planned. The aneurysm was identified in the greater curve and was found to adhere firmly to the transverse colon. Partial resection of the stomach, aneurysmectomy and partial resection of the transverse colon were performed. Clinically, splanchnic arterial aneurysms are rare. Among them, GEAA is especially rare. We report a rare case of a huge GEAA that was treated successfully by surgery. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2015.

  17. Hybrid electroluminescent device based on MEH-PPV and ZnO

    Science.gov (United States)

    Hewidy, Dina.; Gadallah, A.-S.; Fattah, G. Abdel

    2017-02-01

    Hybird organic/inorganic electroluminescent device based on the structure of glass/ITO/PEDOT:PSS/MEH-PPV/ZnO/ZnO submicrorods/Al has been manufactured. Spin coating has been used to deposit both PEDOT:PSS and MEH-PPV. Two-step process has been used to synthesis ZnO submicrorods, namely, spin coating and chemical bath deposition. Changing the dimensions of the ZnO submicrorods in this layer structure has been investigated to improve the performance of the organic/inorganic electroluminescence device. Such layer structure provides electroluminescence with narrow emission bands due to a high gain with this structure. X-ray diffraction patterns and scanning electron microscope images show that ZnO submicrorods have hexagon structure. Current-voltage curve for the structure has been reported. Electroluminescence curves (electroluminescence intensity versus wavelength) at different bias voltages have been presented and these results show narrowing in full width at half maximum in the spectra at high current density compared to photoluminescence excitation. The narrowing in the spectrum has been explained.

  18. Fourier transform infrared spectroscopy approach for measurements of photoluminescence and electroluminescence in mid-infrared

    Science.gov (United States)

    Zhang, Y. G.; Gu, Y.; Wang, K.; Fang, X.; Li, A. Z.; Liu, K. H.

    2012-05-01

    An improved Fourier transform infrared spectroscopy approach adapting to photoluminescence and electroluminescence measurements in mid-infrared has been developed, in which diode-pumped solid-state excitation lasers were adopted for photoluminescence excitation. In this approach, three different Fourier transform infrared modes of rapid scan, double modulation, and step scan were software switchable without changing the hardware or connections. The advantages and limitations of each mode were analyzed in detail. Using this approach a group of III-V and II-VI samples from near-infrared extending to mid-infrared with photoluminescence intensities in a wider range have been characterized at room temperature to demonstrate the validity and overall performances of the system. The weaker electroluminescence of quantum cascade lasers in mid-infrared band was also surveyed at different resolutions. Results show that for samples with relatively strong photoluminescence or electroluminescence out off the background, rapid scan mode is the most preferable. For weaker photoluminescence or electroluminescence overlapped with background, double modulation is the most effective mode. To get a better signal noise ratio when weaker photoluminescence or electroluminescence signal has been observed in double modulation mode, switching to step scan mode should be an advisable option despite the long data acquiring time and limited resolution.

  19. Fourier transform infrared spectroscopy approach for measurements of photoluminescence and electroluminescence in mid-infrared.

    Science.gov (United States)

    Zhang, Y G; Gu, Y; Wang, K; Fang, X; Li, A Z; Liu, K H

    2012-05-01

    An improved Fourier transform infrared spectroscopy approach adapting to photoluminescence and electroluminescence measurements in mid-infrared has been developed, in which diode-pumped solid-state excitation lasers were adopted for photoluminescence excitation. In this approach, three different Fourier transform infrared modes of rapid scan, double modulation, and step scan were software switchable without changing the hardware or connections. The advantages and limitations of each mode were analyzed in detail. Using this approach a group of III-V and II-VI samples from near-infrared extending to mid-infrared with photoluminescence intensities in a wider range have been characterized at room temperature to demonstrate the validity and overall performances of the system. The weaker electroluminescence of quantum cascade lasers in mid-infrared band was also surveyed at different resolutions. Results show that for samples with relatively strong photoluminescence or electroluminescence out off the background, rapid scan mode is the most preferable. For weaker photoluminescence or electroluminescence overlapped with background, double modulation is the most effective mode. To get a better signal noise ratio when weaker photoluminescence or electroluminescence signal has been observed in double modulation mode, switching to step scan mode should be an advisable option despite the long data acquiring time and limited resolution.

  20. Anaesthetic management in a case of huge plunging ranula.

    Science.gov (United States)

    Sheet, Jagabandhu; Mandal, Anamitra; Sengupta, Swapnadeep; Jana, Debaleena; Mukherji, Sudakshina; Swaika, Sarbari

    2014-01-01

    Plunging ranula is a rare form of mucous retention cyst arising from submandibular and sublingual salivary glands, which may occasionally become huge occupying the whole of the floor of the mouth and extending into the neck, thus, restricting the neck movement as well as disfiguring the normal airway anatomy. Without fiberoptic assistance, blind or retrograde nasal intubation remains valuable choices in this type of situation. Here, we present a case of successful management of airway by blind nasal intubation in a patient posted for excision of a huge plunging ranula.

  1. Huge Gastric Teratoma in an 8-Year Old Boy.

    Science.gov (United States)

    Sisodiya, Rajpal S; Ratan, Simmi K; Man, Parveen K

    2016-01-01

    Gastric teratoma is very rare tumor and usually presents in early infancy. An 8-year-old boy presented with a huge mass in abdomen extending from epigastrium to the pelvis. Ultrasound and CT scan of abdomen revealed a huge mass with solid and cystic components and internal calcifications. The preoperative diagnosis was a teratoma but not specifically gastric one. At operation, it was found to be gastric teratoma. The mass was excised completely with part of the stomach wall. The histopathology confirmed it to be mature gastric teratoma. The rarity of the teratoma with delayed presentation prompted us to report the case.

  2. Anaesthetic challenges in a patient presenting with huge neck teratoma

    Directory of Open Access Journals (Sweden)

    Gaurav Jain

    2013-01-01

    Full Text Available Paediatric airway management is a great challenge even for an experienced anaesthesiologist. Difficult airway in huge cervical teratoma further exaggerates the complexity. This case report is intended at describing the intubation difficulties that were confronted during the airway management of a three year old girl presenting with huge neck teratoma and respiratory distress. This patient was successfully intubated with uncuffed endotracheal tubes in second attempt under inhalational anaesthesia with halothane and spontaneous ventilation. This case exemplifies the importance of careful preoperative workup of an anticipated difficult airway in paediatric patients with neck swelling to minimize any perioperative complications.

  3. Huge pelvic mass secondary to wear debris causing ureteral obstruction.

    Science.gov (United States)

    Hananouchi, Takehito; Saito, Masanobu; Nakamura, Nobuo; Yamamoto, Tetsuya; Yonenobu, Kazuo

    2005-10-01

    We report an unusual granulomatous reaction of wear debris that produced a huge pelvic mass causing ureteral obstruction. A 72-year-old woman, who received a cemented total hip arthroplasty 30 years ago, was referred to the department of gynecology for examination of a pelvic mass. A computed tomography scan revealed a huge homogenous mass, measuring approximately 20 x 16 x 12 cm, including extensive osteolysis of the left pelvis around the acetabular component. Intravenous pyelogram revealed complete obstruction of the left ureter resulting in hydronephrosis of the left kidney. Histological examination from the biopsy specimen detected polyethylene wear debris in the mass.

  4. Anaesthetic management in a case of huge plunging ranula

    Science.gov (United States)

    Sheet, Jagabandhu; Mandal, Anamitra; Sengupta, Swapnadeep; Jana, Debaleena; Mukherji, Sudakshina; Swaika, Sarbari

    2014-01-01

    Plunging ranula is a rare form of mucous retention cyst arising from submandibular and sublingual salivary glands, which may occasionally become huge occupying the whole of the floor of the mouth and extending into the neck, thus, restricting the neck movement as well as disfiguring the normal airway anatomy. Without fiberoptic assistance, blind or retrograde nasal intubation remains valuable choices in this type of situation. Here, we present a case of successful management of airway by blind nasal intubation in a patient posted for excision of a huge plunging ranula. PMID:25886120

  5. Design of a superluminal ring laser gyroscope using multilayer optical coatings with huge group delay.

    Science.gov (United States)

    Qu, Tianliang; Yang, Kaiyong; Han, Xiang; Wu, Suyong; Huang, Yun; Luo, Hui

    2014-01-01

    We propose and analyze a superluminal ring laser gyroscope (RLG) using multilayer optical coatings with huge group delay (GD). This GD assisted superluminal RLG can measure the absolute rotation with a giant sensitivity-enhancement factor of ~10(3); while, the broadband FWHM of the enhancement factor can reach 20 MHz. This superluminal RLG is based on a traditional RLG with minimal re-engineering, and beneficial for miniaturization according to theoretical calculation. The idea of using GD coatings as a fast-light medium will shed lights on the design and application of fast-light sensors.

  6. Methods and apparatus of spatially resolved electroluminescence of operating organic light-emitting diodes using conductive atomic force microscopy

    Science.gov (United States)

    Hersam, Mark C. (Inventor); Pingree, Liam S. C. (Inventor)

    2008-01-01

    A conductive atomic force microscopy (cAFM) technique which can concurrently monitor topography, charge transport, and electroluminescence with nanometer spatial resolution. This cAFM approach is particularly well suited for probing the electroluminescent response characteristics of operating organic light-emitting diodes (OLEDs) over short length scales.

  7. Tunneling electron induced molecular electroluminescence from individual porphyrin J-aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Qiushi; Zhang, Chao; Zhang, Yang, E-mail: zhyangnano@ustc.edu.cn, E-mail: zcdong@ustc.edu.cn; Zhang, Yao; Liao, Yuan; Dong, Zhenchao, E-mail: zhyangnano@ustc.edu.cn, E-mail: zcdong@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2015-07-27

    We investigate molecular electroluminescence from individual tubular porphyrin J-aggregates on Au(111) by tunneling electron excitations in an ultrahigh-vacuum scanning tunneling microscope (STM). High-resolution STM images suggest a spiral tubular structure for the porphyrin J-aggregate with highly ordered “brickwork”-like arrangements. Such aggregated nanotube is found to behave like a self-decoupled molecular architecture and shows red-shifted electroluminescence characteristics of J-aggregates originated from the delocalized excitons. The positions of the emission peaks are found to shift slightly depending on the excitation sites, which, together with the changes in the observed spectral profiles with vibronic progressions, suggest a limited exciton coherence number within several molecules. The J-aggregate electroluminescence is also found unipolar, occurring only at negative sample voltages, which is presumably related to the junction asymmetry in the context of molecular excitations via the carrier injection mechanism.

  8. Dye linked conjugated homopolymers: using conjugated polymer electroluminescence to optically pump porphyrin-dye emission

    DEFF Research Database (Denmark)

    Nielsen, K.T.; Spanggaard, H.; Krebs, Frederik C

    2004-01-01

    . Electroluminescent devices of the homopolymer itself and of the zinc-porphyrin containing polymer were prepared and the nature of the electroluminescence was characterized. The homopolymer segments were found to optically pump the emission of the zinc-porphyrin dye moities. The homopolymer exhibits blue......Zinc-porphyrin dye molecules were incorporated into the backbone of a conjugated polymer material by a method, which allowed for the incorporation of only one zinc-porphyrin dye molecule into the backbone of each conjugated polymer molecule. The electronic properties of the homopolymer were......-green emission and the zinc-porphyrin linked homopolymers emit near-infrared/infrared light. This was demonstrated to be due to electroluminescence pumping of the zinc-porphyrin moieties that were covalently linked to homopolymer material. When only one zinc-porphyrin dye was incorporated into the backbone...

  9. Performance evaluation of multi-junction solar cells by spatially resolved electroluminescence microscopy.

    Science.gov (United States)

    Kong, Lijing; Wu, Zhiming; Chen, Shanshan; Cao, Yiyan; Zhang, Yong; Li, Heng; Kang, Junyong

    2015-01-01

    An electroluminescence microscopy combined with a spectroscopy was developed to visually analyze multi-junction solar cells. Triple-junction solar cells with different conversion efficiencies were characterized by using this system. The results showed that the mechanical damages and material defects in solar cells can be clearly distinguished, indicating a high-resolution imaging. The external quantum efficiency (EQE) measurements demonstrated that different types of defects or damages impacted cell performance in various degrees and the electric leakage mostly degraded the EQE. Meanwhile, we analyzed the relationship between electroluminescence intensity and short-circuit current density J SC. The results indicated that the gray value of the electroluminescence image corresponding to the intensity was almost proportional to J SC. This technology provides a potential way to evaluate the current matching status of multi-junction solar cells.

  10. Energy and Charge Transfer from Guest to Host in Doped Organic Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    李宏建; 彭景翠; 许雪梅; 瞿述; 罗小华; 赵楚军

    2002-01-01

    The luminescence properties of doped organic electroluminescent devices are explained by means off Hamiltonian model. The results show that there is a corresponding relation between the amount of transferred charge and the change of the energy originating from charge transfer, and the relation can be influenced by dopant concentration.As the amount of transferred charge increases, the total energy decreases and the luminescence intensity increases.Therefore, we deduce that the energy transfer from guest to host may be derived from the charge transfer. For a given organic electroluminescent device, the maximum value of the conductivity can be observed in a specific dopant concentration. The calculated results show that the greater the transferred charges, the higher the conductivities in doped organic electroluminescent devices. The results agree basically with experimental results.

  11. Electroluminescence from indirect band gap semiconductor ReS2

    Science.gov (United States)

    Gutiérrez-Lezama, Ignacio; Aditya Reddy, Bojja; Ubrig, Nicolas; Morpurgo, Alberto F.

    2016-12-01

    It has been recently claimed that bulk crystals of transition metal dichalcogenide (TMD) ReS2 are direct band gap semiconductors, which would make this material an ideal candidate, among all TMDs, for the realization of efficient opto-electronic devices. The situation is however unclear, because even more recently an indirect transition in the PL spectra of this material has been detected, whose energy is smaller than the supposed direct gap. To address this issue we exploit the properties of ionic liquid gated field-effect transistors (FETs) to investigate the gap structure of bulk ReS2. Using these devices, whose high quality is demonstrated by a record high electron FET mobility of 1100 cm2 V-1 s-1 at 4 K, we can induce hole transport at the surface of the material and determine quantitatively the smallest band gap present in the material, irrespective of its direct or indirect nature. The value of the band gap is found to be 1.41 eV, smaller than the 1.5 eV direct optical transition but in good agreement with the energy of the indirect optical transition, providing an independent confirmation that bulk ReS2 is an indirect band gap semiconductor. Nevertheless, contrary to the case of more commonly studied semiconducting TMDs (e.g., MoS2, WS2, etc) in their bulk form, we also find that ReS2 FETs fabricated on bulk crystals do exhibit electroluminescence when driven in the ambipolar injection regime, likely because the difference between direct and indirect gap is only 100 meV. We conclude that ReS2 does deserve more in-depth investigations in relation to possible opto-electronic applications.

  12. Smart Cities as Support and Legacy of Huge Sport Events

    Directory of Open Access Journals (Sweden)

    TAURION, C.

    2012-12-01

    Full Text Available In this paper we discuss the concept of a smart city and the importance of huge Sport events as an incentive to the creation of the infrastructure necessary for the development of cities that provide quality of life for all its citizens using information technology.

  13. The big, large and huge case of state-building

    DEFF Research Database (Denmark)

    Harste, Gorm

      Using communication theory as point of departure, it is not evident how to study macro phenomena. Michel Foucault limited his studies to a non-Grand Theory when studying discursive events. At the same time, Charles Tilly wrote about Big Structures, Large Processes, Huge Comparisons when trying...

  14. [Experience of surgical treatment of huge mediastinal tumors].

    Science.gov (United States)

    Li, Yuanbo; Zhang, Yi; Xu, Qingsheng; Su, Lei; Zhi, Xiuyi; Wang, Ruotian; Qian, Kun; Hu, Mu; Liu, Lei

    2014-09-23

    The diagnosis and surgical treatment of 36 huge mediastinal tumors were summarized in order to evaluate the effect and safety of the operation. Thirty-six huge mediastinal tumor patients treated in our department from June 2006 to June 2013 were retrospective analyzed, of whom clinical manifestations, diagnosis, surgical treatment and prognosis were carefully collected. Twenty-three cases were men and 13 were women. The average age was 39.2 years old. The pathology turned out to be benign in 23 cases and malignant in 13 cases. Complete resection was achieved in 34 cases while palliative resection in 2 cases with no perioperative death. Six cases had developed postoperative complications but all recovered after active treatment. Patients who had been diagnosed with benign tumors were all alive after follow-up periods of 6 months to 7 years. Nine malignat tumor patients developed recurrence or metastasis, including seven deaths. Surgery played a vital role in the diagnosis and treatment of huge mediastinal tumors. Preoperative diagnosis, accurate surgical approach and careful operation were the key to successful treatment. Benign huge mediastinal tumors had excellent prognosis with surgery.

  15. A Huge Ovarian Dermoid Cyst: Successful Laparoscopic Total Excision.

    Science.gov (United States)

    Uyanikoglu, Hacer; Dusak, Abdurrahim

    2017-08-01

    Giant ovarian cysts, ≥15 cm in diameter, are quite rare in women of reproductive age. Here, we present a case of ovarian cyst with unusual presentation treated by laparoscopic surgery. On histology, mass was found to be mature cystic teratoma. The diagnostic and management challenges posed by this huge ovarian cyst were discussed in the light of the literature.

  16. Huge mediastinal liposarcoma resected by clamshell thoracotomy: a case report.

    Science.gov (United States)

    Toda, Michihito; Izumi, Nobuhiro; Tsukioka, Takuma; Komatsu, Hiroaki; Okada, Satoshi; Hara, Kantaro; Ito, Ryuichi; Shibata, Toshihiko; Nishiyama, Noritoshi

    2017-12-01

    Liposarcoma is the single most common soft tissue sarcoma. Because mediastinal liposarcomas often grow rapidly and frequently recur locally despite adjuvant chemotherapy and radiotherapy, they require complete excision. Therefore, the feasibility of achieving complete surgical excision must be carefully considered. We here report a case of a huge mediastinal liposarcoma resected via clamshell thoracotomy. A 64-year-old man presented with dyspnea on effort. Cardiomegaly had been diagnosed 6 years previously, but had been left untreated. A computed tomography scan showed a huge (36 cm diameter) anterior mediastinal tumor expanding into the pleural cavities bilaterally. The tumor comprised mostly fatty tissue but contained two solid areas. Echo-guided needle biopsies were performed and a diagnosis of an atypical lipomatous tumor was established by pathological examination of the biopsy samples. Surgical resection was performed via a clamshell incision, enabling en bloc resection of this huge tumor. Although there was no invasion of surrounding organs, the left brachiocephalic vein was resected because it was circumferentially surrounded by tumor and could not be preserved. The tumor weighed 3500 g. Pathologic examination of the resected tumor resulted in a diagnosis of a biphasic tumor comprising dedifferentiated liposarcoma and non-adipocytic sarcoma with necrotic areas. The patient remains free of recurrent tumor 20 months postoperatively. Clamshell incision provides an excellent surgical field and can be performed safely in patients with huge mediastinal liposarcomas.

  17. DC and AC electroluminescence in silicon nanoparticles embedded in silicon-rich oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Sanchez, A; Aceves-Mijares, M [INAOE, Electronics Department, Apartado 51, Puebla, 72000 (Mexico); Barreto, J; DomInguez, C [Instituto de Microelectronica de Barcelona, IMB-CNM (CSIC), Barcelona (Spain); Peralvarez, M; Garrido, B [EME, Departament d' Electronica, Universitat de Barcelona, MartI i Franques 1, 08028 Barcelona (Spain); Luna-Lopez, J A, E-mail: amorales@inaoep.mx [CIDS-BUAP, Apartado 1651, Puebla, Pue, 72000 (Mexico)

    2010-02-26

    Electroluminescent properties of silicon-rich oxide (SRO) films were studied using metal oxide semiconductor-(MOS)-like devices. Thin SRO films with 4 at.% of silicon excess were deposited by low pressure chemical vapour deposition followed by a thermal annealing at 1100 deg. C. Intense continuous visible and infrared luminescence has been observed when devices are reversely and forwardly bias, respectively. After an electrical stress, the continuous electroluminescence (EL) is quenched but devices show strong field-effect EL with pulsed polarization. A model based on conductive paths-across the SRO film- has been proposed to explain the EL behaviour in these devices.

  18. Visible electroluminescence on FTO/thin SRO/n-Si structures

    Energy Technology Data Exchange (ETDEWEB)

    Leyva, K.M., E-mail: kmonfil@inaoep.mx [Department of Electronics, INAOE, Apdo., 51, Puebla, 72000 Pue. (Mexico); Aceves-Mijares, M.; Yu, Z. [Department of Electronics, INAOE, Apdo., 51, Puebla, 72000 Pue. (Mexico); Flores, F. [CDIS-ICUAP-BUAP, Apdo. 1651, Puebla, 72000 Pue. (Mexico); Morales-Sanchez, A. [Department of Electronics, INAOE, Apdo., 51, Puebla, 72000 Pue. (Mexico); Alcantara, S. [CDIS-ICUAP-BUAP, Apdo. 1651, Puebla, 72000 Pue. (Mexico)

    2010-10-25

    Photoluminescence (PL) and electroluminescence (EL) of silicon rich oxide (SRO) films deposited by low pressure chemical vapour deposition (LPCVD) have been researched. SRO films emit an intense PL band between 550 and 850 nm. EL was studied using fluorine-doped tin oxide (FTO)/thin SRO/n-Si structures. Intense and stable electroluminescence was observed under reverse bias. EL is observed between 400 and 900 nm with two main peaks around 450 and 600 nm. EL was related to charge injection through conductive paths and radiative recombination between traps or defect levels.

  19. Blue electroluminescence of ZnSe thin film in an organic-inorganic heterostructures device

    Energy Technology Data Exchange (ETDEWEB)

    Yu Wenge [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China) and Changchun Institute of Optics and Fine Mechanics and Physics, CAS, Changchun 130021 (China) and Shenyang Institute of Aeronautical Engineering, Shenyang 110034 (China)]. E-mail: yu_wenge@hotmail.com; Xu Zheng [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Teng, Feng [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Yang Shengyi [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Hou Yanbing [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Qian Lei [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Qu Chong [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Quan Sanyu [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Xu Xurong [Institute of Optoelectronics, Beijing Jiaotong University, Beijing 100044 (China); Changchun Institute of Optics and Fine Mechanics and Physics, CAS, Changchun 130021 (China)

    2005-05-02

    Blue light emission of ZnSe thin film from the ZnSe/poly-(N-vinyl-carbazole) (PVK) heterostructures was obtained. The threshold voltage is about 10 V and the brightness of 12 cd/m{sup 2} was obtained at 17 V. From the electroluminescence (EL), the photoluminescence (PL), the transient electroluminescence and the dependence of EL intensity on the applied voltage and current, we attribute the EL of ZnSe to carrier injection and recombination. This new phenomenon not only opens a new mechanism of II-IV compounds in low voltage injection EL but also provides a new way of obtaining blue emission.

  20. Room temperature electroluminescence from mechanically formed van der Waals III–VI homojunctions and heterojunctions

    OpenAIRE

    Balakrishnan, Nilanthy; Kudrynskyi, Zakhar R.; Fay, Mike W.; Mudd, Garry W.; Svatek, Simon A; Makarovsky, Oleg; Kovalyuk, Zakhar D.; Eaves, Laurence; Peter H. Beton; Patanè, Amalia

    2014-01-01

    Room temperature electroluminescence from semiconductor junctions is demonstrated. The junctions are fabricated by the exfoliation and direct mechanical adhesion of InSe and GaSe van der Waals layered crystals. Homojunction diodes formed from layers of p- and n-type InSe exhibit electroluminescence at energies close to the bandgap energy of InSe (Eg= 1.26 eV). In contrast, heterojunction diodes formed by combining layers of p-type GaSe and n-type InSe emit photons at lower energies, which is ...

  1. Efficient electroluminescence from a perylenediimide fluorophore obtained from a simple solution processed OLED

    Energy Technology Data Exchange (ETDEWEB)

    Cespedes-Guirao, F J; Fernandez-Lazaro, F; Sastre-Santos, A [Division de Quimica Organica, Instituto de Bioingenieria, Universidad Miguel Hernandez, Avda. de la Universidad, s/n, Elche 03202 (Spain); Garcia-Santamaria, S; Bolink, H J [Instituto de Ciencia Molecular, Universidad de Valencia, PO Box 22085, ES-46071 Valencia (Spain)], E-mail: henk.bolink@uv.es, E-mail: asastre@umh.es, E-mail: fdofdez@umh.es

    2009-05-21

    Simple solution processed organic light emitting diodes are used to screen the performance of two types of highly efficient, narrow band red emitting fluorescent perylenediimides (PDIs). PDIs substituted at the diimide positions seem to form aggregates in the thin film architecture as evidenced by the shifted electroluminescent spectrum. When substituted on the bay position and when used both as the emitting and the electron transporting specie, bright electroluminescence with a narrow width around 610 nm reaching 500 cd m{sup -2} at moderate voltages was observed, demonstrating the usefulness of these fluorophores for OLED applications.

  2. Electroluminescent properties of three ternary europium complexes with different phenanthroline derivatives

    Institute of Scientific and Technical Information of China (English)

    BIAN; Zuqiang; GAO; Deqing; GUAN; Min; XIN; Hao; LI; Fuyou

    2004-01-01

    [1]Sun, P. P., Duan, J. P., Shih, H. T. et al., Europium complex as a highly efficient red emitter in electroluminescent devices, Appl.Phys. Lett., 2002, 81: 792-793.[2]Heil, H., Steiger, J., Schmechel, R. et al., Tri(dibenzolymethane)(monophenanthroline) europium(Ⅲ) based red emitting organic light emitting diodes, J. Appl. Phys., 2001, 90: 5357-5362.[3]Liang, C. L., Zhao, D., Hong, Z. R. et al., Improved performance of electroluminescent devices based on an europium complex,Appl. Phys. Lett., 2000, 76: 67-69.[4]Kido, J., Hayase, H., Honggawa, K. et al., Bright red light-emitting organic electroluminescent devices having a europium complex as an emitter, Appl. Phys. Lett., 1994, 65: 2124-2126.[5]Mitsuharu, N., Kazutaka, I., Masanao, E., Efficient red electroluminescence from new europium complex, Chem. Lett., 2001:320-321.[6]Kido, J., Nagai, K., Okamoto, Y., Organic electroluminescem devices using lanthanide complexes, J. Alloys. Compd., 1993, 192:30-33.[7]Wang, J., Wang, R., Yang, J. et al., First oxadiazole-functionalized terbium(Ⅲ) β-diketonate for organic electroluminescence, J. Am.Chem. Soc., 2001, 123: 6179-6180.[8]Capecchi, S., Renault, O., Moon, D. G., High-efficiency organic electroluminescent devices using an organoterbium emitter, Adv.Mater., 2000, 12: 1591-1594.[9]Huang, L., Wang, K. Z., Huang, C. H. et al., Synthetic and electroluminescent properties of two novel europium complexes with benzimidazole derivatives as second ligands, Synth. Met., 2002,128: 241-245.[10]Huang, L., Wang, K. Z., Huang, C. H. et al., Bright red electroluminescent devices using novel second-ligand-contained europium complexes as emitting layers, J. Mater. Chem., 2001, 11: 790-793.[11]Hu, W. P., Matsumura, M., Wang, M. Z. et al., Efficient red electroluminescence from devices having multilayers of an europium complex, Appl. Phys. Lett., Appl. Phys. Lett., 2000, 77: 4271-4273.[12]Yu, G., Liu, Y. Q., Wu, X. et al., Soluble

  3. Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions.

    Science.gov (United States)

    Cueff, Sébastien; Labbé, Christophe; Jambois, Olivier; Berencén, Yonder; Kenyon, Anthony J; Garrido, Blas; Rizk, Richard

    2012-09-24

    We present an analysis of factors influencing carrier transport and electroluminescence (EL) at 1.5 µm from erbium-doped silicon-rich silica (SiOx) layers. The effects of both the active layer thickness and the Si-excess content on the electrical excitation of erbium are studied. We demonstrate that when the thickness is decreased from a few hundred to tens of nanometers the conductivity is greatly enhanced. Carrier transport is well described in all cases by a Poole-Frenkel mechanism, while the thickness-dependent current density suggests an evolution of both density and distribution of trapping states induced by Si nanoinclusions. We ascribe this observation to stress-induced effects prevailing in thin films, which inhibit the agglomeration of Si atoms, resulting in a high density of sub-nm Si inclusions that induce traps much shallower than those generated by Si nanoclusters (Si-ncs) formed in thicker films. There is no direct correlation between high conductivity and optimized EL intensity at 1.5 µm. Our results suggest that the main excitation mechanism governing the EL signal is impact excitation, which gradually becomes more efficient as film thickness increases, thanks to the increased segregation of Si-ncs, which in turn allows more efficient injection of hot electrons into the oxide matrix. Optimization of the EL signal is thus found to be a compromise between conductivity and both number and degree of segregation of Si-ncs, all of which are governed by a combination of excess Si content and sample thickness. This material study has strong implications for many electrically-driven devices using Si-ncs or Si-excess mediated EL.

  4. Red electroluminescence of ruthenium sensitizer functionalized by sulfonate anchoring groups.

    Science.gov (United States)

    Shahroosvand, Hashem; Abbasi, Parisa; Mohajerani, Ezeddin; Janghouri, Mohammad

    2014-06-28

    We have synthesized five novel Ru(ii) phenanthroline complexes with an additional aryl sulfonate ligating substituent at the 5-position [Ru(L)(bpy)2](BF4)2 (1), [Ru(L)(bpy)(SCN)2] (2), [Ru(L)3](BF4)2 (3), [Ru(L)2(bpy)](BF4)2 (4) and [Ru(L)(BPhen)(SCN)2] (5) (where L = 6-one-[1,10]phenanthroline-5-ylamino)-3-hydroxynaphthalene 1-sulfonic, bpy = 2,2'-bipyridine, BPhen = 4,7-diphenyl-1,10-phenanthroline), as both photosensitizers for oxide semiconductor solar cells (DSSCs) and light emitting diodes (LEDs). The absorption and emission maxima of these complexes red shifted upon extending the conjugation of the phenanthroline ligand. Ru phenanthroline complexes exhibit broad metal to ligand charge transfer-centered electroluminescence (EL) with a maximum near 580 nm. Our results indicated that a particular structure (2) can be considered as both DSSC and OLED devices. The efficiency of the LED performance can be tuned by using a range of ligands. Device (2) has a luminance of 550 cd m(-2) and maximum efficiency of 0.9 cd A(-1) at 18 V, which are the highest values among the five devices. The turn-on voltage of this device is approximately 5 V. The role of auxiliary ligands in the photophysical properties of Ru complexes was investigated by DFT calculation. We have also studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phenanthroline complexes and an iodine redox electrolyte. A solar energy to electricity conversion efficiency (η) of 0.67% was obtained for Ru complex (2) under standard AM 1.5 irradiation with a short-circuit photocurrent density (Jsc) of 2.46 mA cm(-2), an open-circuit photovoltage (Voc) of 0.6 V, and a fill factor (ff) of 40%, which are all among the highest values for ruthenium sulfonated anchoring groups reported so far. Monochromatic incident photon to current conversion efficiency was 23% at 475 nm. Photovoltaic studies clearly indicated dyes with two SCN substituents yielded a higher Jsc for the

  5. Huge uterine-cervical diverticulum mimicking as a cyst

    Directory of Open Access Journals (Sweden)

    S Chufal

    2012-01-01

    Full Text Available Here we report an incidental huge uterine-cervical diverticulum from a total abdominal hysterectomy specimen in a perimenopausal woman who presented with acute abdominal pain. The diverticulum was mimicking with various cysts present in the lateral side of the female genital tract. Histopathological examination confirmed this to be a cervical diverticulum with communication to uterine cavity through two different openings. They can attain huge size if left ignored for long duration and present a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, diverticula should also be included as a differential diagnosis. Its histopathological confirmation also highlights that diverticula can present as an acute abdomen, requiring early diagnosis with appropriate timely intervention. Immunohistochemistry CD 10 has also been used to differentiate it from a mesonephric cyst.

  6. Huge uterine-cervical diverticulum mimicking as a cyst.

    Science.gov (United States)

    Chufal, S; Thapliyal, Naveen; Gupta, Manoj; Pangtey, Nirmal

    2012-01-01

    Here we report an incidental huge uterine-cervical diverticulum from a total abdominal hysterectomy specimen in a perimenopausal woman who presented with acute abdominal pain. The diverticulum was mimicking with various cysts present in the lateral side of the female genital tract. Histopathological examination confirmed this to be a cervical diverticulum with communication to uterine cavity through two different openings. They can attain huge size if left ignored for long duration and present a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, diverticula should also be included as a differential diagnosis. Its histopathological confirmation also highlights that diverticula can present as an acute abdomen, requiring early diagnosis with appropriate timely intervention. Immunohistochemistry CD 10 has also been used to differentiate it from a mesonephric cyst.

  7. A case of huge primary liposarcoma in the liver

    Institute of Scientific and Technical Information of China (English)

    Liang-Mou Kuo; Hong-Shiue Chou; Kun-Ming Chan; Ming-Chin Yu; Wei-Chen Lee

    2006-01-01

    Primary liver liposarcoma is a rare disease. Because of its rarity, the knowledge of the clinical course, management, and prognosis of primary liver liposarcoma are all limited for clinicians. A 61-year-old female patient who suffered from a huge primary liposarcoma in the central portion of the liver had the clinical presentations of fever, nausea, vomiting, jaundice, and body weight loss.The huge tumor was resected successfully. However,the tumor recurred repeatedly and she had repeated hepatectomies to remove the tumor. Thetumor became aggravating after repeated surgeries. Eventually, the patient had cervical spinal metastasis of liposarcoma and she survived for 26 months after liver liposarcoma was diagnosed. Although the tumor may become aggravating after repeated surgeries, repeated hepatectomies are still the best policy to achieve a long-term survival for the patients.

  8. Black Hole Firewalls Require Huge Energy of Measurement

    CERN Document Server

    Hotta, Masahiro; Funo, Ken

    2013-01-01

    The unitary moving mirror model is one of the best quantum systems for checking the reasoning of the firewall paradox in quantum black holes. The reasoning of Almheiri et al. inevitably raises a firewall paradox in the model. We resolve this paradox from the viewpoint of the energy cost of quantum measurements. No firewall with a deadly, huge energy flux appears, as long as the energy for the measurement is much smaller than the ultraviolet cutoff scale.

  9. Severe microphthalmos with cyst and unusually huge dermolipoma.

    Science.gov (United States)

    Li, Weidong; Zhang, Ping; Chen, Qiwen; Ye, Xuelian; Li, Jianqun; Yan, Jianhua

    2015-03-01

    The purpose of this study was to report an unusual case of severe microphthalmos, together with an orbital cyst and huge ocular surface dermolipoma. This is a clinical report relating clinical features as well as imaging and histopathologic findings, along with surgical management of the patient. A 5-month-old Chinese male infant was referred, with 2 large masses in the left eye that were present since birth. Ocular examination results revealed a complete absence of any eye structures in the left orbit. In its place were 2 large masses between the left upper and lower palpebral fissure. One was a 3 × 3 × 2.5-cm spherical red tumor with a smooth surface. The other was a large solid spherical tumor, 4 × 4 × 5 cm, covered with normal skin located in the temporal region and attached to the red mass by a pedicle. Orbital magnetic resonance imaging examination findings confirmed that no eye structures were present in the left orbit. However, a cystic lesion was found in the left orbit, with a low signal on T1-weighted imaging and high signal on T2-weighted imaging, and another huge spherical heterogeneous mass was located "outside" the left orbit. Anterior orbitotomy by conjunctival incision was performed under general anesthesia. A spherical cystic mass of 1.5 × 1.5 × 1.6 cm, a small eye of 0.7 × 0.7 × 0.6 cm, and a huge dermolipoma were removed completely. Pathologic examination results confirmed the diagnosis of severe microphthalmos, together with orbital dermoid cyst and dermolipoma. This rare case demonstrates that severe microphthalmos with a cyst may be completely covered by conjunctiva and associated with an unusually huge dermolipoma.

  10. Huge plastic bezoar: a rare cause of gastrointestinal obstruction.

    Science.gov (United States)

    Yaka, Mbarek; Ehirchiou, Abdelkader; Alkandry, Tariq Tajdin Sifeddine; Sair, Khalid

    2015-01-01

    Bezoars are rare causes of gastrointestinal obstruction. Basically, they are of four types: trichobezoars, phytobezoars, pharmacobezoars, and lactobezoars. Some rare types of bezoars are also known. In this article a unique case of plastic bezoars is presented. We describe a girl aged 14 years who ingested large amounts of plastic material used for knitting chairs and charpoys. The conglomerate of plastic threads, entrapped food material and other debris, formed a huge mass occupying the whole stomach and extended into small bowel.

  11. A Huge Cystic Retroperitoneal Lymphangioma Presenting with Back Pain

    Science.gov (United States)

    Kubachev, Kubach; Abdullaev, Elbrus; Babyshin, Valentin; Neronov, Dmitriy; Abdullaev, Abakar

    2016-01-01

    Retroperitoneal lymphangioma is a rare location and type of benign abdominal tumors. The clinical presentation of this rare disease is nonspecific, ranging from abdominal distention to sepsis. Here we present a 73-year-old female patient with 3-month history of back pain. USG and CT revealed a huge cystic mass which was surgically excised and appeared to be lymphangioma on histopathology. PMID:27843456

  12. Huge Left Atrium Accompanied by Normally Functioning Prosthetic Valve.

    Science.gov (United States)

    Sabzi, Feridoun

    2015-01-01

    Giant left atria are defined as those measuring larger than 8 cm and are typically found in patients who have rheumatic mitral valve disease with severe regurgitation. Enlargement of the left atrium may create compression of the surrounding structures such as the esophagus, pulmonary veins, respiratory tract, lung, inferior vena cava, recurrent laryngeal nerve, and thoracic vertebrae and lead to dysphagia, respiratory dysfunction, peripheral edema, hoarse voice, or back pain. However, a huge left atrium is usually associated with rheumatic mitral valve disease but is very rare in a normally functioning prosthetic mitral valve, as was the case in our patient. A 46-year-old woman with a past medical history of mitral valve replacement and chronic atrial fibrillation was admitted to our hospital with a chief complaint of cough and shortness of breath, worsened in the last month. Physical examination showed elevated jugular venous pressure, respiratory distress, cardiac cachexia, heart failure, hepatomegaly, and severe edema in the legs. Chest radiography revealed an inconceivably huge cardiac sell-out. Transthoracic echocardiography demonstrated a huge left atrium, associated with thrombosis, and normal function of the prosthetic mitral valve. Cardiac surgery with left atrial exploration for the extraction of the huge thrombosis and De Vega annuloplasty for tricuspid regurgitation were carried out. The postoperative course was eventful due to right ventricular failure and low cardiac output syndrome; and after two days, the patient expired with multiple organ failure. Thorough literature review showed that our case was the largest left atrium (20 × 22 cm) reported thus far in adults with a normal prosthetic mitral valve function.

  13. Huge Left Atrium Accompanied by Normally Function- ing Prosthetic Valve

    Directory of Open Access Journals (Sweden)

    Feridoun Sabzi

    2015-10-01

    Full Text Available Giant left atria are defined as those measuring larger than 8 cm and are typically found in patients who have rheumatic mitral valve disease with severe regurgitation. Enlargement of the left atrium may create compression of the surrounding structures such as the esophagus, pulmonary veins, respiratory tract, lung, inferior vena cava, recurrent laryngeal nerve, and thoracic vertebrae and lead to dysphagia, respiratory dysfunction, peripheral edema, hoarse voice, or back pain. However, a huge left atrium is usually associated with rheumatic mitral valve disease but is very rare in a normally functioning prosthetic mitral valve, as was the case in our patient. A 46-year-old woman with a past medical history of mitral valve replacement and chronic atrial fibrillation was admitted to our hospital with a chief complaint of cough and shortness of breath, worsened in the last month. Physical examination showed elevated jugular venous pressure, respiratory distress, cardiac cachexia, heart failure, hepatomegaly, and severe edema in the legs. Chest radiography revealed an inconceivably huge cardiac sell-out. Transthoracic echocardiography demonstrated a huge left atrium, associated with thrombosis, and normal function of the prosthetic mitral valve. Cardiac surgery with left atrial exploration for the extraction of the huge thrombosis and De Vega annuloplasty for tricuspid regurgitation were carried out. The postoperative course was eventful due to right ventricular failure and low cardiac output syndrome; and after two days, the patient expired with multiple organ failure. Thorough literature review showed that our case was the largest left atrium (20 × 22 cm reported thus far in adults with a normal prosthetic mitral valve function.

  14. Huge Nevus Lipomatosus Cutaneous Superficialis on Back: An Unusual Presentation.

    Science.gov (United States)

    Das, Dipti; Das, Anupam; Bandyopadhyay, Debabrata; Kumar, Dhiraj

    2015-01-01

    Nevus lipomatosus cutaneous superficialis (NLCS) is a benign dermatosis, histologically characterized by the presence of mature ectopic adipocytes in the dermis. We hereby report a case of a 10-year-old boy who presented with multiple huge swellings on the scapular regions and lower back. The lesions were surmounted by small papules, along with peau-d orange appearance at places. Histology showed features consistent with NLCS. The case is being reported for the unusual clinical presentation.

  15. Huge nevus lipomatosus cutaneous superficialis on back: An unusual presentation

    Directory of Open Access Journals (Sweden)

    Dipti Das

    2015-01-01

    Full Text Available Nevus lipomatosus cutaneous superficialis (NLCS is a benign dermatosis, histologically characterized by the presence of mature ectopic adipocytes in the dermis. We hereby report a case of a 10-year-old boy who presented with multiple huge swellings on the scapular regions and lower back. The lesions were surmounted by small papules, along with peau-d orange appearance at places. Histology showed features consistent with NLCS. The case is being reported for the unusual clinical presentation.

  16. Huge Intravascular Tumor Extending to the Heart: Leiomyomatosis

    Directory of Open Access Journals (Sweden)

    Suat Doganci

    2015-01-01

    Full Text Available Intravenous leiomyomatosis (IVL is a rare neoplasm characterized by histologically benign-looking smooth muscle cell tumor mass, which is growing within the intrauterine and extrauterine venous system. In this report we aimed to present an unusual case of IVL, which is originating from iliac vein and extended throughout to right cardiac chambers. A 49-year-old female patient, who was treated with warfarin sodium due to right iliac vein thrombosis, was admitted to our department with intermittent dyspnea, palpitation, and dizziness. Physical examination was almost normal except bilateral pretibial edema. On magnetic resonance venography, there was an intravenous mass, which is originated from right internal iliac vein and extended into the inferior vena cava. Transthoracic echocardiography and transesophageal echocardiography revealed a huge mass extending from the inferior vena cava through the right atrium, with obvious venous occlusion. Thoracic, abdominal, and pelvic MR showed an intravascular mass, which is concordant with leiomyomatosis. Surgery was performed through median sternotomy. A huge mass with 25-cm length and 186-gr weight was excised through right atrial oblique incision, on beating heart with cardiopulmonary bypass. Histopathologic assessment was compatible with IVL. Exact strategy for the surgical treatment of IVL is still controversial. We used one-stage approach, with complete resection of a huge IVL extending from right atrium to right iliac vein. In such cases, high recurrence rate is a significant problem; therefore it should be kept in mind.

  17. Multimodality treatment with radiotherapy for huge hepatocellular carcinoma.

    Science.gov (United States)

    Han, Hee Ji; Kim, Mi Sun; Cha, Jihye; Choi, Jin Sub; Han, Kwang Hyub; Seong, Jinsil

    2014-01-01

    For huge hepatocellular carcinoma (HCC), therapeutic decisions have varied from local therapy to systemic therapy, with radiotherapy (RT) playing only a palliative role. In this study, we investigated whether multimodality treatment involving RT could be effective in huge HCC. This study was performed in 116 patients with HCC >10 cm. The number of patients in stage II, III and IV was 12, 54 and 50, respectively. RT was given as a combined modality in most patients. The median dose was 45 Gy, with 1.8 Gy per fraction. The median overall survival (OS) and progression-free survival (PFS) were 14.8 and 6.5 months, respectively. The median infield PFS was not reached. Infield failure, outfield intrahepatic and extrahepatic failure were observed in 8.6, 18.1, and 12.1% of patients, respectively. For OS and PFS, number of tumors, initial alpha-fetoprotein (AFP) level, treatment response, percent AFP decrement, and hepatic resection were significant prognostic factors. Tumor characteristics and treatment response were significantly different between long-term survivors and the other patients. Although huge HCC presents an aggressive clinical course, multimodality approaches involving RT can offer an opportunity for prolonged survival. © 2014 S. Karger AG, Basel.

  18. Huge Intravascular Tumor Extending to the Heart: Leiomyomatosis.

    Science.gov (United States)

    Doganci, Suat; Kaya, Erkan; Kadan, Murat; Karabacak, Kubilay; Erol, Gökhan; Demirkilic, Ufuk

    2015-01-01

    Intravenous leiomyomatosis (IVL) is a rare neoplasm characterized by histologically benign-looking smooth muscle cell tumor mass, which is growing within the intrauterine and extrauterine venous system. In this report we aimed to present an unusual case of IVL, which is originating from iliac vein and extended throughout to right cardiac chambers. A 49-year-old female patient, who was treated with warfarin sodium due to right iliac vein thrombosis, was admitted to our department with intermittent dyspnea, palpitation, and dizziness. Physical examination was almost normal except bilateral pretibial edema. On magnetic resonance venography, there was an intravenous mass, which is originated from right internal iliac vein and extended into the inferior vena cava. Transthoracic echocardiography and transesophageal echocardiography revealed a huge mass extending from the inferior vena cava through the right atrium, with obvious venous occlusion. Thoracic, abdominal, and pelvic MR showed an intravascular mass, which is concordant with leiomyomatosis. Surgery was performed through median sternotomy. A huge mass with 25-cm length and 186-gr weight was excised through right atrial oblique incision, on beating heart with cardiopulmonary bypass. Histopathologic assessment was compatible with IVL. Exact strategy for the surgical treatment of IVL is still controversial. We used one-stage approach, with complete resection of a huge IVL extending from right atrium to right iliac vein. In such cases, high recurrence rate is a significant problem; therefore it should be kept in mind.

  19. Organic solution-processible electroluminescent molecular glasses for non-doped standard red OLEDs with electrically stable chromaticity

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Xiaoman; Zuo, Weiwei; Liu, Yingliang, E-mail: liuylxn@sohu.com; Zhang, Zhenru; Zeng, Cen; Xu, Shengang; Cao, Shaokui, E-mail: caoshaokui@zzu.edu.cn

    2015-10-15

    Highlights: • The D–A–D electroluminescent molecular glasses are synthesized. • Non-doped red electroluminescent film is fabricated by spin-coating. • Red OLED shows stable wavelength, luminous efficiency and chromaticity. • CIE1931 coordinate is in accord with standard red light in PAL system. - Abstract: Organic light-emitting molecular glasses (OEMGs) are synthesized through the introduction of nonplanar donor and branched aliphatic chain into electroluminescent emitters. The target OEMGs are characterized by {sup 1}H NMR, {sup 13}C NMR, IR, UV–vis and fluorescent spectra as well as elemental analysis, TG and DSC. The results indicated that the optical, electrochemical and electroluminescent properties of OEMGs are adjusted successfully by the replacement of electron-donating group. The non-doped OLED device with a standard red electroluminescent emission is achieved by spin-coating the THF solution of OEMG with a triphenylamine moiety. This non-doped red OLED device takes on an electrically stable electroluminescent performance, including the stable maximum electroluminescent wavelength of 640 nm, the stable luminous efficiency of 2.4 cd/A and the stable CIE1931 coordinate of (x, y) = (0.64, 0.35), which is basically in accord with the CIE1931 coordinate (x, y) = (0.64, 0.33) of standard red light in PAL system.

  20. Automatic Detection and Evaluation of Solar Cell Micro-Cracks in Electroluminescence Images Using Matched Filters

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    2016-01-01

    A method for detecting micro cracks in solar cell using two dimensional matched filters was developed, derived from the electroluminescence intensity profile of typical microcracks. We describe the image processing steps to obtain a binary map with the location of the micro-cracks. Finally, we sh...

  1. Prosress in long wavelength emission in fluorene-based electroluminescent blue materials

    Institute of Scientific and Technical Information of China (English)

    JIANG HongJi; WAN JunHua; HUANG Wei

    2008-01-01

    On account of the advantages of organic electroluminescent materials compared with their inorganic counterparts, the development of organic electroluminescent materials is one of the hot areas of the optoelectronic materials. Fluorene and its derivatives, which have an aromatic biphenyl structure with a wide energy gap in the backbones and high luminescent efficiency, have drawn much attention of material chemists and device physicists. However, one drawback of fluorene-based electroluminescent blue materials is that there is an occurrence of long wavelength emission after annealing the films in air or after operating organic light-emitting diodes for a long time. To clarify the origin of this long wavelength emission, the scientists at home and abroad have put forward all kinds of correlative explanations. Among the scientists, some thought it was caused by excimer-related species, while some others claimed that it was caused by the fluorenone of photooxdized fluorene. The corresponding solutions to this problem have also been proposed and the problem has been partially resolved in some degree. The present review summarizes and analyzes the progress made on the origin of long wavelength emission in fluorene-based electroluminescent blue materials at home and abroad in the past few years. Some issues to be addressed and hotspots to be further investigated are also presented and discussed.

  2. Relationship between structure and electroluminescence of oligo(y-phenylenevinylene)s

    NARCIS (Netherlands)

    Stalmach, U; Detert, H; Meier, H; Gebhardt, [No Value; Haarer, D; Bacher, A

    1998-01-01

    The preparation of LEDs with poly(p-phenylenevinylene) (PPV) as emitting material is well established, However, due to the presence of a distribution of conjugated chain lengths in the polymer, systematic investigations of the electroluminescence with polymeric materials are difficult, as far as the

  3. Progress in long wavelength emission in fluorene-based electroluminescent blue materials

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    On account of the advantages of organic electroluminescent materials compared with their inorganic counterparts,the development of organic electroluminescent materials is one of the hot areas of the optoelectronic materials.Fluorene and its derivatives,which have an aromatic biphenyl structure with a wide energy gap in the backbones and high luminescent efficiency,have drawn much attention of ma-terial chemists and device physicists.However,one drawback of fluorene-based electroluminescent blue materials is that there is an occurrence of long wavelength emission after annealing the films in air or after operating organic light-emitting diodes for a long time.To clarify the origin of this long wave-length emission,the scientists at home and abroad have put forward all kinds of correlative explana-tions.Among the scientists,some thought it was caused by excimer-related species,while some others claimed that it was caused by the fluorenone of photooxdized fluorene.The corresponding solutions to this problem have also been proposed and the problem has been partially resolved in some degree.The present review summarizes and analyzes the progress made on the origin of long wavelength emission in fluorene-based electroluminescent blue materials at home and abroad in the past few years.Some issues to be addressed and hotspots to be further investigated are also presented and discussed.

  4. [One case of huge cyst at the back end of nasal septum].

    Science.gov (United States)

    Zang, Jian; Liu, Qian; Jiang, Xuejun

    2014-04-01

    A male of 17 years old complained of bilateral nasal congestion with mouth breathing for half a year. The physical examination showed patency of bilateral nasal cavity. Nasopharyngeal fiberscope revealed a huge spherical smooth reddish mass at the nasopharyngeal posterior wall and the back-end of nasal cavity blocking the entire postnaris and contacting with bilateral tubal tori, the size of which is about 3.5 cm x 2.5 cm. The nasopharyngeal 3D-CT showed a low density cystic mass area in the nasopharynx with smooth edges, and the CT value is approximately 32.4 HU. No exact enhancement was observed. The cystic mass originated from and compressed the back end of nasal septum. A semicircular defect in the leading edge of clivus was observed, and the inferior wall of sphenoid sinus is compressed uplifted upwards. The nasopharyngeal MR showed that the nasopharyngeal lesion presented short T1 and long T2 signals with multiple small wall nodules around. Neither the lesion nor the peripheral nodules can be significantly enhanced by enhancement scan. After a nasal endoscopic surgery, the case was definitely diagnosed as nasal septum back-end huge cyst.

  5. Analyzing huge pathology images with open source software.

    Science.gov (United States)

    Deroulers, Christophe; Ameisen, David; Badoual, Mathilde; Gerin, Chloé; Granier, Alexandre; Lartaud, Marc

    2013-06-06

    Digital pathology images are increasingly used both for diagnosis and research, because slide scanners are nowadays broadly available and because the quantitative study of these images yields new insights in systems biology. However, such virtual slides build up a technical challenge since the images occupy often several gigabytes and cannot be fully opened in a computer's memory. Moreover, there is no standard format. Therefore, most common open source tools such as ImageJ fail at treating them, and the others require expensive hardware while still being prohibitively slow. We have developed several cross-platform open source software tools to overcome these limitations. The NDPITools provide a way to transform microscopy images initially in the loosely supported NDPI format into one or several standard TIFF files, and to create mosaics (division of huge images into small ones, with or without overlap) in various TIFF and JPEG formats. They can be driven through ImageJ plugins. The LargeTIFFTools achieve similar functionality for huge TIFF images which do not fit into RAM. We test the performance of these tools on several digital slides and compare them, when applicable, to standard software. A statistical study of the cells in a tissue sample from an oligodendroglioma was performed on an average laptop computer to demonstrate the efficiency of the tools. Our open source software enables dealing with huge images with standard software on average computers. They are cross-platform, independent of proprietary libraries and very modular, allowing them to be used in other open source projects. They have excellent performance in terms of execution speed and RAM requirements. They open promising perspectives both to the clinician who wants to study a single slide and to the research team or data centre who do image analysis of many slides on a computer cluster. The virtual slide(s) for this article can be found here

  6. A NOVEL APPROACH FOR PATTERN ANALYSIS FROM HUGE DATAWAREHOUSE

    Directory of Open Access Journals (Sweden)

    BABITA

    2014-05-01

    Full Text Available Due to the tremendous growth of data and large databases, efficient extraction of required data has become a challenging task. This paper propose a novel approach for knowledge discovery from huge unlabeled temporal databases by employing a combination of HMM and K-means technique. We propose to recursively divide the entire database into clusters having similar characteristics, this process is repeated until we get the cluster’s where no further diversification is possible. Thereafter, the clusters are labeled for knowledge extraction for various purposes.

  7. A young woman with a huge paratubal cyst

    Directory of Open Access Journals (Sweden)

    Ceren Golbasi

    2016-09-01

    Full Text Available Paratubal cysts are asymptomatic embryological remnants. These cysts are usually diagnosed during adolescence and reproductive age. In general, their sizes are small but can be complicated by rupture, torsion, or hemorrhage. Paratubal cysts are often discovered fortuitously on routine ultrasound examination. We report a 19-year-old female patient who presented with irregular menses and abdominal pain. Ultrasound examination revealed a huge cystic mass at the right adnexial area. The diagnosis was confirmed as paratubal cyst during laporotomy and, hence, cystectomy and right salpingectomy were performed. [Cukurova Med J 2016; 41(3.000: 573-576

  8. Modeling huge sound sources in a room acoustical calculation program

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge

    1999-01-01

    A room acoustical model capable of modeling point sources, line sources, and surface sources is presented. Line and surface sources are modeled using a special ray-tracing algorithm detecting the radiation pattern of the surfaces of the room. Point sources are modeled using a hybrid calculation...... method combining this ray-tracing method with image source modeling. With these three source types it is possible to model huge and complex sound sources in industrial environments. Compared to a calculation with only point sources, the use of extended sound sources is shown to improve the agreement...

  9. A huge renal capsular leiomyoma mimicking retroperitoneal sarcoma

    Directory of Open Access Journals (Sweden)

    Lal Anupam

    2009-01-01

    Full Text Available A huge left renal capsular leiomyoma mimicking retroperitoneal sarcoma presented in a patient as an abdominal mass. Computed tomography displayed a large heterogeneous retro-peritoneal mass in the left side of the abdomen with inferior and medial displacement as well as loss of fat plane with the left kidney. Surgical exploration revealed a capsulated mass that was tightly adherent to the left kidney; therefore, total tumor resection with radical left nephrectomy was performed. Histopathology ultimately confirmed the benign nature of the mass. This is the largest leiomyoma reported in literature to the best of our knowledge.

  10. Huge pyometra in a postmenopausal age: a diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Pramila Yadav

    2015-10-01

    Full Text Available Pyometra in postmenopausal women is an extremely rare disease that hardly responds to the usual treatment of antibiotics therapy. Our case presented as a postmenopausal woman with a huge pyometra. Pyometra drainage was done with great difficulty after a blind biopsy. Endometrial and cervical biopsy followed by endometrial curettage was done. An intrauterine foley's catheter was kept for seven days and Histopathological report was suggestive of squamous cell carcinoma of cervix. [Int J Reprod Contracept Obstet Gynecol 2015; 4(5.000: 1549-1551

  11. Antenna-enhanced optoelectronic probing of carbon nanotubes.

    Science.gov (United States)

    Mauser, Nina; Hartmann, Nicolai; Hofmann, Matthias S; Janik, Julia; Högele, Alexander; Hartschuh, Achim

    2014-07-09

    We report on the first antenna-enhanced optoelectronic microscopy studies on nanoscale devices. By coupling the emission and excitation to a scanning optical antenna, we are able to locally enhance the electroluminescence and photocurrent along a carbon nanotube device. We show that the emission source of the electroluminescence can be pointlike with a spatial extension below 20 nm. Topographic and antenna-enhanced photocurrent measurements reveal that the emission takes place at the location of highest local electric field indicating that the mechanism behind the emission is the radiative decay of excitons created via impact excitation.

  12. Microstructure and electroluminescent performance of chemical vapor deposited zinc sulfide doped with manganese films for integration in thin film electroluminescent devices

    Science.gov (United States)

    Topol, Anna Wanda

    Zinc sulfide (ZnS) doped with manganese (Mn), ZnS:Mn, is widely recognized as the brightest and most effective electroluminescent (EL) phosphor used in current thin film electroluminescent (TFEL) devices. ZnS acts as a host lattice for the luminescent activator, Mn, leading to a highly efficient yellow-orange EL emission, and resulting in a wide array of applications in monochrome, multi-color and full color displays. Although this wide band dap (3.7 eV) material can be prepared by several deposition techniques, the chemical vapor deposition (CVD) is the most promising for TFEL applications in terms of viable deposition rates, high thickness and composition uniformity, and excellent yield over large area panels. This study describes the development and optimization of a CVD ZnS:Mn process using diethylzinc [(C2H5)2Zn, DEZ], di-pi-cyclopentadienylmanganese [(C5H5)2Mn, CPMn], and hydrogen sulfide [H2S] as the chemical sources for, respectively, Zn, Mn, and S. The effects of key deposition parameters on resulting Film microstructure and performance are discussed, primarily in the context of identifying an optimized process window for best electroluminescence behavior. In particular, substrate temperature was observed to play a key role in the formation of high quality crystalline ZnS:Mn films leading to improved brightness and EL efficiency. Further investigations of the influence of temperature treatment on the structural characteristics and EL performance of the CVD ZnS:Mn film were carried out. In this study, the influence of post-deposition annealing both in-situ and ex-situ annealing processes, on chemical, structural, and electroluminescent characteristics of the phosphor layer are described. The material properties of the employed dielectric are among the key factors determining the performance, stability and reliability of the TFEL display and therefore, the choice of dielectric material for use in ACTFEL displays is crucial. In addition, the luminous

  13. Errors in Seismic Hazard Assessment are Creating Huge Human Losses

    Science.gov (United States)

    Bela, J.

    2015-12-01

    The current practice of representing earthquake hazards to the public based upon their perceived likelihood or probability of occurrence is proven now by the global record of actual earthquakes to be not only erroneous and unreliable, but also too deadly! Earthquake occurrence is sporadic and therefore assumptions of earthquake frequency and return-period are both not only misleading, but also categorically false. More than 700,000 people have now lost their lives (2000-2011), wherein 11 of the World's Deadliest Earthquakes have occurred in locations where probability-based seismic hazard assessments had predicted only low seismic low hazard. Unless seismic hazard assessment and the setting of minimum earthquake design safety standards for buildings and bridges are based on a more realistic deterministic recognition of "what can happen" rather than on what mathematical models suggest is "most likely to happen" such future huge human losses can only be expected to continue! The actual earthquake events that did occur were at or near the maximum potential-size event that either already had occurred in the past; or were geologically known to be possible. Haiti's M7 earthquake, 2010 (with > 222,000 fatalities) meant the dead could not even be buried with dignity. Japan's catastrophic Tohoku earthquake, 2011; a M9 Megathrust earthquake, unleashed a tsunami that not only obliterated coastal communities along the northern Japanese coast, but also claimed > 20,000 lives. This tsunami flooded nuclear reactors at Fukushima, causing 4 explosions and 3 reactors to melt down. But while this history of huge human losses due to erroneous and misleading seismic hazard estimates, despite its wrenching pain, cannot be unlived; if faced with courage and a more realistic deterministic estimate of "what is possible", it need not be lived again. An objective testing of the results of global probability based seismic hazard maps against real occurrences has never been done by the

  14. MR-based truncation and attenuation correction in integrated PET/MR hybrid imaging using HUGE with continuous table motion.

    Science.gov (United States)

    Lindemann, Maike E; Oehmigen, Mark; Blumhagen, Jan O; Gratz, Marcel; Quick, Harald H

    2017-09-01

    The objective of this study was to introduce and evaluate a method for MR-based attenuation and truncation correction in phantom and patient measurements to improve PET quantification in PET/MR hybrid imaging. The fully MR-based method HUGE (B0 Homogenization using gradient enhancement) provides field-of-view extension in MR imaging, which can be used for truncation correction and improved PET quantification in PET/MR hybrid imaging. The HUGE method in this recent implementation is combined with continuously moving table data acquisition to provide a seamless nontruncated whole-body data set of the outer patient contours to complete the established standard MR-based Dixon-VIBE data for attenuation correction. The method was systematically evaluated in NEMA standard phantom experiments to investigate the impact of HUGE truncation correction on PET quantification. The method was then applied to 24 oncologic patients in whole-body PET/MR hybrid imaging. The impact of MR-based truncation correction with HUGE on PET data was compared to the impact of the established PET-based MLAA algorithm for contour detection. In phantom and in all patient measurements, the standard Dixon-VIBE attenuation correction data show geometric distortions and signal truncations at the edges of the MR imaging field-of-view. In contrast, the Dixon-VIBE-based attenuation correction data additionally extended by applying HUGE shows significantly less distortion and truncations and due to the continuously moving table acquisition robustly provides smooth outer contours of the patient arms. In the investigated patient cases, MLAA frequently showed an overestimation of arm volume and associated artifacts limiting contour detection. When applying HUGE, an average relative increase in SUVmean in patients' lesion of 4.2% and for MLAA of 4.6% were measured, when compared to standard Dixon-VIBE only. In specific lesions maximal differences in SUVmean up to 13% for HUGE and 14% for MLAA were measured

  15. Analysis of defect-related inhomogeneous electroluminescence in InGaN/GaN QW LEDs

    Science.gov (United States)

    Ren, C. X.; Rouet-Leduc, B.; Griffiths, J. T.; Bohacek, E.; Wallace, M. J.; Edwards, P. R.; Hopkins, M. A.; Allsopp, D. W. E.; Kappers, M. J.; Martin, R. W.; Oliver, R. A.

    2016-11-01

    The inhomogeneous electroluminescence (EL) of InGaN/GaN quantum well light emitting diode structures was investigated in this study. Electroluminescence hyperspectral images showed that inhomogeneities in the form of bright spots exhibited spectrally blue-shifted and broadened emission. Scanning electron microscopy combined with cathodoluminescence (SEM-CL) was used to identify hexagonal pits at the centre of approximately 20% of these features. Scanning transmission electron microscopy imaging with energy dispersive X-ray spectroscopy (STEM-EDX) indicated there may be p-doped AlGaN within the active region caused by the presence of the pit. Weak beam dark-field TEM (WBDF-TEM) revealed the presence of bundles of dislocations associated with the pit, suggesting the surface features which cause the inhomogeneous EL may occur at coalescence boundaries, supported by trends in the number of features observed across the wafer.

  16. Mechanism of hot electron electroluminescence in GaN-based transistors

    Science.gov (United States)

    Brazzini, Tommaso; Sun, Huarui; Sarti, Francesco; Pomeroy, James W.; Hodges, Chris; Gurioli, Massimo; Vinattieri, Anna; Uren, Michael J.; Kuball, Martin

    2016-11-01

    The nature of hot electron electroluminescence (EL) in AlGaN/GaN high electron mobility transistors is studied and attributed to Bremsstrahlung. The spectral distribution has been corrected, for the first time, for interference effects due to the multilayered device structure, and this was shown to be crucial for the correct interpretation of the data, avoiding artefacts in the spectrum and misinterpretation of the results. An analytical expression for the spectral distribution of emitted light is derived assuming Bremsstrahlung as the only origin and compared to the simplified exponential model for the high energy tail commonly used for electron temperature extraction: the electron temperature obtained results about 20% lower compared to the approximated exponential model. Comparison of EL intensity for devices from different wafers illustrated the dependence of EL intensity on the material quality. The polarization of electroluminescence also confirms Bremsstrahlung as the dominant origin of the light emitted, ruling out other possible main mechanisms.

  17. A New Distyrylarylene Derivative Used as Blue Light Emitter in Organic Electroluminescent Device

    Institute of Scientific and Technical Information of China (English)

    郑新友; 朱文清; 等

    2002-01-01

    A new blue electroluminescent material,distyrylarylene(DSA)derivative,4,4'-bis[2,2-(1-naphthyl,phenyl)vinyl]-1,1-biphenyl(NPVBi)is designed and synthesized.The DSA derivative shows better thermal stability because of its high glass transition temperature.A blue organic light emitting diode(OLED0with the structure ITO/TPD/NPVBi/Alq/LiF/Al is studied.The electroluminescent(EL0spectrum of the OLED exhibits that light emission originates from NPVBi with a peak at 460nm,its Commission Internationale de l'Eclairage(CIE)color coordinates are x=0.16,y=0.15,and showing independence of CIE color coordinates on current density.The new DSA derivative is expectable as a new candidate for blue light emitter in OLEDs.

  18. Quantification of Solar Cell Failure Signatures Based on Statistical Analysis of Electroluminescence Images

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    2017-01-01

    We demonstrate a method to quantify the extent of solar cell cracks, shunting, or damaged cell interconnects, present in crystalline silicon photovoltaic (PV) modules by statistical analysis of the electroluminescence (EL) intensity distributions of individual cells within the module. From the EL...... operation. The method can be easily automated for quality control by module manufacturers or installers, or as a diagnostic tool by plant operators and diagnostic service providers....

  19. Electroluminescence from a diamond device with ion-beam-micromachined buried graphitic electrodes

    Science.gov (United States)

    Forneris, J.; Battiato, A.; Gatto Monticone, D.; Picollo, F.; Amato, G.; Boarino, L.; Brida, G.; Degiovanni, I. P.; Enrico, E.; Genovese, M.; Moreva, E.; Traina, P.; Verona, C.; Verona Rinati, G.; Olivero, P.

    2015-04-01

    Focused MeV ion microbeams are suitable tools for the direct writing of conductive graphitic channels buried in an insulating diamond bulk, as demonstrated in previous works with the fabrication of multi-electrode ionizing radiation detectors and cellular biosensors. In this work we investigate the suitability of the fabrication method for the electrical excitation of color centers in diamond. Differently from photoluminescence, electroluminescence requires an electrical current flowing through the diamond sub-gap states for the excitation of the color centers. With this purpose, buried graphitic electrodes with a spacing of 10 μm were fabricated in the bulk of a detector-grade CVD single-crystal diamond sample using a scanning 1.8 MeV He+ micro-beam. The current flowing in the gap region between the electrodes upon the application of a 450 V bias voltage was exploited as the excitation pump for the electroluminescence of different types of color centers localized in the above-mentioned gap. The bright light emission was spatially mapped using a confocal optical microscopy setup. The spectral analysis of electroluminescence revealed the emission from neutrally-charged nitrogen-vacancy centers (NV0, λZPL = 575 nm), as well as from cluster crystal dislocations (A-band, λ = 400-500 nm). Moreover, an electroluminescence signal with appealing spectral features (sharp emission at room temperature, low phonon sidebands) from He-related defects was detected (λZPL = 536.3 nm, λZPL = 560.5 nm); a low and broad peak around λ = 740 nm was also observed and tentatively ascribed to Si-V or GR1 centers. These results pose interesting future perspectives for the fabrication of electrically-stimulated single-photon emitters in diamond for applications in quantum optics and quantum cryptography.

  20. Electroluminescence from a diamond device with ion-beam-micromachined buried graphitic electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Forneris, J., E-mail: jacopo.forneris@unito.it [Physics Department and NIS Interdepartmental Centre, University of Torino, Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy); Battiato, A.; Gatto Monticone, D. [Physics Department and NIS Interdepartmental Centre, University of Torino, Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy); Picollo, F. [Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy); Physics Department and NIS Interdepartmental Centre, University of Torino, Torino (Italy); Amato, G.; Boarino, L.; Brida, G.; Degiovanni, I.P.; Enrico, E.; Genovese, M.; Moreva, E.; Traina, P. [Istituto Nazionale di Ricerca Metrologica (INRiM), Torino (Italy); Verona, C.; Verona Rinati, G. [Department of Industrial Engineering, University of Roma “Tor Vergata”, Roma (Italy); Olivero, P. [Physics Department and NIS Interdepartmental Centre, University of Torino, Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy)

    2015-04-01

    Focused MeV ion microbeams are suitable tools for the direct writing of conductive graphitic channels buried in an insulating diamond bulk, as demonstrated in previous works with the fabrication of multi-electrode ionizing radiation detectors and cellular biosensors. In this work we investigate the suitability of the fabrication method for the electrical excitation of color centers in diamond. Differently from photoluminescence, electroluminescence requires an electrical current flowing through the diamond sub-gap states for the excitation of the color centers. With this purpose, buried graphitic electrodes with a spacing of 10 μm were fabricated in the bulk of a detector-grade CVD single-crystal diamond sample using a scanning 1.8 MeV He{sup +} micro-beam. The current flowing in the gap region between the electrodes upon the application of a 450 V bias voltage was exploited as the excitation pump for the electroluminescence of different types of color centers localized in the above-mentioned gap. The bright light emission was spatially mapped using a confocal optical microscopy setup. The spectral analysis of electroluminescence revealed the emission from neutrally-charged nitrogen-vacancy centers (NV{sup 0}, λ{sub ZPL} = 575 nm), as well as from cluster crystal dislocations (A-band, λ = 400–500 nm). Moreover, an electroluminescence signal with appealing spectral features (sharp emission at room temperature, low phonon sidebands) from He-related defects was detected (λ{sub ZPL} = 536.3 nm, λ{sub ZPL} = 560.5 nm); a low and broad peak around λ = 740 nm was also observed and tentatively ascribed to Si-V or GR1 centers. These results pose interesting future perspectives for the fabrication of electrically-stimulated single-photon emitters in diamond for applications in quantum optics and quantum cryptography.

  1. Quantum Dots for Wide Color Gamut Displays from Photoluminescence to Electroluminescence

    Science.gov (United States)

    Kang, Yongyin; Song, Zhicheng; Jiang, Xiaofang; Yin, Xia; Fang, Long; Gao, Jing; Su, Yehua; Zhao, Fei

    2017-02-01

    Monodisperse quantum dots (QDs) were prepared by low-temperature process. The remarkable narrow emission peak of the QDs helps the liquid crystal displays (LCD) and electroluminescence displays (QD light-emitting diode, QLED) to generate wide color gamut performance. The range of the color gamut for QD light-converting device (QLCD) is controlled by both the QDs and color filters (CFs) in LCD, and for QLED, the optimized color gamut is dominated by QD materials.

  2. A Novel Buffer Layer of Alq3 in Organic Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-Feng; DENG Zhen-Bo; LIANG Chun-Jun; LIN Peng; ZHANG Meng-Xin; XU Deng-Hui

    2004-01-01

    @@ Inserting the Alq3 layer in the ITO/NPB interface as the buffer layer can improve the organic electroluminescent devices. The current density efficiency and power efficiency of the device with the Alq3 buffer layer rises to 6.5 cd/A and 1.21 m/W at the current density of 120 mA/cm2, respectively. The improvement is mostly attributed to the balance of the hole and the electron injections.

  3. Green-Light Electroluminescence of Conjugated Copolymer Containing p-Phenylene-ethynylene and Oxadiazole

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The title copolymer(PDEBO) was synthesized. The thermal characteristics of the polymer were determined by means of DSC and TGA, revealing that the polymer has a good thermal stability. The X-ray diffraction measurements of the thin films showed that the polymer is disorder. Electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.

  4. Hybrid silicon nanocrystal-organic light-emitting devices for infrared electroluminescence.

    Science.gov (United States)

    Cheng, Kai-Yuan; Anthony, Rebecca; Kortshagen, Uwe R; Holmes, Russell J

    2010-04-14

    We demonstrate hybrid inorganic-organic light-emitting devices with peak electroluminescence (EL) at a wavelength of 868 nm using silicon nanocrystals (SiNCs). An external quantum efficiency of 0.6% is realized in the forward-emitted direction, with emission originating primarily from the SiNCs. Microscopic characterization indicates that complete coverage of the SiNCs on the conjugated polymer hole-transporting layer is required to observe efficient EL.

  5. Distributed and parallel approach for handle and perform huge datasets

    Science.gov (United States)

    Konopko, Joanna

    2015-12-01

    Big Data refers to the dynamic, large and disparate volumes of data comes from many different sources (tools, machines, sensors, mobile devices) uncorrelated with each others. It requires new, innovative and scalable technology to collect, host and analytically process the vast amount of data. Proper architecture of the system that perform huge data sets is needed. In this paper, the comparison of distributed and parallel system architecture is presented on the example of MapReduce (MR) Hadoop platform and parallel database platform (DBMS). This paper also analyzes the problem of performing and handling valuable information from petabytes of data. The both paradigms: MapReduce and parallel DBMS are described and compared. The hybrid architecture approach is also proposed and could be used to solve the analyzed problem of storing and processing Big Data.

  6. Anaethetic management of a neonate with huge cystic hygroma.

    Directory of Open Access Journals (Sweden)

    Bindi Palkhiwala

    2013-01-01

    Full Text Available We discuss here the case of a 7 day old neonate with huge cystic hygroma on the left side of the neck invading the major vessels of neck, facial nerve, strap muscles and sternocleidomastoid. Anasethtic implications in this case were maintaining airway patency after induction, difficult intubation, risk perioperative dislodgement of tube and judgement of proper time for extubation. Following gaseous induction and adequate mask ventilation, patient was intubated with muscle relaxant. peroperatively to avoid accidental extubation, we choose to manually hold the ET tube after fixing it. At the end of relatively uneventful surgery, we could extubate the patient in OT. patient was shifted to NICU for observation. Post operatively on 3rd day, facial palsy was observed. Ptient was discharged on 21st day.

  7. Huge Intracanal lumbar Disc Herniation: a Review of Four Cases

    Directory of Open Access Journals (Sweden)

    Farzad Omidi-Kashani

    2016-01-01

    Full Text Available Lumbar disc herniation (LDH is the most common cause of sciatica and only in about 10% of the affected patients, surgical intervention is necessary. The side of the patient (the side of most prominent clinical complaints is usually consistent with the side of imaging (the side with most prominent disc herniation on imaging scans. In this case series, we presented our experience in four cases with huge intracanal LDH that a mismatch between the patient’s side and the imaging’s side was present. In these cases, for deciding to do the operation, the physicians need to rely more on clinical findings, but for deciding the side of discectomy, imaging characteristic (imaging side may be a more important criterion.

  8. A parallel solver for huge dense linear systems

    Science.gov (United States)

    Badia, J. M.; Movilla, J. L.; Climente, J. I.; Castillo, M.; Marqués, M.; Mayo, R.; Quintana-Ortí, E. S.; Planelles, J.

    2011-11-01

    HDSS (Huge Dense Linear System Solver) is a Fortran Application Programming Interface (API) to facilitate the parallel solution of very large dense systems to scientists and engineers. The API makes use of parallelism to yield an efficient solution of the systems on a wide range of parallel platforms, from clusters of processors to massively parallel multiprocessors. It exploits out-of-core strategies to leverage the secondary memory in order to solve huge linear systems O(100.000). The API is based on the parallel linear algebra library PLAPACK, and on its Out-Of-Core (OOC) extension POOCLAPACK. Both PLAPACK and POOCLAPACK use the Message Passing Interface (MPI) as the communication layer and BLAS to perform the local matrix operations. The API provides a friendly interface to the users, hiding almost all the technical aspects related to the parallel execution of the code and the use of the secondary memory to solve the systems. In particular, the API can automatically select the best way to store and solve the systems, depending of the dimension of the system, the number of processes and the main memory of the platform. Experimental results on several parallel platforms report high performance, reaching more than 1 TFLOP with 64 cores to solve a system with more than 200 000 equations and more than 10 000 right-hand side vectors. New version program summaryProgram title: Huge Dense System Solver (HDSS) Catalogue identifier: AEHU_v1_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHU_v1_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 87 062 No. of bytes in distributed program, including test data, etc.: 1 069 110 Distribution format: tar.gz Programming language: Fortran90, C Computer: Parallel architectures: multiprocessors, computer clusters Operating system

  9. A huge glandular odontogenic cyst occurring at posterior mandible

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2004-12-15

    The glandular odontogenic cyst is a rare lesion described in 1987. It generally occurs at anterior region of mandible in adults over the age of 40 and has a slight tendency to recur. Histopathologically, a cystic cavity lined by a nonkeratinized, stratified squamous, or cuboidal epithelium varying in thickness is found including a superficial layer with glandular or pseudoglandular structures. A 21-year-old male visited Dankook University Dental Hospital with a chief complaint of swelling of the left posterior mandible. Radiographically, a huge multilocular radiolucent lesion involving impacted 3rd molar at the posterior mandible was observed. Buccolingual cortical expansion with partial perforation of buccal cortical bone was also shown. Histopathologically, this lesion was lined by stratified squamous epithelium with glandular structures in areas of plaque-like thickening. The final diagnosis was made as a glandular odontogenic cyst.

  10. Does China's Huge External Surplus Imply an Undervalued Renminbi?

    Institute of Scientific and Technical Information of China (English)

    Anthony J. Makin

    2007-01-01

    A pegged exchange rate regime has been pivotal to China's export-led development strategy. However, its huge trade surpluses and massive build up of international reserves have been matched by large deficits for major trading partners, creating acute policy concerns abroad, especially in the USA. This paper provides a straightforward conceptual framework for interpreting the effect of China's exchange rate policy on its own trade balance and that of trading partners in the context of discrepant economic growth rates. It shows how pegging the exchange rate when output is outstripping expenditure induces China's trade surpluses and counterpart deficits for its trading partners. An important corollary is that given its strictly regulated capital account, China's persistently large surpluses imply a significantly undervalued renminbi, which should gradually become more flexible.

  11. Transcending the slow bimolecular recombination in lead-halide perovskites for electroluminescence

    Science.gov (United States)

    Xing, Guichuan; Wu, Bo; Wu, Xiangyang; Li, Mingjie; Du, Bin; Wei, Qi; Guo, Jia; Yeow, Edwin K. L.; Sum, Tze Chien; Huang, Wei

    2017-01-01

    The slow bimolecular recombination that drives three-dimensional lead-halide perovskites' outstanding photovoltaic performance is conversely a fundamental limitation for electroluminescence. Under electroluminescence working conditions with typical charge densities lower than 1015 cm−3, defect-states trapping in three-dimensional perovskites competes effectively with the bimolecular radiative recombination. Herein, we overcome this limitation using van-der-Waals-coupled Ruddlesden-Popper perovskite multi-quantum-wells. Injected charge carriers are rapidly localized from adjacent thin few layer (n≤4) multi-quantum-wells to the thick (n≥5) multi-quantum-wells with extremely high efficiency (over 85%) through quantum coupling. Light emission originates from excitonic recombination in the thick multi-quantum-wells at much higher decay rate and efficiency than bimolecular recombination in three-dimensional perovskites. These multi-quantum-wells retain the simple solution processability and high charge carrier mobility of two-dimensional lead-halide perovskites. Importantly, these Ruddlesden-Popper perovskites offer new functionalities unavailable in single phase constituents, permitting the transcendence of the slow bimolecular recombination bottleneck in lead-halide perovskites for efficient electroluminescence. PMID:28239146

  12. Optical and electroluminescent properties of a number of new derivatives of divinyl dibenzothiophene sulfone

    Science.gov (United States)

    Kukhto, A. V.; Kopylova, T. N.; Gadirov, R. M.; Degtyarenko, K. N.; Nikonova, E. N.; Solodova, T. A.; Kukhto, I. N.

    2016-02-01

    Photoluminescent and electroluminescent properties of four new bipolar linear derivatives of divinyl dibenzothiophene sulfone are studied. It is found that amorphous films of solutions, as well as films of the compounds under study in the poly(N-vinylcarbazole) matrix, have a rather high quantum yield of photoluminescence in the blue and blue-green spectrum regions. Bright blue electroluminescence is obtained in the samples with a structure of ITO/PEDOT:PSS/TPD/OC/LiF/Al using vacuum deposition of the compounds under study and in the single-layer ITO/PEDOT:PSS/PVK:OC/LiF/Al structure when applied from the solution with a threshold voltage of 2.5-3.5 V. The influence of a molecule structure on the spectra and quantum yield of fluorescence as well as on the electroluminescent properties of the compounds is shown. Results of quantum-chemical calculations in the context of the density functional theory of the structure and characteristics of main molecular orbitals are presented.

  13. Transcending the slow bimolecular recombination in lead-halide perovskites for electroluminescence.

    Science.gov (United States)

    Xing, Guichuan; Wu, Bo; Wu, Xiangyang; Li, Mingjie; Du, Bin; Wei, Qi; Guo, Jia; Yeow, Edwin K L; Sum, Tze Chien; Huang, Wei

    2017-02-27

    The slow bimolecular recombination that drives three-dimensional lead-halide perovskites' outstanding photovoltaic performance is conversely a fundamental limitation for electroluminescence. Under electroluminescence working conditions with typical charge densities lower than 10(15) cm(-3), defect-states trapping in three-dimensional perovskites competes effectively with the bimolecular radiative recombination. Herein, we overcome this limitation using van-der-Waals-coupled Ruddlesden-Popper perovskite multi-quantum-wells. Injected charge carriers are rapidly localized from adjacent thin few layer (n≤4) multi-quantum-wells to the thick (n≥5) multi-quantum-wells with extremely high efficiency (over 85%) through quantum coupling. Light emission originates from excitonic recombination in the thick multi-quantum-wells at much higher decay rate and efficiency than bimolecular recombination in three-dimensional perovskites. These multi-quantum-wells retain the simple solution processability and high charge carrier mobility of two-dimensional lead-halide perovskites. Importantly, these Ruddlesden-Popper perovskites offer new functionalities unavailable in single phase constituents, permitting the transcendence of the slow bimolecular recombination bottleneck in lead-halide perovskites for efficient electroluminescence.

  14. Photo- and electroluminescence properties of lanthanide tungstate-doped porous anodic aluminum oxide

    Science.gov (United States)

    Staninski, Krzysztof; Piskuła, Zbigniew; Kaczmarek, Małgorzata

    2017-02-01

    A new cathode material for the potential use in light-emitting devices, based on porous anodic alumina (PAA), aluminum and ITO layers has been synthesized. Porous alumina samples with ordered pore arrays were prepared electrochemically from high purity Al sheet in H2SO4 and H3PO4. To be able to apply the matrix obtained in the electroluminescence cell, the thickness of the barrier layer of aluminum oxide was decreased by slow reduction of the anodization voltage to zero. The luminescence and electroluminescence (EL) properties of the Al2O3 matrix admixtured with Eu3+ and Tb3+ ions as well as europium and terbium tungstates, were determined. The particles of inorganic luminophore were synthesized on the walls of the matrix cylindrical nanopores in the two-step process of immersion in solutions of TbCl3 or EuCl3 and Na2WO4. The effect of the nanopores diameter and the thickness of the porous Al2O3 layer on the intensity and relative yield of electroluminescence was analyzed, the best results were obtained for 80-90 μm PAA layers with 140 nm nanopores.

  15. Phosphorescent Iridium(III) Complexes Bearing Fluorinated Aromatic Sulfonyl Group with Nearly Unity Phosphorescent Quantum Yields and Outstanding Electroluminescent Properties.

    Science.gov (United States)

    Zhao, Jiang; Yu, Yue; Yang, Xiaolong; Yan, Xiaogang; Zhang, Huiming; Xu, Xianbin; Zhou, Guijiang; Wu, Zhaoxin; Ren, Yixia; Wong, Wai-Yeung

    2015-11-11

    A series of heteroleptic functional Ir(III) complexes bearing different fluorinated aromatic sulfonyl groups has been synthesized. Their photophysical features, electrochemical behaviors, and electroluminescent (EL) properties have been characterized in detail. These complexes emit intense yellow phosphorescence with exceptionally high quantum yields (ΦP > 0.9) at room temperature, and the emission maxima of these complexes can be finely tuned depending upon the number of the fluorine substituents on the pendant phenyl ring of the sulfonyl group. Furthermore, the electrochemical properties and electron injection/transporting (EI/ET) abilities of these Ir(III) phosphors can also be effectively tuned by the fluorinated aromatic sulfonyl group to furnish some desired characters for enhancing the EL performance. Hence, the maximum luminance efficiency (ηL) of 81.2 cd A(-1), corresponding to power efficiency (ηP) of 64.5 lm W(-1) and external quantum efficiency (ηext) of 19.3%, has been achieved, indicating the great potential of these novel phosphors in the field of organic light-emitting diodes (OLEDs). Furthermore, a clear picture has been drawn for the relationship between their optoelectronic properties and chemical structures. These results should provide important information for developing highly efficient phosphors.

  16. Towards Monodisperse Star-Shaped Ladder-Type Conjugated Systems: Design, Synthesis, Stabilized Blue Electroluminescence and Amplified Spontaneous Emission.

    Science.gov (United States)

    Lai, Wen-Yong; Jiang, Yi; Fang, Mei; Chang, Si-Ju; Huang, Jin-Jin; Chu, Shuang-Quan; Hu, Shan-Ming; Liu, Cheng-Fang; Huang, Wei

    2017-02-14

    A novel series of monodisperse star-shaped ladder-type oligo(p-phenylene)s, named as TrL-n (n = 1-3), have been explored. Their thermal and electrochemical properties, fluorescence transients, photoluminescence quantum yields, density functional theory calculations, electroluminescence (EL) and amplified spontaneous emission (ASE) properties have been systematically investigated to unravel the molecular design on optoelectronic properties. The resulting materials showed excellent structural perfection free of chemical defects, exhibiting great thermal stability (Td: 404-418°C and Tg:147-184°C) and amorphous glassy morphologies. Compared with their corresponding linear counterparts FL-m (m = 1-3), TrL-n showed only little bathochromic shifts (5-12 nm) for the absorption maxima λmax in both solution and films. The star-shaped ladder-type compounds exhibited enhanced optical stability and suppressed low-energy emission. Their EL spectra exhibited excellent stability with increasing the driving voltage from 6 to 12 V. Moreover, superior low ASE thresholds were recorded for TrL-n compared with FL-m. Rather low ASE threshold (29 nJ/pulse or 1.60 μJ/cm2) was recorded for TrL-3, demonstrating their promising potential as excellent gain media. This study provides a novel design concept to develop monodisperse star-shaped ladder-type materials with excellent structural perfection, which are vital for shedding light on exploring robust organic emitters for optoelectronic applications.

  17. EDITORIAL: Enhancing nanolithography Enhancing nanolithography

    Science.gov (United States)

    Demming, Anna

    2012-01-01

    enhancements around an array of nanorods to improve the operation of a Schottky diode device operating in reverse bias. The diode is used for gas sensing, an application that also benefits from the high surface to volume ratio of nanostructures for gas adsorption [5]. Enhancing the electric field is also hugely advantageous for Raman spectroscopy. The vibrational modes probed with Raman spectroscopy provide a useful, highly distinctive molecular signature but the signal is weak. An array of nanoneedles fabricated by researchers in China and Japan has demonstrated controllable and repeatable enhancements to Raman signals of 108 [6]. Researchers in the UK have demonstrated how the field enhancements resulting from the plasmonic properties of metal nanoparticles can be tuned to carefully manipulate their effect on the fluorescence intensity, lifetime and Raman signal from nearby fluorophores. They also successfully decoupled the effects on radiative and non-radiative decay and shed light on the hot spots present in surface-enhanced Raman spectroscopy measurements. Plasmonics has enormous potential in the field of optoelectronics. In recognition of the fertility of research in this field, Nanotechnology will publish a special issue on plasmonics in optoeletronics later this year. The work of Suman Das and colleagues in the USA and Germany reported in this issue combines both field enhancements and laser-interference lithography to impart a nanoporous structure to a polymer with high industrial potential. PEDOT-PSS has high conductivity and is also moderately transparent, making it eligible for transparent conductors in electroluminescent devices, conducting layers in capacitors, photovoltaic cells and sensors. It has also been considered recently for bioelectronic applications, in particular neuronal cell signalling and neural interfaces, as a result of its electronic and ionic conductivity. The researchers irradiated a monolayer of silica nanospheres on a film of PEDOT-PSS with

  18. Late Intervention-Related Complication - A Huge Subepicardial Hematoma.

    Science.gov (United States)

    Ko, Po-Yen; Chang, Chih-Ping; Yang, Chen-Chia; Lin, Jen-Jyh

    2013-05-01

    A 75-year-old man had a history of triple vessel coronary artery disease. In August 2009, he had undergone successful percutaneous coronary intervention to the left circumflex coronary artery (LCX) for management of an in-stent restenosis (ISR) lesion. However, in September 2010, he began experiencing recurrent episodes of exertional chest pain. Chest radiography showed the left cardiac border bulging upwards. Transthoracic echocardiography and chest computed tomography revealed a huge oval mass of about 10.4 cm × 7.9 cm × 8.6 cm, which showed calcification and was obliterating the LCX. Subsequent coronary angiography revealed significant instent restenosis, with extravasation of a small amount of contrast material at the stent location, suggesting that the coronary artery had ruptured. We implanted a polytetrafluoroethylene-covered stent to seal the coronary perforation and to release the occlusion. The patient was symptom-free and had an uneventful outcome until the 1-year follow up. Coronary artery perforation; Covered stent; Hematoma.

  19. A huge posteromedial mediastinal cyst complicated with vertebral dislodgment

    Directory of Open Access Journals (Sweden)

    Manoussaridis Jordan T

    2006-08-01

    Full Text Available Abstract Background Mediastinal cysts compromise almost 20% of all mediastinal masses with bronchogenic subtype accounting for 60% of all cystic lesions. Although compression of adjoining soft tissues is usual, spinal complications and neurological symptoms are outmost rare and tend to characterize almost exclusively the neuroenteric cysts. Case presentation A young patient with intermittent, dull pain in his back and free medical history presented in the orthopaedic department of our hospital. There, the initial clinical and radiologic evaluation revealed a mediastinal mass and the patient was referred to the thoracic surgery department for further exploration. The following computed tomography (CT and magnetic resonance imaging (MRI shown a huge mediastinal cyst compressing the T4-T6 vertebral bodies. The neurological symptoms of the patient were attributed to this specific pathology due to the complete agreement between the location of the cyst and the nervous rule area of the compressed thoracic vertebrae. Despite our strongly suggestions for surgery the patient denied any treatment. Conclusion In controversy with the common faith that the spine plays the role of the natural barrier to the further expansion of cystic lesions, our case clearly indicates that, exceptionally, mediastinal cysts may cause severe vertebral complications. Therefore, early excision should be considered especially in young patients or where close follow up is uncertain.

  20. A probabilistic algorithm for interactive huge genome comparison.

    Science.gov (United States)

    Courtois, P R; Moncany, M L

    1995-12-01

    We designed a new probabilistic algorithm, named PAGEC (probabilistic algorithm for genome comparison), which allowed a highly interactive study of long genomic strings. The comparison between two nucleic acid sequences is based on the creation of multiple index tables, which drastically reduces processing time for huge genomes, e.g. 13 min for a 4 Mb/4 Mb comparison. PAGEC lowered the need for memory when compared with other types of algorithm and took into account the low resolution of the final representation (paper or computer screen). Considering that standard printers permit a 300 d.p.i. resolution, the loss of computed information due to the probabilistic conception of the algorithm was not usually noticeable in the present study, mainly due to increased genomic sizes. Refinement was possible through an interactive zooming system, which enabled the visualization of the lexical base sequences of a considered part of both of the studied genomes. Biological examples of computation based on yeast and animal nucleic acid sequences presented in this paper reveal the flexibility of the PAGEC program, which is a valuable tool for genetic studies as it offers a solution to an important problem that will become even more important as time passes.

  1. Single-Path Sigma from a Huge Dataset in Taiwan

    Science.gov (United States)

    Sung, Chih-Hsuan; Lee, Chyi-Tyi

    2014-05-01

    Ground-motion variability, which was used in the probabilistic seismic hazard analysis (PSHA) in computing annual exceedence probability, is composed of random variability (aleatory uncertainty) and model uncertainty (epistemic uncertainty). Finding random variability of ground motions has become an important issue in PSHA, and only the random variability can be used in deriving the annual exceedence probability of ground-motion. Epistemic uncertainty will be put in the logic tree to estimate the total uncertainty of ground-motion. In the present study, we used about 18,859 records from 158 shallow earthquakes (Mw > 3.0, focal depth ≤ 35 km, each station has at least 20 records) form the Taiwan Strong-Motion Instrumentation Program (TSMIP) network to analyse the random variability of ground-motion. First, a new ground-motion attenuation model was established by using this huge data set. Second, the residuals from the median attenuation were analysed by direct observation on inter-event variability and site-specific variability. Finally, the single-path variability was found by a moving-window method on either single-earthquake residuals or single-station residuals. A variogram method was also used to find minimum variability for intra-event residuals and inter-event residuals, respectively. Results reveal that 90% of the single-path sigma σSP are ranging from 0.219 to 0.254 (ln unit) and are 58% to 64% smaller than the total sigma (σT =0.601). The single-site sigma (σSS) are also 39%-43% smaller. If we use only random variability (single-path sigma) in PSHA, then the resultant hazard level would be 28% and 25% lower than the traditional one (using total sigma) in 475-year and in 2475-year return period, respectively, in Taipei.

  2. Electroluminescence from nonpolar n-ZnO/p-AlGaN heterojunction light-emitting diode on r-sapphire

    Science.gov (United States)

    Chen, Jingwen; Zhang, Jun; Dai, Jiangnan; Wu, Feng; Wang, Shuai; Chen, Cheng; Long, Hanling; Liang, Renli; Zhao, Chong; Chen, Changqing; Tang, Zhiwu; Cheng, Hailing; He, Yunbin; Li, Mingkai

    2017-03-01

    Nonpolar a-plane n-ZnO/p-AlGaN heterojunction light-emitting diodes (LEDs) have been prepared on r-sapphire substrate using metal organic chemical vapor deposition and a pulsed laser deposition method. The dominant electroluminescence emission at 390 nm from the interband transition in n-ZnO layer under a forward bias was observed. Interestingly, electroluminescence with emission at 385 nm based on an avalanche mechanism was also achieved under reverse bias. The mechanisms of both the electroluminescence and I–V characteristics are discussed in detail by considering the avalanche effect. It is demonstrated that the crystalline quality of n-ZnO, not the p-AlGaN, is what affects the performance of the nonpolar ZnO based avalanche LED.

  3. Significant improvement of near-UV electroluminescence from ZnO quantum dot LEDs via coupling with carbon nanodot surface plasmons.

    Science.gov (United States)

    Zhang, Cen; Zhu, Feifei; Xu, Haiyang; Liu, Weizhen; Yang, Liu; Wang, Zhongqiang; Ma, Jiangang; Kang, Zhenhui; Liu, Yichun

    2017-10-05

    Short-wavelength LEDs, a hot research topic in modern optoelectronics, have attracted tremendous attention in recent years because of their great application potential in both civil and military domains. Compared to conventional metallic surface-plasmons (SPs), carbon nanodot (CD) SPs with less optical loss and low cost, broader SP resonant frequency and good biocompatibility are expected to provide more prominent luminescence enhancement for light emitters. Herein, SP-enhanced near-UV emission quantum dot LEDs (Q-LED) were fabricated via introducing CDs into p-GaN/Al2O3/ZnO Q-LEDs by optimizing the molar ratio of ZnO quantum dots to CDs and a significant enhancement (∼20-fold) of the near-UV electroluminescence (EL) intensity from the ZnO-based Q-LEDs was achieved. Time-resolved spectroscopy studies reveal that the observed luminescence enhancement arises due to the resonant coupling between ZnO excitons and CD SPs. The current study not only demonstrates a feasible way to acquire near-UV emission from all-inorganic Q-LEDs, but also provides an effective strategy to enhance the EL intensity of these QD light emitters, which can further be extended to other types of light-emitting devices to improve EL efficiency.

  4. The physical reason of intense electroluminescence in ITO-Si heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Oleksandr [Electronics Department, National Institute for Astrophysics, Optics, and Electronics (INAOE), P.O. 51 and 216, Puebla, 72000 (Mexico)], E-mail: amalik@inaoep.mx; Martinez, Arturo I.; Hidalga W, F.J. de la [Electronics Department, National Institute for Astrophysics, Optics, and Electronics (INAOE), P.O. 51 and 216, Puebla, 72000 (Mexico)

    2007-10-15

    Intense electroluminescence from a spray deposited heavily tin-doped indium oxide (ITO)-n type silicon (Si) heterojunctions, presenting the properties of an induced p-n junction, has been observed. The role of the degenerated n-type ITO film as a good supplier of holes to maintain an inversion layer formed at the silicon interface is discussed. However, the physical mechanism responsible for a significantly higher quantum efficiency of the radiation emission from such structures is not clear. The explanation of this phenomenon, based on the confinement of carriers at the interface due to multi-point contacts between the ITO film and the silicon, is discussed.

  5. Non-Uniformities in Thin-Film Cadmium Telluride Solar Cells Using Electroluminescence and Photoluminescence: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zaunbrecher, K.; Johnston, S.; Yan, F.; Sites, J.

    2011-07-01

    It is the purpose of this research to develop specific imaging techniques that have the potential to be fast, in-line tools for quality control in thin-film CdTe solar cells. Electroluminescence (EL) and photoluminescence (PL) are two techniques that are currently under investigation on CdTe small area devices made at Colorado State University. It is our hope to significantly advance the understanding of EL and PL measurements as applied to CdTe. Qualitative analysis of defects and non-uniformities is underway on CdTe using EL, PL, and other imaging techniques.

  6. Blue and white light electroluminescence in a multilayer OLED using a new aluminium complex

    Indian Academy of Sciences (India)

    Pabitra K Nayak; Neeraj Agarwal; Farman Ali; Meghan P Patankar; K L Narasimhan; N Periasamy

    2010-11-01

    Synthesis, structure, optical absorption, emission and electroluminescence properties of a new blue emitting Al complex, namely, bis-(2-amino-8-hydroxyquinolinato), acetylacetonato Al(III) are reported. Multilayer OLED using the Al complex showed blue emission at 465 nm, maximum brightness of ∼ 425 cd/m2 and maximum current efficiency of 0.16 cd/A. Another multilayer OLED using the Al complex doped with phosphorescent Ir complex showed `white’ light emission, CIE coordinate (0.41, 0.35), maximum brightness of ∼ 970 cd/m2 and maximum current efficiency of 0.53 cd/A.

  7. Temperature-dependent electroluminescence from GeSn heterojunction light-emitting diode on Si substrate

    Science.gov (United States)

    Chang, Chiao; Li, Hui; Huang, Ssu-Hsuan; Lin, Li-Chien; Cheng, Hung-Hsiang

    2016-04-01

    The electroluminescence from a Ge/GeSn/Ge p-i-n light-emitting diode on Si was investigated under different temperatures ranging from 25 to 150 K. The diode was operated at a low injection current density of 13 A/cm2. We obtained no-phonon- and phonon-assisted replicas in emission spectra. Also, the relationship between indirect bandgap energy and temperature was investigated. The temperature-dependent bandgap energy followed Varshni’s empirical expression with α = 4.884 × 10-4 eV/K and β = 130 K.

  8. About the Nature of Electroluminescence Centers in Plastically Deformed Crystals of p-type Silicon

    Directory of Open Access Journals (Sweden)

    B.V. Pavlyk

    2015-10-01

    Full Text Available The paper describes research of dislocation electroluminescence of single crystal p-type silicon with a high concentration of dislocations on the surface (111. It is shown the reaction of the luminescence spectra and capacitive-modulation spectra of samples after high-temperature annealing in an atmosphere of flowing oxygen. The analysis of the results lets us to establish the nature of recombination centers and their reorganization under high-temperature annealing. It is shown that deposition of Al film on the substrate p-Si leads to the formation of strain capacity and the localization of defects in the surface layer that corresponds to luminescence centers.

  9. Electroluminescence in organic single-layer light-emitting diodes at high fields

    Institute of Scientific and Technical Information of China (English)

    杨盛谊; 徐征; 王振家; 侯延冰; 徐叙; 张希清

    2001-01-01

    By considering the interaction between Fowler-Nordheim tunneling injection theory and charge carriers transporting through the bulk, an electroluminescence model for organic single-layer diodes is presented. The expressions of the recombination current density, recombination efficiency and conductivity of the diodes are provided, which elucidate the controlling role of the electric field on mobility and recombination zone. The equilibrium of two opposite charge carriers injection and the central position of recombination zone are two important preconditions for reducing the leakage current. Space-charge-limited current occurs only over a certain high bias, meanwhile, the quantity of injection carriers increases over the transport capacity of the bulk.

  10. Transport and electroluminescence mechanism in Au/(Si/SiO2)/P-Si film

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kai-biao; MA Shu-yi; MA Zi-jun; CHEN Hai-xia

    2006-01-01

    The samples of Au/(Si/SiO2)/p-Si structure were fabricated by using the R.F magnetron sputtering technique.Its carrier transport and electroluminescence mechanism were studied from the I-V curves and EL spectra by using the Configuration Coordinate as a theoretical model.The result indicates that there are two defect centers in SiO2 films.The electron in Au and the hole in p-Si went into SiO2 film by the Fowler-Nordheim tunneling model at a high bias voltage and recombined through these defect centers in SiO2 film.

  11. Electroluminescence from Si/SiO2 films deposited on p-Si substrates

    Institute of Scientific and Technical Information of China (English)

    马书懿; 萧勇; 陈辉

    2002-01-01

    The structure of Au/Si/SiO2/p-Si has been fabricated using the magnetron sputtering technique. It has a verygood rectifying behaviour. Visible electroluminescence (EL) has been observed from the Au/Si/SiO2/p-Si structureat a forward bias of 5V or larger. A broad band with one peak around 650-660 nm appears in all the EL spectra ofthe structure. The effects of the thickness of the Si layer in the Si/SiO2 films and of the input electrical power on ELspectra are studied systematically.

  12. Pulmonary hypertension with a huge thrombosis in main stem of pulmonary artery

    Institute of Scientific and Technical Information of China (English)

    杨萍; 曾红; 孟繁波; 赵林阳

    2001-01-01

    @@A huge thrombosis in the main stem of the pulmonary artery (PA) with pulmonary hypertension has rarely been reported. We present two cases diagnosed and treated in our hospital. One suffered from polyarteritis with a huge thrombus in PA revealed at autopsy. The second case had congenital heart disease of the patent artery duct; and the huge thrombus was found on echocardiogram and extirpated in surgery.

  13. Efficacy of hepatic resection for huge (≥ 10 cm) hepatocellular carcinoma: good prognosis associated with the uninodular subtype.

    Science.gov (United States)

    Zhu, Shao-Liang; Chen, Jie; Li, Hang; Li, Le-Qun; Zhong, Jian-Hong

    2015-01-01

    The value of hepatic resection (HR) for huge hepatocellular carcinomas (HCC) (≥ 10 cm in diameter) remains controversial. The aim of this study is to evaluate the efficacy of hepatic resection (HR) for patients with huge HCC. A total of 739 patients with huge HCC (≥ 10 cm in diameter) (huge HCC group, n = 244) or small HCC (huge HCC were identified based on Cox regression analyses. The hospital mortality of these two groups were similar (P = 0.252). The 5-year OS of huge HCC group and small HCC group were 30.3% and 51.9%, respectively (P huge HCC had a significant higher 5-year OS (50.6%) than mutinodular huge HCC (26.9%) (P = 0.016). Multivariate analysis revealed that uninodular huge HCC and absence of PVTT independently predicted better OS for huge HCC patients. HR is a safe and effective approach for the treatment of huge HCC, especially for the uninodular subtype.

  14. Syntheses, structures and luminescent properties of Sm (III) and Eu (III) chelates for organic electroluminescent device applications

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Y.J.; Wong, T.K.S.; Yan, Y.K.; Hu, X

    2003-08-25

    Samarium(III) and europium(III) complexes of the {beta}-diketone ligand (2-thienyl)trifluoroacetylacetone (HTTA) and triphenylphosphine oxide (TPPO) were prepared. The complexes, Sm(TTA){sub 2}(TPPO){sub 2}NO{sub 3} (1), Eu(TTA){sub 2}(TPPO){sub 2}NO{sub 3}H{sub 2}O (2), and Eu(TTA){sub 3}(TPPO){sub 2} (3) were characterized. Single crystal X-ray diffraction molecular structures of complexes 1 and 3 are presented and some of the crystal parameters for complex 1 are: space group, P1; a=11.019(4) A, b=11.791(6) A, c=12.535(5) A; {alpha}=102.68(3) deg., {beta}=102.06(3) deg., {gamma}=117.75(3) deg. ; for complex 3: space group, P-1, a=11.1946(9) A, b=12.117(2) A, c=23.535(2) A, {alpha}=80.047(13) deg., {beta}=76.498(7) deg., {gamma}=70.450(9) deg. . Electroluminescent devices were fabricated by vacuum evaporation. Apart from single layer devices, double and triple layer devices with the following structures: ITO/TPD/Complex 2/Al; ITO/TPD/Complex 3/Al; ITO/TPD/Complex 2/Alq/Al were studied, where N,N-bis(3-methylphenyl)-N,N'-diphenyl-benzidine (TPD) was used as a hole transporting layer and tris(8-hydroxyquinolinate)aluminum (Alq) as an electron transporting layer. The results indicate that single layer devices show very low quantum efficiency, while the double layer devices with a hole transporting layer exhibit enhanced efficiency and a well defined EL spectrum. No significant improvement was observed in the triple layer devices with an additional electron transporting layer.

  15. Wavelength-Tunable Electroluminescent Light Sources from Individual Ga-Doped ZnO Microwires.

    Science.gov (United States)

    Jiang, Mingming; He, Gaohang; Chen, Hongyu; Zhang, Zhenzhong; Zheng, Lingxia; Shan, Chongxin; Shen, Dezhen; Fang, Xiaosheng

    2017-03-07

    Electrically driven wavelength-tunable light emission from biased individual Ga-doped ZnO microwires (ZnO:Ga MWs) is demonstrated. Single crystalline ZnO:Ga MWs with different Ga-doping concentrations have been synthesized using a one-step chemical vapor deposition method. Strong electrically driven light emission from individual ZnO:Ga MW based devices is realized with tunable colors, and the emission region is localized toward the center of the wires. Increasing Ga-doping concentration in the MWs can lead to the redshift of electroluminescent emissions in the visible range. Interestingly, owing to the lack of rectification characteristics, relevant electrical measurement results show that the alternating current-driven light emission functions excellently on the ZnO:Ga MWs. Consequently, individual ZnO:Ga MWs, which can be analogous to incandescent sources, offer unique possibilities for future electroluminescence light sources. This typical multicolor emitter can be used to rival and complement other conventional semiconductor devices in displays and lighting.

  16. Proportional electroluminescence in two-phase argon and its relevance to rare-event experiments

    CERN Document Server

    Bondar, A; Dolgov, A; Nosov, V; Shekhtman, L; Shemyakina, E; Sokolov, A

    2015-01-01

    Proportional electroluminescence (EL) in gaseous Ar has for the first time been systematically studied in the two-phase mode, at 87 K and 1.00 atm. Liquid Ar had a minor (56 ppm) admixture of N2, which allowed to understand, inter alia, the effect of N2 doping on the EL mechanism in rare-event experiments using two-phase Ar detectors. The measurements were performed in a two-phase Cryogenic Avalanche Detector (CRAD) with EL gap located directly above the liquid-gas interface. The EL gap was optically read out in the Vacuum Ultraviolet (VUV), near 128 nm (Ar excimer emission), and in the near Ultraviolet (UV), at 300-450 nm (N2 Second Positive System emission), via cryogenic PMTs and a Geiger-mode APD (GAPD). Proportional electroluminescence was measured to have an amplification parameter of 109+-10 photons per drifting electron per kV overall in the VUV and UV, of which 51+-6% were emitted in the UV. The measured EL threshold, at an electric field of 3.7+-0.2 kV/cm, was in accordance with that predicted by th...

  17. Efficient Blue Electroluminescence Using Quantum-Confined Two-Dimensional Perovskites.

    Science.gov (United States)

    Kumar, Sudhir; Jagielski, Jakub; Yakunin, Sergii; Rice, Peter; Chiu, Yu-Cheng; Wang, Mingchao; Nedelcu, Georgian; Kim, Yeongin; Lin, Shangchao; Santos, Elton J G; Kovalenko, Maksym V; Shih, Chih-Jen

    2016-10-03

    Solution-processed hybrid organic-inorganic lead halide perovskites are emerging as one of the most promising candidates for low-cost light-emitting diodes (LEDs). However, due to a small exciton binding energy, it is not yet possible to achieve an efficient electroluminescence within the blue wavelength region at room temperature, as is necessary for full-spectrum light sources. Here, we demonstrate efficient blue LEDs based on the colloidal, quantum-confined 2D perovskites, with precisely controlled stacking down to one-unit-cell thickness (n = 1). A variety of low-k organic host compounds are used to disperse the 2D perovskites, effectively creating a matrix of the dielectric quantum wells, which significantly boosts the exciton binding energy by the dielectric confinement effect. Through the Förster resonance energy transfer, the excitons down-convert and recombine radiatively in the 2D perovskites. We report room-temperature pure green (n = 7-10), sky blue (n = 5), pure blue (n = 3), and deep blue (n = 1) electroluminescence, with record-high external quantum efficiencies in the green-to-blue wavelength region.

  18. A green emitting phosphorescent copper(I) complex with tetrazole derived ligand for electroluminescence application.

    Science.gov (United States)

    Tong, Senmiao; Yuan, Donglin; Yi, Lita

    2014-09-15

    In this paper, a tetrazole derived diamine ligand of 2-(1H-tetrazol-5-yl)pyridine (TP) owing electron-donors and short conjugation chain was synthesized to increase the band gap of its corresponding phosphorescent Cu(I) complex. This Cu(I) complex was characterized in detail, including its single crystal structure, singlet electronic transitions, photophysical parameters, thermal stability and electrochemical property. Upon on photoexcitation, this Cu(I) complex emitted green emission peaking at 497 nm with biexponential decay pattern of τ1=5.5414 μs (A1=0.137) and τ2=1.0679 μs (A2=0.11503). Cyclic voltammerty experiment suggested that this Cu(I) complex owned HOMO and LUMO energy levels of -5.79 eV and -2.39 eV. The thermal decomposition temperature was 170°C as indicated by thermogravimetric analysis. The optimal electroluminescence device constructed by solution processed coating procedure showed green electroluminescence peaking at 525 nm, with maximum luminance of 2860 cd/m2 and maximum current efficiency of 5.9 cd/A.

  19. A Successive Scans Method of Adjusting Scan-Time for Injection Electroluminescent Display Panels

    Institute of Scientific and Technical Information of China (English)

    OU Peng; YANG Gang; JIANG Quan; WANG Jun; HU Jian-Hua; WU Qi-Peng; LUO Kai-Jun

    2011-01-01

    @@ Aiming at the problem of luminance uniformity for injection electroluminescent display panels, we present a new scan method for display panels according to successive scans theory.First, on the basis of the number of pixels requiring light emitting in one frame period, we adjust the scan time for each row.Secondly, for ensuring image transmission synchronization, the frame period must to be a constant.We adopt a 64 × 32 LED display panel as an example to expound the new scan method and we obtain the good result that the reduce amplitude of luminance non-uniformity is 31.34% and the increase amplitude of the average luminance value is 7.8258%.%Aiming at the problem of luminance uniformity for injection electroluminescent display panels,we present a new scan method for display panets according to successive scans theory.First,on the basis of the number of pixels requiring light emitting in one frame period,we adjust the scan time for each row.Secondly,for ensuring image transmission synchronization,the frame period must to be a constant.We adopt a 64×32 LED display panel as an example to expound the new scan method and we odtain the good result that the reduce amplitude of luminance non-uniformity is 31.34% and the increase amplitude of the average luminance value is 7.8258%.

  20. Efficient visualization of unsteady and huge scalar and vector fields

    Science.gov (United States)

    Vetter, Michael; Olbrich, Stephan

    2016-04-01

    The simulation of climate data tends to produce very large data sets, which hardly can be processed in classical post-processing visualization applications. Within the most traditional post-processing scenarios the visualization pipeline consisting of the processes data generation, visualization mapping and rendering is distributed into two parts over the network or separated via file transfer: the data generation on a supercomputer on the one hand and the other tasks on a special visualization system on the other hand. That way either temporary data sets with huge volume have to be transferred over the network, which leads to bandwidth bottlenecks and volume limitations. As an alternative all simulation and visualization processes are integrated in a monolithic application, where just 2D pixel data is stored, which reduces the user's possibilities for 3D interaction with visualization to frame skipping. Within the Climate Visualization Lab - as part of the Cluster of Excellence "Integrated Climate System Analysis and Prediction" (CliSAP at the University of Hamburg, in cooperation with the German Climate Computing Center (DKRZ) - we plan to integrate a different approach, which has been proven to be successful in former meteorology applications, e.g. PALM (Parallel Large Eddy Simulation Model). Our software framework DSVR is based on the separation of the process chain between the mapping and the rendering processes. We have developed a parallelized visualization library based on MPI and evaluated on various supercomputers. DSVR can be used to integrate the visualization into a parallel simulation model to support in-situ processing, resulting in a sequence of time-based geometric 3D objects which can be interactively rendered in a separate 3D viewer application. To meet the actual requirements (a) to visualize existing data sets, (b) to support more than rectilinear grids, and (c) to integrate in-situ processing in the ICON model, all based on our DSVR framework

  1. Electroluminescence of SrS, BaS and SrSe Phosphors Activated by Cu and Er

    Science.gov (United States)

    Kulkarni, V. W.; Patwardhan, S. S.; Ghanbahadur, R. Y.

    1982-03-01

    Results of the investigations of the spectral characteristics of electroluminescence of SrS:Cu, Er, BaS:Cu, Er and SrSe:Cu, Er phosphors are presented. Some new features of the voltage and frequency dependence of EL-emission are reported.

  2. Fibrous dysplasia of the rib presenting as a huge chest wall tumor: report of a case.

    Science.gov (United States)

    Chang, B S; Lee, S C; Harn, H J

    1994-07-01

    Fibrous dysplasia of the rib is not uncommon, but is rarely demonstrated as a huge chest wall mass with severe clinical symptoms. A 59-year-old patient, presenting with a huge, rapidly expanding chest wall tumor compressing the lung, liver and heart accompanied by chest pain and dyspnea, is reported. The tumor was success-fully excised by local radical resection.

  3. Huge van Bordeeus : een ridder van Karel de Grote op avontuur in het Oosten

    NARCIS (Netherlands)

    Lens, Maria Johanna

    2004-01-01

    'Huge van Bordeeus' is de dissertatie van Maria Lens. Hierin doet zij verslag van haar onderzoek naar de Middelnederlandse overlevering van een Franse tekst, 'Huon de Bordeaux', over de ridder Huge van Bordeeus. Deze veertiende-eeuwse ridder, leenman van Karel de Grote, moet de baard en vier tanden

  4. Transarterial chemoembolization for huge hepatocellular carcinoma with diameter over ten centimeters: a large cohort study.

    Science.gov (United States)

    Xue, Tongchun; Le, Fan; Chen, Rongxin; Xie, Xiaoying; Zhang, Lan; Ge, Ningling; Chen, Yi; Wang, Yanhong; Zhang, Boheng; Ye, Shenglong; Ren, Zhenggang

    2015-03-01

    Patients with huge hepatocellular carcinoma >10 cm in diameter represent a special subgroup for treatment. To date, there are few data and little consensus on treatment strategies for huge hepatocellular carcinoma. In this study, we summarized the effects and safety of transarterial chemoembolization for huge hepatocellular carcinoma. A retrospective study was performed based on a large cohort of patients (n = 511) with huge hepatocellular carcinoma who underwent serial transarterial chemoembolization between January 2008 to December 2011 and were followed up until March 2013. We found median survival time was 6.5 months. On multivariate analysis, Child-Pugh class (A versus B) (p huge hepatocellular carcinoma and is recommended as a component of combination therapy. In addition, patients with good liver function and low alpha-fetoprotein levels may acquire greater survival benefits from transarterial chemoembolization.

  5. Far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge triple-junction solar cell under forward DC bias

    Institute of Scientific and Technical Information of China (English)

    Xiao Wenbo; He Xingdao; Gao Yiqing; Zhang Zhimin; Liu Jiangtao

    2012-01-01

    The far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge solar cell are investigated under forward DC bias at room temperature in dark conditions.An electroluminescence viewgraph shows the clear device structures,and the electroluminescence intensity is shown to increases exponentially with bias voltage and linearly with bias current.The results can be interpreted using an equivalent circuit of a single ideal diode model for triple-junction solar cells.The good fit between the measured and calculated data proves the above conclusions.This work is of guiding significance for current solar cell testing and research.

  6. Molecular-scale simulation of electroluminescence in a multilayer white organic light-emitting diode

    DEFF Research Database (Denmark)

    Mesta, Murat; Carvelli, Marco; de Vries, Rein J;

    2013-01-01

    we show that it is feasible to carry out Monte Carlo simulations including all of these molecular-scale processes for a hybrid multilayer organic light-emitting diode combining red and green phosphorescent layers with a blue fluorescent layer. The simulated current density and emission profile......In multilayer white organic light-emitting diodes the electronic processes in the various layers--injection and motion of charges as well as generation, diffusion and radiative decay of excitons--should be concerted such that efficient, stable and colour-balanced electroluminescence can occur. Here...... are shown to agree well with experiment. The experimental emission profile was obtained with nanometre resolution from the measured angle- and polarization-dependent emission spectra. The simulations elucidate the crucial role of exciton transfer from green to red and the efficiency loss due to excitons...

  7. Visible electroluminescence from p-n junction porous Si diode with a polyaniline film contact

    Institute of Scientific and Technical Information of China (English)

    Hongjian Li (李宏建); Baiyun Huang (黄伯云); Danqing Yi (易丹青); Haoyang Gui (崔昊杨); Jingcui Peng (彭景翠)

    2003-01-01

    We have fabricated a light emitting diode using a p-type conducting polyaniline layer deposited on a n-type porous silicon (PS) layer. The contact formed between a p-type conducting polyaniline layer and a n-type PS wafer has rectified behaviour demonstrated clearly by the I-V curves. The series resistance Rs in the p-type conducting polyaniline/n-PS diode is reduced greatly and has a lower onset voltage compared with ITO/n-PS diode. The PS has an orange photoluminescence (PL) band after coating with polyaniline.Visible electroluminescence (EL) has been obtained from this junction when a forward bias is applied. The emission band is very broad extending from 600 - 803 nm with a peak at 690 nm.

  8. A Noble Gas Detector with Electroluminescence Readout based on an Array of APDs

    CERN Document Server

    Bourguille, B; Gil-Botella, I; Lux, T; Palomares, C; Sanchez, F; Santorelli, R

    2015-01-01

    We present the results of the operation of an array of avalanche photodiodes (APDs) for the readout of an electroluminescence detector. The detector contains 24 APDs with a pitch of 15 mm between them allowing energy and position measurements simultaneously. Measurements were performed in xenon (3.8 bar) and argon (4.8 bar) showing a good energy resolution of 5.3% FWHM at 60 keV in xenon and 9.4% in argon respectively. In X-ray energies of 13 could be clearly separated from the pedestals indicating that this kind of technology might be also interesting for dark matter detectors. Following Monte Carlo studies the performance could be improved significantly by reducing the pitch between the sensors.

  9. Democratizing an electroluminescence imaging apparatus and analytics project for widespread data acquisition in photovoltaic materials.

    Science.gov (United States)

    Fada, Justin S; Wheeler, Nicholas R; Zabiyaka, Davis; Goel, Nikhil; Peshek, Timothy J; French, Roger H

    2016-08-01

    We present a description of an electroluminescence (EL) apparatus, easily sourced from commercially available components, with a quantitative image processing platform that demonstrates feasibility for the widespread utility of EL imaging as a characterization tool. We validated our system using a Gage R&R analysis to find a variance contribution by the measurement system of 80.56%, which is typically unacceptable, but through quantitative image processing and development of correction factors a variance contribution by the measurement system of 2.41% was obtained. We further validated the system by quantifying the signal-to-noise ratio (SNR) and found values consistent with other systems published in the literature, at SNR values of 10-100, albeit at exposure times of greater than 1 s compared to 10 ms for other systems. This SNR value range is acceptable for image feature recognition, providing the opportunity for widespread data acquisition and large scale data analytics of photovoltaics.

  10. Investigation of electroluminescence properties of CdTe@CdS core-shell nanocrystals (NCs)

    Indian Academy of Sciences (India)

    M Molaei; S Pourjafari

    2014-02-01

    In this work, CdTe@CdS NCs were synthesized using a thermochemical approach and synthesized NCs were used as an emissive layer, a light emitting device, with ITO/MoO3/PVK/CdTe@CdS(core-shell)/Mg:Ag structure. Structural and optical properties of synthesized NCs were investigated by means of XRD, UV–Vis and photoluminescence (PL) analyses. Fabricated device was characterized by electroluminescence spectra. XRD analysis demonstrated cubic phase NCs. Photoluminescence spectra showed a narrow band emission with a peak centred at about 600 nm. Fabricated device showed an emission at 600 nm, which is related to CdTe@CdS NCs. Turn on voltage of fabricated device is about 8 V and brightness is 53.7 Cd/m2 at a working voltage of about 14.57 V.

  11. Development and Characterization of a Multi-APD Xenon Electroluminescence TPC

    CERN Document Server

    Lux, T; Ballester, O; Bordoni, S; Gil-Botella, I; Hamer, N; Illa, J; Mañas, G Jover; Martin-Mari, C; Palomares, C; Rico, J; Sanchez, F; Santorelli, R; Verdugo, A

    2014-01-01

    The performance of an electroluminescence (EL) time projection chamber (TPC) with a multi avalanche photodiode (APD) readout was studied in pure xenon at 3.8 bar. Intercalibration and reconstruction methods were developed and applied to the data yielding energy resolutions as good as 5.3$+-$0.1 % FWHM for 59.5 keV gammas from 241-Am. The result was verified with a Monte Carlo (MC) based on Geant4 and Penelope predicting 5.2 % FWHM for the used setup. Point resolutions of about 0.5 mm were obtained by a pitch of 15 mm between the APDs. The results show that a multi-APD readout is a competitive technology for EL detectors filled with pure xenon with possible applications as Compton Cameras.

  12. Colour electroluminescence with end light-emitting from ZnO nanowire/polymer film

    Energy Technology Data Exchange (ETDEWEB)

    He Ying; Wang Junan [Institute of Materials, School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Zhang Wenfei; Chen Xiaoban; Huang Zonghao; Gu Qiuwen [Department of Polymer Materials, School of Materials Science and Engineering, Shanghai University, 149 Yanchang Road, Shanghai 200072 (China)], E-mail: yinghe@staff.shu.edu.cn

    2009-03-01

    The ZnO nanowires with polymer film were self-assembly grown on n-type (111) plane of the silicon substrate using polymer assisted complexing soft-template process through a simple polymer complexation and low-temperature oxidizing-sintering, which have smooth top and fine hexagonal columnar structure with average length of about 6 {mu}m and the diameter of about 40 nm. These columnar structured ZnO nanowires had strong near-band ultraviolet emission at {approx}383 nm and blue electrically driven emission at {approx} 400 nm with a relatively low turn-on voltage, as well as a typical diode characteristic property at room temperature. In particular, these structures, being of high aspect ratio and small tip radius of curvature, may possess a good amplified stimulated emission and lasing property. These results suggested a potential application of ZnO nanowire/polymer film as electroluminescence flat panel displays or illuminations in the future.

  13. An Electroluminescence Delay Time Model of Bilayer Organic Light-Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    LI Hong-Jian; ZHU Ru-Hui; LI Xue-Yong; YANG Bing-Chu

    2007-01-01

    @@ Based on the mechanism of injection, transport and recombination of the charge carriers, we develop a model to calculate the delay time of electroluminescence (EL) from bilayer organic light emitting diodes. The effect of injection, transport and recombination processes on the EL delay time is discussed, and the relationship between the internal interface barrier and the recombination time is revealed. The results show that the EL delay time is dominated by the recombination process at lower applied voltage and by the transport process at higher applied voltage. When the internal interface barrier varies from 0.15 eV to 0.3 eV, the recombination delay time increases rapidly, while the internal interface barrier exceeds about 0.3eV, the dependence of the recombination delay time on applied voltage is almost undiversified, which may serve as a guideline for designing of a high-speed EL response device.

  14. Electroluminescence from Ge1-ySny diodes with degenerate pn junctions

    Science.gov (United States)

    Gallagher, J. D.; Senaratne, C. L.; Wallace, P. M.; Menéndez, J.; Kouvetakis, J.

    2015-09-01

    The light emission properties of GeSn pn diodes were investigated as a function of alloy composition and doping levels. Very sharp interfaces between contiguous ultra-highly doped p- and n-layers were obtained using in situ doping with B2H6 and P(SiH3)3 in a chemical vapor deposition environment, yielding nearly ideal model systems for systematic studies. Changes in the doping levels and layer Sn concentrations are shown to greatly affect the electroluminescence spectra. This sensitivity should make it possible to optimize the emission efficiency for these structures in the interesting quasi-direct regime, for which direct gap luminescence is observed due to the proximity of the conduction band quasi-Fermi level to the minimum of the conduction band at the center of the Brillouin zone. Such structures represent the basic building block of Ge-based electrically pumped lasers.

  15. Infrared electroluminescence from GeSn heterojunction diodes grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Jay Prakash; Bhargava, Nupur; Kim, Sangcheol; Kolodzey, James [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Adam, Thomas [Nanofab, University of Albany, SUNY, Albany, New York 12203 (United States)

    2013-06-24

    Infrared electroluminescence was observed from GeSn/Ge p-n heterojunction diodes with 8% Sn, grown by molecular beam epitaxy. The GeSn layers were boron doped, compressively strained, and pseudomorphic on Ge substrates. Spectral measurements indicated an emission peak at 0.57 eV, about 50 meV wide, increasing in intensity with applied pulsed current, and with reducing device temperatures. The total integrated emitted power from a single edge facet was 54 {mu}W at an applied peak current of 100 mA at 100 K. These results suggest that GeSn-based materials maybe useful for practical light emitting diodes operating in the infrared wavelength range near 2 {mu}m.

  16. Visible and near-infrared electroluminescence from TiO2/p+-Si heterostructured device

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2014-04-01

    Full Text Available We report on visible and near-infrared (NIR electroluminescence (EL from the device based on the TiO2/p+-Si heterostructure, in which the TiO2 film is composed of anatase and rutile phases. As the device is applied with sufficiently high forward bias with the positive voltage connecting to p+-Si, the visible EL peaking at ∼600 nm along with the NIR EL centered at ∼810 nm occur simultaneously. It is proposed that the oxygen vacancies in the anatase TiO2 and Ti3+ defect states in the rutile TiO2 are the responsible centers for the visible and NIR EL, respectively.

  17. Novel Alternating Current Electroluminescent Devices with an Asymmetric Structure Based on a Polymer Heterojunction

    Institute of Scientific and Technical Information of China (English)

    谭海曙; 姚建铨; 王昕; 王鹏; 谢洪泉

    2002-01-01

    Novel alternating current electroluminescent devices with an asymmetric structure are successfully fabricated by using a hole-type polymer, poly(2,5-bis (dodecyloxy)-phenylenevinylene) (PDDOPV), and an electron-type polymer, poly(phenyl quinoxaline) (PPQ). The performance of the polymer devices with heteto junctions under ac operation is insensitive to the thickness of the two polymer layers, compared to that under dc operation. This new advantage means easy and cheap production facility on a large scale in the near future. Different emission spectra are obtained when our ac devices are operated in an ac mode, forward or reverse bias. The emission spectrum at reverse bias includes two parts: one from PDDOPV and the other from PPQ.

  18. Experimental and theoretical study of photo- and electroluminescence of divinyldiphenyl and divinylphenanthrene derivatives

    Science.gov (United States)

    Samsonova, L. G.; Valiev, R. R.; Degtyarenko, K. M.; Sunchugashev, D. A.; Kukhta, I. N.; Kukhta, A. V.; Kopylova, T. N.

    2017-02-01

    Electronic absorption and luminescence spectra of four new compounds of divinyldiphenyl and divinylphenanthrene derivatives are investigated experimentally in tetrahydrofuran solutions and thin films obtained by thermal vacuum deposition and by spin coating of these substances embedded into polyvinylcarbazole matrix. Molecular geometry optimizations and electronic spectra have been calculated in the framework of XMC-QDPT2/6-31G (d, p) and TDDFT/B3LYP/6-31G (d, p) levels of theory. We have fabricated and studied OLED devices with the structure ITO/PEDOT:PSS/NPD/L/Ca/Al and ITO/PEDOT:PSS/PVK + L/Ca, where L is the luminophore. It is demonstrated that the photo-and electroluminescence spectra of divinyldiphenyl are not identical and undergo strong changes depending on the method of sample preparation.

  19. Room-temperature direct band-gap electroluminescence from germanium (111)-fin light-emitting diodes

    Science.gov (United States)

    Tani, Kazuki; Saito, Shin-ichi; Oda, Katsuya; Miura, Makoto; Wakayama, Yuki; Okumura, Tadashi; Mine, Toshiyuki; Ido, Tatemi

    2017-03-01

    Germanium (Ge) (111) fins of 320 nm in height were successfully fabricated using a combination of flattening sidewalls of a silicon (Si) fin structure by anisotropic wet etching with tetramethylammonium hydroxide, formation of thin Ge fins by selective Si oxidation in SiGe layers, and enlargement of Ge fins by Ge homogeneous epitaxial growth. The excellent electrical characteristics of Ge(111) fin light-emitting diodes, such as an ideality factor of 1.1 and low dark current density of 7.1 × 10‑5 A cm‑2 at reverse bias of ‑2 V, indicate their good crystalline quality. A tensile strain of 0.2% in the Ge fins, which originated from the mismatch of the thermal expansion coefficients between Ge and the covering SiO2 layers, was expected from the room-temperature photoluminescence spectra, and room-temperature electroluminescence corresponding to the direct band-gap transition was observed from the Ge fins.

  20. Probe beam-free detection of terahertz wave by electroluminescence induced by intense THz pulse

    Science.gov (United States)

    Shin, J.; Jin, Z.; Nosaka, Y.; Nakazawa, T.; Kodama, R.

    2016-03-01

    Recently, a table-top fs laser system can generate MW terahertz (THz) pulse with its electric field higher than 100 kV/cm can be generated by several schemes. Such a strong THz field can directly drive electrons inside various materials. Here, we demonstrated a direct THz electric field detection method by measuring the electroluminescence induced by intense THz pulse inside commonly available light emitting diode. An intense THz wave obtained by the two-color laser scheme was focused onto LED along with an external DC bias to induce luminescence which we found proportional to the amplitude of the incident THz field. The scheme can be useful to realize a low-cost, probe-free THz detection and imaging system.

  1. Automatic Detection and Evaluation of Solar Cell Micro-Cracks in Electroluminescence Images Using Matched Filters

    Energy Technology Data Exchange (ETDEWEB)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    2016-11-21

    A method for detecting micro-cracks in solar cells using two dimensional matched filters was developed, derived from the electroluminescence intensity profile of typical micro-cracks. We describe the image processing steps to obtain a binary map with the location of the micro-cracks. Finally, we show how to automatically estimate the total length of each micro-crack from these maps, and propose a method to identify severe types of micro-cracks, such as parallel, dendritic, and cracks with multiple orientations. With an optimized threshold parameter, the technique detects over 90 % of cracks larger than 3 cm in length. The method shows great potential for quantifying micro-crack damage after manufacturing or module transportation for the determination of a module quality criterion for cell cracking in photovoltaic modules.

  2. Drift mobility measurements in a-C:H films by time-resolved electroluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Foulani, A

    2002-12-30

    Carrier transport mechanism has been studied in thin insulating hydrogenated amorphous carbon (a-C:H) films. The layers were prepared by plasma polymerization of methane (CH{sub 4}) at a frequency of 20 kHz. Electron mobility was derived from time-resolved luminescence experiments. Between the application of a rectangular voltage pulse and the first appearance of electroluminescence (EL) a time lag exists, which depends on the pulse height. Transit times are in the order of 10{sup -3} to {approx}10{sup -6} s in a voltage rabetween 10 and 25 V. And the estimated electron mobility varies accordingly from 8x10{sup -8} to {approx}10{sup -6} cm{sup 2}/(V s). The field dependence of the carriers mobility is characteristic of Poole-Frenkel-detrapping conduction model, and thus confirms the results obtained by dc experimental data.

  3. Democratizing an electroluminescence imaging apparatus and analytics project for widespread data acquisition in photovoltaic materials

    Science.gov (United States)

    Fada, Justin S.; Wheeler, Nicholas R.; Zabiyaka, Davis; Goel, Nikhil; Peshek, Timothy J.; French, Roger H.

    2016-08-01

    We present a description of an electroluminescence (EL) apparatus, easily sourced from commercially available components, with a quantitative image processing platform that demonstrates feasibility for the widespread utility of EL imaging as a characterization tool. We validated our system using a Gage R&R analysis to find a variance contribution by the measurement system of 80.56%, which is typically unacceptable, but through quantitative image processing and development of correction factors a variance contribution by the measurement system of 2.41% was obtained. We further validated the system by quantifying the signal-to-noise ratio (SNR) and found values consistent with other systems published in the literature, at SNR values of 10-100, albeit at exposure times of greater than 1 s compared to 10 ms for other systems. This SNR value range is acceptable for image feature recognition, providing the opportunity for widespread data acquisition and large scale data analytics of photovoltaics.

  4. Wannier-Stark localization and terahertz electroluminescence of natural SiC superlattice

    Energy Technology Data Exchange (ETDEWEB)

    Sankin, V. I.; Andrianov, A. V.; Petrov, A. G.; Zakhar' in, A. O. [A.F. Ioffe Physical Technical Institute, 194021 St. Petersburg (Russian Federation)

    2013-12-04

    We report on efficient terahertz electroluminescence in the region of 1.5-2 THz from high electric field biased 6H-SiC n{sup +}−n{sup −}−n{sup +} structures with a natural superlattice at 7 K. The properties of the terahertz emission allow it to be attributed to spontaneous radiation resulting from electron Bloch oscillations in SiC natural superlattice. The use of the unique object, namely, natural superlattice of SiC allowed us to demonstrate a whole series of remarkable effects of Wannier-Stark localization and to get the intensive terahertz emission under steady-state electrical excitation of Bloch oscillations.

  5. Emission of white light from 2-(2'-hydroxyphenyl) benzothiazole in polymer electroluminescent devices

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.M. [Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei, Taiwan (China)]. E-mail: f10914@ntut.edu.tw; Tzeng, Y.J. [Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei, Taiwan (China); Wu, S.Y. [Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei, Taiwan (China); Li, K.Y. [Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei, Taiwan (China); Hsueh, K.L. [Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei, Taiwan (China)

    2005-04-22

    Single-layer polymer devices that emit bright light from dye dispersed in the polymer matrix are fabricated. The active layer consists only of one polymer layer sandwiched between two electrodes-indium tin oxide and Mg:Ag. 2-(2-hydroxyphenyl) benzothiazole (HBT), a UV absorbent, is synthesized and exhibits bright blue-green fluorescence. Bright white emission is observed when the concentration of the dye in poly(N-vinylcarbazole) (PVK) polymer matrix is adjusted appropriately. The single-layered polymer blended electroluminescent (EL) device (ITO/polymer/Mg/Ag) has a relatively low driving voltage of 8 V. The EL spectrum includes three emission peaks at 420, 530 and 600 nm, representing deep blue, green and red light, respectively. The chromaticity coordinates, as specified by the Commission Internationale de l'Eclairage are (0.34, 0.36)

  6. White Electroluminescence Using ZnO Nanotubes/GaN Heterostructure Light-Emitting Diode

    Directory of Open Access Journals (Sweden)

    Sadaf JR

    2010-01-01

    Full Text Available Abstract We report the fabrication of heterostructure white light–emitting diode (LED comprised of n-ZnO nanotubes (NTs aqueous chemically synthesized on p-GaN substrate. Room temperature electroluminescence (EL of the LED demonstrates strong broadband white emission spectrum consisting of predominating peak centred at 560 nm and relatively weak violet–blue emission peak at 450 nm under forward bias. The broadband EL emission covering the whole visible spectrum has been attributed to the large surface area and high surface states of ZnO NTs produced during the etching process. In addition, comparison of the EL emission colour quality shows that ZnO nanotubes have much better quality than that of the ZnO nanorods. The colour-rendering index of the white light obtained from the nanotubes was 87, while the nanorods-based LED emit yellowish colour.

  7. Photo and electroluminescence of ZnSe: Sn and ZnSe:(Sn, Pr) phosphors

    Science.gov (United States)

    Mishra, A. K.; Mishra, S. K.; Pandey, S. P.; Lakshmi Mishra, Kshama

    2016-09-01

    We have prepared ZnSe (luminescent grade) phosphor doped with Sn and (Sn,Pr) with varying concentration in an inert atmosphere in a silica tubular furnace at temperature of (780 ± 20) °C for 1 hr to obtain ZnSe:Sn and ZnSe: (Sn,Pr) phosphors. The photo luminescence (PL) and electroluminescence (EL) spectra of these phosphors have been studied at room temperature and results were discussed in the light of existing models. Dependence of EL emission on the voltage frequency has also been carried out. It is found that the plot between the integrated light intensity versus 1/√Vrms is a straight line suggesting the existence of Mott-Schottky type barrier on the metal semiconductor interface.

  8. Light emitting devices based on Si nanoclusters: the integration with a photonic crystal and electroluminescence properties

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We present the properties and potentialities of light emitting devices based on amorphous Si nanoclusters. Amorphous nanostructures may constitute an interesting alternative to Si nanocrystals for the monolithic integration of optical and electrical functions in Si technology. In fact, they exhibit an intense room temperature electroluminescence (EL). The EL properties of these devices have been studied as a function of current and of temperature. Moreover, to improve the extraction efficiency of the light, we have integrated the emitting system with a 2D photonic crystal structure opportunely fabricated by using conventional optical lithography to reduce the total internal reflection of the emitted light. The extraction efficiency in such devices increases by a factor of 4 at a resonance wavelength.

  9. Nanoscale electroluminescence from n-type GaAs(110) in tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X L; Fujita, D; Niori, N; Keisuke, S; Onishi, K [Advanced Nanocharacterization Center, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2007-05-16

    Nanoscale electroluminescence (EL) was induced from n-type GaAs(110) in tunnel junctions using an indium tin oxide (ITO)-coated optical fibre probe at both polarities, room temperature (RT), and 80 K. The quantum efficiency of photon emission at negative bias is much higher than at positive bias at both RT and 80 K. A high quantum efficiency of about {approx}10{sup -4}(photons/electron) was achieved at 80 K. The well-defined optical spectra exhibit two-peak features at 1.49 and 1.39 eV which are generated by the radiative recombination of hole-electron pairs over the direct band gap and surface states, respectively.

  10. Kinetics of electroluminescence of thin-film emitters based on zinc sulfide at ultralow frequencies

    CERN Document Server

    Gurin, N T; Sabitov, O Y

    2002-01-01

    Paper presents the results of investigation into kinetics of luminescence instantaneous luminance of thin-film electroluminescent structures excited by 0.1-2 Hz frequency triangular sing-variable voltage. One detected two regions with time rise of instantaneous luminance and of current (slow and quick ones) to which corresponded various regions at field and charge dependences of instantaneous luminance and at other electrophysical characteristics. On the basis of solution of kinetic equation one derived time dependences of instantaneous luminance and of inner quantum yield. The results are explained by generation of space charges within luminophore layer followed by reduction of the efficient thickness of the layer and by variation of mechanism of excitation of luminescence centers

  11. Structure–property relationships of electroluminescent polythiophenes: role of nitrogen-based heterocycles as side chains

    Indian Academy of Sciences (India)

    S Radhakrishnan; S J Ananthakrishnan; N Somanathan

    2011-07-01

    A series of conjugated polythiophenes containing nitrogen-containing heterocycles as side chain, with differing substituent nature and linkage have been studied using quantum-chemical calculations. The optical properties of synthesized polymers were compared with that of model compounds with intricate structural variations. The theoretically predicted optical characteristics are correlated with the experimentally determined parameters. Experimentally determined band gap and absorption maxima found to follow the predicted trends. Single emissive layer polymeric light emitting diodes are fabricated and the structural influence on photo- and electro-emission was studied in detail. The study shows that the nature of side chain substituent such as number/position of nitrogen atoms and mode of linking of side chain plays a crucial role in deciding the geometry which in turn controls the voltage response of the electroluminescence.

  12. Huge hepatocellular carcinoma with multiple intrahepatic metastases: An aggressive multimodal treatment

    Directory of Open Access Journals (Sweden)

    Satoshi Yasuda

    2015-01-01

    Conclusion: Multimodal treatment involving hepatectomy and TACE might be a good treatment strategy for patients with huge HCC with multiple intrahepatic metastases if the tumors are localized in the liver without distant or peritoneal metastasis.

  13. A huge ovarian mucinous cystadenoma causing virilization, preterm labor, and persistent supine hypotensive syndrome during pregnancy.

    Science.gov (United States)

    Kucur, Suna Kabil; Acar, Canan; Temizkan, Osman; Ozagari, Aysim; Gozukara, Ilay; Akyol, Atif

    2016-01-01

    Mucinous cystadenoma (MC) of the ovary is an unilateral, multilocular cystic benign epithelial tumor. Supposed to be hormone responsive, MC reaches huge sizes during pregnancy. Aortocaval compression is common during pregnancy, especially when the pregnant woman is in the supine position. However, the compression recovers with a change in position. The authors report the first case of a huge mucinous cystadenoma of the ovary complicating pregnancy and causing virilization, premature labor, and persistent supine hypotensive syndrome.

  14. Robot-assisted laparoscopic resection of a huge pelvic tumor: A case report.

    Science.gov (United States)

    Jia, Zhuomin; Lyu, Xiangjun; Xu, Yong; Leonardi, Rosario; Zhang, Xu

    2016-07-04

    The traditional open surgery, for the treatment of huge tumor in the narrow space of pelvic cavity and in close proximity to pelvic organs and neurovascular structures, is very difficult and challenging. We report a case of huge neurilemmoma operated using the robot-assisted laparoscopy. We used interventional pre-operation embolization to control blood supply of tumor because MRI showed the tumor had a sufficient blood supply.

  15. Case of huge neurofibroma expanding extra- and intracranially through the enlarged jugular foramen. CT scan findings and surgical approach

    Energy Technology Data Exchange (ETDEWEB)

    Hanakita, Junya; Imataka, Kiyoharu; Handa, Hajime (Kyoto Univ. (Japan). Faculty of Medicine)

    1984-01-01

    The surgical approach to the jugular foramen has been considered to be very difficult and troublesome, because of the location in which important structures, such as the internal jugular vein, internal carotid artery and lower cranial nerves, converge in the narrow deep space. A case of huge neurofibroma, which extended from the tentorium cerebelli through the dilated jugular foramen to the level of the vertebral body of C/sub 3/ was presented. A 12-year-old girl was admitted with complaints of visual disturbance and palsy of the V-XII cranial nerves of the left side. Plain skull film showed prominent widening of the cranial sutures and enlargement of the sella turcica. Horizontal CT scan with contrast showed symmetrical ventricular dilatation and a heterogeneously enhanced mass, which was situated mainly in the left CP angle. Coronal CT scan with contrast revealed a huge mass and enlarged jugular foramen, through which the tumor extended to the level of the vertebral body of C/sub 3/. Occlusion of the sigmoid sinus and the internal jugular vein of the left side was noticed in the vertebral angiography. Two-stage approach, the first one for removal of the intracranial tumor and the second one for extracranial tumor, was performed for its huge tumor. Several authors have reported excellent surgical approaches for the tumors situated in the jugular foramen. By our approach, modifying Gardner's original one, a wide operative field was obtained to remove the tumor around the jugular foramen with success. Our approach for the jugular foramen was described with illustrations.

  16. The HUGE formula (hematocrit, urea and gender): association with cardiovascular risk.

    Science.gov (United States)

    Robles, N R; Felix, F J; Fernandez-Berges, D; Perez-Castán, J; Zaro, M J; Lozano, L; Alvarez-Palacios, P; Garcia-Trigo, A; Tejero, V; Morcillo, Y; Hidalgo, A B

    2013-07-01

    To evaluate the relationship between chronic renal failure (CFR) defined through HUGE (hematocrit, urea and gender) formula score and the patient's cardiovascular risk measured through cardiovascular disease antecedents such as ischemic cardiopathy, cerebrovascular disease and peripheral arterial disease. The sample consisted of 2,831 subjects. Mean age was 51.2±14.7 years and 53.5% were female. Serum creatinine, urea, hematocrit and 24h proteinuria were analyzed. HUGE score was calculated from gender, urea and hematocrit. GFR was estimated from uncalibrated serum creatinine using the abbreviated Modification of Diet in Renal Disease equation (MDRD-4). UAE was measured in first morning urine sample. Using HUGE formula 2.2% (n = 61) of subjects had CRF. Of them, 12 (19.7%) had cardiovascular disease history. Among patients without CRF (n = 2770), 194 subjects had history of previous cardiovascular diseases (0.07%; p HUGE definition of CRF was 3.25 (p = 0.001, Mantel-Haenszel test). CFR was associated to higher pulse pressure (PP) and increased urinary albumin excretion. A significant cardiovascular risk was associated to the diagnosis of CRF through HUGE formula. This relation was closer than the obtained using MDRD estimated GFR in spite of a bigger sample. HUGE formula seems to be a useful tool for diagnosing CRF and evaluate the cardiovascular risk of these patients.

  17. Large magneto-conductance and magneto-electroluminescence in exciplex-based organic light-emitting diodes at room temperature

    Science.gov (United States)

    Ling, Yongzhou; Lei, Yanlian; Zhang, Qiaoming; Chen, Lixiang; Song, Qunliang; Xiong, Zuhong

    2015-11-01

    In this work, we report on large magneto-conductance (MC) over 60% and magneto-electroluminescence (MEL) as high as 112% at room temperature in an exciplex-based organic light-emitting diode (OLED) with efficient reverse intersystem crossing (ISC). The large MC and MEL are individually confirmed by the current density-voltage characteristics and the electroluminescence spectra under various magnetic fields. We proposed that this type of magnetic field effect (MFE) is governed by the field-modulated reverse ISC between the singlet and triplet exciplex. The temperature-dependent MFEs reveal that the small activation energy of reverse ISC accounts for the large MFEs in the present exciplex-based OLEDs.

  18. Luminescence properties of composites made of a europium(III) complex and electroluminescent polymers with different energy gaps

    Energy Technology Data Exchange (ETDEWEB)

    Morgado, Jorge [Instituto de Telecomunicacoes, Av. Rovisco Pais, P-1049-001 Lisbon (Portugal); Charas, Ana [Instituto de Telecomunicacoes, Av. Rovisco Pais, P-1049-001 Lisbon (Portugal); Fernandes, Jose A [Departamento de Quimica and CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Goncalves, Isabel S [Departamento de Quimica and CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Carlos, Luis D [Departamento de Fisica and CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Alcacer, Luis [Instituto de Telecomunicacoes, Av. Rovisco Pais, P-1049-001 Lisbon (Portugal)

    2006-08-21

    We present the optoelectronic properties of composites made of a europium(III) complex, Eu(NTA){sub 3} phen (where NTA=1-(2-naphthoyl)-3,3,3-trifluoroacetonate; phen=1,10-phenantroline), dispersed in three electroluminescent polymers, namely, poly(N-vinylcarbazole), poly(9,9-dioctylfluorene) and poly(9,9-dioctylfluorene-alt-benzothiadiazole). We find that the photo- and electroluminescence (EL) properties of these composites are well rationalized in terms of the relative position of the frontier levels of the host polymers and of the europium complex. We find also that charge recombination at the europium complex sites plays a key role on the EL properties of the composites.

  19. Electroluminescence from InGaN quantum dots in a fully monolithic GaN/AlInN cavity

    Science.gov (United States)

    Dartsch, Heiko; Tessarek, Christian; Aschenbrenner, Timo; Figge, Stephan; Kruse, Carsten; Schowalter, Marco; Rosenauer, Andreas; Hommel, Detlef

    2011-04-01

    We present for the first time electroluminescence from InGaN quantum dots inside a monolithic nitride based cavity. The structure consists of a 40-fold bottom GaN/Al 0.82In 0.18N distributed Bragg reflector (DBR), a single InGaN quantum dot layer inside a 5λ n-type (bottom) and p-type (top) doped GaN cavity and a 10-fold GaN/Al 0.82In 0.18N top DBR. Structural properties have been investigated by scanning transmission electron microscopy. Optical reflectivity measurements are in good agreement with calculations which predict a peak reflectivity of 92% and a quality factor of 220. Electroluminescence shows a pronounced emission at the spectral position of the cavity mode near 500 nm.

  20. The effect of absorption and coherent interference in the photoluminescence and electroluminescence spectra of SRO/SRN MIS capacitors.

    Science.gov (United States)

    Juvert, Joan; González-Fernández, Alfredo Abelardo; Llobera, Andreu; Domínguez, Carlos

    2013-04-22

    In this paper we present a technique that can be used to study the effect of absorption and coherent interference in the luminescence of multilayer structures. We apply the technique to the measured photoluminescence and electroluminescence spectra of MIS capacitors where the insulator is composed of a silicon rich oxide (SRO)/silicon rich nitride (SRN) bilayer structure. We remove the effect of the multilayer stack on the measured photoluminescence spectrum of the samples without the metal contact to find the intrinsic spectrum. Then we apply the effect of the MIS structure on the intrinsic spectrum in order to calculate the electroluminescence spectrum. Good agreement with the experimentally measured EL spectrum is found. We discuss which parameters affect the spectra most significantly.

  1. Luminescence and Electroluminescence of Nd, Tm and Yb Doped GaAs and some II-Vi Compounds

    Science.gov (United States)

    1994-02-28

    the Sixth International Workshop on Electroluminescence, El Paso, Texas, 1992 ( Cingo Puntos Press, El Paso, Texas, 1992), and references therein. 2. R...34. impurity seems to be traps (represented by ellipse) with the atomiclike 4f" core ideal . states. (a) Trapping (liberation) "r.(,r) of electron on REI traps...34structured" impurity seems to be ideal . KINETIC MODEL AND COMPUTATION RESULTS The luminescence kinetic model involving RE`3 "structured" isoelectronic

  2. Strong room temperature electroluminescence from lateral p-SiGe/i-Ge/n-SiGe heterojunction diodes on silicon-on-insulator substrate

    Science.gov (United States)

    Lin, Guangyang; Yi, Xiaohui; Li, Cheng; Chen, Ningli; Zhang, Lu; Chen, Songyan; Huang, Wei; Wang, Jianyuan; Xiong, Xihuan; Sun, Jiaming

    2016-10-01

    A lateral p-Si0.05Ge0.95/i-Ge/n-Si0.05Ge0.95 heterojunction light emitting diode on a silicon-on-insulator (SOI) substrate was proposed, which is profitable to achieve higher luminous extraction compared to vertical junctions. Due to the high carrier injection ratio of heterostructures and optical reflection at the SiO2/Si interface of the SOI, strong room temperature electroluminescence (EL) at around 1600 nm from the direct bandgap of i-Ge with 0.30% tensile strain was observed. The EL peak intensity of the lateral heterojunction is enhanced by ˜4 folds with a larger peak energy than that of the vertical Ge p-i-n homojunction, suggesting that the light emitting efficiency of the lateral heterojunction is effectively improved. The EL peak intensity of the lateral heterojunction, which increases quadratically with injection current density, becomes stronger for diodes with a wider i-Ge region. The CMOS compatible fabrication process of the lateral heterojunctions paves the way for the integration of the light source with the Ge metal-oxide-semiconductor field-effect-transistor.

  3. Newtonian self-gravitating system in a relativistic huge void universe model

    Science.gov (United States)

    Nishikawa, Ryusuke; Nakao, Ken-ichi; Yoo, Chul-Moon

    2016-12-01

    We consider a test of the Copernican Principle through observations of the large-scale structures, and for this purpose we study the self-gravitating system in a relativistic huge void universe model which does not invoke the Copernican Principle. If we focus on the the weakly self-gravitating and slowly evolving system whose spatial extent is much smaller than the scale of the cosmological horizon in the homogeneous and isotropic background universe model, the cosmological Newtonian approximation is available. Also in the huge void universe model, the same kind of approximation as the cosmological Newtonian approximation is available for the analysis of the perturbations contained in a region whose spatial size is much smaller than the scale of the huge void: the effects of the huge void are taken into account in a perturbative manner by using the Fermi-normal coordinates. By using this approximation, we derive the equations of motion for the weakly self-gravitating perturbations whose elements have relative velocities much smaller than the speed of light, and show the derived equations can be significantly different from those in the homogeneous and isotropic universe model, due to the anisotropic volume expansion in the huge void. We linearize the derived equations of motion and solve them. The solutions show that the behaviors of linear density perturbations are very different from those in the homogeneous and isotropic universe model.

  4. Synthesis, Photophysical Properties and Near Infrared Electroluminescence of 1 (4),8(11),15(18),22(25)-Tetra- (methoxy-phenoxy) phthalocyanine

    Institute of Scientific and Technical Information of China (English)

    白青龙; 张春花; 程传辉; 李万程; 王瑾; 杜国同

    2012-01-01

    A new soluble phthalocyaine 1 (4),8(11), 15(18),22(25)-tetra-(methoxy-phenoxy)phthalocyanine (MPPc) was synthesized and verified by mass spectrum (MS), 1H NMR, IR and elemental analysis. The methoxy-phenoxy groups were introduced in order to enhance the solubility of the phthalocyanine. The photophysical and electrolu- minescent properties were investigated. The organic light-emitting diodes (OLEDs) with the structure of ITO/PVK:MPPc(40 nm)/BCP(20 nm)/Alq3(30 nm)/Al were fabricated. Room-temperature near infrared (NIR) electroluminescence (EL) was observed near 891 nm that effectively covered the first optical communication win- dow near 850 nm.

  5. Hydrogen-terminated mesoporous silicon monoliths with huge surface area as alternative Si-based visible light-active photocatalysts

    KAUST Repository

    Li, Ting

    2016-07-21

    Silicon-based nanostructures and their related composites have drawn tremendous research interest in solar energy storage and conversion. Mesoporous silicon with a huge surface area of 400-900 m2 g-1 developed by electrochemical etching exhibits excellent photocatalytic ability and stability after 10 cycles in degrading methyl orange under visible light irradiation, owing to its unique mesoporous network, abundant surface hydrides and efficient light harvesting. This work showcases the profound effects of surface area, crystallinity, pore topology on charge migration/recombination and mass transportation. Therein the ordered 1D channel array has outperformed the interconnected 3D porous network by greatly accelerating the mass diffusion and enhancing the accessibility of the active sites on the extensive surfaces. © 2016 The Royal Society of Chemistry.

  6. Colonic Angiodysplasia with a Huge Submucosal Hematoma in the Sigmoid Colon.

    Science.gov (United States)

    Shimizu, Takayuki; Koike, Daisuke; Nomura, Yukihiro; Ooe, Kenji

    2016-01-01

    Colonic angiodysplasia (AD) with bleeding as a comorbidity in the aging population is being increasingly reported. However, to our knowledge, there is no report on colonic AD accompanied by a huge hematoma. Herein, we report a case of colonic AD with a huge submucosal hematoma. A 75-year-old man with sudden melena was referred to our hospital. Helical computed tomographic angiography (CTA) revealed bleeding from the sigmoid colon. Additionally, colonoscopy showed a huge submucosal hematoma with bleeding in the sigmoid colon. As endoscopic hemostasis was difficult, sigmoidectomy was performed. The pathological diagnosis was colonic AD. The present case indicates that colonic AD should be considered in the differential diagnosis for melena. In addition, the case shows that helical CTA, which is a noninvasive imaging modality, is useful for the diagnosis of colonic AD and is as effective as colonoscopy and angiography for diagnosis.

  7. Robotic resection of huge presacral tumors: case series and comparison with an open resection.

    Science.gov (United States)

    Oh, Jae Keun; Yang, Moon Sool; Yoon, Do Heum; Rha, Koon Ho; Kim, Keung Nyun; Yi, Seong; Ha, Yoon

    2014-06-01

    Clinical case series and analysis. The purpose of the present study is to evaluate the advantages and disadvantages of robotic presacral tumor resection compared with conventional open approach. Conventional open approach for huge presacral tumors in the retroperitoneal space often demands excessive hospitalization and poor cosmesis. Furthermore, narrow surgical field sometimes interrupt delicate procedures. Nine patients with huge (diameter >10 cm) presacral tumors underwent surgery. Five patients among them had robotic procedure and the others had open transperitoneal tumor resection. Operation time, blood loss, hospitalization, and complications were analyzed. Robotic presacral tumor resection showed shorter operation time, less bleeding, and shorter hospitalization. Moreover, there was no complication related to abdominal adhesion. Although robotic resection for presacral tumor still has limitations technically and economically, robotic resection for huge presacral tumors demonstrated advantages over open resection specifically for benign neurogenic tumors.

  8. Giant pulmonary teratoma with huge splenic lymphangiomatosis: a very rare case.

    Science.gov (United States)

    Alsubaie, Hemail M; Alsubaie, Khaled M; Mahfouz, Mohammed Eid

    2017-09-01

    Teratomas are tumors composed of tissues derived from more than one germ cell line. They manifested with a great variety of clinical and radiological features. We report a case of a giant left hemithorax teratoma in a female with huge spleen tumor and review the relevant literature. A 38-year-old female with progressively aggravating dyspnea at rest from a mild trauma. Absent breath sounds on the left side. There was splenomegaly. Computed tomography scan revealed a huge mass (20 × 15 × 18 cm), containing elements of heterogeneous density in the left hemithorax. The spleen tumor was occupying most of the spleen without any other abdominal manifestations. The patient underwent left thoracotomy and laparoscopic splenectomy. Histopathological examination revealed a benign mature teratoma and cystic lymphangiomatosis of the spleen. To the best of our knowledge and after reviewing the available literature this is the first case of huge mature pulmonary teratoma with large cystic spleen lymphangiomatosis.

  9. Huge splenic epidermoid cyst with elevation of serum CA19-9 level.

    Science.gov (United States)

    Matsumoto, Sayo; Mori, Toshifumi; Miyoshi, Jinsei; Imoto, Yoshitaka; Shinomiya, Hirohiko; Wada, Satoshi; Nakao, Toshihiro; Shinohara, Hisamitsu; Yoshida, Sadahiro; Izumi, Keisuke; Okazaki, Jun; Muguruma, Naoki; Takayama, Tetsuji

    2015-01-01

    A 30-year-old female was referred to our hospital for further examination of liver dysfunction. A huge, soft mass was noted in her left upper quadrant on physical examination. Abdominal ultrasonography and computed tomography revealed a huge cystic tumor of 20 cm in the hilus of the spleen. Serum CA19-9 was 491 U/ml, and splenectomy was performed under suspicion of a malignant cystic tumor. The inner surface of the cyst was lined by squamous epithelial cells that were immunohistochemically positive for CA19-9. Serum CA19-9 level was normalized after the surgery. Our case of a very rare, huge epidermoid cyst of the spleen suggests that measurement of the serum CA19-9 level is useful for evaluating therapeutic efficacy of a splenic epidermoid cyst.

  10. Endovascular Treatment of a Huge Hepatic Artery Aneurysm by Coil Embolization Method: A Case Report.

    Science.gov (United States)

    Hemmati, Hossein; Karimian, Mehdi; Moradi, Habibollah; Farid Marandi, Kambiz; Haghdoost, Afrooz

    2015-07-01

    Hepatic artery aneurysms are rare but potentially life threatening. We describe a novel case of a successful endovascular coil embolization of a huge hepatic artery aneurysm. A 67-year-old woman presented with recent abdominal pain that had begun from 2 weeks before referring to our hospital. Sonographic and computerized tomographic (CT) findings revealed a huge hepatic artery aneurysm with 95 mm × 83 mm diameter. The patient underwent an endovascular technique. In aortic angiography, the celiac artery orifice and superior mesenteric artery were so narrow, so sonography was used in order to determine the exact position of the catheter in the celiac artery orifice. The aneurysm was thrombosed using coil embolization. Pulsation of the aneurysm immediately disappeared. Huge hepatic artery aneurysm can be safely treated using coil embolization.

  11. Collaborative treatment of huge intrathoracic meningoceles associated with neurofibromatosis type 1: a case report.

    Science.gov (United States)

    Cho, Deog Gon; Chang, Yong Jin; Cho, Kyu Do; Hong, Jae Taek

    2015-11-10

    An intrathoracic meningocele is a relatively rare disease, and it commonly accompanies neurofibromatosis type 1. Patients tend to have no symptom but if its size is too large and compresses a lung and neighboring organs, it needs shunt drainage or surgical resection. Herein, we present the case of a 52 year-old female patient with huge intrathoracic meningoceles associated with neurofibromatosis type 1, who has complained about chest discomfort and dyspnea at rest. As for a preliminary treatment, a neurosurgeon had performed a cystoperitoneal shunt, but the symptoms continued and the size of mass and the amount of pleural effusion did not change significantly. Therefore, the huge thoracic meningoceles were successfully treated through the thoracotomic approach in combination with lumbar puncture and cerebrospinal fluid drainage. It is reported that double huge intrathoracic meningoceles associated with neurofibromatosis type 1 was successfully treated by a shunting procedure followed by thoracotomic resection with collaboration of a neurosurgeon.

  12. Three-Colour Single-Mode Electroluminescence from Alq3 Tuned by Microcavities

    Institute of Scientific and Technical Information of China (English)

    赵家民; 马凤英; 刘星元; 刘云; 初国强; 宁永强; 王立军

    2002-01-01

    Organic metal microcavities were fabricated by using full-reflectivity aluminium film and semi-transparent silverfilm as cavity mirrors. Unlike conventional organic microcavities, such as the typical structure of glass/DBR/ITO/-organic layers/metal mirror, a microcavity with a shorter cavity length was obtained by using two metal mirrors,where DBR is the distributed Bragg reflector consisting of alternate quarter-wave layers of high and low refractiveindex materials. It is realized that red, green and blue single-mode electroluminescence (EL) from the micro-cavities with the structure, glass/Ag/TPD/Alqa/A1, are electrically-driven when the thickness of the Alqa layerchanges. Compared to a non-cavity reference sample whose EL spectrum peak is located at 520nm with a fullwidth at half maximum (FWHM) of 93 nm, the microcavity devices show apparent cavity effects. The EL spectraof red, green and blue microcavities are peaked at 604nm, 540nm and 491 nm, with FWHM of 43 nm, 38nm and47nm, respectively.

  13. The Study of Electroluminescence and Reliability of Polyimide Films in High DC Fields

    Directory of Open Access Journals (Sweden)

    Jiaqi LIN

    2015-11-01

    Full Text Available Electroluminescence (EL intensity of the polyimide (PI films was tested under dc high electric field by home-made experimental device. The results showed that the EL intensity of PI films increased along with the electric field. EL intensity is approximately to background intensity when the electric-field intensity was less than 2.00 MV/cm. EL intensity increases along with increasing the electric field when electric-field intensity greater than 2.00 MV/cm. When electric-field at 2.80 MV/cm, EL intensity increasing strongly suggests that the excitation process related to hot electrons accelerated by the field approaching a critical threshold. Meanwhile, this work elaborates a method to deal with identical samples get different experimental data by using Weibull distribution method, and the concept of the reliability was presented. The nine groups of EL experimental data were analyzed, and the result showed that the lifetime of mid-value (t = 164.9 min. Mid-value of the breakdown field is E = 2.76 MV/cm.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9694

  14. Defect-assisted tuning of electroluminescence from p-GaN/n-ZnO nanorod heterojunction

    Indian Academy of Sciences (India)

    Lawrence S Vikas; C K Sruthi; Madambi K Jayaraj

    2015-08-01

    Growth of nanostructured ZnO by solution process always lead to the formation of various kinds of defects. Defect states also can aid in improving different properties of the material. In the case of light-emitting diodes (LEDs), major research is focused on tuning the emission colour so as to achieve white emission without the use of any phosphors. Vertically aligned ZnO nanorods were grown over Mg:GaN substrate by hydrothermal process. High-resolution X-ray diffraction (HRXRD) analysis confirms the epitaxial growth of nanorods over the substrate. The photoluminescence (PL) studies revealed a narrow near band edge emission and a broad defect-induced deep level emission. The intensity of deep level emissions related to Zni, Vo, Oi defects decreases on annealing. The - characteristics of the heterojunction showed excellent rectifying nature with electroluminescence emission on forward bias. Device fabricated by as-grown ZnO nanorods emits in the UV–blue region and broad emission in the visible region. While the annealed device emitted only in UV–blue region. The emission wavelengths closely matched with that of defect state emissions obtained in the PL studies. By annealing, various defect states density can be controlled, thereby emission colour tuned from white to blue.

  15. Pure circular polarization electroluminescence at room temperature with spin-polarized light-emitting diodes

    CERN Document Server

    Nishizawa, N; Munekata, H

    2016-01-01

    We report the room-temperature electroluminescence (EL) with nearly pure circular polarization (CP) from GaAs-based spin-polarized light-emitting diodes (spin-LEDs). External magnetic fields are not used during device operation. There are two small schemes in the tested spin-LEDs: firstly, the stripe-laser-like structure that helps intensifying the EL light at the cleaved side walls below the spin injector Fe slab, and secondly, the crystalline AlOx spin tunnel barrier that ensures electrically stable device operation. The purity of CP is depressively low in the low current density (J) region, whereas it increases steeply and reaches close to the pure CP when J = 100 A/cm2. There, either right- or left-handed CP component is significantly suppressed depending on the direction of magnetization of the spin injector. Spin-polarized-current induced birefringence and optical spin-axis conversion are suggested to account for the observed experimental results.

  16. Origin of the Electroluminescence from Annealed-ZnO/GaN Heterojunction Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Kai-Chiang Hsu

    2015-11-01

    Full Text Available This paper addressed the effect of post-annealed treatment on the electroluminescence (EL of an n-ZnO/p-GaN heterojunction light-emitting diode (LED. The bluish light emitted from the 450 °C-annealed LED became reddish as the LED annealed at a temperature of 800 °C under vacuum atmosphere. The origins of the light emission for these LEDs annealed at various temperatures were studied using measurements of electrical property, photoluminescence, and Auger electron spectroscopy (AES depth profiles. A blue-violet emission located at 430 nm was associated with intrinsic transitions between the bandgap of n-ZnO and p-GaN, the green-yellow emission at 550 nm mainly originating from the deep-level transitions of native defects in the n-ZnO and p-GaN surfaces, and the red emission at 610 nm emerging from the Ga-O interlayer due to interdiffusion at the n-ZnO/p-GaN interface. The above-mentioned emissions also supported the EL spectra of LEDs annealed at 700 °C under air, nitrogen, and oxygen atmospheres, respectively.

  17. Near-infrared roll-off-free electroluminescence from highly stable diketopyrrolopyrrole light emitting diodes

    Science.gov (United States)

    Sassi, Mauro; Buccheri, Nunzio; Rooney, Myles; Botta, Chiara; Bruni, Francesco; Giovanella, Umberto; Brovelli, Sergio; Beverina, Luca

    2016-09-01

    Organic light emitting diodes (OLEDs) operating in the near-infrared spectral region are gaining growing relevance for emerging photonic technologies, such as lab-on-chip platforms for medical diagnostics, flexible self-medicated pads for photodynamic therapy, night vision and plastic-based telecommunications. The achievement of efficient near-infrared electroluminescence from solution-processed OLEDs is, however, an open challenge due to the low photoluminescence efficiency of most narrow-energy-gap organic emitters. Diketopyrrolopyrrole-boron complexes are promising candidates to overcome this limitation as they feature extremely high photoluminescence quantum yield in the near-infrared region and high chemical stability. Here, by incorporating suitably functionalized diketopyrrolopyrrole derivatives emitting at ~760 nm in an active matrix of poly(9,9-dioctylfluorene-alt-benzothiadiazole) and without using complex light out-coupling or encapsulation strategies, we obtain all-solution-processed NIR-OLEDs with external quantum efficiency as high as 0.5%. Importantly, our test-bed devices show no efficiency roll-off even for high current densities and high operational stability, retaining over 50% of the initial radiant emittance for over 50 hours of continuous operation at 10 mA/cm2, which emphasizes the great applicative potential of the proposed strategy.

  18. Polarization-induced pn diodes in wide-band-gap nanowires with ultraviolet electroluminescence.

    Science.gov (United States)

    Carnevale, Santino D; Kent, Thomas F; Phillips, Patrick J; Mills, Michael J; Rajan, Siddharth; Myers, Roberto C

    2012-02-08

    Almost all electronic devices utilize a pn junction formed by random doping of donor and acceptor impurity atoms. We developed a fundamentally new type of pn junction not formed by impurity-doping, but rather by grading the composition of a semiconductor nanowire resulting in alternating p and n conducting regions due to polarization charge. By linearly grading AlGaN nanowires from 0% to 100% and back to 0% Al, we show the formation of a polarization-induced pn junction even in the absence of any impurity doping. Since electrons and holes are injected from AlN barriers into quantum disk active regions, graded nanowires allow deep ultraviolet LEDs across the AlGaN band-gap range with electroluminescence observed from 3.4 to 5 eV. Polarization-induced p-type conductivity in nanowires is shown to be possible even without supplemental acceptor doping, demonstrating the advantage of polarization engineering in nanowires compared with planar films and providing a strategy for improving conductivity in wide-band-gap semiconductors. As polarization charge is uniform within each unit cell, polarization-induced conductivity without impurity doping provides a solution to the problem of conductivity uniformity in nanowires and nanoelectronics and opens a new field of polarization engineering in nanostructures that may be applied to other polar semiconductors.

  19. Extended structural defects and their influence on the electroluminescence in efficient Si light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Sobolev, N.A.; Emel' yanov, A.M.; Shek, E.I.; Vdovin, V.I

    2003-12-31

    We report our results on electroluminescence (EL) in the range of 1.0-1.6 {mu}m, structural defects and electrophysical properties of light-emitting diodes fabricated by implantation of B and P ions into Si substrates with a subsequent thermal annealing at 700-1200 deg. C in argon. A band-to-band emission peak dominates in the EL spectra of all the samples at 80-500 K. The internal quantum efficiency of the band-to-band EL, {eta}{sub int}, and the minority carrier lifetime, {tau}{sub p}, increase with annealing temperature to 1100 deg. C, with the efficiency practically proportional to the lifetime. The maximum {eta}{sub int} was registered after annealing at 1100 deg. C, when there are no extended structural defects. Rod-like defects, partial Frank and perfect prismatic dislocation loops are formed after annealing at lower temperatures. No correlation between the quantum efficiency and the defect structure was revealed with the variation of the annealing temperature. An increase of the value {tau}{sub p}/{eta}{sub int}, proportional to the radiative lifetime, with an increasing temperature has been observed.

  20. Electroluminescence from GeSn heterostructure pin diodes at the indirect to direct transition

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, J. D.; Menéndez, J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States); Senaratne, C. L.; Sims, P.; Kouvetakis, J. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Aoki, T. [LeRoy Eyring Center for Solid State Science, Arizona State University, Tempe, Arizona 85287- 1704 (United States)

    2015-03-02

    The emission properties of GeSn heterostructure pin diodes have been investigated. The devices contain thick (400–600 nm) Ge{sub 1−y}Sn{sub y} i-layers spanning a broad compositional range below and above the crossover Sn concentration y{sub c} where the Ge{sub 1−y}Sn{sub y} alloy becomes a direct-gap material. These results are made possible by an optimized device architecture containing a single defected interface thereby mitigating the deleterious effects of mismatch-induced defects. The observed emission intensities as a function of composition show the contributions from two separate trends: an increase in direct gap emission as the Sn concentration is increased, as expected from the reduction and eventual reversal of the separation between the direct and indirect edges, and a parallel increase in non-radiative recombination when the mismatch strains between the structure components is partially relaxed by the generation of misfit dislocations. An estimation of recombination times based on the observed electroluminescence intensities is found to be strongly correlated with the reverse-bias dark current measured in the same devices.

  1. Electroluminescence from ZnO/Si heterojunctions fabricated by PLD with bias voltage application

    Energy Technology Data Exchange (ETDEWEB)

    Seno, Yuuki; Konno, Daisuke; Komiyama, Takao; Chonan, Yasunori; Yamaguchi, Hiroyuki; Aoyama, Takashi [Electronics and Information Systems, Akita Prefectural Univ. Yuri-honjo, Akita 015-0055 (Japan)

    2014-02-21

    Electroluminescence (EL) for ZnO films has been investigated by fabricating n-ZnO/p-Si heterojunctions and changing the VI/II (O/Zn) ratio of the films. In the photoluminescence (PL) spectra, both the near band edge (NBE) emission and the defect-related emission were observed, while in the EL spectra only defect-related emission was observed. The EL spectra were divided into three components: green (550 nm), yellow (618 nm) and red (700 nm) bands; and their intensities were compared. As the VI/II (O/Zn) ratio was increased, the red band emission intensity decreased and the green band emission intensity increased. This implies that the oxygen and the zinc vacancies are related to the red and the green band emissions, respectively. Electron transitions from the conduction band minimum (Ec) to the deep energy levels of these vacancies are suggested to cause the red and the green luminescences while the energy levels of the Zn interstitials are close to the Ec in the band gap and no NBE emission is observed.

  2. Properties of ZnS:Cu,Cl Thick Film Electroluminescent Devices by Screen Printing Method

    Energy Technology Data Exchange (ETDEWEB)

    Rho, J. S.; Yoo, S. H.; Chang, H. J. [Dankook University, Chonan (Korea)

    2001-06-01

    The ZnS:Cu,Cl thick film electroluminescent devices with the stacking type(separated with phosphors and insulator layers) and the composite type (mixed with phosphor and insulator materials) emission layers were fabricated on ITO/glass substrates by the screen printing methods. The optical and electrical properties were investigated as functions of applied voltages and frequencies. In the stacking type, the luminance was about 58 cd/m{sup 2} at the applied voltage of 400Hz, 200V and increased to 420 cd/m{sup 2} with increasing the frequency to 30Hz. For the composite type devices, the threshold voltage was 45V and the maximum luminance was 670 cd/m{sup 2} at the driving condition of 200V, 30Hz. The value of luminance of the composite type device showed 1.5 times higher than that of stacking type device. The main emission peak was 512 nm of bluish-green color at 1 Hz frequency below and shifted to 452 nm in the driving frequency over 5Hz showing the blue emission color. There were no distinct differences of the main emission peaks and color coordinate for both samples. (author). 13 refs., 8 figs.

  3. Near-infrared roll-off-free electroluminescence from highly stable diketopyrrolopyrrole light emitting diodes

    Science.gov (United States)

    Sassi, Mauro; Buccheri, Nunzio; Rooney, Myles; Botta, Chiara; Bruni, Francesco; Giovanella, Umberto; Brovelli, Sergio; Beverina, Luca

    2016-01-01

    Organic light emitting diodes (OLEDs) operating in the near-infrared spectral region are gaining growing relevance for emerging photonic technologies, such as lab-on-chip platforms for medical diagnostics, flexible self-medicated pads for photodynamic therapy, night vision and plastic-based telecommunications. The achievement of efficient near-infrared electroluminescence from solution-processed OLEDs is, however, an open challenge due to the low photoluminescence efficiency of most narrow-energy-gap organic emitters. Diketopyrrolopyrrole-boron complexes are promising candidates to overcome this limitation as they feature extremely high photoluminescence quantum yield in the near-infrared region and high chemical stability. Here, by incorporating suitably functionalized diketopyrrolopyrrole derivatives emitting at ~760 nm in an active matrix of poly(9,9-dioctylfluorene-alt-benzothiadiazole) and without using complex light out-coupling or encapsulation strategies, we obtain all-solution-processed NIR-OLEDs with external quantum efficiency as high as 0.5%. Importantly, our test-bed devices show no efficiency roll-off even for high current densities and high operational stability, retaining over 50% of the initial radiant emittance for over 50 hours of continuous operation at 10 mA/cm2, which emphasizes the great applicative potential of the proposed strategy. PMID:27677240

  4. Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices

    CERN Document Server

    Li Juan Zo

    2003-01-01

    Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatorial method was employed in device preparation. Both continuous wave and transient electroluminescence (EL) were studied. A new efficient and intense UV-violet light emitting device was developed. At a current density of 10 mA/cm sup 2 , the optimal radiance R could reach 0.38 mW/cm sup 2 , and the quantum efficiency was 1.25%. using the delayed EL technique, electron mobilities in DPVBi and CBP were determined to be approx 10 sup - sup 5 cm sup 2 /Vs and approx 10 sup - sup 4 cm sup 2 /Vs, respectively. Overshoot effects...

  5. Spray deposition of organic electroluminescent coatings for application in flexible light emitting devices

    Directory of Open Access Journals (Sweden)

    Mariya Aleksandrova

    2015-12-01

    Full Text Available Organic electroluminescent (EL films of tris(8-hydroxyquinolinatoaluminum (Alq3 mixed with polystyrene (PS binder were produced by spray deposition. The influence of the substrate temperature on the layer’s morphology and uniformity was investigated. The deposition conditions were optimized and simple flexible light-emitting devices consisting of indium-tin oxide/Alq3:PS/aluminum were fabricated on polyethylene terephthalate (PET foil to demonstrate the advantages of the sprayed organic coatings. Same structure was produced by thermal evaporation of Alq3 film as a reference. The influence of the deposition method on the film roughness and contact resistance at the electrode interfaces for both types of structures was estimated. The results were related to the devices’ efficiency. It was found that the samples with sprayed films turn on at 4 V, which is 2 V lower in comparison to the device with thermal evaporated Alq3. The current through the sprayed device is six times higher as well (17 mA vs. 2.8 mA at 6.5 V, which can be ascribed to the lower contact resistance at the EL film/electrode interfaces. This is due to the lower surface roughness of the pulverized layers.

  6. First proof of topological signature in high pressure xenon gas with electroluminescence amplification

    CERN Document Server

    Ferrario, P.; López-March, N.; Gómez-Cadenas, J.J.; Álvarez, V.; Azevedo, C.D.R.; Borges, F.I.G.; Cárcel, S.; Cebrián, S.; Cervera, A.; Conde, C.A.N.; Dafni, T.; Díaz, J.; Diesburg, M.; Esteve, R.; Fernandes, L.M.P.; Ferreira, A.L.; Freitas, E.D.C.; Gehman, V.M.; Goldschmidt, A.; González-Díaz, D.; Gutiérrez, R.M.; Hauptman, J.; Henriques, C.A.O.; Hernando Morata, J.A.; Irastorza, I.G.; Labarga, L.; Lebrun, P.; Liubarsky, I.; Lorca, D.; Losada, M.; Luzón, G.; Marí, A.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C.M.B.; Mora, F.J.; Moutinho, L.M.; Muñoz Vidal, J.; Nebot-Guinot, M.; Novella, P.; Nygren, D.; Para, A.; Pérez, J.; Pérez Aparicio, J.L.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F.P.; dos Santos, J.M.F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J.F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J.F.C.A.; Villar, J.A.; Webb, R.; White, J.T.; Yahlali, N.; Yepes-Ramírez, H.

    2016-01-01

    The NEXT experiment aims to observe the neutrinoless double beta decay of xenon in a high-pressure Xe136 gas TPC using electroluminescence (EL) to amplify the signal from ionization. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qbb. This paper presents the first demonstration that the topology provides extra handles to reject background events using data obtained with the NEXT-DEMO prototype. Single electrons resulting from the interactions of Na22 1275 keV gammas and electron-positron pairs produced by conversions of gammas from the Th228 decay chain were used to represent the background and the signal in a double beta decay. These data were used to develop algorithms for the reconstruction of tracks and the identification of the energy deposited at the end-points, providing an extra background rejection factor of 24.3 +- 1.4 (stat.)%, while maintaining an efficiency of 66.7 +- 0.6 (stat.)% for signal events.

  7. Porous Silicon and Indium Doped Zinc Oxide Junctions: Synthesis, Characterization, and Application to Electroluminescent Devices

    Directory of Open Access Journals (Sweden)

    F. Severiano

    2017-01-01

    Full Text Available We report the obtaining of electroluminescent devices (ELD from porous silicon (PS and indium doped zinc oxide (ZnO:In junctions. PS presented photoluminescence (PL in the visible region of the electromagnetic spectrum. ZnO:In thin film was obtained by dip coating technique. SEM images and IR measurements showed the incorporation of the ZnO:In in the PS structure. Once obtained, the device was optically and electrically characterized. The ELD showed emission in the visible (450–850 nm and infrared region (900–1200 nm where it was electrically polarized. The visible emission was detected as luminescent spots on the surface. Electrical characterization was carried out by current-voltage (I-V curves. The I-V curves showed rectifying behavior. It was related to the quenching of the EL with the process that takes place in the PS when it was immersed in the precursor solution of the ZnO:In.

  8. Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices

    Energy Technology Data Exchange (ETDEWEB)

    Lijuan Zou

    2003-08-05

    Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatorial method was employed in device preparation. Both continuous wave and transient electroluminescence (EL) were studied. A new efficient and intense UV-violet light emitting device was developed. At a current density of 10 mA/cm{sup 2}, the optimal radiance R could reach 0.38 mW/cm{sup 2}, and the quantum efficiency was 1.25%. using the delayed EL technique, electron mobilities in DPVBi and CBP were determined to be {approx} 10{sup -5} cm{sup 2}/Vs and {approx} 10{sup -4} cm{sup 2}/Vs, respectively. Overshoot effects in the transient El of blue light emitting devices were also observed and studied. This effect was attributed to the charge accumulation at the organic/organic and organic/cathode interfaces.

  9. Electroluminescence and Photoluminescence from a Fluorescent Cobalt Porphyrin Grafted on Graphene Oxide

    Science.gov (United States)

    Janghouri, Mohammad

    2017-10-01

    A new graphene oxide-cobalt porphyrin (GO-CoTPP) hybrid material has been used as an emissive layer in organic light-emitting diodes (OLEDs). Devices with fundamental structure of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS, 45 nm)/polyvinylcarbazole (PVK):2-(4-biphenyl)-5-(4- t-butylphenyl)-1,3,4-oxadiazole (PBD):GO-CoTPP (70 nm)/1,3,5-tris( N-phenylbenzimidazol-2-yl)-benzene (TPBI, 20 nm)/Al (150 nm) were fabricated. A red electroluminescence (EL) was obtained from thin-film PVK:PBD:CoTPP at 70 nm thickness. When CoTPP was covalently grafted on graphene oxide (GO) sheets, near-white EL was obtained. The white emission, which was composed of bluish green and red, is attributed to electroplex formation at the GO-CoTPP/PBD interface. Such electroplex emission between electrons and holes is a reason for the low turn-on voltage of the GO-CoTPP-based OLED. Maximum luminance efficiency of 1.43 cd/A with Commission International de l'Eclairage coordinates of 0.33 and 0.40 was achieved at current of 0.02 mA and voltage of 14 V.

  10. The dependences of electroluminescent characteristics of ZnS:Mn thin films upon their device parameters

    Science.gov (United States)

    Sasakura, Hiroshi; Kobayashi, Hiroshi; Tanaka, Shosaku; Mita, Juro; Tanaka, Toshihiko; Nakayama, Hirofumi

    1981-11-01

    The dependences of brightness, emission efficiency η, average electric field EA, conduction current JA, and emission lifetime τ upon the device parameters such as film thickness, substrate temperature during evaporation, and Mn concentration have been systematically investigated in ZnS:Mn thin-film electroluminescent devices. The value of η increases rapidly with film thicknesses below 3000 Å but EA decreases slowly. These results can be explained by the increase of the crystallinity of the ZnS:Mn films. The value of η increases with the Mn concentration and reaches its maximum at about 0.45 wt %. At above this Mn concentration, η and τ decrease rapidly, EA increases, and JA decreases slowly. These results may be attributed to a decrease of hot electron energy and/or an increase of the nonradiative transition probability of the excited Mn centers. The brightness-voltage (B-V) hysteresis characteristic is observed in this Mn concentration region. This memory effect is also discussed.

  11. Synthesis and electroluminescent properties of anthracene derivatives containing electron-withdrawing oxide moieties

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jhin-yeong; Na, Eun Jae; Park, Soo Na [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Lee, Seok Jae [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@wow.hongik.ac.kr [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)

    2014-10-15

    Highlights: • Blue fluorescent material is important for application in full-color displays. • We have synthesized emitters based on anthracene connected with oxide moieties. • 1C shows a highly efficient blue EL emission due to electron-injection property. - Abstract: A series of new blue-emitting materials: (4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)(phenyl)methanone (1); 9-(naphthalen-2-yl)-10-(4-((diphenyl)phosphine oxide)phenyl)anthracene (2); 9-(naphthalen-2-yl)-10-(4-(phenylsulfonyl)phenyl)anthracene (3) were designed and synthesized via Suzuki cross-coupling reaction. Multilayer OLEDs were fabricated in the following sequence: ITO (180 nm)/NPB (50 nm)/blue materials 1–3 (30 nm)/TPBi (15 nm)/Liq (2 nm)/Al (100 nm). All devices showed the efficient blue EL emissions. In particular, the device using 1 as an emitter exhibited efficient blue electroluminescent properties with a maximum luminous, power, external quantum efficiency and CIE coordinates of 0.36 cd/A, 0.90 lm/W, 0.55% at 20 mA/cm{sup 2} and (x = 0.16, y = 0.20) at 10.0 V, respectively.

  12. First proof of topological signature in high pressure xenon gas with electroluminescence amplification

    CERN Document Server

    Ferrario, P; López-March, N.; Gómez-Cadenas, J.J.; Álvarez, V.; Azevedo, C.D.R.; Borges, F.I.G.; Cárcel, S.; Cebrián, S.; Cervera, A.; Conde, C.A.N.; Dafni, T.; Díaz, J.; Diesburg, M.; Esteve, R.; Fernandes, L.M.P.; Ferreira, A.L.; Freitas, E.D.C.; Gehman, V.M.; Goldschmidt, A.; González-Díaz, D.; Gutiérrez, R.M.; Hauptman, J.; Henriques, C.A.O.; Hernando Morata, J.A.; Irastorza, I.G.; Labarga, L.; Lebrun, P.; Liubarsky, I.; Lorca, D.; Losada, M.; Luzón, G.; Marí, A.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C.M.B.; Mora, F.J.; Moutinho, L.M.; Muñoz Vidal, J.; Nebot-Guinot, M.; Novella, P.; Nygren, D.; Para, A.; Pérez, J.; Pérez Aparicio, J.L.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F.P.; dos Santos, J.M.F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J.F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J.F.C.A.; Villar, J.A.; Webb, R.; White, J.T.; Yahlali, N.; Yepes-Ramírez, H.

    2016-01-01

    The NEXT experiment aims to observe the neutrinoless double beta decay of xenon in a high-pressure Xe136 gas TPC using electroluminescence (EL) to amplify the signal from ionization. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qbb. This paper presents the first demonstration that the topology provides extra handles to reject background events using data obtained with the NEXT-DEMO prototype. Single electrons resulting from the interactions of Na22 1275 keV gammas and electron-positron pairs produced by conversions of gammas from the Th228 decay chain were used to represent the background and the signal in a double beta decay. These data were used to develop algorithms for the reconstruction of tracks and the identification of the energy deposited at the end-points, providing an extra background rejection factor of 24.3 +- 1.4 (stat.)%, while maintaining an efficiency of 66.7 +- 0.6 (stat.)% for signal events.

  13. Ultrabroad Photoluminescence and Electroluminescence at New Wavelengths from Doped Organometal Halide Perovskites.

    Science.gov (United States)

    Zhou, Yang; Yong, Zi-Jun; Zhang, Kai-Cheng; Liu, Bo-Mei; Wang, Zhao-Wei; Hou, Jing-Shan; Fang, Yong-Zheng; Zhou, Yi; Sun, Hong-Tao; Song, Bo

    2016-07-21

    Doping of semiconductors by introducing foreign atoms enables their widespread applications in microelectronics and optoelectronics. We show that this strategy can be applied to direct bandgap lead-halide perovskites, leading to the realization of ultrawide photoluminescence (PL) at new wavelengths enabled by doping bismuth (Bi) into lead-halide perovskites. Structural and photophysical characterization reveals that the PL stems from one class of Bi doping-induced optically active center, which is attributed to distorted [PbI6] units coupled with spatially localized bipolarons. Additionally, we find that compositional engineering of these semiconductors can be employed as an additional way to rationally tune the PL properties of doped perovskites. Finally, we accomplished the electroluminescence at cryogenic temperatures by using this system as an emissive layer, marking the first electrically driven devices using Bi-doped photonic materials. Our results suggest that low-cost, earth-abundant, solution-processable Bi-doped perovskite semiconductors could be promising candidate materials for developing optical sources operating at new wavelengths.

  14. Molecular-scale simulation of electroluminescence in a multilayer white organic light-emitting diode

    Science.gov (United States)

    Mesta, Murat; Carvelli, Marco; de Vries, Rein J.; van Eersel, Harm; van der Holst, Jeroen J. M.; Schober, Matthias; Furno, Mauro; Lüssem, Björn; Leo, Karl; Loebl, Peter; Coehoorn, Reinder; Bobbert, Peter A.

    2013-07-01

    In multilayer white organic light-emitting diodes the electronic processes in the various layers—injection and motion of charges as well as generation, diffusion and radiative decay of excitons—should be concerted such that efficient, stable and colour-balanced electroluminescence can occur. Here we show that it is feasible to carry out Monte Carlo simulations including all of these molecular-scale processes for a hybrid multilayer organic light-emitting diode combining red and green phosphorescent layers with a blue fluorescent layer. The simulated current density and emission profile are shown to agree well with experiment. The experimental emission profile was obtained with nanometre resolution from the measured angle- and polarization-dependent emission spectra. The simulations elucidate the crucial role of exciton transfer from green to red and the efficiency loss due to excitons generated in the interlayer between the green and blue layers. The perpendicular and lateral confinement of the exciton generation to regions of molecular-scale dimensions revealed by this study demonstrate the necessity of molecular-scale instead of conventional continuum simulation.

  15. Photovoltaic and Electroluminescence Bifunctional Devices with Starburst Amine and Rare-Earth-Complexes

    Institute of Scientific and Technical Information of China (English)

    WEN Fu-Shan; LI Wen-Lian; WEI Han-Zhi; LIU Yun-Qi; KIM Jin-Hyeok

    2007-01-01

    We fabricate the organic photovoltaic (P V) devices, in which 4,4',4"-tris-(2-methylphenylphenylamino)triphenylamine (m-MTDATA) and rare earth (RE) (dibenzoylmethanato)3(bathohenanthroline) (RE(DBM)3bath) (RE = Nd or Pr) are used as electron donor and acceptor, and investigate their PV properties. The PV diode fabricated in the ptimum processing conditions shows the open-circuit voltage of 1.91 V, short-circuit current of 0.1mA/cm2, fill factor of 0.38, and the overall power conversion efficiency of 1.9% when it is irradiated under UV light (4mW/cm2). The photocurrent density exhibits an increase of 20% at least when a very thin LiF layer is inserted between the RE-complexes and the Al cathode. A strong electroluminescence from the interface is also observed and the maximum luminance of a yellow emission resulted from the exciplex is 580 cd/m2 at 17V bias.

  16. Room-temperature near-infrared electroluminescence from boron-diffused silicon pn junction diodes

    Directory of Open Access Journals (Sweden)

    Si eLi

    2015-02-01

    Full Text Available Silicon pn junction diodes with different doping concentrations were prepared by boron diffusion into Czochralski (CZ n-type silicon substrate. Their room-temperature near-infrared electroluminescence (EL was measured. In the EL spectra of the heavily boron doped diode, a luminescence peak at ~1.6 m (0.78 eV was observed besides the band-to-band line (~1.1eV under the condition of high current injection, while in that of the lightly boron doped diode only the band-to-band line was observed. The intensity of peak at 0.78 eV increases exponentially with current injection with no observable saturation at room temperature. Furthermore, no dislocations were found in the cross-sectional transmission electron microscopy image, and no dislocation-related luminescence was observed in the low-temperature photoluminescence spectra. We deduce the 0.78 eV emission originates from the irradiative recombination in the strain region of diodes caused by the diffusion of large number of boron atoms into silicon crystal lattice.

  17. Piezo-phototronic effect on electroluminescence properties of p-type GaN thin films.

    Science.gov (United States)

    Hu, Youfan; Zhang, Yan; Lin, Long; Ding, Yong; Zhu, Guang; Wang, Zhong Lin

    2012-07-11

    We present that the electroluminescence (EL) properties of Mg-doped p-type GaN thin films can be tuned by the piezo-phototronic effect via adjusting the minority carrier injection efficiency at the metal-semiconductor (M-S) interface by strain induced polarization charges. The device is a metal-semiconductor-metal structure of indium tin oxide (ITO)-GaN-ITO. Under different straining conditions, the changing trend of the transport properties of GaN films can be divided into two types, corresponding to the different c-axis orientations of the films. An extreme value was observed for the integral EL intensity under certain applied strain due to the adjusted minority carrier injection efficiency by piezoelectric charges introduced at the M-S interface. The external quantum efficiency of the blue EL at 430 nm was changed by 5.84% under different straining conditions, which is 1 order of magnitude larger than the change of the green peak at 540 nm. The results indicate that the piezo-phototronic effect has a larger impact on the shallow acceptor states related EL process than on the one related to the deep acceptor states in p-type GaN films. This study has great significance on the practical applications of GaN in optoelectronic devices under a working environment where mechanical deformation is unavoidable such as for flexible/printable light emitting diodes.

  18. Huge Bilateral Paramesonephric Cysts in a 25 year old Nulliparous woman

    Science.gov (United States)

    Sagili, Haritha; Krishnan, Manikandan; Dasari, Papa

    2013-01-01

    Paraovarian cysts are uncommon adnexal masses which are usually asymptomatic. We describe a case of bilateral huge paramesonephric cysts in a nulliparous woman. A 25-year-old lady presented with abdominal distension for one year duration. Examination and imaging revealed large abdominopelvic cystic masses with no solid areas or septations. Intraoperatively there were huge bilateral paraovarian cysts which were excised. Histopathology revealed low cuboidal to ciliated columnar epithelium with no evidence of ovarian parenchyma suggestive of paramesonephric cyst. Paraovarian cyst should be included in the differential diagnosis of a cystic mass visualised on ultrasound. PMID:24392412

  19. Huge dissected ascending aorta associated with pseudo aneurysm and aortic coarctation feridoun.

    Science.gov (United States)

    Sabzi, Feridoun; Khosravi, Donya

    2015-07-01

    We report a unique case of chronic dissection of the ascending aorta complicated with huge and thrombotic pseudoaneurysm in a patient with coarctation of descending aorta. Preoperative investigations such as transesophageal echocardiography (TEE) confirmed the diagnosis of dissection. Intraoperative findings included a12 cm eccentric bulge of the right lateral side of dilated the ascending aorta filled with the clot and a circular shaped intimal tear communicating with an extended hematoma and dissection of the media layer. The rarity of the report is an association of the chronic dissection with huge pseudoaneurysm and coarctation. The patient underwent staged repair of an aneurysm and coarctation and had an uneventful postoperative recovery period.

  20. Endovascular repair for a huge vertebral artery pseudoaneurysm caused by Behcet's disease

    Institute of Scientific and Technical Information of China (English)

    DONG Zhi-hui; FU Wei-guo; GUO Da-qiao; XU Xin; CHEN Bin; JIANG Jun-hao; YANG Jue; SHI Zheng-yu; WANG Yu-qi

    2006-01-01

    @@ Behcet's disease (BD), a multisystem chronic autoimmune process of unknown etiology,usually leads to arterial impairment. Isolated case reports have described BD-related arterial dissections, pseudoaneurysms or aneurysms.1-4 Recently, we successfully treated a huge vertebral artery pseudoaneurysm (VAPA) in a patient with BD by stent-grafting with preservation of the affected vertebral artery.

  1. Unusual Huge Keratoacanthoma in Sites of in the Previous Split-Thickness Skin Grafted Area

    Directory of Open Access Journals (Sweden)

    Fatih Uygur

    2009-09-01

    Full Text Available Keratoacanthoma (KA is a fairly common keratinizing, squamous neoplasm. The exact etiology of KA is unknown. However, ultraviolet radiation, trauma, chemical carcinogens, viral infections, immunosuppression, genetic factors, radiation and thermal burns have been accused of pathogenesis. In here, we represent an unusual huge KA arising from the previous reconstructed with split-thickness skin graft on the dorsal foot.

  2. Constructing Optimal Coarse-Grained Sites of Huge Biomolecules by Fluctuation Maximization.

    Science.gov (United States)

    Li, Min; Zhang, John Zenghui; Xia, Fei

    2016-04-12

    Coarse-grained (CG) models are valuable tools for the study of functions of large biomolecules on large length and time scales. The definition of CG representations for huge biomolecules is always a formidable challenge. In this work, we propose a new method called fluctuation maximization coarse-graining (FM-CG) to construct the CG sites of biomolecules. The defined residual in FM-CG converges to a maximal value as the number of CG sites increases, allowing an optimal CG model to be rigorously defined on the basis of the maximum. More importantly, we developed a robust algorithm called stepwise local iterative optimization (SLIO) to accelerate the process of coarse-graining large biomolecules. By means of the efficient SLIO algorithm, the computational cost of coarse-graining large biomolecules is reduced to within the time scale of seconds, which is far lower than that of conventional simulated annealing. The coarse-graining of two huge systems, chaperonin GroEL and lengsin, indicates that our new methods can coarse-grain huge biomolecular systems with up to 10,000 residues within the time scale of minutes. The further parametrization of CG sites derived from FM-CG allows us to construct the corresponding CG models for studies of the functions of huge biomolecular systems.

  3. Anatomic trisegmentectomy: An alternative treatment for huge or multiple hepatocellular carcinoma of right liver.

    Science.gov (United States)

    Jia, Changku; Weng, Jie; Qin, Qifan; Chen, Youke; Huang, Xiaolong; Fu, Yu

    2017-04-01

    The patients with huge (≥10cm) or multiple hepatocellular carcinoma (HCC) in the right liver and insufficient size of the remnant left liver can not be performed an operation of right hemihepatectomy because of that liver failure will occur post operation. We designed anatomic trisegmentectomy in right liver to increase the ratio of future liver remnant volume (%FLRV), thus increasing resectability of huge or multiple HCC. Thirteen patients were analyzed by preoperative CT scan for liver and tumor volumetries. If the right hemihepatectomy was done, %FLRV would be at the range of 29.6%-37.5%. However, if trisegmentectomy was done, %FLRV would increase by an average of 14.0%. So patients will not undergo postoperative liver failure due to sufficient %FLRV. Therefore, we designed anatomic trisegmentectomy, with retention of segment 5 or segment 8, to increase %FLRV and increase the resectability for huge or multiple HCC. After trisegmentectomy, the inflow and outflow of remnant liver were maintained well. Severe complications and mortality were not happened post operation. Of the 13 patients, 10 survived up to now. Of the 10 living cases, postoperative lung metastasis was found in 2 and intrahepatic recurrence was found in 1. These 3 patients survive with tumor after comprehensive therapies including oral administration of Sorafenib. Compared to right hemihepatectomy, anatomic trisegmentectomy in right liver guarantees the maximum preservation of %FLRV to increase the resectability of huge or multiple HCC, thus improving the overall resection rate. Copyright © 2017. Published by Elsevier Masson SAS.

  4. Huge hepatocellular carcinoma with multiple intrahepatic metastases: An aggressive multimodal treatment.

    Science.gov (United States)

    Yasuda, Satoshi; Nomi, Takeo; Hokuto, Daisuke; Yamato, Ichiro; Obara, Shinsaku; Yamada, Takatsugu; Kanehiro, Hiromichi; Nakajima, Yoshiyuki

    2015-01-01

    Huge hepatocellular carcinoma (HCC) possesses a potential risk for spontaneous rupture, which leads to a life-threatening complication with a high mortality rate. In addition, a large HCC is frequently accompanied by intrahepatic metastases. We describe, the case of a 74-year-old woman with a huge extrahepatically expanding HCC with multiple intrahepatic metastases who was treated by liver resection with repeated transcatheter arterial chemoembolization (TACE). To prevent tumor rupture or bleeding, we performed right hepatectomy. After the operation, TACE was applied for multiple intrahepatic metastases in the remnant liver. Furthermore, the elevated protein induced vitamin K absence (PIVKA II) level had decreased to limits within the normal range. Three months after the first TACE, computed tomography revealed several recurrences in the liver. TACE was applied for the second and third time and the tumors were well controlled. Although, liver resection is occasionally performed for patients with huge HCC to avoid spontaneous tumor rupture, only surgical approach might not be sufficient for such advanced HCC. To achieve long-term survival, it is necessary to control the residual intrahepatic tumors. We could control multiple intrahepatic metastases with repeated TACEs after hepatectomy. Multimodal treatment involving hepatectomy and TACE might be a good treatment strategy for patients with huge HCC with multiple intrahepatic metastases if the tumors are localized in the liver without distant or peritoneal metastasis. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Hepatic arterial infusion chemotherapy for patients with huge unresectable hepatocellular carcinoma.

    Science.gov (United States)

    Tsai, Wei-Lun; Lai, Kwok-Hung; Liang, Huei-Lung; Hsu, Ping-I; Chan, Hoi-Hung; Chen, Wen-Chi; Yu, Hsien-Chung; Tsay, Feng-Woei; Wang, Huay-Min; Tsai, Hung-Chih; Cheng, Jin-Shiung

    2014-01-01

    The optimal treatment for huge unresectable hepatocellular carcinoma (HCC) remains controversial. The outcome of transcatheter arterial chemoembolization (TACE) for patients huge unresectable HCC is generally poor and the survival benefit of TACE in these patients is unclear. The aim of the study is to compare the effect of hepatic arterial infusion chemotherapy (HAIC) versus symptomatic treatment in patients with huge unresectable HCC. Since 2000 to 2005, patients with huge (size >8 cm) unresectable HCC were enrolled. Fifty-eight patients received HAIC and 44 patients received symptomatic treatment. In the HAIC group, each patient received 2.4+1.4 (range: 1-6) courses of HAIC. Baseline characteristics and survival were compared between the HAIC and symptomatic treatment groups. The HAIC group and the symptomatic treatment group were similar in baseline characteristics and tumor stages. The overall survival rates at one and two years were 29% and 14% in the HAIC group and 7% and 5% in the symptomatic treatment group, respectively. The patients in the HAIC group had significantly better overall survival than the symptomatic treatment group (Phuge unresectable HCC.

  6. A Computational Method for Enabling Teaching-Learning Process in Huge Online Courses and Communities

    Science.gov (United States)

    Mora, Higinio; Ferrández, Antonio; Gil, David; Peral, Jesús

    2017-01-01

    Massive Open Online Courses and e-learning represent the future of the teaching-learning processes through the development of Information and Communication Technologies. They are the response to the new education needs of society. However, this future also presents many challenges such as the processing of online forums when a huge number of…

  7. A Huge Subcutaneous Hematoma in an Adult with Kasabach-Merritt Syndrome.

    Science.gov (United States)

    Wu, Kuan-Lin; Liao, Chiung-Ying; Chang, Chen-Kuang; Ho, Shang-Yun; Tyan, Yeu-Sheng; Huang, Yuan-Chun

    2017-06-19

    BACKGROUND Kasabach-Merritt syndrome is a potentially fatal disease that consists of hemangioma(s) with thrombocytopenia, microangiopathic hemolytic anemia, and coagulopathy. Extensive hemangiomatosis is rare. We present the radiological features and treatment strategy of a young adult suffering from Kasabach-Merritt syndrome with widespread hemangiomas and an infected huge hematoma in the right thigh. CASE REPORT A 33-year-old Taiwanese male presented with a painful 20-cm mass over his right thigh and gross hematuria for 2 days. Hemangiomatosis was bioptically proven in infancy and the patient was under regular follow-up. Physical examination revealed normal heart rate, respiratory rate, and body temperature. Multiple palpable lumps with brown and purple areas of skin over the neck, trunk, and right thigh were noted. Laboratory examinations revealed thrombocytopenia anemia and elevated fibrin degradation products. There were no signs of sepsis. Blood transfusion and steroid therapy were executed. Computed tomography showed a huge complicated subcutaneous hematoma in the right thigh. Drainage of the huge hematoma was performed and antibiotics were prescribed. After the local infection in the right thigh and the bleeding tendency were controlled, the patient was discharged in a stable condition two weeks later. CONCLUSIONS A huge infected hematoma and widespread hemangiomas are extremely rare complications of Kasabach-Merritt syndrome. There are no known treatment guidelines currently available. Our patient was successfully treated with steroids, drainage, and antibiotics.

  8. A Huge Ovarian Cyst in a Middle-Aged Iranian Female

    Directory of Open Access Journals (Sweden)

    Mohammad Kazem Moslemi

    2010-05-01

    Full Text Available A 38-year-old Iranian woman was found to have a huge ovarian cystic mass. Her presenting symptom was vague abdominal pain and severe abdominal distention. She underwent laparotomy and after surgical removal, the mass was found to be mucinous cystadenoma on histology.

  9. Huge right atrial myxoma causing fixed tricuspid stenosis with constitutional symptoms.

    Science.gov (United States)

    Kuralay, Erkan; Cingöz, Faruk; Günay, Celalettin; Demirkiliç, Ufuk; Tatar, Harun

    2003-01-01

    Nonspecific constitutional symptoms are reported mostly in patients with left-atrial myxomas, which occur five times as often as its right-atrial counterpart. We present huge right-atrial myxoma, which obstructs tricuspid orifice with nonspecific constitutional symptoms without any pulmonary embolism attack.

  10. Preserving stability of huge agriculture machines with internal mobilities: Application to a grape harvester

    OpenAIRE

    Dieumet, D.; Thuilot, B.; Lenain, R.; Berducat, M.

    2012-01-01

    International audience; This paper proposes an algorithm for estimating on-line the rollover risk of huge machine moving on natural ground. The approach is based on the reconstruction of lateral load transfer thanks to an observer, able to take into account terrain specificities (grip conditions and geometry). Capabilities are tested through experiments on a grape harvester.

  11. Biliary obstruction due to a huge simple hepatic cyst treated with laparoscopic resection.

    Science.gov (United States)

    Kaneya, Yohei; Yoshida, Hiroshi; Matsutani, Takeshi; Hirakata, Atsushi; Matsushita, Akira; Suzuki, Seiji; Yokoyama, Tadashi; Maruyama, Hiroshi; Sasajima, Koji; Uchida, Eiji

    2011-01-01

    Most hepatic cysts are asymptomatic, but complications occasionally occur. We describe a patient with biliary obstruction due to a huge simple hepatic cyst treated with laparoscopic resection. A 60-year-old Japanese woman was admitted to our hospital because of a nontender mass in the right upper quadrant of the abdomen. Laboratory tests revealed the following: serum total bilirubin, 0.6 mg/dL; serum aspartate aminotransferase, 100 IU/L; serum alanine aminotransferase, 78 IU/L; serum alkaline phosphatase, 521 IU/L; and serum gamma glutamic transpeptidase, 298 IU/L. Abdominal computed tomography, ultrasonography, and magnetic resonance cholangiopancreatography revealed a huge hepatic cyst, 13 cm in diameter, at the hepatic hilum, accompanied by dilatation of the intrahepatic bile duct and obstruction of the common bile duct. We diagnosed biliary obstruction due to a huge hepatic cyst at the hepatic hilum, and laparoscopic surgery was performed. A huge hepatic cyst was seen at the hepatic hilum. After needle puncture of the huge cyst, the anterior wall of the cyst was unroofed, and cholecystectomy was done. Intraoperative cholangiography through a cystic duct revealed stenosis of the duct. Subsequent decapsulation of the cyst was performed in front of the common bile duct. After this procedure, cholangiography revealed that the stenosis of the common bile duct had resolved. Histopathological examination of the surgical specimen confirmed the hepatic cyst was benign. The postoperative course was uneventful, and the results of liver function tests normalized. The patient was discharged 7 days after operation. Computed tomography 3 months after operation revealed disappearance of the hepatic cyst and no dilatation of the intrahepatic bile duct.

  12. Photo- and electroluminescent properties of zinc(II) complexes with tetradentate Schiff bases, derivatives of salicylic aldehyde

    Science.gov (United States)

    Vashchenko, A. A.; Lepnev, L. S.; Vitukhnovskii, A. G.; Kotova, O. V.; Eliseeva, S. V.; Kuz'mina, N. P.

    2010-03-01

    It is studied how the introduction of various substituents into the composition of organic ligands affects the photoluminescence spectra of new zinc(II) complexes with tetradentate Schiff bases H2L (derivatives of salicylic aldehyde (H2SAL1, H2SAL2) and o-vanillin (H2MO1, H2MO2) with ethylenediamine and o-phenylenediamine) in the form of bulk solids and thin films. It is demonstrated that the emission spectra of bulk solid complexes without o-phenylenediamine bridges (ZnSAL1 and ZnMO1) contain additional long-wavelength bands compared to the spectra of corresponding thin films. In the case of films obtained from [ZnSAL1]2 dimer complexes, the long-wavelength band is dominant. At the same time, the photoluminescence spectra of ZnSAL2 and ZnMO2 complexes with o-phenylenediamine bridges are similar in the case of solid samples and thin films. The electroluminescent properties of organic light-emitting diodes (OLEDs) with the ITO/α-NPD/ZnL/Ca:Al structure are studied. The bathochromic shift of the electroluminescence peaks of OLEDs with respect to the photoluminescence spectra of bulk solid samples and thin films is probably related to the formation of exciplexes at the α-NPD/ZnL interface. The electroluminescence spectra of OLEDs based on [ZnSAL1]2 show a hypsochromic shift of the emission maximum, which can be caused by a shift of the recombination region into the α-NPD layer.

  13. Synthesis, photophysical, electrochemical and electroluminescence studies of red emitting phosphorescent Ir(III) heteroleptic complexes

    Indian Academy of Sciences (India)

    FARMAN ALI; PABITRA K NAYAK; N PERIASAMY; NEERAJ AGARWAL

    2017-09-01

    Five heteroleptic, cyclometalated (C∧N) Iridium(III) complexes of acetylacetone (acac) and 1-phenyl-isoquinoline (piq) derivatives, Ir(acac)(piq) ₂, Ir(acac)(2,4-difluoro-piq) ₂, Ir(acac)(4-trifluoromethylpiq) ₂, Ir(acac)(4-N,N-dimethyl-piq) ₂, Ir(acac)(4-acetyl-piq) ₂, were synthesized and characterized. The ((C∧N) ₂ Ir(acac) complexes in toluene showed phosphorescence (λmax = 598 nm to 658 nm) with quantum yields (0.1 to 0.32) and microsecond lifetimes (0.43 to 1.9 μs). The complexes were non-luminescent in thin films due to self-quenching but luminescent when lightly doped (5%) in a host organic material, 4,4' -Bis(Ncarbazolyl)- 1,1' -biphenyl (CBP). The HOMO levels determined using cyclic voltammetric oxidation potentials were in the range−5.48 to−5.80 eV. Electroluminescence properties and performance of the Ir complexes dopedin CBP (active layer) were studied in a multilayer (ITO/F4TCNQ/TPD/doped CBP/BCP/LiF/Al) organic light emitting device (OLED). The electroluminescense (EL) spectra of the device matched with the phosphorescent spectra of the Ir complexes. The turn-on voltage at ∼4.5 V, maximum brightness of 7600 cd/m² and current efficiency of ∼7.0 cd/A at a brightness of ∼100 cd/m² indicate that these are promising OLED materials.

  14. Synthesis and Electroluminescent Properties of Julolidine-π-Juloidine Type Materials with the Bulky Adamantane Groups

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kum Hee; Yoon, Seung Soo [Sungkyunkwan Univ., Suwon (Korea, Republic of); Lee, Seok Jae; Kim, Young Kwan [Hongik Univ., Seoul (Korea, Republic of)

    2012-11-15

    A main problem of red emitting material, which contributes to their low EL performances, is the concentration quenching due to the effective self aggregation and the consequent formation of excimers. To avoid this drawback and thus improve the EL properties of red fluorescent OLED devices, many synthetic efforts have been conducted to develop new emitting materials with the structural motifs to suppress self-aggregation by the weakening intermolecular attractive interactions. Particularly, the introduction of bulky moieties in the emitters would provide the steric hindrance between emitting materials in solid state devices and thus reduce the self-aggregation. Nevertheless, EL performances of red materials still need to be improved for the practical applications. In conclusion, we designed and synthesized three julolidine-π-juloidine type emitting materials (1-3) with the bulky adamantane groups. To study their electroluminescent properties, the multilayered OLED devices with the structure of ITO/NPB (40 nm)/ADN : 1-3 (x%) (20 nm)/Alq{sub 3} (40 nm)/Liq (2 nm)/Al were fabricated. All devices using emitters 1-3 showed the efficient emissions, in which their EL performances depend on the structure of emitters sensitively. Particularly, a device using emitter 3 exhibited the efficient orange-red emission with the luminous and power efficiencies of 4.79 cd/A and 1.76 lm/W at 20 mA/cm{sup 2}, respectively. The CIE coordinates of this device was (0.57, 0.42) at 7.0 V.

  15. Synthesis and light-emitting properties of organic electroluminescent compounds and their metal complexes

    Institute of Scientific and Technical Information of China (English)

    CUI Jianzhong; Kim Sung-Hoon

    2004-01-01

    Several organic electroluminescent (EL) compounds, 2,2′-(1,4-phenylenedivinylene)bis-3,3-dimethyl-in- dolenine (1), 2,2′-(1,4-phenylenedivinylene)bis-benzoxazole (2), 2,2′-(1,4-phenylenedivinylene)bis-benzothiazole (3), 4,4′- (1,4-phenylenedivinylene)bis-quinoline (4), 2,2′-(1,4-phenyle- nedivinylene)bis-quinoline (5), 2,2′-(1,4-phenylenedivinyle- ne)bis-1,3,3-trimethyl-indolenine dichlo ride (6), 2,2′-(1,4- phenylene-divinylene)bis-1-hydro-3,3-dimethyl-indolenine dichloride (7), 2,2′-(1,4-phenylenedivinylene)bis-8-acetoxy- quinoline (8), 2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyq- uinoline (9) and metal complexes of 9, Al(PHQ) (10) and Zn(PHQ) (11), have been synthesized and characterized. The crystal structure of 6 was determined. Light emitting properties of the prepared compounds have been investigated. 1 produces an orange-yellow emission (λmax = 575 nm). The cation, 6, gives a red emission (λmax = 607 nm), which is shifted 32 nm to the red compared to 1. 8 produces a yellow emission (λmax = 567 nm). The metal complex 10 gives a red emission (λmax = 610 nm), which is a red shift of 43 nm compared to 8. The change in structure in the prepared compound caused a change in the electron distribution in the compounds, which induces a large wavelength shift of the emitted-light. Thermal analysis showed that the decomposition temperatures of the metal complexes (10, 11) were higher than those for the smaller organic molecular compounds (1-9). Therefore, metal complexes (10, 11) can be used as EL materials over a larger temperature range.

  16. Electroluminescence emission patterns of organic light-emitting transistors based on crystallized fluorene-type polymers

    Science.gov (United States)

    Kajii, Hirotake; Ohtomo, Takahiro; Ohmori, Yutaka

    2017-03-01

    The electroluminescence (EL) emission patterns of organic light-emitting transistors (OLETs) based on crystallized poly(9,9-dioctylfluorene) (F8), poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) and poly(9,9-dioctylfluorene-co-dithienyl-benzothiadiazole) (F8TBT) films are investigated. For the single-layer devices and the mixed-layer device without an F8/F8BT interface, only line-shaped EL emission patterns are observed between source/drain (S/D) electrodes. For an F8BT (F8TBT)/F8 heterostructure device, a localized electric field is generated by the positive (negative) charges of the accumulated holes (electrons) in the F8 upper layer, which allow the injection of electrons (holes) in the F8BT (F8TBT) lower layer at a lower (higher) gate voltage. The F8/F8BT device exhibits unique light emission properties with a surface like EL emission pattern between S/D electrodes at a lower gate voltage. The interfacial structure is important for forming field-effect transistor channels along different organic layers to obtain a surface like emission between S/D electrodes. For the F8TBT/F8 OLET, the hole carrier transport mainly occurs at the F8TBT lower layer, and line-shaped EL emission patterns are observed in the vicinity of the source electrode upon varying the gate voltages owing to the worse carrier balance between the F8TBT lower layer and the F8 upper layer.

  17. Electroluminescent properties of three ternary europium complexes with different phenanthroline derivatives

    Institute of Scientific and Technical Information of China (English)

    BIAN Zuqiang; GAO Deqing; GUAN Min; XIN Hao; LI Fuyou; HUANG Chunhui; WANG Kezhi; JIN Linpei

    2004-01-01

    Three ternary Eu(Ⅲ) complexes with general formula of Eu(DBM)3LN (DBM =dibenzoylmethanate, and LN (N= 1-3 ) stand for three different 1,1 0-phenanthroline derivatives)have been synthesized for vacuum deposition films-based electroluminescent devices. The complex Eu(DBM)3L3 (L3 = 2-phenyl-3-[3-(carbazol-9-yl)propyl]imidazo[4,5-f]1,10-phenanthroline) was designed with an effort to combine the electron-transporting phenanthroline platform and the hole-transporting carbazole group into one molecule expecting to improve both electron and hole transporting properties simultaneously. The results show that the variation of the neutral ligands in Eu(Ⅲ) mixed ligand complexes is a simple and effective approach to the improvement in the thermal stability, PL and EL properties of materials. A double-layer device with the configuration of ITO/TPD (50 nm)/Eu(DBM)3L3 (50 nm)/Mgo.9Ago.1 (200 nm)/Ag (100 nm)exhibited Eu(Ⅲ)-based pure red emission with a maximum brightness of 561 cd/m2 at 16 V, and an onset driving voltage of 8 V. A device with the configuration of ITO/TPD (50 nm)/[Eu(DBM)3L3(5 nm):BCP (5 nm)]4/BCP (20 nm)/AIQ (10 nm) Mgo.gAgo.1 (110 nm)/Ag (100 nm) gave high efficient and pure red light emission with a luminance of 1419 cd/m2.

  18. A comparative study of electroluminescence from Ge/SiO2 and Si/SiO2 films

    Institute of Scientific and Technical Information of China (English)

    Ma Shu-Yi; Chen Hui; Xiao Yong; Ma Zi-Jun; Sun Ai-Min

    2004-01-01

    Ge/SiO2 and Si/SiO2 films were deposited using the two-target alternation magnetron sputtering technique. The Au/Ge/SiO2/p-Si and Au/Si/SiO2/p-Si structures were fabricated and their electroluminescence (EL) characteristics were comparatively studied. Both Au/Ge/SiO2/p-Si and Au/Si/SiO2/p-Si structures have rectifying property. All the EL spectra from the two types of the structure have peak positions around 650-660 nm. The EL mechanisms of the structures are discussed.

  19. Organic Electroluminescent Device Based on TPP%基于TPP的有机电致发光器件

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A kind of pyrazoline derivative 1,3-bis(phenyl)-5-(2-phenanthrene)-2-pyrazoline(TPp) was synthesized in order to obtain stable film and applied to organic electroluminecsent diode as hole transporting material. Two devices with structures as indium-tin-oxide(ITO) TPP (50 nm)/tris-(8-hydroxyquinoline) aluminum(Alq3) (50 nm)/Al (150 nm) and ITO /TPP (50 nm)/lithium tera-(8-hydroxy-uinolinato)boron(LiBq4 (50 nm)/Alq3 (5 nm)/Al (150 nm) were fabricated, they showed good electroluminescent(EL) performance and TPP was proved to be a good hole transporting material.

  20. Organic Electroluminescent Device Based on TPP%基于TPP的有机电致发光器件

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A kind of pyrazoline derivative 1,3-bis(phenyl)-5-(2-phenanthrene)-2-pyrazoline(TPp) was synthesized in order to obtain stable film and applied to organic electroluminecsent diode as hole transporting material. Two devices with structures as indium-tin-oxide(ITO) TPP (50 nm)/tris-(8-hydroxyquinoline) aluminum(Alq3) (50 nm)/Al (150 nm) and ITO /TPP (50 nm)/lithium tera-(8-hydroxy-uinolinato)boron(LiBq4 (50 nm)/Alq3 (5 nm)/Al (150 nm) were fabricated, they showed good electroluminescent(EL) performance and TPP was proved to be a good hole transporting material.

  1. SYNTHESIS OF POLY(2,5-DIPHENYL-1,3,4-THIADIAZOLYL)-4,4'-VINYLENE AND ITS ELECTROLUMINESCENT PERFORMANCE

    Institute of Scientific and Technical Information of China (English)

    Shou-gen Yin; Zheng Xu; Yan-bing Hou; Yong-sheng Wang; Xu-rong Xu; Wen-qiang Huang; Fu-qiang Zhang

    1999-01-01

    The synthesis, characterization and electroluminescence performance of a new type of conjugated polymer, poly(2,5-diphenyl-1,3,4-thiadiazolyl)-4,4'-vinylene (TPPV) are presented. A light-emitting diode consisted of ITO/TPPV/Al is driven at about 4.0 V and has a peak emission wavelength of 485 nm. This blue-shift of the peak is due to the decrease of conjugate degree of TPPV compared to PPV. This result is in accord with that determined by XPS and theoretical model of MNDO/3

  2. The Electroluminescence Characterization of Poly(p-phenyleneethynylene)——The π-conjugated Backbone Interrupted by a Butylene Unit

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    π-Conjugated poly(p-phenyleneethynylene) with the interruption of the conjugation by a butylene unit was synthesized. Its absorption, PL and EL spectra were investigated respectively. The spectral peaks shifted to the higher energy side with the interruption of the conjugation lengths. The model compound was synthesized, by which the results were proved. The thermal characteristics of the polymer was determined by DSC and TGA, indicating that the polymer has a good thermal stability. The electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.

  3. Thermo-optical properties of 1H[3,4-b] quinoline films used in electroluminescent devices

    Science.gov (United States)

    Jaglarz, Janusz; Kępińska, Mirosława; Sanetra, Jerzy

    2014-06-01

    Electroluminescence cells with H[3,4-b] quinoline layers are promising devices for a blue light emitting EL diode. This work measured the optical reflectance as a function of temperature in copolymers PAQ layers deposited on Si crystalline substrate. Using the extended Cauchy dispersion model of the film refractive index we determined the thermo-optical coefficients for quinoline layers in the temperature range of 76-333 K from combined ellipsometric and spectrofotometric studies. The obtained values of thermo-optical coefficients of thin PAQ film, were negative and ranged in 5-10 × 10-4 [1/K].

  4. Performances Evaluation of a Novel Hadoop and Spark Based System of Image Retrieval for Huge Collections

    Directory of Open Access Journals (Sweden)

    Luca Costantini

    2015-01-01

    Full Text Available A novel system of image retrieval, based on Hadoop and Spark, is presented. Managing and extracting information from Big Data is a challenging and fundamental task. For these reasons, the system is scalable and it is designed to be able to manage small collections of images as well as huge collections of images. Hadoop and Spark are based on the MapReduce framework, but they have different characteristics. The proposed system is designed to take advantage of these two technologies. The performances of the proposed system are evaluated and analysed in terms of computational cost in order to understand in which context it could be successfully used. The experimental results show that the proposed system is efficient for both small and huge collections.

  5. A New Pixels Flipping Method for Huge Watermarking Capacity of the Invoice Font Image

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-01-01

    Full Text Available Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  6. Huge mucinous cystadenoma of ovary, describing a young patient: case report

    Directory of Open Access Journals (Sweden)

    Soheila Aminimoghaddam

    2017-08-01

    Conclusion: Ovarian cysts in young women who are associated with elevated levels of tumor markers and ascites require careful evaluation. Management of ovarian cysts depends on patient's age, size of the cyst, and its histopathological nature. Conservative surgery such as ovarian cystectomy or salpingo-oophorectomy is adequate in mucinous tumors of ovary. Multiple frozen sections are very important to know the malignant variation of this tumor and helps accurate patient management. Surgical expertise is required to prevent complications in huge tumors has distorted the anatomy, so gynecologic oncologist plays a prominent role in management. In this case, beside of the huge tumor and massive ascites uterine and ovaries were preserved by gynecologist oncologist and patient is well up to now.

  7. Huge gastric diospyrobezoars successfully treated by oral intake and endoscopic injection of Coca-Cola.

    Science.gov (United States)

    Chung, Y W; Han, D S; Park, Y K; Son, B K; Paik, C H; Jeon, Y C; Sohn, J H

    2006-07-01

    A diospyrobezoar is a type of phytobezoar that is considered to be harder than any other types of phytobezoars. Here, we describe a new treatment modality, which effectively and easily disrupted huge gastric diospyrobezoars. A 41-year-old man with a history of diabetes mellitus was admitted with lower abdominal pain and vomiting. Upper gastrointestinal endoscopy revealed three huge, round diospyrobezoars in the stomach. He was made to drink two cans of Coca-Cola every 6 h. At endoscopy the next day, the bezoars were partially dissolved and turned to be softened. We performed direct endoscopic injection of Coca-Cola into each bezoar. At repeated endoscopy the next day, the bezoars were completely dissolved.

  8. Successful Vaginal Delivery despite a Huge Ovarian Mucinous Cystadenoma Complicating Pregnancy: A Case Report

    Directory of Open Access Journals (Sweden)

    Dipak Mandi

    2013-12-01

    Full Text Available A 22-year-old patient with 9 months of amenorrhea and a huge abdominal swelling was admitted to our institution with an ultrasonography report of a multiloculated cystic space-occupying lesion, almost taking up the whole abdomen (probably of ovarian origin, along with a single live intrauterine fetus. She delivered vaginally a boy baby within 4 hours of admission without any maternal complication, but the baby had features of intrauterine growth restriction along with low birth weight. On the 8th postpartum day, the multiloculated cystic mass, which arose from the right ovary and weighed about 11 kg, was removed via laparotomy. A mucinous cystadenoma with no malignant cells in peritoneal washing was detected in histopathology examination. This report describes a rare case of a successful vaginal delivery despite a huge cystadenoma of the right ovary complicating the pregnancy.

  9. Huge Neck Masses Causing Respiratory Distress in Neonates: Two Cases of Congenital Cervical Teratoma.

    Science.gov (United States)

    Gezer, Hasan Özkan; Oğuzkurt, Pelin; Temiz, Abdulkerim; Bolat, Filiz Aka; Hiçsönmez, Akgün

    2016-12-01

    Congenital cervical teratomas are rare and usually large enough to cause respiratory distress in the neonatal period. We present two cases of congenital huge cystic neck masses in which distinguishing cervical cystic hygroma and congenital cystic teratoma was not possible through radiologic imaging techniques. Experience with the first case, which was initially diagnosed and treated as cystic hygroma by injection sclerotherapy, led to early suspicion and surgery in the second case. The masses were excised completely and histopathologic diagnoses were congenital teratoma in both patients. Our aim is to review congenital huge neck masses causing respiratory distress in early neonatal life to highlight this dilemma briefly with these interesting cases. Copyright © 2014. Published by Elsevier B.V.

  10. Huge echinococcal cyst of the liver managed by hepatectomy: Report of two cases.

    Science.gov (United States)

    Pavlidis, Efstathios T; Symeonidis, Nikolaos; Psarras, Kyriakos; Pavlidis, Theodoros E

    2017-01-01

    Echinococcocal cysts are predominantly located in the right liver. They are usually solitary and asymptomatic, but large cysts can cause compression symptoms. We report two cases of huge (25cm and 20cm in diameter, respectively) echinococcal cysts located in the left liver, which presented as a large palpable mass causing compression symptoms. Diagnosis was established with CT scan showing a cystic mass with the characteristic daughter cysts and reactive layer (pericystic wall) consisting of fibrous connective tissue and calcifications. Both patients were treated radically with left hepatectomy and had uneventful postoperative course and no recurrence upon follow-up. The treatment of liver echinococcal cysts represent a unique surgical challenge. Even though conservative approaches are less technically demanding, the radical approach with resection has better outcome with less recurrences, when performed by experienced surgeons. Resection rather than drainage is the management of choice for such huge liver echinococcal cysts. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. The huge Package for High-dimensional Undirected Graph Estimation in R

    Science.gov (United States)

    Zhao, Tuo; Liu, Han; Roeder, Kathryn; Lafferty, John; Wasserman, Larry

    2015-01-01

    We describe an R package named huge which provides easy-to-use functions for estimating high dimensional undirected graphs from data. This package implements recent results in the literature, including Friedman et al. (2007), Liu et al. (2009, 2012) and Liu et al. (2010). Compared with the existing graph estimation package glasso, the huge package provides extra features: (1) instead of using Fortan, it is written in C, which makes the code more portable and easier to modify; (2) besides fitting Gaussian graphical models, it also provides functions for fitting high dimensional semiparametric Gaussian copula models; (3) more functions like data-dependent model selection, data generation and graph visualization; (4) a minor convergence problem of the graphical lasso algorithm is corrected; (5) the package allows the user to apply both lossless and lossy screening rules to scale up large-scale problems, making a tradeoff between computational and statistical efficiency. PMID:26834510

  12. Mitral valve regurgitation due to annular dilatation caused by a huge and floating left atrial myxoma.

    Science.gov (United States)

    Kaya, Mehmet; Ersoy, Burak; Yeniterzi, Mehmet

    2015-09-01

    We describe a case of mitral valve annular dilatation caused by a huge left atrial myxoma obstructing the mitral valve orifice. A 50-year-old man presenting with palpitation was found to have a huge left atrial myxoma protruding into the left ventricle during diastole, causing severe mitral regurgitation. The diagnosis was made with echocardiogram. Transoesophageal echocardiography revealed a solid mass of 75 × 55 mm. During operation, the myxoma was completely removed from its attachment in the atrium. We preferred to place a mechanical heart valve after an annuloplasty ring because of severely dilated mitral annulus and chordae elongation. The patient had an uneventful recovery. Our case suggests that immediate surgery, careful evaluation of mitral valve annulus preoperatively is recommended.

  13. [Resection of a Huge Gastrointestinal Stromal Tumor of the Stomach Following Neoadjuvant Chemotherapy with Imatinib].

    Science.gov (United States)

    Sato, Yoshihiro; Karasawa, Hideaki; Aoki, Takeshi; Imoto, Hirofumi; Tanaka, Naoki; Watanabe, Kazuhiro; Abe, Tomoya; Nagao, Munenori; Ohnuma, Shinobu; Musha, Hiroaki; Takahashi, Masanobu; Motoi, Fuyuhiko; Naitoh, Takeshi; Ishioka, Chikashi; Unno, Michiaki

    2016-11-01

    We report a case of a huge gastric gastrointestinal stromal tumor(GIST)that was safely resected followingpreoperative imatinib therapy. A 72-year-old woman was hospitalized with severe abdominal distension. Computed tomography revealed a 27×17 cm tumor in the left upper abdominal cavity. The patient was diagnosed with high risk GIST by EUS-FNA. We initiated preoperative adjuvant chemotherapy with imatinib to achieve a reduction of operative risks and functional preservation. After 6 months of chemotherapy, CT showed a reduction in the tumor size and the patient underwent partial gastrectomy and partial resection of the diaphragm. Histologically, most of the tumor cells were replaced by hyalinized collagen and viable cells were scattered only around the blood vessels. Neoadjuvant chemotherapy with imatinib has the potential to become an important therapeutic option for the treatment of huge GISTs.

  14. Huge mass in right side of the heart: A rare case report.

    Science.gov (United States)

    Ghasemi, Reza; Ghanei-Motlagh, Fahimeh; Nazari, Susan; Yaghubi, Mohsen

    2016-11-01

    The presence of primary intracardiac tumors are scarce, and most of them are myxomas. We reported, in this paper, a case with huge mass in the right side of the heart. A 45-year-old man, with a complaint of bilateral lower limbs edema and exertional dyspnea, was admitted to intensive cardiac care unit. Cardiac auscultation revealed soft grade systolic murmur without any evidence of "tumor plop." Echocardiography showed a huge mobile mass in right side of the heart that suggested myxoma. Our patient underwent cardiac surgery with excision of 13 cm mass. Histopathological study was confirmed the diagnosis of mass type. In this case report, it shows that in the differential diagnosis of right-sided heart failure, the right sided myxoma must be considered. The preferable approach in patient with cardiac myxomas is surgical excision to alleviate symptoms, early identification, and removal.

  15. Huge Dissected Ascending Aorta Associated with Pseudo Aneurysm and Aortic Coarctation Feridoun

    Directory of Open Access Journals (Sweden)

    Feridoun Sabzi

    2015-10-01

    Full Text Available We report a unique case of chronic dissection of the ascending aorta complicated with huge and thrombotic pseudoaneurysm in a patient with coarctation of descending aorta. Preoperative investigations such as transesophageal echocardiography (TEE confirmed the diagnosis of dissection. Intraoperative findings included a12 cm eccentric bulge of the right lateral side of dilated the ascending aorta filled with the clot and a circular shaped intimal tear communicating with an extended hematoma and dissection of the media layer. The rarity of the report is an association of the chronic dissection with huge pseudoaneurysm and coarctation. The patient underwent staged repair of an aneurysm and coarctation and had an uneventful postoperative recovery period.

  16. A new pixels flipping method for huge watermarking capacity of the invoice font image.

    Science.gov (United States)

    Li, Li; Hou, Qingzheng; Lu, Jianfeng; Xu, Qishuai; Dai, Junping; Mao, Xiaoyang; Chang, Chin-Chen

    2014-01-01

    Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  17. Air conditioning management of huge rooms; Gestion climatique des locaux de grande dimension

    Energy Technology Data Exchange (ETDEWEB)

    Guitton, P. [Electricite de France (EDF), 78 - Chatou (France); Izard, J.L. [Ecole d`Architecture de Marseille-Luminy, 13 - Marseille-Luminy (France); Wurtz, E. [La Rochelle Universite, 17 - La Rochelle, LEPTAB (France)] [and others

    1999-09-01

    This conference was organized by the section `air-conditioning engineering` of the French society of thermal engineers (SFT). This document comprises the abridged versions of the communications and deals with: air-conditioning using displacement: experience feedback on tertiary applications and development of a dimensioning tool, thermal response of linear atria, application of the zonal method to the description of the temperature field and flows pattern inside an auditorium, theoretical and experimental study of air renewal inside industrial rooms, management of huge rooms, design of new optimized buildings and use of the TAS software, can TRNSYS and Comis codes be used for huge spaces?, experimental study of the thermal-aeraulic conditions generated by a displacement air-conditioning device. (J.S.)

  18. Therapeutic benefit of radiotherapy in huge (≥10 cm) unresectable hepatocellular carcinoma.

    Science.gov (United States)

    Kim, Kyung Hwan; Kim, Mi Sun; Chang, Jee Suk; Han, Kwang-Hyub; Kim, Do Young; Seong, Jinsil

    2014-05-01

    Huge (≥10 cm) hepatocellular carcinomas (HCCs) show dismal prognosis and only a limited number of cases are eligible for curative resection. We studied the therapeutic benefit of radiotherapy (RT) in patients with huge unresectable HCCs. Data from 283 patients with huge HCCs and preserved liver function who underwent non-surgical treatment from July 2001 to March 2012 were retrospectively reviewed. Patients were divided into 4 groups according to the initial treatment: Group A (N= 49), transarterial chemoembolization (TACE); Group B (N = 35), TACE + RT; Group C (N = 50), hepatic arterial infusion chemotherapy; and Group D (n = 149), concurrent chemoradiotherapy (CCRT). The median follow-up period was 27.8 months (range, 12.9-121.9 months). The median overall survival (OS) was longer in Groups B (15.3 months) and D (12.8 months) than in Groups A (7.5 months) and C (8.2 months; Group B vs. A, Bonferroni corrected P [P(c)] = 0.04; Group B vs. C, P(c) = 0.02; Group D vs. A, P(c) = 0.01; Group D vs. C, Pc = 0.006). Groups B and D also showed superior progression-free survival (PFS) and intrahepatic control than Groups A and C. In multivariate analysis, tumour multiplicity, serum alpha-foetoprotein level (≥200 ng/ml) and initial treatment were independent prognostic factors for OS and PFS. Patients with huge unresectable HCCs treated with RT, either as CCRT or in combination with TACE, showed excellent intrahepatic control and prolonged survival. RT could be considered a promising treatment modality in these patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Interaction-induced huge magnetoresistance in a high mobility two-dimensional electron gas

    Energy Technology Data Exchange (ETDEWEB)

    Bockhorn, L.; Haug, R. J. [Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover (Germany); Gornyi, I. V. [Institut für Nanotechnologie, Karlsruher Institut of Technology, D-76021 Karlsruhe (Germany); Schuh, D. [Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93053 Regensburg (Germany); Wegscheider, W. [ETH Zürich (Switzerland)

    2013-12-04

    A strong negative magnetoresistance is observed in a high-mobility two-dimensional electron gas in a GaAs/Al{sub 0.3}Ga{sub 0.7}As quantum well. We discuss that the negative magnetoresistance consists of a small peak induced by a combination of two types of disorder and a huge magnetoresistance explained by the interaction correction to the conductivity for mixed disorder.

  20. A HUGE SILENT INTRACRANIA L HYDATID CYST IN AN ADULT MALE: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Sonal

    2015-04-01

    Full Text Available Hydatid disease of the brain is a rare parasitic infestation caused by larval stage of Echinococcus granulosus. It has an insidious onset with a slow rate of growth resulting in late diagnosis. Its occurence is rare in India, being endemic in Mediterranean countries and Middle East. We report a case of a huge, slow - growing, silent intracranial left parieto - temporo - occipital hydatid cyst in an 18 year old male presenting as a large cystic space occupying lesion.

  1. Synthesis, structure, photophysical and electroluminescent properties of a blue-green self-host phosphorescent iridium(III) complex

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jing; Wang, Hua [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Xu, Huixia, E-mail: xuhuixiatyut@163.com [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Li, Jie; Wu, Yuling; Du, Xiaogang [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Xu, Bingshe, E-mail: xubs@tyut.edu.cn [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2015-07-15

    A kind of blue-green self-host phosphorescent iridium(III) complex, (CzPhBI){sub 2}Ir(tfmptz) [CzPhBI = 9-(6-(2-phenyl-1-benzimidazolyl)hexyl)-9-carbazole; tfmptz = 2-(5-trifluoromethyl-1,2,4-triazolyl)pyridine], was designed and synthesized. The synthesized iridium(III) complex was characterized by {sup 1}H NMR, {sup 19}F NMR, FT-IR, elemental analysis and X-ray single-crystal diffraction, respectively. Its thermal properties, optical properties and electrochemical properties were also investigated. The host-free organic electroluminescent devices with the configuration of ITO/MoO{sub 3} (3 nm)/NPB (30 nm)/TAPC (15 nm)/(CzPhBI){sub 2}Ir(tfmptz) (30 nm)/TBPI (30 nm)/LiF (1 nm)/Al (100 nm) had been fabricated. The devices exhibited excellent performance indicating that (CzPhBI){sub 2}Ir(tfmptz) was a promising phosphorescent material. - Highlights: • A blue-green self-host phosphorescent iridium(III) complex was synthesized. • The molecular structure, and photophysical properties were investigated. • Electroluminescent performance in host-free devices were discussed. • The maximum current efficiency 8.2 cd A{sup −1} and the maximum brightness 5420 cd m{sup −2} were achieved.

  2. Probing space charge effect on electroluminescence of indium tin oxide (ITO)/N,N′-di-[(1-naphthyl)-N,N′-diphenyl]-(1,1′-biphenyl)-4, 4′-diamine (α-NPD)/tris(8-hydroxy-quinolinato) aluminum (III) (Alq{sub 3})/Al diodes by time-resolved electric-field-induced optical second-harmonic generation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sadakata, Atsuo; Osada, Kenshiro; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp

    2014-03-03

    By using time-resolved electric-field-induced optical second-harmonic generation measurement, we studied the electroluminescence (EL) mechanism which is activated in double-layer organic light-emitting diodes (indium tin oxide/N,N′-di-[(1-naphthyl)-N,N′-diphenyl]-(1,1′-biphenyl)-4,4′-diamine (α-NPD)/tris(8-hydroxy-quinolinato) aluminum (III) (Alq{sub 3})/Al) in the high frequency region with application of AC square voltages at various duty-ratios. Results showed that holes were accumulated at the α-NPD/Alq{sub 3} interface in proportion to the duty-ratio, and corresponded well to the increasing EL enhancement at the high frequency. Our previous proposed model on the EL enhancement assisted by electron injection from the Al electrode in the presence of the space charge field was well confirmed. - Highlights: • We studied space charge (SC) effects in double-layer organic light emitting diodes. • The second-harmonic generation measurement was used to directly probe the SC field. • Space charge fields due to interfacial accumulated charge were verified. • We showed that SC electric fields contribute to electroluminescence emissions.

  3. Post-renal acute renal failure due to a huge bladder stone.

    Science.gov (United States)

    Celik, Orcun; Suelozgen, Tufan; Budak, Salih; Ilbey, Yusuf Ozlem

    2014-06-30

    A 63-year old male was referred to our emergency unit due to acute renal failure. The level of serum renal function tests levels, blood urea nitrogen (BUN)/creatinine, were 63 mmol/L/848 μmol/L. CT (Computarised Tomography) scan showed a huge bladder stone (5 cm x 6 cm x 5 cm) with increased bladder wall thickness. Post-renal acute renal failure due to bilateral ureterohydronephrosis was diagnosed. The huge bladder stone was considered to be the cause of ureterohydronephrosis and renal failure. The patient was catheterised and received haemodialysis immediately. He received haemodialysis four times during ten days of hospitalization and the level of serum renal function tests levels (BUN/ creatinine) decreased 18 mmol/L/123 μmol/L. After improvement of renal function, we performed cystoscopy that demonstrated normal prostatic urethra and bladder neck and bilaterally normal ureteral orifices. Bladder wall was roughly trabeculated and Bladder outlet was completely obstructed by a huge bladder stone. After cystoscopy open, cystolithotomy was performed to remove calcium phosphate and magnesium ammonium phosphate stone weighing 200 g removed. Four days after operation the patient was discharged uneventfully and urethral catheter was removed on the seventh day. Post-renal acute renal failure due to large bladder stones is rare in literature. According to the our knowledge; early diagnosis of the stone avoid growth to large size and prevent renal failure.

  4. Safety and efficacy of partial hepatectomy for huge (≥10 cm) hepatocellular carcinoma: A systematic review

    Science.gov (United States)

    Zhou, Yan-Ming; Li, Bin; Xu, Dong-Hui; Yang, Jia-Mei

    2011-01-01

    Summary Huge (≥10 cm) hepatocellular carcinoma (HCC) is not uncommon at clinical presentation, and the surgical outcomes of such tumors are poor. This systematic review aimed to assess the safety and efficacy of partial hepatectomy for huge HCC. We performed a search on Medline and PubMed databases for all relevant studies published prior to December 2009. After exclusions, 21 studies remained for appraisal and data extraction. All studies were classified as level-4 evidence. The median overall perioperative morbidity and mortality rates were 29.2% (range: 13.6–72%) and 3.5% (range: 0–18.2%), respectively. The overall median survival since the partial hepatectomy was 20.7 months (range: 10.1–32 months), with median 1-, 3- and 5-year survival of 60.7% (range: 41–72.2%), 34% (range: 0–60.3%) and 28.6% (range: 0–54%), respectively. The median disease-free survival since the partial hepatectomy was 11.3 months (range: 5.5–32months), with median 1-, 3- and 5-year disease-free survival rates of 48.7% (range: 32–65.4%), 27.5% (range: 14.1–49%) and 20.7% (range: 9.5–43%), respectively. Partial hepatectomy can be performed safely and is associated with long-term survival in a subset of patients with huge HCC, but the evidence of benefit is currently weak. PMID:21358616

  5. Huge focal nodular hyperplasia presenting in a 6-year-old child: A case presentation.

    Science.gov (United States)

    Zhuang, Lin; Ni, Chuangye; Din, Wenbing; Zhang, Feng; Zhuang, Yi; Sun, Yawei; Xi, Dong

    2016-01-01

    Focal nodular hyperplasia (FNH) is a benign lesion of the liver which is usually found in healthy adults, however, FNH is rare in children, and comprises only 2% of all pediatric liver tumors. Herein, we report the case of a 6-year-old child (male) with a huge FNH which size is more than 10cm. This could be the biggest FNH among all children's FNH cases ever reported. A 6-year-old boy was found a hepatic space-occupying lesion two years ago. As the time went by, the lesion became bigger gradually. The last CT examination showed the size of the tumor to be 10.5×9.9cm in the right hepatic lobe. This child underwent surgical resection of the tumor which was confirmed as FNH (11×8×7cm) by pathology. FNH is a benign lesion of the liver, and it is characterized by hepatocyte hyperplasia and a central stellate scar. It is uncommon for FNH to be diagnosed in children. Such huge FNH (about 11cm) is extremely rare. Surgical operation may be the effective method to cure huge FNH. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Modified concentric craniotomy for the removal of a huge calvarial metastatic tumor: technical note.

    Science.gov (United States)

    Kao, Ying; Yang, Shih-Hung; Kuo, Meng-Fai

    2016-02-01

    It is challenging for neurosurgeons to remove huge tumors involving the skull that may possibly invade the dura or intracranial neural tissue. In this situation, excision of the tumor may cause profound blood loss, unexpected opening of the dura, or neurological injury. We describe a technique of craniotomy in a pediatric patient to avoid surgical complications. A 15-year-old boy had a huge metastatic calvarial Ewing's sarcoma. We removed the tumor successfully with modified concentric craniotomy. First, two oval burr holes are made on both sides of the tumor. The inner craniotomy uses the internal margin of the oval holes, while the outer cut uses the outer margins. The skull bone in between the two craniotomies is removed easily in two pieces and the dura surrounding the tumor can be exposed early in the procedure. In this way, the huge skull tumor can be removed en bloc under direct vision to avoid unwanted complications. Minimal blood and bone loss can be achieved. Blood transfusion was not necessary during the surgery. The patient did not have new neurological symptoms and signs after surgery. The goal of the modified concentric craniotomy is to develop an accessible margin of the dura surrounding the bulky tumor in the early phase of surgery. Blood and bone loss can be reduced significantly.

  7. Intraoperative fluorescent cholangiography using indocyanine green for laparoscopic fenestration of nonparasitic huge liver cysts.

    Science.gov (United States)

    Kitajima, Toshihiro; Fujimoto, Yasuhiro; Hatano, Etsuro; Mitsunori, Yusuke; Tomiyama, Koji; Taura, Kojiro; Mizumoto, Masaki; Uemoto, Shinji

    2015-02-01

    Bile duct injury is one of the known serious complications of laparoscopic fenestration for nonparasitic liver cysts. Herein, we report the case of a huge liver cyst for which we performed laparoscopic fenestration using intraoperative fluorescent cholangiography with indocyanine green. A 71-year-old woman with abdominal distention was referred to our hospital. CT demonstrated a 17 × 11.5-cm simple cyst replacing the right lobe of the liver, so laparoscopic fenestration was performed. Although the biliary duct could not be detected because of compression by the huge cyst, fluorescent cholangiography with indocyanine green through endoscopic naso-biliary drainage tube clearly delineated the intrahepatic bile duct in the remaining cystic wall. The patient had no complications at 3 months after surgery. Fluorescent cholangiography using indocyanine green is a safe and effective procedure to avoid bile duct injury during laparoscopic fenestration, especially in patients with a huge liver cyst. © 2015 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

  8. Efficacy of hepatic resection vs transarterial chemoembolization for solitary huge hepatocellular carcinoma.

    Science.gov (United States)

    Zhu, Shao-Liang; Zhong, Jian-Hong; Ke, Yang; Ma, Liang; You, Xue-Mei; Li, Le-Qun

    2015-08-28

    To compare the efficacy of hepatic resection (HR) and transarterial chemoembolization (TACE) for patients with solitary huge (≥ 10 cm) hepatocellular carcinoma (HCC). Records were retrospectively analyzed of 247 patients with solitary huge HCC, comprising 180 treated by HR and 67 by TACE. Long-term overall survival (OS) was compared between the two groups using the Kaplan-Meier method, and independent predictors of survival were identified by multivariate analysis. These analyses were performed using all patients in both groups and/or 61 pairs of propensity score-matched patients from the two groups. OS at 5 years was significantly higher in the HR group than the TACE group, across all patients (P = 0.002) and across propensity score-matched pairs (36.4% vs 18.2%, P = 0.039). The two groups showed similar postoperative mortality and morbidity. Multivariate analysis identified alpha-fetoprotein ≥ 400 ng/mL, presence of vascular invasion and TACE treatment as independent predictors of poor OS. Our findings suggest that HR can be safe and more effective than TACE for patients with solitary huge HCC.

  9. Huge Intramural Hematoma in a Thrombosed Middle Cerebral Artery Aneurysm: A Case Report.

    Science.gov (United States)

    Kim, Hak Jin; Lee, Sang Won; Lee, Tae Hong; Kim, Young Soo

    2015-09-01

    We describe a case of a huge intramural hematoma in a thrombosed middle cerebral artery aneurysm. A 47-year-old female patient with liver cirrhosis and thrombocytopenia presented to the neurosurgical unit with a 5-day history of headache and cognitive dysfunction. Magnetic resonance imaging and computed tomography of the brain showed a thrombosed aneurysm located in the right middle cerebral artery with a posteriorly located huge intramural hematoma mimicking an intracerebral hematoma. Imaging studies and cerebrospinal fluid analysis showed no evidence of subarachnoid hemorrhage. Angiography showed a partially thrombosed aneurysm at the origin of the right anterior temporal artery and an incidental aneurysm at the bifurcation of the right middle cerebral artery. Both aneurysms were embolized by coiling. After embolization, the thrombosed aneurysmal sac and intramural hematoma had decreased in size 4 days later and almost completely disappeared 8 months later. This is the first reported case of a nondissecting, nonfusiform aneurysm with a huge intramural hematoma, unlike that of a dissecting aneurysm.

  10. Electrical Properties and Electroluminescence of 4H-SiC p-n Junction Diodes

    Institute of Scientific and Technical Information of China (English)

    Sun Guosheng; Zhang Yongxing; Gao Xin; Wang Lei; Zhao Wanshun; Zeng Yiping; Li Jinmin

    2004-01-01

    Homoepitaxial growth of 4H-SiC on off-oriented Si-face(0001 ) substrates was performed by using the step-controlled epitaxy technique in a newly developed low-pressure hot-wall CVD (LP-HWCVD) system with a horizontal aircooled quartz tube at around 1500 ℃and 1.33 × 104 Pa by employing SiH4 + C2H4 + H2. In-situ doping during growth was carried out by adding NH3 gas into the precursor gases. It was shown that the maximum Hall mobility of the undoped 4H-SiC epilayers at room temperature is about 430 cm2 ·V -1 ·s -1 with a carrier concentration of ~ 1016 cm-3 and the highest carrier concentration of the N-doped 4H-SiC epilayer obtained at NH3 flow rate of 3 sccm is about 2.7 × 1021 cm-3 with a mobility of 0.75 cm2 ·V -1 ·S -1. SiC p-n junctions were obtained by epitaxially growing N-doped 4H-SiC epilayers on Aldoped 4H-SiC substrates. The C-V characteristics of the diodes were linear in the 1/C3-V coordinates indicating that the obtained p-n junctions were graded with a built-in voltage of 2.7 eV. The room temperature electroluminescence spectra of 4H-SiC p-n junctions are studied as a function of forward current. The D-A pair recombination due to nitrogen donors and the unintentional, deep boron center is dominant at low forward bias, while the D-A pair recombination due to nitrogen donors and aluminum acceptors are dominant at higher forward biases. The p-n junctions could operate at temperature of up to 400 ℃, which provides a potential for high-temperature applications.

  11. Sputter deposition of rare earth doped zinc sulfide for near infrared electroluminescence

    Science.gov (United States)

    Glass, William Robert, III

    2003-10-01

    Near infrared emitting alternating current thin film electroluminescent (ACTFEL) phosphors were fabricated by simultaneous R.F. magnetron sputtering from both a target of doped ZnS and an undoped ZnS target. The intensities of both near infrared (NIR) and visible emission from ZnS doped with thulium (Tm), neodymium (Nd), or erbium (Er) fluorides were dependent on deposition parameters such as target duty cycle (varied from 25 to 100% independently for the two targets) and substrate temperature (140--180°C), with lower temperatures giving 400% better NIR brightness. By optimizing the rare earth concentration between 0.8 and 1.1 at%, the near infrared irradiance was improved by 400% for each dopant. The increase in brightness and optimal concentrations are attributed to decreased crystallinity and increased dopant interaction at higher rare earth concentrations. The brightness increase with decreasing deposition temperature was attributed to a reduction of thermal desorption of the ZnS during deposition, and consequently thicker films and optimized rare earth concentration. Luminescent decay lifetimes were short (20--40 musec) because of a high concentration of non-radiative pathways due to defects from the strain of the large rare earth ions on the ZnS lattice. The threshold voltage for visible and near infrared emission was identical despite emission of NIR and visible light resulting from electrons relaxing from low and high energy excited levels, respectively. The optical threshold voltages were identical to the electrical threshold voltages, and it was concluded that at the voltages necessary for electrical breakdown, the accelerated electrons had enough energy to excite either the visible or NIR emitting levels. Phosphors doped with Nd exhibited increased internal charge at higher dopant concentrations despite a reduction in phosphor field (i.e. reduced applied voltage) In contrast; the charge did not change appreciably for Er and decreased for Tm doped films

  12. Disaster Characteristics and Mitigation Measures of Huge Glacial Debris Flows along the Sichuan-Tibet Railway

    Science.gov (United States)

    Liu, Jinfeng; You, Yong; Zhang, Guangze; Wang, Dong; Chen, Jiangang; Chen, Huayong

    2017-04-01

    The Ranwu-Tongmai section of the Sichuan-Tibet Railway passes through the Palongzangbu River basin which locates in the southeast Qinghai-Tibetan Plateau. Due to widely distributed maritime glacier in this area, the huge glacier debris flows are very developed. Consequently, the disastrous glacier debris flows with huge scale (106-108 m3 for one debris flow event) and damage become one of the key influencing factors for the route alignment of the Sichuan-Tibet Railway. The research on disaster characteristics and mitigation measures of huge glacial debris flows in the study area were conducted by the remote sensing interpretation, field investigation, parameter calculation and numerical simulation. Firstly, the distribution of the glaciers, glacier lakes and glacier debris flows were identified and classified; and the disaster characteristics for the huge glacier debris flow were analyzed and summarized. Secondly, the dynamic parameters including the flood peak discharge, debris flow peak discharge, velocity, total volume of a single debris flow event were calculated. Based on the disaster characteristics and the spatial relation with the railway, some mitigation principles and measures were proposed. Finally, the Guxiang Gully, where a huge glacier debris flow with 2*108m3 in volume occurred in 1953, was selected as a typical case to analyze its disaster characteristics and mitigation measures. The interpretation results show that the glacier area is about 970 km2 which accounts for 19% of the total study area. 130 glacier lakes and 102 glacier debris flows were identified and classified. The Sichuan-Tibet Railway passes through 43 glacier debris flows in the study area. The specific disaster characteristics were analyzed and corresponding mitigation measures were proposed for the route selection of the railway. For the Guxiang Gully, a numerical simulation to simulate the deposition condition at the alluvial fan was conducted. the simulation results show that the

  13. Near-Intrinsic Energy Resolution for 30 to 662 keV Gamma Rays in a High Pressure Xenon Electroluminescent TPC

    CERN Document Server

    Álvarez, V; Cárcel, S; Castel, J; Cebrián, S; Cervera, A; Conde, C A N; Dafni, T; Dias, T H V T; Díaz, J; Egorov, M; Esteve, R; Evtoukhovitch, P; Fernandes, L M P; Ferrario, P; Ferreira, A L; Freitas, E D C; Gehman, V M; Gil, A; Goldschmidt, A; Gómez, H; Gómez-Cadenas, J J; González-Díaz, D; Gutiérrez, R M; Hauptman, J; Morata, J A Hernando; Herrera, D C; Iguaz, F J; Irastorza, I G; Jinete, M A; Labarga, L; Laing, A; Liubarsky, I; Lopes, J A M; Lorca, D; Losada, M; Luzón, G; Marí, A; Martín-Albo, J; Martínez, A; Miller, T; Moiseenko, A; Monrabal, F; Monteiro, C M B; Mora, F J; Moutinho, L M; Vidal, J Muñoz; da Luz, H Natal; Navarro, G; Nebot, M; Nygren, D; Oliveira, C A B; Palma, R; Pérez, J; Aparicio, J L Pérez; Renner, J; Ripoll, L; Rodríguez, A; Rodríguez, J; Santos, F P; Santos, J M F dos; Segui, L; Serra, L; Shuman, D; Simón, A; Sofka, C; Sorel, M; Toledo, J F; Tomás, A; Torrent, J; Tsamalaidze, Z; Vázquez, D; Veloso, J F C A; Villar, J A; Webb, R; White, J T; Yahlali, N

    2012-01-01

    We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time projection chamber (TPC) that was built at the Lawrence Berkeley National Laboratory. It is a prototype of the planned NEXT-100 $^{136}$Xe neutrino-less double beta decay ($0\

  14. Severe progressive scoliosis due to huge subcutaneous cavernous hemangioma: A case report

    Directory of Open Access Journals (Sweden)

    Toyama Yoshiaki

    2011-03-01

    Full Text Available Abstract Cavernous hemangioma consists mainly of congenital vascular malformations present before birth and gradually increasing in size with skeletal growth. A small number of patients with cavernous hemangioma develop scoliosis, and surgical treatment for the scoliosis in such cases has not been reported to date. Here we report a 12-year-old male patient with severe progressive scoliosis due to a huge subcutaneous cavernous hemangioma, who underwent posterior correction and fusion surgery. Upon referral to our department, radiographs revealed a scoliosis of 85° at T6-L1 and a kyphosis of 58° at T4-T10. CT and MR images revealed a huge hemangioma extending from the subcutaneous region to the paraspinal muscles and the retroperitoneal space and invading the spinal canal. Posterior correction and fusion surgery using pedicle screws between T2 and L3 were performed. Massive hemorrhage from the hemangioma occurred during the surgery, with intraoperative blood loss reaching 2800 ml. The scoliosis was corrected to 59°, and the kyphosis to 45° after surgery. Seven hours after surgery, the patient suffered from hypovolemic shock and disseminated intravascular coagulation due to postoperative hemorrhage from the hemangioma. The patient developed sensory and conduction aphasia caused by cerebral hypoxia during the shock on the day of the surgery. At present, two years after the surgery, although the patient has completely recovered from the aphasia. This case illustrates that, in correction surgery for scoliosis due to huge subcutaneous cavernous hemangioma, intraoperative and postoperative intensive care for hemodynamics should be performed, since massive hemorrhage can occur during the postoperative period as well as the intraoperative period.

  15. High platelet counts increase metastatic risk in huge hepatocellular carcinoma undergoing transarterial chemoembolization.

    Science.gov (United States)

    Xue, Tong-Chun; Ge, Ning-Ling; Xu, Xin; Le, Fan; Zhang, Bo-Heng; Wang, Yan-Hong

    2016-09-01

    Accumulating evidence suggests platelets play critical roles in tumor metastasis. Moreover, the role of platelets in metastasis is partially correlated with inflammation. However, evidence regarding the contribution of platelets to hepatocellular carcinoma (HCC) metastasis is lacking. This study investigated the association between platelets and metastatic risk in HCC. We used huge HCC (diameter over 10 cm), a tumor subgroup with a strong inflammatory background, as a model to evaluate the potential predictive role of platelets and platelet-related biomarkers for metastasis in HCC patients undergoing transarterial chemoembolization. A logistic regression model was used to analyze risk factors for metastasis. Patients with huge HCC (n = 178) were enrolled, and 24.7% (44/178) of patients had remote metastases after treatment. Univariate analyses showed high platelet counts (P = 0.012), pretreatment platelet-to-lymphocyte ratios (pre-PLR) of 100 or more (P = 0.018) and post-PLR of 100 or more (P = 0.013) were potential risk factors for metastasis. Furthermore, multivariate analyses showed high platelet counts (odds ratio, 2.18; 95% confidence interval, 1.074-4.443; P = 0.031) and platelet-related biomarkers were independent risk factors for HCC metastasis. Particularly, the risk of metastasis in patients with high post-PLR values was significantly greater than patients with low post-PLR values. For tumor response and survival, patients with high platelet counts had faster disease progression (P = 0.002) and worse survival (P huge HCC undergoing chemoembolization, which supply clinical verification of the association between high platelet counts and HCC metastasis. © 2016 The Japan Society of Hepatology.

  16. The efficacy of stereotactic body radiation therapy on huge hepatocellular carcinoma unsuitable for other local modalities.

    Science.gov (United States)

    Que, Jenny Y; Lin, Li-Ching; Lin, Kuei-Li; Lin, Chia-Hui; Lin, Yu-Wei; Yang, Ching-Chieh

    2014-05-28

    To evaluate the safety and efficacy of Cyberknife stereotactic body radiation therapy (SBRT) and its effect on survival in patients with unresectable huge hepatocellular carcinoma (HCC) unsuitable of other standard treatment option. Between 2009 and 2011, 22 patients with unresectable huge HCC (≧10 cm) were treated with SBRT. dose ranged from 26 Gy to 40 Gy in five fractions. Overall survival (OS) and disease-progression free survival (DPFS) were determined by Kaplan-Meier analysis. Tumor response and toxicities were also assessed. After a median follow-up of 11.5 month (range 2-46 months). The objective response rate was achieved in 86.3% (complete response (CR): 22.7% and partial response (PR): 63.6%). The 1-yr. local control rate was 55.56%. The 1-year OS was 50% and median survival was 11 months (range 2-46 months). In univariate analysis, Child-Pugh stage (p = 0.0056) and SBRT dose (p = 0.0017) were significant factors for survival. However, in multivariate analysis, SBRT dose (p = 0.0072) was the most significant factor, while Child-Pugh stage of borderline significance. (p = 0.0514). Acute toxicities were mild and well tolerated. This study showed that SBRT can be delivered safely to huge HCC and achieved a substantial tumor regression and survival. The results suggest this technique should be considered a salvage treatment. However, local and regional recurrence remain the major cause of failure. Further studies of combination of SBRT and other treatment modalities may be reasonable.

  17. The big, large and huge case of state-building

    DEFF Research Database (Denmark)

    Harste, Gorm

      Using communication theory as point of departure, it is not evident how to study macro phenomena. Michel Foucault limited his studies to a non-Grand Theory when studying discursive events. At the same time, Charles Tilly wrote about Big Structures, Large Processes, Huge Comparisons when trying...... to establish a perspective on a macro phenomena as European state formation. With Luhmann's system theory, the claim is that there is no such contradiction between Grand evolution and particular semantic history. Passing through some classic studies of the historical establishment of interaction systems...

  18. The  Big, Large and Huge Case of State-Building

    DEFF Research Database (Denmark)

    Harste, Gorm

    2009-01-01

      Using communication theory as point of departure it is not evident how to study macro phenomena. Michel Foucault delimited his studies to a non-Grand Theory when he studied discursive events. At the same time Charles Tilly wrote about Big Structures, Large Processes, Huge Comparisons when he...... tried to establish a perspective on a macro phenomena as European state formation. With Luhmann's system theory, the claim is that there is no such contradiction between Grand evolution and particular semantic history. Passing through some classic studies of the historical establishment of interaction...

  19. Huge malignant phyllodes breast tumor: a real entity in a new era of early breast cancer.

    Science.gov (United States)

    Testori, Alberto; Meroni, Stefano; Errico, Valentina; Travaglini, Roberto; Voulaz, Emanuele; Alloisio, Marco

    2015-02-27

    Phyllodes tumor is an extremely rare tumor of the breast. It occurs in females in the third and fourth decades. The difficulty in distinguishing between phyllodes tumors and benign fibroadenoma may lead to misdiagnosis. Lymph node involvement is rarely described in phyllodes tumors; for this reason, sentinel node biopsy may be warranted. We present a case of a 33-year-old woman affected by huge tumor of the right breast with ulceration in the skin with a rapid tumor growth and with omolateral axillary metastasis.

  20. Huge Benign Ovarian Cystic Teratoma in a Patient with a History of Hansen's Disease.

    Science.gov (United States)

    Okonta, Patrick I; Mofon, Chukwuemeke

    2014-01-01

    Mature ovarian cystic teratomas are common benign ovarian neoplasm derived from germ cells. With increasing availability of ultrasound services even in developing countries, the diagnosis of benign ovarian tumour is made earlier and the size of the ovarian tumour at diagnosis is relatively small. It is unusual to find an ovarian cystic teratoma larger than 10 cm. We report a huge mature ovarian cystic teratoma in a multipara with a history of Hansen's disease. We conclude that, in circumstances where women have restricted access to health care, the unusual finding of mature ovarian cystic teratoma larger than 10 cm is possible due to delayed presentation for diagnosis and treatment.

  1. Creating and Exploring Huge Parameter Spaces: Interactive Evolution as a Tool for Sound Generation

    DEFF Research Database (Denmark)

    Dahlstedt, Palle

    2001-01-01

    of huge synthesis parameter spaces, and presents a possibility for the sound artist to create new sound engines customized for this kind of creation and exploration – sound engines too complex to control in any other way. Different sound engines are presented, together with a discussion of compositional......In this paper, a program is presented that applies interactive evolution to sound generation, i.e., preferred individuals are repeatedly selected from a population of genetically bred sound objects, created with various synthesis and pattern generation algorithms. This simplifies aural exploration...

  2. Huge capacity fiber-optic sensing network based on ultra-weak draw tower gratings

    Science.gov (United States)

    Yang, Minghong; Bai, Wei; Guo, Huiyong; Wen, Hongqiao; Yu, Haihu; Jiang, Desheng

    2016-03-01

    This paper reviews the work on huge capacity fiber-optic sensing network based on ultra-weak draw tower gratings developed at the National Engineering Laboratory for Fiber Optic Sensing Technology (NEL-FOST), Wuhan University of Technology, China. A versatile drawing tower grating sensor network based on ultra-weak fiber Bragg gratings (FBGs) is firstly proposed and demonstrated. The sensing network is interrogated with time- and wavelength-division multiplexing method, which is very promising for the large-scale sensing network.

  3. En bloc resection of huge cemento-ossifying fibroma of mandible: avoiding lower lip split incision.

    Science.gov (United States)

    Ayub, Tahera; Katpar, Shahjahan; Shafique, Salman; Mirza, Talat

    2011-05-01

    Cemento-ossifying Fibroma (COF) is an osteogenic benign neoplasm affecting the jaws and other craniofacial bones. It commonly presents as a progressively slow growing pathology, which can sometimes attain an enormous size, causing facial deformity. A case of a huge cemento-ossifying fibroma, appearing as a mandibular dumbell tumour in a male patient is documented, which caused massive bone destruction and deformity. It was surgically removed by performing en bloc resection of mandible avoiding the splitting of lower lip incision technique, thereby maintaining his normal facial appearance.

  4. Huge Intrathoracic Malignant Peripheral Nerve Sheath Tumor in an Adolescent with Neurofibromatosis Type 1

    Directory of Open Access Journals (Sweden)

    Jong Hyung Yoon

    2014-01-01

    Full Text Available Malignant peripheral nerve sheath tumor (MPNST is a rare soft tissue malignancy usually found in patients with neurofibromatosis type 1 (NF1 with a poor outcome. Although MPNST can be found in any part of the body including head and neck or extremities, intrathoracic MPNST with or without NF1 is uncommon, especially in children or adolescents. Reported herein is a case of huge intrathoracic MPNST in a 16-year-old girl with NF1, and a brief review of the literature.

  5. Huge gastric bezoar caused by honeycomb, an unusual complication of health faddism: a case report

    Science.gov (United States)

    Katsinelos, Panagiotis; Pilpilidis, Ioannis; Katsinelos, Taxiarchis; Lazaraki, Georgia; Fasoulas, Kostas; Zavos, Christos; Kountouras, Jannis

    2009-01-01

    We report a young healthy woman, who believed that the consumption of large amounts of honeycomb would lead to good health and who finally developed a huge gastric bezoar of hard consistency. The conventional endoscopic techniques failed to manage the bezoar. Using the combination of injection of hydrogen peroxide 3% solution inside the bezoar to induce disintegration and a special designed needle-knife sphincterotome (bezotome) we managed to remove the bezoar in fragments. To the best of our knowledge this is the first reported bezoar caused by honeycomb. PMID:19829904

  6. A huge chondromyxoid fibroma of the nasal cavity in a newborn baby.

    Science.gov (United States)

    Yoo, Young Tae; Park, Joo Hyun; Sunwoo, Woong Sang; Rhee, Chae-Seo

    2012-08-01

    Chondromyxoid fibroma is a rare benign tumor that usually occurs in the long bones. A 2-month newborn presented with huge masses in the both nasal cavities, which turned out to be chondromyxoid fibroma. The masses originated from both inferior turbinates. Total turbinectomy on the left side and submucosal mass excision on the right side were performed. No recurrence or new lesion was observed during the 2 years of follow up. We report here on a rare case of nasal cavity chondromyxoid fibroma in a neonate and we review the relevant literature.

  7. Totally laparoscopic gastrectomy for early gastric cancer accompanied by huge hiatal hernia: A case report.

    Science.gov (United States)

    Hagiwara, Chie; Yajima, Kazuhito; Iwasaki, Yoshiaki; Oohinata, Ryouki; Yuu, Ken; Ishiyama, Satoshi; Amaki, Misato; Nakano, Daisuke; Yamaguchi, Tatsuro; Matsumoto, Hiroshi; Takahashi, Keiichi

    2016-02-01

    We herein present a case in which we used a totally laparoscopic approach for early gastric cancer accompanied by a huge hiatal hernia. An 80-year-old Japanese woman was referred with a chief complaint of dysphagia. A clinical diagnosis of early gastric cancer, T1b (SM) N0M0, stage IA, accompanied by hiatal hernia, was made. Distal gastrectomy with D1 plus lymphadenectomy was carried out. After the gastrectomy, the hernial sac was excised and the hernial orifice was closed. Reconstruction using the Roux-en-Y method was selected. The postoperative course was uneventful and she was discharged on postoperative day 10.

  8. Huge aneurysm and coronary-cameral fistula from right coronary branch: First case.

    Science.gov (United States)

    Ahmad, Tanveer; Pasarad, Ashwini Kumar; Kishore, Kolkebaile Sadanand; Maheshwarappa, Nandakumar Neralakere

    2016-02-01

    Coronary-cameral fistulas are rare cardiovascular anomalies. A giant coronary artery aneurysm associated with a coronary-cameral fistula is a very rare condition, with an estimated prevalence of 0.02%. We report the case of middle-aged woman who presented with a huge extracardiac aneurysmal mass and a coronary-cameral fistula from a right coronary artery branch. It was successfully repaired by ligation and excision plus marsupialization of the aneurysm. We believe this is the first such a case reported in literature.

  9. Enhanced Brightness of Eu3+ Complex in Organic Electroluminescent Devices by Using Another Rare-Earth Ion

    Institute of Scientific and Technical Information of China (English)

    白峰; 邓振波; 高新; 李勇; 徐怡庄; 吴瑾光

    2002-01-01

    Rare-earth ions Tb3+ and La3+ were used as a bridge to improve the energy transfer from the polymer to an Eu complex. The material Tb(La)0.5Eu0.5 (BSA)3phen was synthesized and used as the emission layer in the device:ITO/PVK:Tb(La)0.5Eu0.5 (BSA)3phen/Alq/Al. The two device were compared in detail and it was found that the device using La0.5Eu0.5 (BSA)3phen as the emission material had better monochromatic characteristics with the maximal brightness of 102cd/m2 and the colour coordinates x = 0.55 and y = 0.36.

  10. Long-term survival after surgical resection for huge hepatocellular carcinoma: comparison with transarterial chemoembolization after propensity score matching.

    Science.gov (United States)

    Min, Yang Won; Lee, Jun Hee; Gwak, Geum-Youn; Paik, Yong Han; Lee, Joon Hyoek; Rhee, Poong-Lyul; Koh, Kwang Cheol; Paik, Seung Woon; Yoo, Byung Chul; Choi, Moon Seok

    2014-05-01

    Surgical resection (SR) and transarterial chemoembolization (TACE) have been commonly applied for patients with huge hepatocellular carcinoma (HCC). However, optimal treatment has not been established. Between 2000 and 2009, 267 patients with huge HCC (≥ 10 cm) underwent TACE and 84 underwent SR as the first treatment. Propensity score matching generated a matched cohort composed of 152 patients. We investigated overall survival and possible prognostic factors. At baseline, the surgery group showed a tendency to have solitary tumor (72.6% vs 39.3%, P huge HCC. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  11. Ultraviolet electroluminescence properties from devices based on n-ZnO/i-NiO/p-Si light-emitting diode

    Science.gov (United States)

    Wang, Hui; Zhao, Yang; Wu, Chao; Wu, Guoguang; Ma, Yan; Dong, Xin; Zhang, Baolin; Du, Guotong

    2017-07-01

    We fabricated the Ultraviolet light-emitting diode (LED) based on n-ZnO/i-NiO/p-Si heterostructure by metal-organic chemical vapor deposition (MOCVD). The device exhibited diode-like rectifying characteristics with a turn-on voltage of 3.2 V. The NiO film with high resistance state and [200] preferred orientation acted as an electron blocking layer, which produced a larger ZnO/NiO conduction band offset of 2.93 eV than that of ZnO/Si (0.30 eV). Under forward bias, prominent ultraviolet emissions peaked around 375 nm accompanying with rather weak blue-white emissions peaked around 480 nm were observed at room temperature. Furthermore, the mechanism of the electroluminescence was tentatively discussed in terms of the band diagram of the diode.

  12. Electroluminescence and negative differential resistance studies of TPD:PBD:Alq3 blend organic-light-emitting diodes

    Indian Academy of Sciences (India)

    M A Mohd Sarjidan; S H Basri; N K Za’aba; M S Zaini; W H Abd Majid

    2015-02-01

    Ternary system of single-layer organic-light-emitting diodes (OLEDs) were fabricated containing tris(8-hydroxyquinoline) aluminium (Alq3) blended with N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine and 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole small molecules. Electroluminescence properties were investigated with respect to blend systems. Significant improvement in turn-on voltage and luminance intensity was observed by employing the blends technique. Negative differential resistance (NDR) characteristics observed at a low voltage region in blended OLED is related to the generation of guest hopping site and phonon scattering phenomenon. However, luminescence of the devices is not altered by the NDR effect.

  13. Effect of Electric Field and Polarity on Light Emission in Metal-Insulator-Semiconductor Structure Thin-Film Electroluminescent Devices

    Science.gov (United States)

    Ohwaki, Jun-ichi; Kozawaguchi, Haruki; Tsujiyama, Bunjiro

    1983-01-01

    Changes in the emission intensities and spectra with applied electric fields in Metal-Insulator-Semiconductor (MIS) structure thin-film electroluminescent (TFEL) devices have been investigated using devices with stacked emitting layer structures, such as ITO/ZnS: Mn/ZnS: Tb/Sm2O3/Al. In MIS-TFEL devices, the emission distribution in the direction of the ZnS film thickness is nonhomogeneous. In particular, the emission intensity in the region near the ZnS-insulator interface increases with increasing applied voltage more than in the other region in the ZnS layer, when electrons exciting emission centers are accelerated from the insulator side. On the other hand, the emission is homogeneous at the opposite polarity. It is found that the emission color for stacked emitting layer MIS-TFEL devices can be modulated by changing the applied voltage.

  14. Spectral and Electroluminescent Properties of Binuclear Zinc Complexes with Halogen-Substituted Derivatives of 1,2,4-Triazole

    Science.gov (United States)

    Kopylova, T. N.; Degtyarenko, K. M.; Samsonova, L. G.; Gadirov, R. M.; Gusev, A. N.; Shul'gin, V. F.; Meshkova, S. B.

    2015-03-01

    Spectral properties of binuclear zinc complexes in chloroform solutions and polyvinylcarbazole (PVC) films are investigated. It is demonstrated that incorporation of a halogen atom (chlorine or bromine) in a ligand benzene ring leads to a small shift of the spectrum toward the red region and a reduction of the fluorescence quantum yield. The fluorescence and phosphorescence spectra at T = 77K are investigated. The fluorescence undergoes a blue shift of about 30 nm and multiply increases in the intensity, and the phosphorescence is observed at 540-580 nm. The phosphorescence lifetime is estimated. The electroluminescent properties of metal complexes in structures with thermal vacuum spin coating of complexes and in PVC films are investigated.

  15. Blue to red electroluminescence emission from organic light-emitting diodes based on π-conjugated organic semiconductor materials

    Science.gov (United States)

    Sharbati, Mohammad Taghi; Panahi, Farhad; Nekoei, Abdo-Reza; Emami, Farzin; Niknam, Khodabakhsh

    2014-01-01

    Blue to red organic light-emitting diodes based on a series of newly synthesized distyrylbenzenes have been demonstrated. Their optical properties have been theoretically and experimentally studied in order to inquire into the substitution effects (such as electron-donating, electron-withdrawing, and steric hindrance) on the emission color. Density functional theory at B3LYP/6-311+G(d) level of calculation was employed to obtain the molecular structures and highest occupied molecular orbital and lowest unoccupied molecular orbital surfaces. Electroluminescence emission range of compounds could be tuned by changing the strength of the acceptor component and using push-pull and nonplanarity effects from 483 (blue) to 600 (red) nm.

  16. Poly(meta-phenylene) Derivative with Rigid Twisted Biphenyl Units in Backbone: Synthesis, Structural Characterization,Photophysical Properties and Electroluminescence

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yan; YANG Bing; ZHANG Hai-quan; LU Ping; SHEN Fang-zhong; LIU Lin-lin; XU Hai; YANG Guang-di; MA Yu-guang

    2007-01-01

    A soluble poly(meta-phenylene) derivative with rigid twisted biphenyl unit was synthesized by the Yamamoto coupling reaction. The polymer is soluble in common organic solvents, and the number-average molecular weight is about 6500. The UV-Vis and quantum chemical calculation indicate that the different conformation segments named "conformers" exist in the polymer backbones; it was also further confirmed by the single crystal X-ray diffraction study of the dimeric model compound. The π-π* transition of biphenyl segments of twisted and planar conformations made the polymer exhibit a strong absorption around 256 nm and a weak absorption at about 300 nm. Furthermore,the polymer exhibits a strong UV photoluminescence at 372 nm when the excitation wavelengths are longer than 300 nm. The ultraviolet-emitting electroluminescence(EL) device with the single layer structure shows EL λmax of the derivative at 370 nm.

  17. Theoretical Investigation on the Electron and Energy Transfer between Peripheral Carrier Transport Groups and Central Chromophores in Electroluminescent Materials

    Institute of Scientific and Technical Information of China (English)

    潘玉钰; 刘丹丹; 许海; 刘晓冬; 孙冠楠; 杨兵; 马於光

    2012-01-01

    The molecular materials with structures of luminescent core and peripheral carrier groups (e.g. carbazoles), have exhibited high-performance in organic light-emitting diodes (OLEDs). Present work is to understand the basic process of electronic and energy exchange between the peripheral functional groups and the central core through quantum chemical analysis. As an example, 4,7-bis(9,9-bis(6-(9H-carbazol-9-yl)hexyl)-9H-fluoren-2-yl)benzo[c]- [1,2,5]thiadiazole (TCBzC) is investigated in regards to optoelectronic properties using density functional theory (DFT). The results suggest that the forbidden transition from peripheral carbazole to the central chromophore core makes for separated electrical and optical properties, and high performance electroluminescence (EL) is mainly at- tributed to the energy-transfer from carbazoles to the fluorene derivative core.

  18. Cathodoluminescence and electroluminescence from multi-layered organic structures induced by field electron emission from carbon nanotubes

    Science.gov (United States)

    Kuznetzov, Alexander A.; Zakhidov, Alexander A.; Ovalle, Raquel; Nanjundaswami, Rashmi; Williams, Christopher; Zhang, Mei; Lee, Sergey B.; Ferraris, John; Zakhidov, Anvar A.

    2005-10-01

    We report the observation of cathodoluminescence (CL) of organic multilayers of tris-(8-hydroxyquinoline) aluminium (Alq3) and 2- (4biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) deposited on ITO-coated glass, with and without hole transport layer and compare it with electroluminescence (EL) from similar devices. Excitation of the CL of such multilayer organic anodes was accomplished by low energy electrons field emitted by single walled carbon nanotube cathodes. The dependence of CL spectrum and intensity on voltage (V), current (I), type of transport layer and the cathode-anode geometry has been studied. We propose carbon nanotubes as efficient cathodes for stable CL emission from multi-layer anodes at small cathode-anode separations. The role of hole-transport layer is also discussed.

  19. Near infrared electroluminescence of ZnMgO/InN core-shell nanorod heterostructures grown on Si substrate.

    Science.gov (United States)

    Wu, Guoguang; Zheng, Weitao; Gao, Fubin; Yang, Hang; Zhao, Yang; Yin, Jingzhi; Zheng, Wei; Li, Wancheng; Zhang, Baolin; Du, Guotong

    2016-07-27

    This paper presents a systematic investigation of a ZnMgO/InN core-shell nanorods heterojunction device on a p-Si substrate. Here we demonstrated the heteroepitaxial growth of the well-aligned ZnMgO/InN core-shell nanorods structure, which enabled an increased heterojunction area to improve the carrier injection efficiency of nanodevices by plasma-assisted molecular beam epitaxy combined with metal-organic chemical vapor deposition. In situ X-ray photoelectron spectroscopy measurements were performed on the ZnMgO nanorods, the interface of ZnMgO/InN and the InN core-shell nanorods to fully understand the structure and working mechanism of the heterojunction device. The current transport mechanism has been discussed in terms of the characteristics of current-voltage and the energy band diagram of the n-InN/ZnMgO/p-Si heterojunction. At a low forward voltage, the current transport followed the dependence of I ∼ V(1.47), which was attributed to the deep-level assisted tunneling. When the forward voltage was larger than 10 V, the current followed the relation of I ∼ V(2) because of the radiative recombination process. In accordance with the above conclusion, the near-infrared electroluminescence of the diode could be observed after the forward bias voltage up to 11.6 V at room temperature. In addition, the size quantization effect and the intrinsic electron accumulation of the InN core-shell nanorods were investigated to explain the blueshift and broadened bandwidth. Furthermore, the light output power of about 0.6 microwatt at a fixed wavelength of 1500 nm indicated that our study will further provide a useful route for realizing the near-infrared electroluminescence of InN on Si substrate.

  20. A huge 6.2 kilogram uterine myoma coinciding with omental leiomyosarcoma: case report.

    Science.gov (United States)

    Ruan, C W; Lee, C L; Yen, C F; Wang, C J; Soong, Y K

    1999-12-01

    Surgery for massive abdominal tumors is both interesting and challenging. We present a case involving a multiple uterine myoma weighing 6.2 Kg which coincided with omental leiomyosarcoma. To our knowledge, this is the first report of this type of condition in the English literature. A 44-year-old nulliparous woman had suffered from abdominal pain for a long time. A huge abdominal mass was palpated on physical examination. Computed tomography scanning revealed a huge pelvic-abdominal mass with the possibility of small bowel loops invaded by the mass. A 6-cm omental mass was incidentally found during the subsequent hysterectomy procedure. Perforation of the urinary bladder occurred during the dissection of adhesion. Resection of the omental mass, wide wedge resection of the invaded small bowel, primary repair of the bladder, and hysterectomy were performed. The final pathologic diagnosis was uterine leiomyomata with omental leiomyosarcoma. The patient returned home on postoperative day 14 and was well at the 18-month follow-up examination. The challenge of these tumors lies in their proper diagnosis and surgical management. More case reports and follow-up studies are needed to confirm the efficacy of their management.

  1. Treatment of Huge Hepatocellular Carcinoma Using Cinobufacini Injection in Transarterial Chemoembolization: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Jun Dong

    2016-01-01

    Full Text Available The aim of this study is to examine the safety and efficacy of Cinobufacini injection in transarterial chemoembolization (TACE for treatment of huge hepatocellular carcinoma (HCC. Clinical data of 56 consecutive patients with HCC larger than 10 cm who had been treated with TACE between December 2010 and August 2014 were retrospectively analyzed. Among these patients, 31 belonged to the Cinobufacini group and 25 belonged to the epirubicin group. The clinical efficacy, survival time, and adverse events in patients in the two groups were compared. The objective response rate in the Cinobufacini group was significantly higher than that in the epirubicin group (53.6% versus 23.1%, P=0.022. The median survival time (10.6 versus 14.1 months, χ2=0.092, P=0.762 and the median time to progression (4.9 versus 5.7 months, χ2=0.097, P=0.756 were similar between the groups. The incidence rate of adverse events was lower in the Cinobufacini group than in the epirubicin group (P<0.05. The short-term clinical efficacy of Cinobufacini is better than that of epirubicin in TACE for treating huge HCC, while their long-term clinical efficacy is similar. However, lower incidence of adverse events was noted in TACE using Cinobufacini rather than epirubicin.

  2. Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach.

    Science.gov (United States)

    Cheng, Xiao-Bing; Li, Yun-Peng; Lei, De-Lin; Li, Xiao-Dong; Tian, Lei

    2011-03-01

    Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

  3. The technical research on the huge glazed brick from the relic of Nanyue Kingdom Palace

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    'Qin brick and Han tile' has a great worldwide reputation in the architectural history of China. According to the former archaeological materials, the big hollow brick is usually one meter long and thirty to forty centimeters wide, while the solid brick is generally much smaller. But in 1995, large scale vestiges and structures were unearthed at the center of Guangzhou's old district, from the relic of Nanyue Kingdom Palace, which was built some 2000 years ago during the Western-Han Dynasty, A great number of earthen structural members were discovered, especially the solid glazed bricks in various beautiful patterns with an astonishing thickness and size. Some of them are one meter square, more than 20 centimeters thick, and weight half a ton, which are named ‘Brick No.1 in the world' by excavators. People have shown great interest in how to make these huge glazed bricks at the ancient technical conditions, because it is very difficult to manufacture such huge bricks even with the modern technology. At the request of Guangdong Nanyue Kingdom Palace Museum, Shanghai Institute of Ceramics carried out systematical measurements and analysis on these bricks and studied the physical and chemical forming mechanisms from their chemical compositions, structure, and physical characteristics. Here the technical characteristics of the bricks are also discussed.

  4. The technical research on the huge glazed brick from the relic of Nanyue Kingdom Palace

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    ‘Qin brick and Han tile’ has a great worldwide reputation in the architectural history of China. According to the former archaeological materials, the big hollow brick is usually one meter long and thirty to forty centimeters wide, while the solid brick is generally much smaller. But in 1995, large scale vestiges and structures were un- earthed at the center of Guangzhou’s old district, from the relic of Nanyue Kingdom Palace, which was built some 2000 years ago during the Western-Han Dynasty. A great number of earthen structural members were discovered, especially the solid glazed bricks in various beautiful patterns with an astonishing thickness and size. Some of them are one meter square, more than 20 centimeters thick, and weight half a ton, which are named ‘Brick No.1 in the world’ by excavators. People have shown great interest in how to make these huge glazed bricks at the ancient tech- nical conditions, because it is very difficult to manufacture such huge bricks even with the modern technology. At the request of Guangdong Nanyue Kingdom Palace Museum, Shanghai Institute of Ceramics carried out systematical measurements and analysis on these bricks and studied the physical and chemical forming mechanisms from their chemical compositions, structure, and physical character- istics. Here the technical characteristics of the bricks are also discussed.

  5. Treatment of Huge Hepatocellular Carcinoma Using Cinobufacini Injection in Transarterial Chemoembolization: A Retrospective Study.

    Science.gov (United States)

    Dong, Jun; Zhai, Xiaofeng; Chen, Zhe; Liu, Qun; Ye, Hua; Chen, Wei; Ling, Changquan

    2016-01-01

    The aim of this study is to examine the safety and efficacy of Cinobufacini injection in transarterial chemoembolization (TACE) for treatment of huge hepatocellular carcinoma (HCC). Clinical data of 56 consecutive patients with HCC larger than 10 cm who had been treated with TACE between December 2010 and August 2014 were retrospectively analyzed. Among these patients, 31 belonged to the Cinobufacini group and 25 belonged to the epirubicin group. The clinical efficacy, survival time, and adverse events in patients in the two groups were compared. The objective response rate in the Cinobufacini group was significantly higher than that in the epirubicin group (53.6% versus 23.1%, P = 0.022). The median survival time (10.6 versus 14.1 months, χ (2) = 0.092, P = 0.762) and the median time to progression (4.9 versus 5.7 months, χ (2) = 0.097, P = 0.756) were similar between the groups. The incidence rate of adverse events was lower in the Cinobufacini group than in the epirubicin group (P huge HCC, while their long-term clinical efficacy is similar. However, lower incidence of adverse events was noted in TACE using Cinobufacini rather than epirubicin.

  6. Addressing huge spatial heterogeneity induced by virus infections in lentil breeding trials.

    Science.gov (United States)

    Kargiotidou, Anastasia; Vlachostergios, Dimitrios N; Tzantarmas, Constantinos; Mylonas, Ioannis; Foti, Chrysanthi; Menexes, George; Polidoros, Alexios; Tokatlidis, Ioannis S

    2016-12-01

    Spatial heterogeneity can have serious effects on the precision of field experimentation in plant breeding. In the present study the capacity of the honeycomb design (HD) to sample huge spatial heterogeneity was appraised. For this purpose, four trials were conducted each comprising a lentil landrace being screened for response to viruses. Huge spatial heterogeneity was reflected by the abnormally high values for coefficient of variation (CV) of single-plant yields, ranging 123-162 %. At a given field area, increasing the number of simulated entries was followed by declined effectiveness of the method, on account of the larger circular block implying greater intra-block heterogeneity; a hyperbolic increasing pattern of the top to bottom entry mean gap (TBG) indicated that a number of more than 100 replicates (number of plants per entry) is the crucial threshold to avoid significant deterioration of the sampling degree. Nevertheless, the honeycomb model kept dealing with variation better than the randomized complete block (RCB) pattern, thanks to the circular shape and standardized type of block that ensure the less possible extra heterogeneity with expanding the area of the block. Owing to the even and systematic entry allocation, breeders do not need to be concerned with the extra spatial heterogeneity that might induce the extra surface needed to expand the size of the block when many entries are considered. Instead, they could improve accuracy of comparisons with increasing the number of replicates (circular blocks) despite the concomitant greater overall spatial heterogeneity.

  7. Challenging the time complexity of exact subgraph isomorphism for huge and dense graphs with VF3.

    Science.gov (United States)

    Carletti, Vincenzo; Foggia, Pasquale; Saggese, Alessia; Vento, Mario

    2017-04-24

    Graph matching is essential in several fields that use structured information, such as biology, chemistry, social networks, knowledge management, document analysis and others. Except for special classes of graphs, graph matching has in the worst-case an exponential complexity; however, there are algorithms that show an acceptable execution time, as long as the graphs are not too large and not too dense. In this paper we introduce a novel subgraph isomorphism algorithm, VF3, particularly efficient in the challenging case of graphs with thousands of nodes and a high edge density. Its performance, both in terms of time and memory, has been assessed on a large dataset of 12700 random graphs with a size up to 10000 nodes, made publicly available. VF3 has been compared with four other state-of-the-art algorithms, and the huge experimentation required more than two years of processing time. The results confirm that VF3 definitely outperforms the other algorithms when the graphs become huge and dense, but also has a very good performance on smaller or sparser graphs.

  8. Strontium-89 therapy for the treatment of huge osseous metastases in prostate carcinoma: A case report.

    Science.gov (United States)

    Zhang, Wenjie; Zhao, Weiwei; Jia, Zhiyun; Deng, Houfu

    2013-02-01

    Prostate cancer is a growing public health problem. The palliation of pain in patients with painful bone metastases is of primary importance in the clinical management of advanced cancer. Internal therapy with radionuclides, which concentrate at sites of increased bone turnover, is used to control pain and improve quality of life as an alternative to conventional therapies. In the present study, we report the case of a 52-year-old male who had been diagnosed with prostate cancer. The patient presented with severe pain in multiple areas, but particularly in the right hip. A whole-body bone scan revealed that the right hip, ilium and ischium were covered with huge metastatic lesions. Treatment with radionuclide strontium-89 chloride ((89)Sr) resulted in a partial response which was confirmed by the successful relief of pain and other imaging modalities. No significant change in the leukocyte or thrombocyte levels was observed. The results of the present study indicate that systemic radionuclide therapy using (89)Sr is an effective, well-tolerated and safe palliative treatment in patients with huge osseous metastases in prostate carcinoma.

  9. Resection of Huge Liver Cancer Involving the Second Porta Hepatis:A Report of 55 Cases

    Institute of Scientific and Technical Information of China (English)

    CHENHan; WUMengchao; WANGYi; WEIGongtian; HULei

    2002-01-01

    Objective To investigate the possibility and surgical procedures for huge liver cancer involving the second porta hepatis.Methods 55 cases of huge liver cancer, with the diameter of 8-28 cm(mean 12.7 cm) were studied. Right subcostal or “rooftop” incision was made, the liver ligments were divided, good exposure of the tumor and access to retrohepatic inferior vena cava were achieved.Hepatectomies were completed under intermittent interruption of first porta hepatis. Occluding tape around vena cava was applied before liver resection if necessary.Results All tumors were successfully resected without death during operation.The longest survival time was now 4 years in one case. The 1-4 year postoperative survival rates were 63%,50%,50% and 30% respectively.Conclusion Young patients with solitary large liver tumor, which grows slowly over a long period on basis of non-cirrhotic or mild cirrhotic liver, should undergo an exploration in an attempt of resection irrespective of the image contraindication, provided that there is no extra-hepatic metastasis.

  10. The HUGE formula (hematocrit, urea, gender) for screening for chronic kidney disease in elderly patients: a study of diagnostic accuracy.

    Science.gov (United States)

    Musso, Carlos G; de Los Rios, Eduardo; Vilas, Manuel; Terrasa, Sergio; Bratti, Griselda; Varela, Federico; Diez, Guillermo Rosa; Jauregui, Jose; Luna, Daniel

    2017-04-01

    Chronically reduced glomerular filtration rate (GFR) in old people does not always mean that they suffer from chronic kidney disease (CKD) since their GFR can just be reduced by aging. The HUGE equation has been recently described and validated in Spain for screening CKD without taking into account the patient's GFR value. This equation is based on patient's hematocrit, plasma urea levels and gender. The present study documented that the HUGE equation had and acceptable performance for screening CKD in elderly Argentine patients.

  11. 巨大阑尾黏液性囊腺瘤1例%1 case of huge appendiceal mucinous cystadenoma

    Institute of Scientific and Technical Information of China (English)

    王磊; 刘雯雯

    2016-01-01

    Huge appendiceal mucinous cystadenoma is rare in clinic,and the preoperative misdiagnosis rate is high.The data of 1 case of huge appendiceal mucinous cystadenoma was introduced in this paper.%巨大阑尾黏液性囊腺瘤临床较少见,术前误诊率高。本文对巨大阑尾黏液性囊腺瘤1例的病例资料进行介绍。

  12. Huge hepatocellular carcinoma greater than 10 cm in diameter worsens prognosis by causing distant recurrence after curative resection.

    Science.gov (United States)

    Wakayama, Kenji; Kamiyama, Toshiya; Yokoo, Hideki; Orimo, Tatsuya; Shimada, Shingo; Einama, Takahiro; Kamachi, Hirofumi; Taketomi, Akinobu

    2017-03-01

    This study aimed to evaluate the impact of huge (≥10 cm) hepatocellular carcinoma (HCC) to the recurrence pattern and the prognosis after hepatectomy. 574 patients who underwent hepatectomy by 17 surgeons (Open 536 and Laparoscopic 38) for HCC without major vascular invasion from 1990 to 2013 at single institute were retrospectively analyzed. Huge tumor, age, HCV, multiple tumors and microscopic portal invasion are independent risk factors for overall survival (OS), and huge tumor, ICGR15 ≥16%, multiple tumors, moderate/poor histology, microscopic portal invasion and a positive pathological margin are risk factors for relapse-free survival (RFS). The 5-year OS and RFS of patients with huge HCC (n = 53) (42.9 and 14.2%) were significantly worse than those of patients with HCC Huge tumor is an independent risk factor for initial extra-hepatic recurrence (Hazard ratio 7.86, P Huge HCC (≥10 cm) is an independent risk factor due to a high risk for initial extra-hepatic recurrence. Future systemic adjuvant therapy is needed for these patients. J. Surg. Oncol. 2017;115:324-329. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Treatment of huge hypertensive putaminal hemorrhage by surgery and cerebrospinal fluid drainage.

    Science.gov (United States)

    Zhang, Hong-Tian; Xue, Sha; Li, Pei-Jian; Fu, Yan-Bin; Xu, Ru-Xiang

    2013-09-01

    There is limited information available regarding the treatment of huge hypertensive putaminal hemorrhage (HPH). This study aimed to evaluate our experience of 33 patients with huge HPH who were treated by open surgery (decompressive craniectomy and hematoma evacuation) and external cerebrospinal fluid (CSF) drainage. We reviewed the records of 33 consecutive patients admitted to our hospital with huge HPH (≥ 60 cm(3)). All patients were treated by decompressive craniectomy, hematoma evacuation, and CSF drainage. Data collected included age, gender, blood pressure at admission, Glasgow Coma Scale (GCS) score, intracranial hemorrhage (ICH) location, ICH volume, degree of midline shift, presence/absence of basal cistern obliteration at admission and before surgery, and presence/absence of intraventricular hemorrhage (IVH). Outcome was assessed by the Glasgow Outcome Scale score at 30 days after surgery. The median GCS score was 5.0 at admission, and improved to 8.0 at 1 week after surgery. The median ICH volume was 95 cm(3) before surgery and 4 cm(3) after surgery. IVH was observed in 93.9% of patients. The overall survival rate to discharge was 75.6% (25/33), including 15.1% (4/33) with good function, 36.4% (12/33) with disability, and 24.3% (8/33) in a vegetative state. The mortality rate was 24.3% (8/33). Patients with right-sided ICH had better outcomes than those with left-sided ICH. No patients with GCS score ≤ 6 and ICH volume ≥ 90cm(3) at admission achieved good postoperative function. Operative time was significantly shorter with hematoma evacuation via the transcortical approach than via the transsylvian approach (3.41 ± 0.75 h vs. 4.14 ± 0.59 h, Phuge HPH by decompressive craniectomy, hematoma evacuation, and CSF drainage is life-saving. Patients with GCS score 7-8, ICH volume 60-90 cm(3), and right-sided ICH may achieve good recovery. The transcortical approach appears to be more effective than the transsylvian approach for rapid decompression of

  14. Huge pelvic parachordoma: fine needle aspiration cytology and histological differential diagnosis

    Directory of Open Access Journals (Sweden)

    Mona A. Kandil

    2012-10-01

    Full Text Available Parachordoma is an extremely rare soft tissue tumor of unknown lineage. Parachordoma develops most often on the extremities. Only 2 cases have been reported as pelvic parachordoma. A 46-year old Egyptian woman with a huge painful pelvic mass was found to have a parachordoma with ectopic pelvic right kidney. There is only one report in the literature of fine needle aspiration cytology in this setting. The microscopic picture of parachordoma is not new to pathologists but the gross picture of this rare tumor has not previously been published; not even in the World Health Organization classification of soft tissues tumors. Diagnosis was confirmed by immuno-histochemistry. The patient is in good clinical condition without any evidence of recurrence or metastasis after 84 months of follow up.

  15. Shape Memory and Huge Superelasticity in Ni–Mn–Ga Glass-Coated Fibers

    Directory of Open Access Journals (Sweden)

    Lei Shao

    2017-01-01

    Full Text Available Ni–Mn–Ga polycrystalline alloy fibers with diameters of 33 μm are reported to exhibit significantly improved ductility and huge superelastic and shape memory strains in comparison to conventional brittle bulk polycrystalline alloys. Particularly, the recoverable strain of the Ni54.9–Mn23.5–Ga21.6 fiber can be as high as 10% at 40 °C. Such optimized behavior has been achieved by a suitable fabrication process via a glass-coating melt spinning method. The superelastic properties at different temperatures and the shape memory effect of Ni54.9–Mn23.5–Ga21.6 fibers were investigated.

  16. Tiny grains give huge gains: nanocrystal-based signal amplification for biomolecule detection.

    Science.gov (United States)

    Tong, Sheng; Ren, Binbin; Zheng, Zhilan; Shen, Han; Bao, Gang

    2013-06-25

    Nanocrystals, despite their tiny sizes, contain thousands to millions of atoms. Here we show that the large number of atoms packed in each metallic nanocrystal can provide a huge gain in signal amplification for biomolecule detection. We have devised a highly sensitive, linear amplification scheme by integrating the dissolution of bound nanocrystals and metal-induced stoichiometric chromogenesis, and demonstrated that signal amplification is fully defined by the size and atom density of nanocrystals, which can be optimized through well-controlled nanocrystal synthesis. Further, the rich library of chromogenic reactions allows implementation of this scheme in various assay formats, as demonstrated by the iron oxide nanoparticle linked immunosorbent assay (ILISA) and blotting assay developed in this study. Our results indicate that, owing to the inherent simplicity, high sensitivity and repeatability, the nanocrystal based amplification scheme can significantly improve biomolecule quantification in both laboratory research and clinical diagnostics. This novel method adds a new dimension to current nanoparticle-based bioassays.

  17. Development of a huge varix following endovascular embolization for cerebellar arteriovenous malformation

    Energy Technology Data Exchange (ETDEWEB)

    Mineura, K.; Sasajima, H.; Itoh, Y.; Kowada, M. [Akita Univ. Hospital (Japan). Neurosurgical Service; Tomura, N. [Akita Univ. Hospital (Japan). Dept. of Radiology; Goto, K. [Iizuka Hospital, Fukuoka (Japan). Dept. of Interventional Neuroradiology

    1998-03-01

    We report on the case of a huge varix that developed after the endovascular embolization of a cerebellar arteriovenous malformation (AVM) with a single drainer. A 21-year-old male presented with trigeminal neuralgia which was caused by the dilated drainer of the AVM. A varix was found at the basal vein of Rosenthal 2 months after an initial stage of embolization with polyvinyl alcohol particles; it diminished after the surgical extirpation of the AVM. The varix formation might have been facilitated by the stenosis in the vein of Galen and by the dynamic changes that followed the embolization. This rare complication should be kept in mind when embolization is performed for AVMs with impaired venous outlets. (orig.).

  18. Huge spin-transfer torque in a magnetic tunnel junction by a superlattice barrier

    Science.gov (United States)

    Chen, C. H.; Tseng, P.; Ko, C. W.; Hsueh, W. J.

    2017-09-01

    Huge spin-transfer torque (STT) in a magnetic tunnel junction (MTJ) achieved by superlattice barrier composed of alternate layers of a nonmagnetic metal and an insulator is proposed. The magnitude of the STT depends on the number of cells in the superlattice barrier and the nonmagnetic metal layer's thickness. The result shows that the STT of the novel superlattice-barrier MTJ can reach values up to four orders of magnitude greater than those of traditional single-barrier stacks based on three cells superlattice by designing the nonmagnetic metal layer's thickness. In addition, the spin-transfer torque of the proposed MTJ can also be thousands of magnitude greater than those of traditional double-barrier MTJs.

  19. Unusual Large Sporadic Angiomyolipoma Co-existing with Huge Simple Renal Cyst

    Directory of Open Access Journals (Sweden)

    Sunil V Jagtap

    2011-07-01

    Full Text Available Renal Angiomyolipoma (AML is an unusual benign mesenchymal tumor with no malignant potential. It is composed of adipose tissue, smooth muscle and abnormal thick walled blood vessels. It can occur sporadically or may be associated with tuberous sclerosis. Sporadic angiomyolipoma (AML coexisting with simple renal cyst is extremely rare and only one case report is available in the literature. In our case, unique combination of sporadic AML along with simple renal cyst with huge size and weight was noted. To the best of our knowledge, ours is the second such case and first case from India. Due to its large size, complete nephrectomy was performed to avoid chances of rupture and retroperitoneal hemorrhage. Post-operative period was uneventful and the patient ahs been on regular follow-up.

  20. Bilateral ureteral complete obstruction with huge spontaneous urinoma formation in a patient with advanced bladder cancer.

    Science.gov (United States)

    Jou, Yeong-Chin; Shen, Cheng-Huang; Cheng, Ming-Chin; Lin, Chang-Te; Chen, Pi-Che

    2012-02-01

    Spontaneous rupture of the collecting system with extravasation of urine and urinoma formation is usually associated with urinary tract obstruction by a ureteral calculus. Tumor growth is an extremely rare cause of urinary extravasation. Here we report a case of bilateral obstructive uropathy with a huge spontaneous left retroperitoneal urinoma caused by advanced infiltrative transitional cell carcinoma of the urinary bladder. The point of leakage was located in the left renal pelvis. The urinary leakage ceased after percutaneous nephrostomy drainage, and the patient subsequently underwent radical cystoprostatectomy. Histopathology revealed a high-grade urothelial carcinoma of the urinary bladder with pelvic lymph node metastasis. The patient refused any adjuvant treatment and expired 6 months after the operation from disseminated metastasis from bladder cancer. Copyright © 2011. Published by Elsevier B.V.

  1. Bilateral ureteral complete obstruction with huge spontaneous urinoma formation in a patient with advanced bladder cancer

    Directory of Open Access Journals (Sweden)

    Yeong-Chin Jou

    2012-02-01

    Full Text Available Spontaneous rupture of the collecting system with extravasation of urine and urinoma formation is usually associated with urinary tract obstruction by a ureteral calculus. Tumor growth is an extremely rare cause of urinary extravasation. Here we report a case of bilateral obstructive uropathy with a huge spontaneous left retroperitoneal urinoma caused by advanced infiltrative transitional cell carcinoma of the urinary bladder. The point of leakage was located in the left renal pelvis. The urinary leakage ceased after percutaneous nephrostomy drainage, and the patient subsequently underwent radical cystoprostatectomy. Histopathology revealed a high-grade urothelial carcinoma of the urinary bladder with pelvic lymph node metastasis. The patient refused any adjuvant treatment and expired 6 months after the operation from disseminated metastasis from bladder cancer.

  2. PRS: PERSONNEL RECOMMENDATION SYSTEM FOR HUGE DATA ANALYSIS USING PORTER STEMMER

    Directory of Open Access Journals (Sweden)

    T N Chiranjeevi

    2016-04-01

    Full Text Available Personal recommendation system is one which gives better and preferential recommendation to the users to satisfy their personalized requirements such as practical applications like Webpage Preferences, Sport Videos preferences, Stock selection based on price, TV preferences, Hotel preferences, books, Mobile phones, CDs and various other products now use recommender systems. The existing Pearson Correlation Coefficient (PCC and item-based algorithm using PCC, are called as UPCC and IPCC respectively. These systems are mainly based on only the rating services and does not consider the user personal preferences, they simply just give the result based on the ratings. As the size of data increases it will give the recommendations based on the top rated services and it will miss out most of user preferences. These are main drawbacks in the existing system which will give same results to the users based on some evaluations and rankings or rating service, they will neglect the user preferences and necessities. To address this problem we propose a new approach called, Personnel Recommendation System (PRS for huge data analysis using Porter Stemmer to solve the above challenges. In the proposed system it provides a personalized service recommendation list to the users and recommends the most useful services to the users which will increase the accuracy and efficiency in searching better services. Particularly, a set of suggestions or keywords are provided to indicate user preferences and we used Collaborative Filtering and Porter Stemmer algorithm which gives a suitable recommendations to the users. In real, the broad experiments are conducted on the huge database which is available in real world, and outcome shows that our proposed personal recommender method extensively improves the precision and efficiency of service recommender system over the KASR method. In our approach mainly consider the user preferences so it will not miss out the any of the data

  3. Huge epithelial nonparasitic splenic cyst: A case report and a review of treatment methods.

    Science.gov (United States)

    Farhangi, Bahman; Farhangi, Arezo; Firouzjahi, Alireza; Jahed, Babak

    2016-01-01

    Splenic cysts are rare in all age groups and there are a few reports in the world literature. Primary cysts occur most frequently in children and young adults, comprising around 25% of all nonparasitic splenic cysts. Various techniques are suggested for the treatment of splenic cysts. In this case report, a huge epithelial splenic cyst in a 17-year-old female is presented and different treatment methods of splenic cysts are evaluated. A 17-year-old female presented with progressive abdominal mass in left upper quadrant associated with abdominal pain and food intolerance of duration of several months. There was no history of trauma. On physical examination, there was a huge mass located in the upper left side of abdomen. Computerized tomography scan revealed that a large cystic lesion had occupied the spleen with dimensions of 32x21xI5.6 cm. After patient preparation laparotomy was performed and complete cyst excision was done with splenectomy, patient was discharged after 2 days. This is a report of a case of epithelial splenic cyst of the spleen in a 17-year old female. The management of splenic cysts continues to evolve and the optimum treatment of patients with nonparasitic splenic cysts is controversial, as a principle preservation technique of the spleen with minimally invasive methods such as laparoscopy is preferred to splenectomy with the exception of very large cysts and when splenic hilum is involved in cyst wall. However, significant cyst recurrences were encountered with these techniques. Recently open partial splenectomy has been proposed as a safe and effective method in the management of NPSCs it ensures complete cyst removal, lack of cyst recurrence, and preservation of the spleen functions.

  4. Bioinspired oil strider floating at the oil/water interface supported by huge superoleophobic force.

    Science.gov (United States)

    Liu, Xueli; Gao, Jun; Xue, Zhongxin; Chen, Li; Lin, Ling; Jiang, Lei; Wang, Shutao

    2012-06-26

    Oil pollution to aquatic devices, especially to those oil-cleaning devices and equipment-repairing robots during oil spill accidents, has drawn great attention and remains an urgent problem to be resolved. Developing devices that can move freely in an oil/water system without contamination from oil has both scientific and practical importance. In nature, the insect water strider can float on water by utilizing the superhydrophobic supporting force received by its legs. Inspired by this unique floating phenomenon, in this article, we designed a model device named "oil strider" that could float stably at the oil/water interface without contamination by oil. The floating capability of the oil strider originated from the huge underwater superoleophobic supporting force its "legs" received. We prepared the micro/nanohierarchical structured copper-oxide-coated copper wires, acting as the artificial legs of oil strider, by a simple base-corrosion process. The surface structures and hydrophilic chemical components of the coatings on copper wires induced the huge superoleophobic force at the oil/water interface, to support the oil strider from sinking into the oil. Experimental results and theoretical analysis demonstrate that this supporting force is mainly composed of three parts: the buoyancy force, the curvature force, and the deformation force. We anticipate that this artificial oil strider will provide a guide for the design of smart aquatic devices that can move freely in an oil/water system with excellent oil repellent capability, and be helpful in practical situations such as oil handling and oil spill cleanup.

  5. A Stable Blue Organic Electroluminescent Material%一种稳定的蓝色有机电致发光材料

    Institute of Scientific and Technical Information of China (English)

    郑新友; 吴有智; 朱文清; 张步新; 蒋雪茵; 张志林; 许少鸿

    2002-01-01

    In order to compare two kinds of blue electroluminescent materials, we have investigated two kinds of blue OLEDs with the similar structrue ITO/CuPc/NPB/JBEM: perylene/Alq/Mg: Ag [ device (J) ] and ITO/CuPc/NPB/DPVBi: perylene/Alq/Mg: Ag [device(D) ]. The difference of luminance and efficiency was not obvious for the two devices. However, there was remarkable difference for their lifetime. The device(J) achieved longer half lifetime of 1035 h at initial luminance of 100 cd/m2, and that of device(D) was only 255 h. According to their energy level diagrams , the difference of their stability may originate from different host materials in the two devices. It may be attributed to the better thermal stability of JBEM molecules than that of DPVBi. It is shown that JBEM may be a promising blue organic electroluminescent material with great stability.

  6. Circularly polarized electroluminescence of light-emitting InGaAs/GaAs (III, Mn)V diodes on the basis of structures with a tunneling barrier

    Energy Technology Data Exchange (ETDEWEB)

    Malysheva, E. I., E-mail: malysheva@phys.unn.ru; Dorokhin, M. V.; Ved’, M. V.; Kudrin, A. V.; Zdoroveishchev, A. V. [Lobachevsky State University of Nizhny Novgorod (Russian Federation)

    2015-11-15

    The comparative investigation of circularly polarized electroluminescence in Zener diodes based on InGaAs/n-GaAs/n{sup +}-GaAs/GaMnAs and InGaAs/n-GaAs/n{sup +}-GaAs/GaMnSb is carried out. It is established that the circularly polarized electroluminescence is associated with the spin injection of electrons from a ferromagnetic semiconductor layer. The luminescence parameters are determined by the properties of these layers. It is shown that the ferromagnetic properties of the GaMnSb layer allow us to obtain circularly polarized emission at room temperature from InGaAs/n-GaAs/n{sup +}-GaAs/GaMnSb heterostructures.

  7. Hole-exciton interaction induced high field decay of magneto-electroluminescence in Alq{sub 3}-based organic light-emitting diodes at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tingting; Holford, D. F.; Gu, Hang; Kreouzis, T. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Zhang, Sijie, E-mail: Sijie.zhang@scu.edu.cn, E-mail: w.gillin@qmul.ac.uk [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Gillin, W. P., E-mail: Sijie.zhang@scu.edu.cn, E-mail: w.gillin@qmul.ac.uk [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)

    2016-01-11

    The magnetic field effects on the electroluminescence of aluminium tris-(8-hydroxyqinoline) (Alq{sub 3}) based organic light emitting diodes have been investigated by varying the electron/hole ratio in the emissive layer. Experimental results reveal that a negative high field effect in the magneto-electroluminescence (MEL) can be found in devices with very low triplet exciton concentration at room temperature. This suggests triplet-triplet annihilation cannot be used to explain the negative high field MEL in the Alq{sub 3} system. Our results suggest that hole-exciton interaction may be the origin of the negative high field MEL and also, in parallel with this interaction, there is also the more common positive high field process occurring which has been tentatively attributed to electron-exciton interactions. The competition between these different processes decides the final shape of the MEL at high fields.

  8. Electroluminescence imaging of Morgan Solar Inc.'s 4th generation CPV technology for in-line quality control and optical efficiency estimation

    Science.gov (United States)

    Sinclair, Michael; Dufour, Pascal; Drew, Kristine; Myrskog, Stefan; Morgan, John Paul

    2014-10-01

    An electroluminescence test for a Concentrated PV system is presented with the objective of capturing high resolution pseudo-efficiency maps that highlight optical defects in the concentrator system. Key parameters of the experimental setup and imaging system are presented. Image processing is discussed, including comparison of experimental to nominal results and the quantitative estimation of optical efficiency. Efficiency estimates are validated using measurements under a collimated solar simulator and ray-tracing software. Further validation is performed by comparison of the electroluminescence technique to direct mapping of the optical efficiency. Initial results indicate the mean estimation error for Isc is -2.4% with a standard deviation is 6.9% and a combined measurement and analysis time of less than 5 seconds per optic. An extension of this approach to in-line quality control is discussed.

  9. [Anesthetic management of a patient with aortocaval fistula caused by rupture of a huge abdominal aortic aneurysm into the inferior vena cava].

    Science.gov (United States)

    Tanaka, Motonari; Kawashima, Akira; Kuremoto, Yoshito; Tanada, Kazuko

    2013-12-01

    Aortocaval fistula is a rare complication of ruptured abdominal aortic aneurysm. We report anesthetic management of a patient with aortocaval fistula caused by rupture of a huge abdominal aortic aneurysm into the inferior vena cava. A 51-year-old man who had complained of low back pain and general fatigue was referred to our hospital because of his liver damage. Aortocaval fistula due to rupture of a huge abdominal aortic aneurysm was diagnosed from physical examination, enhanced computed tomography and color Doppler ultrasonography. Anesthesia was induced with propofol and rocuronium, and was maintained with sevoflurane and remifentanil. After induction of anesthesia, the central venous pressure and cardiac index showed remarkably high values because of arteriovenous shunt. When the aneurysm was incised after the clamping of the abdominal aorta, massive venous bleeding occurred from the fistula and caused severe hypotension. Blood pressure recovered by digital compression of the bleeding point and the use of an autotransfusion device. After the repair of the aortocaval fistula, the hemodynamics became stable. The patient had a high output but a good cardiac function in preoperative examination. Therefore anesthesia was managed successfully without worsening high-output heart failure.

  10. Electroluminescence in Potassium Iodide Single Crystals Containing Potassium Metal Colloids (VII) -Theory of the Frequency Dependence of the Threshold a.c. Electric Field-

    OpenAIRE

    HAGIHARA, Takeshi; HAYASHIUCHI, Yoshihiro

    1996-01-01

    Electroluminescence(EL) in colored KI single crystals containing potassium metal colloids has been studied theoretically to understand the characteristics of the EL. A simple rate equation is introduced to describe the dynamical change in numbers of both luminescence centers and conduction electrons produced from the potassium metal colloids by external high a.c. electric field excitation. The present model explains well the EL experimental results reported previously, e.g., the frequency dep...

  11. Single-layer electroluminescent devices based on fluorene-1H-pyrazolo[3,4-b]quinoxaline co-polymers

    Science.gov (United States)

    Pokladko-Kowar, Monika; Danel, Andrzej; Chacaga, Łukasz

    2013-11-01

    A fluorene based copolymer was synthesized for electroluminescent application. To the main chain of polymer the nitrogen heterocyclic, 1H-pyrazolo[3,4-b]quinoxaline, unit was introduced. The incorporation of this derivative tuned the emission from the blue to yellow-green one. A simple, single layered device was fabricated with the configuration ITO/PEDOT/co-poly-FLU-PQX/Ca/Mg.

  12. Syntheses and electroluminescent properties of two europium ternary complexes Eu(DBM){sub 3}(PBO) and Eu(DBM){sub 3}(PBT)

    Energy Technology Data Exchange (ETDEWEB)

    Guan Min [State Key Laboratory of Rare Earth Materials Chemistry and Applications, Peking University, Beijing 100871 (China); Gao Lihua [Department of Chemistry, Beijing Normal University, Beijing 100875 (China); Wang Shanshan [State Key Laboratory of Rare Earth Materials Chemistry and Applications, Peking University, Beijing 100871 (China); Huang Chunhui [State Key Laboratory of Rare Earth Materials Chemistry and Applications, Peking University, Beijing 100871 (China)], E-mail: chhuang@pku.edu.cn; Wang Kezhi [Department of Chemistry, Beijing Normal University, Beijing 100875 (China)

    2007-12-15

    Two europium complexes, Eu(DBM){sub 3}(PBO) and Eu(DBM){sub 3}(PBT) (DBM=dibenzoylmethanato, PBO=2-(2-pyridyl)benzoxazole, PBT=2-(2-pyridyl)benzothiazole), were prepared and used as emitting materials in organic electroluminescent (EL) devices. The devices with the structures ITO/TPD/Eu(DBM){sub 3}(PBO) (or Eu(DBM){sub 3}(PBT)/BCP/Alq{sub 3}/Mg:Ag/Ag emit red light originating from the europium complexes.

  13. Electroluminescence from InGaN quantum dots in a monolithically grown GaN/AlInN cavity

    Energy Technology Data Exchange (ETDEWEB)

    Dartsch, Heiko; Tessarek, Christian; Figge, Stephan; Aschenbrenner, Timo; Kruse, Carsten; Hommel, Detlef [University of Bremen, Institute of Solid State Physics - Semiconductor Epitaxy (Germany); Schowalter, Marco; Rosenauer, Andreas [University of Bremen, Institute of Solid State Physics - Electron Microscopy (Germany)

    2011-07-01

    InGaN quantum dots (QDs) and their implementation into the micro cavity of a vertical distributed Bragg reflector (DBR) resonator are the key elements to achieve single photon emission required for quantum cryptography. However, the epitaxial overgrowth of InGaN QDs is challenging because they are easily destroyed by elevated temperatures. For this reason a common approach is the fabrication of a hybrid cavity structure by non epitaxial deposition of a dielectric top DBR. We present the first successful implementation of electrically driven InGaN QDs into a monolithic GaN/AlInN cavity structure fully epitaxial grown by metal organic vapor phase epitaxy. A single layer of InGaN QDs has been embedded in a n- and p-type doped 5{lambda} GaN cavity surrounded by a 40 fold bottom- and a 10 fold GaN/AlInN top-DBR. The bottom DBR shows a reflectivity of 97%. Structural properties were investigated by scanning transmission microscopy (STEM) and will be discussed. Electroluminescence of the InGaN QDs was achieved by the application of intra cavity contacts. This demonstrates for the first time the possibility of using InGaN QD in fully epitaxial made devices like vertical cavity surface emitting lasers or single photon sources. We present the first successful implementation of electrically driven InGaN QDs into a monolithic GaN/AlInN cavity structure fully epitaxial grown by metal organic vapor phase epitaxy. Therefore a single layer of InGaN QDs has been embedded in a n- and p-type doped 5{lambda} GaN cavity surrounded by a 40 fold bottom- and a 10 fold GaN/AlInN top-DBR. The bottom DBR shows a reflectivity of 97%. Electroluminescence of the InGaN QDs was achieved by the application of intra cavity contacts. Optical and structural properties of the device are discussed. This demonstrates for the first time the possibility of using InGaN QD in fully epitaxial made devices like vertical cavity surface emitting lasers or single photon sources.

  14. The platelet-to-lymphocyte ratio predicts poor survival in patients with huge hepatocellular carcinoma that received transarterial chemoembolization.

    Science.gov (United States)

    Xue, Tong-Chun; Jia, Qing-An; Ge, Ning-Ling; Zhang, Bo-Heng; Wang, Yan-Hong; Ren, Zheng-Gang; Ye, Sheng-Long

    2015-08-01

    Inflammation is particularly strong in huge hepatocellular carcinoma (HCC). However, it is unclear whether the platelet-to-lymphocyte ratio (PLR), as an inflammatory-related marker, can predict survival of patients with huge HCC. In this study, we enrolled 291 patients with huge HCC (diameter over 10 cm) who were undergoing repeated transarterial chemoembolization (TACE) at our institute. The baseline PLR was calculated from complete serum blood counts before the first chemoembolization. We found that a baseline PLR cutoff value over 150 best predicted huge HCC survival. The 12, 24, and 36 months survival rates in the high PLR group (22.6, 8.1, and 4.1 %, respectively) were significantly lower than in the low PLR group (35.6, 22.4, and 14 %, respectively). Thus, a significant difference was found in overall survival (log-rank test, p huge HCC, a high baseline PLR is a useful predictor of poor survival in patients undergoing chemoembolization. Additional anti-inflammatory or anti-platelet treatments, in combination with TACE, may improve survival in HCC patients with high PLR.

  15. The value of a formula including haematocrit, blood urea and gender (HUGE) as a screening test for chronic renal insufficiency.

    Science.gov (United States)

    Alvarez-Gregori, J A; Robles, N R; Mena, C; Ardanuy, R; Jauregui, R; Macas-Nu Nunez, J F

    2011-06-01

    Despite increasing use in clinical practice, an estimated glomerular filtration rate value (eGFR) of HUGE formula. A formula including haematocrit , blood urea, and gender (HUGE), diagnoses CRI regardless of the variables of age, blood creatinine, creatinine clearance, or other eGFR. The HUGE formula is: L = 2.505458 - (0.264418 x Hematocrit) + (0.118100 x Urea) [+ 1.383960 if male]. If L is a negative number the individual does not have CRI; if L is a positive number, CRI is present. Our data demonstrate that the HUGE formula is more reliable than MDRD and CKD-EPI, particularly in persons aged over 70. Our HUGE screening formula offers a straightforward, easily available and inexpensive method for differentiating between CRI and eGFR < 60 ml/min/1.73 m2 that will prevent a considerable number of aged healthy persons, as much as 1.700.000 in Spain and 2.600.000 in U.K., to be excluded from clinical assays or treatments contraindicated in CRI.

  16. [COMBINED POSTERIOR AND ANTERIOR APPROACHES FOR RESECTION OF THORACOLUMBAR SPINAL HUGE DUMBBELL-SHAPED TUMOR].

    Science.gov (United States)

    Shi, Jiandang; Zhao, Chen; Ding, Huiqiang; Fu, Bin; Niu, Ningkui; Yue, Xuefeng; Yang, Zongqiang; He, Yin

    2016-02-01

    To investigate the surgical outcome of combined posterior and anterior approaches for the resection of thoracolumbar spinal canal huge dumbbell-shaped tumor. Between January 2009 and March 2015, 12 patients with thoracolumbar spinal canal huge dumbbell-shaped tumor were treated by posterior approach and anterolateral approach through diaphragmatic crura and thoracoabdominal incision for complete resection. There were 9 males and 3 females, with an average age of 45 years (range, 30-65 years). The disease duration was 8-64 weeks (mean, 12.7 weeks). The tumor was located at T(12), L1 in 6 cases, at L(1,2) in 5 cases, and at L(2,3) in 1 case. The tumor size ranged from 4.3 cm x 4.0 cm x 3.5 cm to 7.5 cm x 6.3 cm x 6.0 cm. According to tumor outside the spinal involvement scope and site and based on the typing of Eden, 5 cases were rated as type b, 2 cases as type d, 4 cases as type e, and 1 case as type f in the transverse direction; two segments were involved in 8 cases, and more than two segments in 4 cases. The degree of tumor excision, tumor recurrence, and the spine stability were observed during follow-up. The verbal rating scale (VRS) was used to evaluate pain improvement. The average surgical time was 170 minutes (range, 150-230 minutes); the average intraoperative blood loss was 350 mL (range, 270-600 mL). All incisions healed by first intention, and no thoracic cavity infection and other operation related complication occurred. Of 12 cases, 10 were histologically confirmed as schwannoma, and 2 as neurofibroma. The patients were followed up 6 months to 6 years (mean, 31 months). Neurological symptoms were significantly improved in all patients, without lower back soreness. The thoracolumbar X-ray film and MRI showed no tumor residue. No tumor recurrence, internal fixator loosening, scoliosis, and other complications were observed during follow-up. VRS at last follow-up was significantly improved to grade 0 (10 cases) or grade 1 (2 cases) from preoperative

  17. Partial reactivation of a huge deep-seated ancient rock slide: recognition, formation mechanism, and stability

    Science.gov (United States)

    Tang, Minggao; Xu, Qiang; Li, Yusheng; Huang, Runqiu; Rengers, Niek; Zhu, Xing

    2016-08-01

    About 18 years ago, a large-scale discontinuous layer in properties and colour was found in the new Fengjie town at the shore of the Three Gorges Reservoir area in China. There are many resettled residents and buildings on the sloping area, the safety of which is potentially affected by this layer, so it has become the focus of attention. Before this study started there were two viewpoints regarding the origin of this layer. One was that is was from a huge ancient slide and the other was that is was from a fault graben. In order to find out how it was formed and to be able to carry out a stability analysis of the slope the authors have carried out a research program, including geological field investigations and mapping, a deep drilling hole, a geotechnical centrifuge model test, and a simulation analysis. The results of the research led to the conclusion that the layer is the sliding plane of a huge deep-seated ancient rock slide, which we called the Sanmashan landslide. An important argument for the conclusion is the recognition of a regional compressive tectonic stress field in this area, which cannot lead to the formation of a fault graben because it needs a tensional tectonic stress field. Moreover, numerous unique geological features, sliding marks, and other relics of the ancient slide have been discovered in the field. The formation process of the ancient slide could be repeated in a large geotechnical centrifuge model test. The test shows that a deformation and failure process of "creep-crack-cut" has occurred. The type of the ancient slide can be classified as a "successive rotational rock slide". Finally, the role of seepage in the stability of the Sanmashan landslide has been analysed. Our final conclusions are that, during rainfall and filling-drawdown cycles in the Three Gorges Reservoir, the Sanmashan landslide as a whole is dormant and stable and the secondary landslides in the toe area of the slope are presently stable but can be reactivated. This

  18. Modified simultaneous integrated boost radiotherapy for an unresectable huge refractory pelvic tumor diagnosed as a rectal adenocarcinoma.

    Science.gov (United States)

    Nomiya, Takuma; Akamatsu, Hiroko; Harada, Mayumi; Ota, Ibuki; Hagiwara, Yasuhito; Ichikawa, Mayumi; Miwa, Misako; Kawashiro, Shouhei; Hagiwara, Motohisa; Chin, Masahiro; Hashizume, Eiji; Nemoto, Kenji

    2014-12-28

    A clinical trial of radiotherapy with modified simultaneous integrated boost (SIB) technique against huge tumors was conducted. A 58-year-old male patient who had a huge pelvic tumor diagnosed as a rectal adenocarcinoma due to familial adenomatous polyposis was enrolled in this trial. The total dose of 77 Gy (equivalent dose in 2 Gy/fraction) and 64.5 Gy was delivered to the center of the tumor and the surrounding area respectively, and approximately 20% dose escalation was achieved with the modified SIB technique. The tumor with an initial maximum size of 15 cm disappeared 120 d after the start of the radiotherapy. Performance status of the patient improved from 4 to 0. Radiotherapy with modified SIB may be effective for patients with a huge tumor in terms of tumor shrinkage/disappearance, improvement of QOL, and prolongation of survival.

  19. Huge nanodielectric effects in polyimide/boron nitride nanocomposites revealed by the nanofiller size

    Science.gov (United States)

    Diaham, S.; Saysouk, F.; Locatelli, M.-L.; Lebey, T.

    2015-09-01

    The dielectric properties of polyimide/boron nitride (PI/BN) nanocomposite films are investigated as a function of the BN nanofiller size from 20 to 350 °C and at low filler content (1-2 vol.%). The role of the BN nanofiller size on the large reduction of the electrode polarization relaxation phenomenon due to ionic movements is reported. For the two smallest BN nanoparticles (95 nm and 35 nm), the permittivity, dielectric losses and dc conductivity are strongly attenuated above 200 °C by a factor of 10 to 1000 compared to neat PI. Thus, the dc conductivity at 350 °C is reduced from 4   ×   10-8 Ω-1 cm-1 for neat PI to 3   ×   10-11 Ω-1 cm-1 for PI/BN (35 nm). Moreover, a further decrease is obtained by functionalizing the nanofiller surface with a silane coupling agent which improves the grafting of PI chains on those latter nanoparticles. These results highlight the trapping efficiency in the interphase region introduced by the small BN nanofillers (<100 nm) and provides evidence as to the huge nanodielectric effects on the charge carrier transport controlled by the nanoparticle diameter. This finding should be of great importance for advanced high temperature electrical insulation in the future.

  20. Synovial sarcoma presenting with huge mediastinal mass: a case report and review of literature

    Science.gov (United States)

    2013-01-01

    Background Synovial sarcoma presenting in the mediastinum is exceedingly rare. Furthermore, data addressing optimal therapy is limited. Herein we present a case where an attempt to downsize the tumor to a resectable state with chemotherapy was employed. Case presentation A 32 year female presented with massive pericardial effusion and unresectable huge mediastinal mass. Computed axial tomography scan - guided biopsy with adjunctive immunostains and molecular studies confirmed a diagnosis of synovial sarcoma. Following three cycles of combination Ifosfamide and doxorubicin chemotherapy, no response was demonstrated. The patient refused further therapy and had progression of her disease 4 months following the last cycle. Conclusion Synovial sarcoma presenting with unresectable mediastinal mass carry a poor prognosis. Up to the best of our knowledge there are only four previous reports where primary chemotherapy was employed, unfortunately; none of these cases had subsequent complete surgical resection. Identification of the best treatment strategy for patients with unresectable disease is warranted. Our case can be of benefit to medical oncologists and thoracic surgeons who might be faced with this unique and exceedingly rare clinical scenario. PMID:23800262

  1. Unexpected Huge Dimerization Ratio in One-Dimensional Carbon Atomic Chains.

    Science.gov (United States)

    Lin, Yung-Chang; Morishita, Shigeyuki; Koshino, Masanori; Yeh, Chao-Hui; Teng, Po-Yuan; Chiu, Po-Wen; Sawada, Hidetaka; Suenaga, Kazutomo

    2017-01-11

    Peierls theory predicted atomic distortion in one-dimensional (1D) crystal due to its intrinsic instability in 1930. Free-standing carbon atomic chains created in situ in transmission electron microscope (TEM)1-3 are an ideal example to experimentally observe the dimerization behavior of carbon atomic chain within a finite length. We report here a surprisingly huge distortion found in the free-standing carbon atomic chains at 773 K, which is 10 times larger than the value expected in the system. Such an abnormally distorted phase only dominates at the elevated temperatures, while two distinct phases, distorted and undistorted, coexist at lower or ambient temperatures. Atom-by-atom spectroscopy indeed shows considerable variations in the carbon 1s spectra at each atomic site but commonly observes a slightly downshifted π* peak, which proves its sp(1) bonding feature. These results suggest that the simple model, relaxed and straight, is not fully adequate to describe the realistic 1D structure, which is extremely sensitive to perturbations such as external force or boundary conditions.

  2. A Huge Capital Drop with Compression of Femoral Vessels Associated with Hip Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Tomoya Takasago

    2015-01-01

    Full Text Available A capital drop is a type of osteophyte at the inferomedial portion of the femoral head commonly observed in hip osteoarthritis (OA, secondary to developmental dysplasia. Capital drop itself is typically asymptomatic; however, symptoms can appear secondary to impinge against the acetabulum or to irritation of the surrounding tissues, such as nerves, vessels, and tendons. We present here a case of unilateral leg edema in a patient with hip OA, caused by a huge bone mass occurring at the inferomedial portion of the femoral head that compressed the femoral vessels. We diagnosed this bone mass as a capital drop secondary to hip OA after confirming that the mass occurred at least after the age of 63 years based on a previous X-ray. We performed early resection and total hip arthroplasty since the patient’s hip pain was due to both advanced hip OA and compression of the femoral vessels; moreover, we aimed to prevent venous thrombosis secondary to vascular compression considering the advanced age and the potent risk of thrombosis in the patient. A large capital drop should be considered as a cause of vascular compression in cases of unilateral leg edema in OA patients.

  3. Acute abdomen in early pregnancy caused by torsion of bilateral huge multiloculated ovarian cysts

    Directory of Open Access Journals (Sweden)

    Sathiyakala Rajendran

    2015-10-01

    Full Text Available The association of pregnancy and torsion of bilateral huge benign ovarian cyst is rare. We report a case of multigravida at 13 weeks of pregnancy presenting with acute onset of lower abdominal pain. Ultrasound revealed bilateral multiloculated ovarian cysts of size 10x10 cm on right side and 15x10cm on left side with evidence of torsion and a single live intrauterine fetus of gestational age 13 weeks 4 days. Emergency laparotomy was done with vaginal susten 200 mg as perioperative tocolysis. Intra operatively, uterus was enlarged to 14 weeks size. Both ovaries were replaced with multiloculated cysts of size 15x10 cm on left side and 10x10 cm on right side. Ovarian pedicle was found to be twisted once on right side and twice on left side. On right side, untwisting of pedicle was done and the ovarian cyst was punctured at multiple sites to drain the clear fluid. Biopsy was taken from the right ovarian cyst wall. On left side, ovariotomy was done. Histopathology revealed mucinous cyst adenoma of left ovary and multiple corpus luteum in right ovarian biopsy specimen. The patient was followed up with regular antenatal check-ups and ultrasound to rule out the recurrence of ovarian cyst on right side. The patient successfully delivered a term male baby at 39 weeks. [Int J Reprod Contracept Obstet Gynecol 2015; 4(5.000: 1598-1601

  4. Propranolol in Treatment of Huge and Complicated Infantile Hemangiomas in Egyptian Children

    Directory of Open Access Journals (Sweden)

    Basheir A. Hassan

    2014-01-01

    Full Text Available Background. Infantile hemangiomas (IHs are the most common benign tumours of infancy. Propranolol has recently been reported to be a highly effective treatment for IHs. This study aimed to evaluate the efficacy and side effects of propranolol for treatment of complicated cases of IHs. Patients and Methods. This prospective clinical study included 30 children with huge or complicated IHs; their ages ranged from 2 months to 1 year. They were treated by oral propranolol. Treatment outcomes were clinically evaluated. Results. Superficial cutaneous hemangiomas began to respond to propranolol therapy within one to two weeks after the onset of treatment. The mean treatment period that was needed for the occurrence of complete resolution was 9.4 months. Treatment with propranolol was well tolerated and had few side effects. No rebound growth of the tumors was noted when propranolol dosing stopped except in one case. Conclusion. Propranolol is a promising treatment for IHs without obvious side effects. However, further studies with longer follow-up periods are needed.

  5. Computational AstroStatistics Fast and Efficient Tools for Analysing Huge Astronomical Data Sources

    CERN Document Server

    Nichol, R C; Connolly, A J; Davies, S; Genovese, C; Hopkins, A M; Miller, C J; Moore, A W; Pelleg, D; Richards, G T; Schneider, J; Szapudi, I; Wasserman, L H

    2001-01-01

    I present here a review of past and present multi-disciplinary research of the Pittsburgh Computational AstroStatistics (PiCA) group. This group is dedicated to developing fast and efficient statistical algorithms for analysing huge astronomical data sources. I begin with a short review of multi-resolutional kd-trees which are the building blocks for many of our algorithms. For example, quick range queries and fast n-point correlation functions. I will present new results from the use of Mixture Models (Connolly et al. 2000) in density estimation of multi-color data from the Sloan Digital Sky Survey (SDSS). Specifically, the selection of quasars and the automated identification of X-ray sources. I will also present a brief overview of the False Discovery Rate (FDR) procedure (Miller et al. 2001a) and show how it has been used in the detection of ``Baryon Wiggles'' in the local galaxy power spectrum and source identification in radio data. Finally, I will look forward to new research on an automated Bayes Netw...

  6. Distributed data organization and parallel data retrieval methods for huge laser scanner point clouds

    Science.gov (United States)

    Hongchao, Ma; Wang, Zongyue

    2011-02-01

    This paper proposes a novel method for distributed data organization and parallel data retrieval from huge volume point clouds generated by airborne Light Detection and Ranging (LiDAR) technology under a cluster computing environment, in order to allow fast analysis, processing, and visualization of the point clouds within a given area. The proposed method is suitable for both grid and quadtree data structures. As for distribution strategy, cross distribution of the dataset would be more efficient than serial distribution in terms of non-redundant datasets, since a dataset is more uniformly distributed in the former arrangement. However, redundant datasets are necessary in order to meet the frequent need of input and output operations in multi-client scenarios: the first copy would be distributed by a cross distribution strategy while the second (and later) would be distributed by an iterated exchanging distribution strategy. Such a distribution strategy would distribute datasets more uniformly to each data server. In data retrieval, a greedy algorithm is used to allocate the query task to a data server, where the computing load is lightest if the data block needing to be retrieved is stored among multiple data servers. Experiments show that the method proposed in this paper can satisfy the demands of frequent and fast data query.

  7. Series resistance mapping of Cu(In,Ga)Se{sub 2} solar cells by voltage dependent electroluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Daume, Felix; Puttnins, Stefan [Solarion AG, Ostende 5, 04288 Leipzig (Germany); Institut fuer Experimentelle Physik II, Universitaet Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Scheit, Christian; Rahm, Andreas [Solarion AG, Ostende 5, 04288 Leipzig (Germany); Grundmann, Marius [Institut fuer Experimentelle Physik II, Universitaet Leipzig, Linnestr. 5, 04103 Leipzig (Germany)

    2011-07-01

    Cu(In,Ga)Se{sub 2} (CIGSe) thin film solar cells deposited on flexible polyimide foil promising innovative applications and a fabrication in continuous roll-to-roll processes currently reach efficiencies up to 17.6 %. The optimization of the solar cell efficiency requires the reduction of inherent losses in the cell. In order to achieve this goal preferably spatially resolved access to parameters characterizing ohmic losses like series and shunt resistances are indispensable. We apply an interpretation method for electroluminescence (EL) images taken at different voltages which is known for solar cells made of crystalline silicon from literature to solar cells made of polycrystalline CIGSe. The theory of this method to obtain a mapping of the series resistance and the EL imaging process as well as the data interpretation ils reviewed and demonstrated on an example. Furthermore, the benefit of this method for the characterization of solar cells under accelerated aging conditions (damp heat) which is important for the estimation of the long-term stability is shown.

  8. Indium-Induced Effect on Polarized Electroluminescence from InGaN/GaN MQWs Light Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    RUAN Jun; YU Tong-Jun; JIA Chuan-Yu; TAO Ren-Chun; WANG Zhan-Guo; ZHANG Guo-Yi

    2009-01-01

    Polarization-resolved edge-emitting electroluminescence (EL) studies of InGaN/GaN MQWs of wavelengths from near-UV (390nm) to blue (468nm) light-emitting diodes (LEDs) are performed.Although the TE mode is dominant in all the samples of InGaN/GaN MQW LEDs,an obvious difference of light polarization properties is found in the InGaN/GaN MQW LEDs with different wavelengths.The polarization degree decreases from 52.4% to 26.9% when light wavelength increases.Analyses of band structures of InGaN/GaN quantum wells and luminescence properties of quantum dots imply that quantum-dot-like behavior is the dominant reason for the low luminescence polarization degree of blue LEDs,and the high luminescence polarization degree of UV LEDs mainly comes from QW confinement and the strain effect.Therefore,indium induced carrier confinement (quantum-dot-like behavior) might play a major role in the polarization degree change of InGaN/GaN MQW LEDs from near violet to blue.

  9. Electroluminescence and Photoluminescence from Scored Si-Rich SiO2 Film/p-Si Structure

    Institute of Scientific and Technical Information of China (English)

    冉广照; 孙永科; 陈源; 戴伦; 崔晓明; 张伯蕊; 乔永平; 马振昌; 宗婉华; 秦国刚

    2003-01-01

    Electroluminescence (EL) is observed from the Au/Si-rich SiO2 film/p-Si diodes, in which the Si-rich SiO2 films are scored deliberately by a diamond tip. The EL intensity of the scored diode annealed at 800°C is about 6times of that of the unscored counterpart. The EL spectrum of the unscored diode could be decomposed into two Gaussian luminescence bands with peaks at about 1.83 and 2.23 eV, while for the EL spectrum of the scored diode, an additional Gaussian band at about 3.0eV appears, and the 1.83-eV peak increases significantly in intensity. The photoluminescence (PL) spectrum of an unscored Si-rich SiO2 film has only one band peaking at about 1.48eV, whereas the PL spectrum of the scored one has two bands at about 1.48 and 1.97eV. We consider that the high-density defect regions produced by the scoring provide new luminescence centres and become some types of nonradiative centres in the Si oxide layer, which thus result in changes of the EL and PL spectra.

  10. Electroluminescence and Photoluminescence from Scored Si-Rich SiO2 Film/p-Si Structure

    Science.gov (United States)

    Ran, Guang-Zhao; Sun, Yong-Ke; Chen, Yuan; Dai, Lun; Cui, Xiao-Ming; Zhang, Bo-Rui; Qiao, Yong-Ping; Ma, Zhen-Chang; Zong, Wan-Hua; Qin, Guo-Gang

    2003-02-01

    Electroluminescence (EL) is observed from the Au/Si-rich SiO2 film/p-Si diodes, in which the Si-rich SiO2 films are scored deliberately by a diamond tip. The EL intensity of the scored diode annealed at 800°C is about 6 times of that of the unscored counterpart. The EL spectrum of the unscored diode could be decomposed into two Gaussian luminescence bands with peaks at about 1.83 and 2.23 eV, while for the EL spectrum of the scored diode, an additional Gaussian band at about 3.0 eV appears, and the 1.83-eV peak increases significantly in intensity. The photoluminescence (PL) spectrum of an unscored Si-rich SiO2 film has only one band peaking at about 1.48 eV, whereas the PL spectrum of the scored one has two bands at about 1.48 and 1.97 eV. We consider that the high-density defect regions produced by the scoring provide new luminescence centres and become some types of nonradiative centres in the Si oxide layer, which thus result in changes of the EL and PL spectra.

  11. Large Size Color-tunable Electroluminescence from Cationic Iridium Complexes-based Light-emitting Electrochemical Cells

    Science.gov (United States)

    Zeng, Qunying; Li, Fushan; Guo, Tailiang; Shan, Guogang; Su, Zhongmin

    2016-06-01

    Solution-processable light-emitting electrochemical cells (LECs) with simple device architecture have become an attractive candidate for application in next generation lighting and flat-panel displays. Herein, single layer LECs employing two cationic Ir(III) complexes showing highly efficient blue-green and yellow electroluminescence with peak current efficiency of 31.6 cd A‑1 and 40.6 cd A‑1, respectively, have been reported. By using both complexes in the device, color-tunable LECs with a single spectral peak in the wavelength range from 499 to 570 nm were obtained by varying their rations. In addition, the fabrication of efficient LECs was demonstrated based on low cost doctor-blade coating technique, which was compatible with the roll to roll fabrication process for the large size production. In this work, for the first time, 4 inch LEC devices by doctor-blade coating were fabricated, which exhibit the efficiencies of 23.4 cd A‑1 and 25.4 cd A‑1 for the blue-green and yellow emission, respectively. The exciting results indicated that highly efficient LECs with controllable color could be realized and find practical application in large size lighting and displays.

  12. Effect of n-type doping level on direct band gap electroluminescence intensity for asymmetric metal/Ge/metal diodes

    Science.gov (United States)

    Maekura, T.; Tanaka, K.; Motoyama, C.; Yoneda, R.; Yamamoto, K.; Nakashima, H.; Wang, D.

    2017-10-01

    The direct band gap electroluminescence (EL) intensity was investigated for asymmetric metal/Ge/metal diodes fabricated on n-type Ge with doping levels in the range of 4.0 × 1013-3.1 × 1018 cm-3. Up to a doping level of 1016 cm-3 order, commercially available (100) n-Ge substrates were used. To obtain a doping level higher than 1017 cm-3 order, which is commercially unavailable, n+-Ge/p-Ge structures were fabricated by Sb doping on p-type (100) Ge substrates with an in-diffusion at 600 °C followed by a push-diffusion at 700 °C-850 °C. The EL intensity was increased with increasing doping level up to 1.0 × 1018 cm-3. After that, it was decreased with a further increase in n-type doping level. This EL intensity decrease is explained by the decreased number of holes in the active region. One reason is the difficulty in hole injection through the PtGe/n-Ge contact due to the occurring of tunneling electron current. Another reason is the loss of holes caused by both the small thickness of n+-Ge layer and the existence of n+p junction.

  13. Sharp green electroluminescence from 1H-pyrazolo[3,4-b]quinoline-based light-emitting diodes

    Science.gov (United States)

    Tao, Y. T.; Balasubramaniam, E.; Danel, A.; Jarosz, B.; Tomasik, P.

    2000-09-01

    A multilayer organic light-emitting diode was fabricated using a fluorescent compound {6-N,N-diethylamino-1-methyl-3-phenyl-1H-pyrazolo[3,4-b]quinoline} (PAQ-NEt2) doped into the hole-transporting layer of NPB {4,4'-bis[N-(1-naphthyl-1-)-N-phenyl-amino]-biphenyl}, with the TPBI {2,2',2″-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole]} as an electrontransporting material. At 16% PAQ-NEt2 doping concentration, the device gave a sharp, bright, and efficient green electroluminescence (EL) peaked at around 530 nm. The full width at half maximum of the EL is 60 nm, which is 60% of the green emission from typical NPB/AlQ [where AlQ=tris(8-hydroxyquinoline) aluminum] device. For the same concentration, a maximum luminance of 37 000 cd/m2 was obtained at 10.0 V and the maximum power, luminescence, and external quantum efficiencies were obtained 4.2 lm/W, 6.0 cd/A, and 1.6%, respectively, at 5.0 V.

  14. Endovascular Treatment of the Huge Dissecting Aneurysms Involving the Basilar Artery by the Internal Trapping Technique: Technical Note

    Directory of Open Access Journals (Sweden)

    Shi-Qing Mu

    2015-01-01

    Full Text Available Background: The endovascular strategy of the huge dissecting aneurysms involving the basilar artery (BA is controversial and challenging. This study was to investigate the clinical and angiographic outcomes of the treatment of the huge dissecting aneurysms involving the BA by the internal trapping (IT technique. Methods: We retrospectively studied 15 patients with the huge dissecting aneurysms involving the BA treated by the IT technique between September 2005 and September 2014 in Department of Interventional Neuroradiology of Beijing Tiantan Hospital. Clinical and angiographic data were reviewed and evaluated. Results: All patients were treated by the IT technique. That meant the dissecting artery and aneurysm segments were completed occlusion. After the procedure, the angiography demonstrated that all the dissecting artery and aneurysm segments were completed occlusion. Follow-up angiography was performed at 3-6 months or 12-18 months after the endovascular treatment (median 8 months, 14 patients had a good recovery. Re-canalization occurred in one patient whose aneurysm involved in bilateral vertebral arteries and the two third of the middle-lower BA. After the second treatment, the patient died by the ventricular tachycardia. Conclusions: The IT technique is a technically feasible and safe alternative for the treatment of BA dissecting aneurysms, but it is not necessarily the safest or most definitive treatment modality. The ideal treatment of the huge dissecting aneurysms involving the BA remains debatable and must be investigated on a case-by-case basis.

  15. Endovascular Treatment of the Huge Dissecting Aneurysms Involving the Basilar Artery by the Internal Trapping Technique: Technical Note

    Institute of Scientific and Technical Information of China (English)

    Shi-Qing Mu; Xin-Jian Yang; You-Xiang Li; Chu-Han Jiang; Zhong-Xue Wu

    2015-01-01

    Background:The endovascular strategy of the huge dissecting aneurysms involving the basilar artery (BA) is controversial and challenging.This study was to investigate the clinical and angiographic outcomes of the treatment of the huge dissecting aneurysms involving the BA by the internal trapping (IT) technique.Methods:We retrospectively studied 15 patients with the huge dissecting aneurysms involving the BA treated by the IT technique between September 2005 and September 2014 in Department of lnterventional Neuroradiology of Beijing Tiantan Hospital.Clinical and angiographic data were reviewed and evaluated.Results:All patients were treated by the IT technique.That meant the dissecting artery and aneurysm segments were completed occlusion.After the procedure,the angiography demonstrated that all the dissecting artery and aneurysm segments were completed occlusion.Follow-up angiography was performed at 3-6 months or 12-18 months after the endovascular treatment (median 8 months),14 patients had a good recovery.Re-canalization occurred in one patient whose aneurysm involved in bilateral vertebral arteries and the two third of the middle-lower BA.After the second treatment,the patient died by the ventricular tachycardia.Conclusions:The IT technique is a technically feasible and safe alternative for the treatment of BA dissecting aneurysms,but it is not necessarily the safest or most definitive treatment modality.The ideal treatment of the huge dissecting aneurysms involving the BA remains debatable and must be investigated on a case-by-case basis.

  16. Treating Huge Tear-Drop Fracture of Axis With Trapezoidal Bone: A Case Report and Literature Review.

    Science.gov (United States)

    Yang, Xiaobin; Zheng, Bolong; Hao, Dingjun; Liu, Benyin; Yan, Liang; He, Baorong

    2015-11-01

    Case report and review of relevant literature. To discuss the surgical strategies and clinical outcome of managing huge tear drop fracture of axis. Teardrop fracture of axis is rarely seen, especially the huge type. The surgical technique is demanding because of the special anatomical structure and difficulty with bone grafting. Moreover, the surgical approach is controversial in the literature. A 51-year-old male patient suffered from neck pain after falling from the bicycle, neck movement was limited with no neurological compromise. X-ray suggested huge tear-drop fracture of anterior-inferior corner of axis, narrowing of C2/3 intervertebral disc. Fusion with self-designed tricortical trapezoidal iliac bone was performed. Treating huge teardrop fracture of axis by anterior bone grafting with self-designed tricortical trapezoidal iliac bone is effective and stable. A 3-month follow-up showed fusion was achieved, upper cervical curvature was restored, and neck pain disappeared. Self-designed tricortical trapezoidal iliac bone provided adequate fusion area of bone grafting, restoring the normal intervertebral height and cervical alignment, and the midterm outcome is satisfactory. 5.

  17. Huge pseudomyxoma peritonei: Surgical strategies and procedures to employ to optimize the rate of complete cytoreductive surgery.

    Science.gov (United States)

    Benhaim, L; Honoré, C; Goéré, D; Delhorme, J-B; Elias, D

    2016-04-01

    Complete cytoreductive surgery (CCRS) plus Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is the best-known treatment for pseudomyxoma peritonei (PMP). In 30% of the cases, PMP realize a widespread involvement of the peritoneal cavity. In these extreme situations, we developed, devoted strategies to optimize the feasibility and safety of CCRS. This study describes the surgical resections required for CCRS and the consequent approaches that we propose to achieve CCRS. We defined "huge PMP" by a peritoneal cancer index (PCI) ≥ 28. Surgical procedures of patients operated on between 1994 and 2014 were retrospectively reviewed from a prospective database in a single institution. During this period, 311 patients were operated on and 247 (79%) underwent CCRS + HIPEC. Among them, 100 patients presented "huge" PMP and 54 patients underwent CCRS + HIPEC. In patients with "huge" PMP, the rate of CCRS + HIPEC was 25% before 2002 and reached 71% between 2011 and 2014. We identified 3 conditions for CCRS 1) to guaranty a sufficient length of residual small bowel 2) to preserve the left gastric vessels in order to preserve the superior third of the stomach 3) to ensure that the hepatic pedicle can be entirely cleared from its tumor involvement. None of the other peritonectomy procedures were decisional for CCRS. Our learning curve improved the selection and completion rate of CCRS + HIPEC for "huge PMP". Some anatomical and physiological prerequisites guarantee the feasibility and safety of such extensive surgeries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Endovascular Treatment of the Huge Dissecting Aneurysms Involving the Basilar Artery by the Internal Trapping Technique: Technical Note.

    Science.gov (United States)

    Mu, Shi-Qing; Yang, Xin-Jian; Li, You-Xiang; Jiang, Chu-Han; Wu, Zhong-Xue

    2015-07-20

    The endovascular strategy of the huge dissecting aneurysms involving the basilar artery (BA) is controversial and challenging. This study was to investigate the clinical and angiographic outcomes of the treatment of the huge dissecting aneurysms involving the BA by the internal trapping (IT) technique. We retrospectively studied 15 patients with the huge dissecting aneurysms involving the BA treated by the IT technique between September 2005 and September 2014 in Department of Interventional Neuroradiology of Beijing Tiantan Hospital. Clinical and angiographic data were reviewed and evaluated. All patients were treated by the IT technique. That meant the dissecting artery and aneurysm segments were completed occlusion. After the procedure, the angiography demonstrated that all the dissecting artery and aneurysm segments were completed occlusion. Follow-up angiography was performed at 3-6 months or 12-18 months after the endovascular treatment (median 8 months), 14 patients had a good recovery. Re-canalization occurred in one patient whose aneurysm involved in bilateral vertebral arteries and the two third of the middle-lower BA. After the second treatment, the patient died by the ventricular tachycardia. The IT technique is a technically feasible and safe alternative for the treatment of BA dissecting aneurysms, but it is not necessarily the safest or most definitive treatment modality. The ideal treatment of the huge dissecting aneurysms involving the BA remains debatable and must be investigated on a case-by-case basis.

  19. Is hepatectomy for huge hepatocellular carcinoma (≥ 10 cm in diameter) safe and effective? A single-center experience.

    Science.gov (United States)

    Yang, Jian; Li, Chuan; Wen, Tian-Fu; Yan, Lu-Nan; Li, Bo; Wang, Wen-Tao; Yang, Jia-Yin; Xu, Ming-Qing

    2014-01-01

    This retrospective study aimed to validate the safety and effectiveness of hepatectomy for huge hepatocellular carcinoma (HCC). Data of patients who underwent hepatectomy for HCC between January 2006 and December 2012 were reviewed. The patients were divided into three groups: huge HCC(≥ 10 cm in diameter), large HCC(≥ 5 buthuge and large HCC groups were lower than that of the small HCC group (OS: 32.5% vs 36.3% vs 71.2%, p=0.000; DFS: 20.0% vs 24.8% vs 40.7%, p=0.039), but there was no difference between the huge and large HCC groups (OS: 32.5% vs 36.3%, p=0.667; DFS: 20.0% vs 24.8%, p=0.540). In multivariate analysis, five independent poor prognostic factors that affected OS were significantly associated with worse survival (phuge HCC is similar to that for large and small HCC; and this approach for huge HCC may achieve similar long-term survival and disease-free survival as for large HCC.

  20. Flume tests to study the initiation of huge debris flows after the Wenchuan earthquake in S-WChina

    NARCIS (Netherlands)

    Hu, Wei; Xu, Qiang; van Asch, Theo.W.J.; Zhua, X; Xu, Q.Q.

    2014-01-01

    In the Wenchuan area in the southwest of China, a huge amount of loose co-seismic landslide material was deposited on slopes during the Wenchuan earthquake of May 2008. These loose deposits formed the source material for rainfall-induced debris flows or shallow landslides in the years after the eart

  1. Clinicopathological profile, airway management, and outcome in huge multinodular goiters: an institutional experience from an endemic goiter region.

    Science.gov (United States)

    Agarwal, Amit; Agarwal, Sudhi; Tewari, Prabhat; Gupta, Sushil; Chand, Gyan; Mishra, Anjali; Agarwal, Gaurav; Verma, A K; Mishra, S K

    2012-04-01

    Huge goiters are common in iodine-deficient endemic regions. They are of concern to the surgeons because of the anticipated risk of difficult dissection and increased chances of surgical complications. Similarly, they are of concern to the anesthesiologists because of anticipated intubation-related difficulties and post-thyroidectomy tracheomalacia. In the present study we aimed to present our experience of managing goiters based on their gross weight, highlighting their clinicopathological profile, perioperative airway-related difficulties, and management of surgical morbidity. Retrospective analysis of patients who underwent total thyroidectomy in the primary setting at our institute from 1995 to 2009 was carried out based on the gross gland weight. The patients were thus grouped into group A: ≤200 g; group B: 201 to ≤400 g; group C: 401 to ≤600 g; group D: >600 g. Group A (660 cases); group B (108 cases); group C (36 cases); and group D (9 cases) were included. As the goiter size increased, the mean duration of goiter, compressive symptoms, retrosternal extension (RSE), airway deformity, intubation difficulty, and tracheomalacia increased. The rate of tracheostomy, sternotomy, hemorrhage, visceral injury, and hospital stay was high with huge goiters. These features were more marked in malignant goiters compared to benign goiters. However, the postoperative complications were comparable in both of those groups. Long-standing huge goiters are common in iodine-deficient endemic areas. The majority of patients have symptomatic or clinicoradiological evidence of airway involvement. The incidence of RSE, airway deformity, intubation difficulty, and tracheomalacia is high with huge goiters. The surgery is technically demanding with greater associated chances of injury to native structures. Malignancy influences the presentation and outcome in smaller goiters. In centers with experienced endocrine surgeons and dedicated anesthetists, huge goiters can be

  2. Thickness effects of SiO xN y interlayer inserted between BaTiO 3 insulating layer and ZnS:Mn phosphor layer in thin film electroluminescent devices

    Science.gov (United States)

    Song, M. H.; Lee, Y. H.; Hahn, T. S.; Oh, M. H.; Yoon, K. H.

    1996-09-01

    We investigated the effects of a SiO xN y interlayer on a thin film electroluminescent device, inserted between an amorphous BaTiO 3 thin film and a ZnS:Mn phosphor layer. The effects on the thin film electroluminescent device was studied as a function of the thickness of the interlayer. We found that the introduction of the interlayer affected the growth behavior of the phosphor layer. With increasing thickness of the interlayer, the average grain size and the crystallinity of the phosphor layer was improved. The turn-on voltage of the electroluminescent device increased, and the saturation brightness slightly decreased with increasing interlayer thickness. In the case of the TFELD without the interlayer, Poole-Frenkel conduction was observed in the low dc field region, the devices with the interlayer exhibited effective electron tunneling from interface traps. The efficiency of the devices increased with increasing interlayer thickness.

  3. Discrimination between spin-dependent charge transport and spin-dependent recombination in π-conjugated polymers by correlated current and electroluminescence-detected magnetic resonance

    Science.gov (United States)

    Kavand, Marzieh; Baird, Douglas; van Schooten, Kipp; Malissa, Hans; Lupton, John M.; Boehme, Christoph

    2016-08-01

    Spin-dependent processes play a crucial role in organic electronic devices. Spin coherence can give rise to spin mixing due to a number of processes such as hyperfine coupling, and leads to a range of magnetic field effects. However, it is not straightforward to differentiate between pure single-carrier spin-dependent transport processes which control the current and therefore the electroluminescence, and spin-dependent electron-hole recombination which determines the electroluminescence yield and in turn modulates the current. We therefore investigate the correlation between the dynamics of spin-dependent electric current and spin-dependent electroluminescence in two derivatives of the conjugated polymer poly(phenylene-vinylene) using simultaneously measured pulsed electrically detected (pEDMR) and optically detected (pODMR) magnetic resonance spectroscopy. This experimental approach requires careful analysis of the transient response functions under optical and electrical detection. At room temperature and under bipolar charge-carrier injection conditions, a correlation of the pEDMR and the pODMR signals is observed, consistent with the hypothesis that the recombination currents involve spin-dependent electronic transitions. This observation is inconsistent with the hypothesis that these signals are caused by spin-dependent charge-carrier transport. These results therefore provide no evidence that supports earlier claims that spin-dependent transport plays a role for room-temperature magnetoresistance effects. At low temperatures, however, the correlation between pEDMR and pODMR is weakened, demonstrating that more than one spin-dependent process influences the optoelectronic materials' properties. This conclusion is consistent with prior studies of half-field resonances that were attributed to spin-dependent triplet exciton recombination, which becomes significant at low temperatures when the triplet lifetime increases.

  4. White Polymer Light-Emitting Diodes Based on Exciplex Electroluminescence from Polymer Blends and a Single Polymer.

    Science.gov (United States)

    Liang, Junfei; Zhao, Sen; Jiang, Xiao-Fang; Guo, Ting; Yip, Hin-Lap; Ying, Lei; Huang, Fei; Yang, Wei; Cao, Yong

    2016-03-01

    In this Article, we designed and synthesized a series of polyfluorene derivatives, which consist of the electron-rich 4,4'-(9-alkyl-carbazole-3,6-diyl)bis(N,N-diphenylaniline) (TPA-Cz) in the side chain and the electron-deficient dibenzothiophene-5,5-dioxide (SO) unit in the main chain. The resulting copolymer PF-T25 that did not comprise the SO unit exhibited blue light-emission with the Commission Internationale de L'Eclairage coordinates of (0.16, 0.10). However, by physically blending PF-T25 with a blue light-emitting SO-based oligomer, a novel low-energy emission correlated to exciplex emerged due to the appropriate energy level alignment of TPA-Cz and the SO-based oligomers, which showed extended exciton lifetime as confirmed by time-resolved photoluminescent spectroscopy. The low-energy emission was also identified in copolymers consisting of SO unit in the main chain, which can effectively compensate for the high-energy emission to produce binary white light-emission. Polymer light-emitting diodes based on the exciplex-type single greenish-white polymer exhibit the peak luminous efficiency of 2.34 cd A(-1) and the maximum brightness of 12 410 cd m(-2), with Commission Internationale de L'Eclairage color coordinates (0.27, 0.39). The device based on such polymer showed much better electroluminescent stability than those based on blending films. These observations indicated that developing a single polymer with the generated exciplex emission can be a novel and effective molecular design strategy toward highly stable and efficient white polymer light-emitting diodes.

  5. Efficient Deep-Blue Electroluminescence Based on Phenanthroimidazole-Dibenzothiophene Derivatives with Different Oxidation States of the Sulfur Atom.

    Science.gov (United States)

    Tang, Xiangyang; Shan, Tong; Bai, Qing; Ma, Hongwei; He, Xin; Lu, Ping

    2017-03-02

    Developing efficient deep-blue materials is a long-term research focus in the field of organic light-emitting diodes (OLEDs). In this paper, we report two deep-blue molecules, PITO and PISF, which share similar chemical structures but exhibit different photophysical and device properties. These two molecules consist of phenanthroimidazole and dibenzothiophene analogs. The distinction of their chemical structures lies in the different oxidation states of the S atom. For PITO, the S atom is oxidized and the resulting structure dibenzothiophene S,S-dioxide becomes electron deficient. Therefore, PITO displays remarkable solvatochromism, implying a charge-transfer (CT) excited state formed between the donor (D) phenanthroimidazole and acceptor (A) dibenzothiophene S,S-dioxide. For PISF, it is constituted of phenanthroimidazole and dibenzothiophene in which the S atom is not oxidized. PISF displays locally excited (LE) emission with little solvatochromism. Compared with PISF, the D-A molecule PITO with an electron-deficient group shows a much lower LUMO energy level, which is in favor of electron injection in device. In addition, PITO exhibits more balanced carrier transport. However, PISF is capable of emitting in the shorter wavelength region, which is beneficial to obtain better color purity. The doped electroluminescence (EL) device of the D-A molecule PITO manifests deep-blue emission with CIE coordinates of (0.15, 0.08) and maximum external quantum efficiency (EQE) of 4.67 %. The doped EL device of the LE molecule PISF, however, reveals an even bluer emission with CIE coordinates of (0.15, 0.06) and a maximum EQE of 4.08 %.

  6. Electrical properties of III-Nitride LEDs: Recombination-based injection model and theoretical limits to electrical efficiency and electroluminescent cooling

    Science.gov (United States)

    David, Aurelien; Hurni, Christophe A.; Young, Nathan G.; Craven, Michael D.

    2016-08-01

    The current-voltage characteristic and ideality factor of III-Nitride quantum well light-emitting diodes (LEDs) grown on bulk GaN substrates are investigated. At operating temperature, these electrical properties exhibit a simple behavior. A model in which only active-region recombinations have a contribution to the LED current is found to account for experimental results. The limit of LED electrical efficiency is discussed based on the model and on thermodynamic arguments, and implications for electroluminescent cooling are examined.

  7. Synthesis, characterization, photoluminescence and electroluminescence properties of new 1,3,4-oxadiazole-containing rhenium(Ⅰ)complex Re(CO)3(Bphen)(PTOP)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new 1,3,4-oxadiazole-contanining rhenium(Ⅰ) complex, with the formula [Re(CO)3(Bphen)(PTOP)], (Bphen = bathophenardine, PTOP = 4-(5-p-tolyl-1, 3, 4-oxadiazd-2-yl) pyridine), is synthesized and characterized by elemental analysis, IR, 1H NMR,UV-vis and luminescence spectroscopy. The double-layer electroluminescence devices based on the Re(Ⅰ) complex have been fabricated by spin-coating technique. The turn-on voltage, maximum efficiency, and brightness for green emission obtained from the devices are 9 V, 2.1 cd/A and 165 cd/m2, respectively.

  8. Electroluminescence of a Multi-Layered Organic Light-Emitting Diode Utilizing Trans-4-[p-[Nmethyl-N-(hydroxymethyl)amino]styryl]-N-Methylphridinium Tetraphenylborate as the Active Layer

    Institute of Scientific and Technical Information of China (English)

    FENG Xue-Yuan; ZHANG Jia-Yu; XU Chun-Xiang; QIAO Yi; GUI Yi-Ping

    2006-01-01

    Employing an organic dye salt oftrans-4-[p-[N-methyl-N-(hydroxymethyl)amino]styryl]-N-methylphridinium tetraphenylborate (ASPT) as the active layer, 8-hydrocyquinoline aluminium (Alqa) as the electron transporting layer and N,Nt-diphenyl-N,Nl-bis(3-methylphenyl)-[l,l'-biphenyl]-4,4'-diamine (TPD) as the hole transporting layer, respectively, we fabricate a multi-layered organic light-emitting diode and observe the colour tunable electroluminescence (EL). The dependence of the EL spectra on the applied voltage is investigated in detail, and the recombination mechanism is discussed by considering the variation of the hole-electron recombination region.

  9. Analysis of the electroluminescence features of silicon metal-insulator-semiconductor structures as a tool for diagnostics of the injection properties of a dielectric layer

    Science.gov (United States)

    Illarionov, Yu. Yu.; Vexler, M. I.; Isakov, D.; Fedorov, V. V.; Sing, Yew Kwang

    2013-10-01

    A technique for diagnostics of the injection properties of thin dielectric layers based on analysis of the data on silicon electroluminescence in a metal-insulator-semiconductor structure is proposed. The possibility of applying this technique to control the electron injection energy (in particular, when the barrier parameters are poorly known) is demonstrated by the example of samples with CaF2 and HfO2/SiO2. The results obtained are important for application of the insulators under study in microelectronic devices.

  10. Synthesis, photophysics, electrochemistry, thermal stability and electroluminescent performances of a new europium complex with bis(β-diketone) ligand containing carbazole group.

    Science.gov (United States)

    Liu, Jian; Liang, Quan-Bin; Wu, Hong-Bin

    2016-09-07

    We synthesized a new europium complex [Eu(ecbpd)3 (Phen)] with bis(β-diketone) ligand containing a carbazole group, in which ecbpd and Phen are dehydro-3,3'-(9-ethyl-9H-carbazole-3,6-diyl)bis(1-phenylpropane-1,3-dione) and 1,10-phenanthroline, respectively. Its UV/vis and photoluminescent spectra, quantum yield, luminescence lifetime, electrochemistry, thermal stability and electroluminescent performances were studied. This europium complex showed low efficiency luminescence, which is probably due to the mismatching energy levels of its ligand and Eu(3)(+) , as well as the double Eu(3)(+) core resonance.

  11. Osmium Complexes Useful in the Preparation of Metal Thin Film and Highly Efficient Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    Yun Chi

    2004-01-01

    Treatment of β-diketone ligand, such as hfacH (hexafluoroacetylacetone), with Os3(CO)12 in a stainless steel autoclave at elevated temperature afforded the corresponding mononuclear osmium complex [Os(CO)3(hfac)(tfa)] (1) in good yield. This complex is highly volatile and displays moderate stability at the higher temperatures; thus, it can be utilized for depositing metal thin-film material with overall quality comparable or better than those deposited using the commercially available chemical reagents. Moreover, combination of Os3(CO)12 with another class of chelate ligand such as 3-trifluoromethyl-5-(2-pyridyl) pyrazole (ppz)H gave formation of the Os(H) dicarbonyl complex [Os(CO)2(ppz)2] (2). This osmium complex shows blue phosphorescence at room temperature, which is characteristic for the 3ππ* emission with vibronic progressions at 430,457 and 480 nm. The remarkable photophysical properties were rationalized by a combination of π electron accepting CO ligand, relative ppz orientation and heavy-atom enhanced spin-orbit coupling effects. Related chemical transformations that afforded other useful luminescent Os complexes are presented.

  12. Climate change adaptation accounting for huge uncertainties in future projections - the case of urban drainage

    Science.gov (United States)

    Willems, Patrick

    2015-04-01

    Hydrological design parameters, which are currently used in the guidelines for the design of urban drainage systems (Willems et al., 2013) have been revised, taking the Flanders region of Belgium as case study. The revision involved extrapolation of the design rainfall statistics, taking into account the current knowledge on future climate change trends till 2100. Uncertainties in these trend projections have been assessed after statistically analysing and downscaling by a quantile perturbation tool based on a broad ensemble set of climate model simulation results (44 regional + 69 global control-scenario climate model run combinations for different greenhouse gas scenarios). The impact results of the climate scenarios were investigated as changes to rainfall intensity-duration-frequency (IDF) curves. Thereafter, the climate scenarios and related changes in rainfall statistics were transferred to changes in flood frequencies of sewer systems and overflow frequencies of storage facilities. This has been done based on conceptual urban drainage models. Also the change in storage capacity required to exceed a given overflow return period, has been calculated for a range of return periods and infiltration or throughflow rates. These results were used on the basis of the revision of the hydraulic design rules of urban drainage systems. One of the major challenges while formulating these policy guidelines was the consideration of the huge uncertainties in the future climate change projections and impact assessments; see also the difficulties and pitfalls reported by the IWA/IAHR Joint Committee on Urban Drainage - Working group on urban rainfall (Willems et al., 2012). We made use of the risk concept, and found it a very useful approach to deal with the high uncertainties. It involves an impact study of the different climate projections, or - for practical reasons - a reduced set of climate scenarios tailored for the specific type of impact considered (urban floods in our

  13. Huge Congenital Segmental Dilatation of the Sigmoid Colon in a Neonate: A "Rarity to Meet" and a "Challenge to Treat".

    Science.gov (United States)

    Kaiser, Margarita; Castellani, Christoph; Singer, Georg; Marterer, Robert; Ratschek, Manfred; Till, Holger

    2016-01-01

    Only ten cases of neonatal congenital segmental dilatation (CSD) of the colon have been described so far. We present a full-term female newborn with trisomy 21, ventricular septal defect, and gross abdominal distension. Plain abdominal radiographs revealed a huge cystic lesion occupying the left hemiabdomen. Upon laparotomy on day 4 a CSD of the distal sigmoid and proximal rectum was confirmed and resected. The proximal colon was exteriorized and the distal part closed as a Hartmann pouch. Histology confirmed a huge segmental dilatation of the sigmoid without dysganglionosis or pseudodiverticula, but normal intestinal architecture. After correction of the ventricular septal defect a low rectal end-to-end anastomosis could be performed at an age of 5 months. The postoperative course was uneventful. CSD of the sigmoid colon is extremely "rare to meet" and a "challenge to treat" in the newborn period, but clinical awareness of this entity prompts pediatric surgical success.

  14. Surgical technique for single-port laparoscopy in huge ovarian tumors: SW Kim's technique and comparison to laparotomy.

    Science.gov (United States)

    Kim, Jeong Sook; Lee, In Ok; Eoh, Kyung Jin; Chung, Young Shin; Lee, Inha; Lee, Jung-Yun; Nam, Eun Ji; Kim, Sunghoon; Kim, Young Tae; Kim, Sang Wun

    2017-03-01

    This study aimed to introduce a method to remove huge ovarian tumors (≥15 cm) intact with single-port laparoscopic surgery (SPLS) using SW Kim's technique and to compare the surgical outcomes with those of laparotomy. Medical records were retrospectively reviewed for patients who underwent either SPLS (n=21) with SW Kim's technique using a specially designed 30×30-cm(2)-sized 3XL LapBag or laparotomy (n=22) for a huge ovarian tumor from December 2008 to May 2016. Perioperative surgical outcomes were compared. In 19/21 (90.5%) patients, SPLS was successfully performed without any tumor spillage or conversion to multi-port laparoscopy or laparotomy. There was no significant difference in patient characteristics, including tumor diameter and total operation time, between both groups. The postoperative hospital stay was significantly shorter for the SPLS group than for the laparotomy group (median, 2 [1 to 5] vs. 4 [3 to 17] days; Phuge ovarian tumors.

  15. Using tiltmeters for early warning of tsunamis, generated by huge submarine landslides. A case study for Spitsbergen.

    OpenAIRE

    Sascha Brune; Andrey Babeyko; Stephan V. Sobolev

    2007-01-01

    A submarine landslide west of Spitsbergen could induce a destructive tsunami in the North Atlantic. Here we suggest an effective tool for early warning of tsunamis generated by huge underwater landslides. The method is based on the fact that a displacement of ~1000 km3 of sediment produces a permanent and detectable deformation of earth's lithosphere. We numerically model the ground tilting imposed by the hypothetical Spitsbergen landslide. Virtual inclinometers, positioned at the three dist...

  16. Isolated huge aneurysm of the left main coronary artery in a 22-year-old patient with type 1 neurofibromatosis.

    Science.gov (United States)

    Pontailler, Margaux; Vilarem, Didier; Paul, Jean-François; Deleuze, Philippe H

    2015-03-01

    A 22-year-old patient with neurofibromatosis type 1 presented with acute chest pain. A computed tomography scan and coronary angiography revealed a partially thrombosed huge aneurysm of the left main coronary artery. Despite medical treatment, the patient's angina recurred. The patient underwent a coronary bypass grafting operation and surgical exclusion of the aneurysm. Postoperative imaging disclosed good permeability of the 3 coronary artery bypass grafts and complete thrombosis of the excluded aneurysm.

  17. The prostatic utricle cyst with huge calculus and hypospadias: A case report and a review of the literature

    OpenAIRE

    Wang, Weigang; WANG, YUANTAO; Zhu, Dechun; Yan, Pengfei; Dong, Biao; Zhou, Honglan

    2015-01-01

    Prostatic utricle cysts with calculus and hypospadias are rare. There are a few reported cases. We present a case of a prostatic utricle cyst with huge calculus in a 25-year-old male. He had a history of left cryptorchidism and surgery for penoscrotal hypospadias in his infancy. He was referred for frequent micturition, urgency of urination, urine pain, terminal hematuria, and dysuria. A computed tomography (CT) revealed a retrovesical cystic lesion of low density, showing a 5 × 5-cm calcific...

  18. Huge Left Ventricular Thrombus and Apical Ballooning associated with Recurrent Massive Strokes in a Septic Shock Patient

    Directory of Open Access Journals (Sweden)

    Hyun-Jung Lee

    2016-02-01

    Full Text Available The most feared complication of left ventricular thrombus (LVT is the occurrence of systemic thromboembolic events, especially in the brain. Herein, we report a patient with severe sepsis who suffered recurrent devastating embolic stroke. Transthoracic echocardiography revealed apical ballooning of the left ventricle with a huge LVT, which had not been observed in chest computed tomography before the stroke. This case emphasizes the importance of serial cardiac evaluation in patients with stroke and severe medical illness.

  19. Huge saphenous vein graft aneurysm presenting as non-ST elevation myocardial infarction and compressing the heart.

    Science.gov (United States)

    Zencir, Cemil; Akpek, Mahmut; Onay, Sevil; Selvi, Mithat

    2016-09-01

    Coronary artery bypass grafting (CABG) surgery maintains an important role in the treatment of coronary artery disease. The huge saphenous vein graft aneurysm (HSVGA) is rare and occurs as a late complication after CABG. Here, we reported a case of HSVGA presenting as non-ST elevation myocardial infarction. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  20. Long-Term Outcome After Resection of Huge Hepatocellular Carcinoma ≥ 10 cm: Single-Institution Experience with 471 Patients.

    Science.gov (United States)

    Hwang, Shin; Lee, Young-Joo; Kim, Ki-Hun; Ahn, Chul-Soo; Moon, Deok-Bog; Ha, Tae-Yong; Song, Gi-Won; Jung, Dong-Hwan; Lee, Sung-Gyu

    2015-10-01

    Tumor recurrence is very common after resection of huge hepatocellular carcinoma (HCC). This study intended to evaluate early recurrence and long-term outcomes in patients with huge HCC ≥ 10 cm after primary resection and treatment of recurrence. Recurrence and survival outcomes were retrospectively evaluated in 471 patients with huge HCCs who underwent resection between January 2000 and April 2012. Mean tumor diameter was 13.6 ± 3.1 cm, with 93 % of patients having single tumors. Anatomic and R0 resection rates were 91.1 and 89.4 %, respectively. Perioperative mortality rate was 1.7 %. Tumor recurrence and patient survival rates were 62.2 and 69.2 % at 1 year and 76.0 and 35.5 % at 5 years, respectively. Of patients with recurrence, 92.5 % received specific treatment. Median patient survival period after initial intrahepatic recurrence was 16 months. Tumor volume did not affect recurrence or survival outcomes. Independent risk factors for tumor recurrence and patient survival were serum alpha-fetoprotein ≥ 100 ng/mL, hypermetabolic uptake on positron emission tomography, satellite nodules, and microvascular invasion. These four factors were used to develop a risk prediction model, in which 1-year HCC recurrence rates in patients with 0, 1, 2, 3, and 4 risk factors were 18.7, 30.3, 58.7, 79.0, and 92.1 %, respectively, and their 1-year patient survival rates were 100, 97.0, 75.5, 63.9, and 42.1 %, respectively. In patients with huge HCCs, hepatic resection with active recurrence treatment resulted in improved long-term survival. Our 4-factor risk prediction model appears to contribute to quantitative postoperative risk estimation for early HCC recurrence and patient survival in patients with HCC ≥ 10 cm.

  1. Imbalance in systemic inflammation and immune response following transarterial chemoembolization potentially increases metastatic risk in huge hepatocellular carcinoma.

    Science.gov (United States)

    Xue, Tong-Chun; Jia, Qing-An; Ge, Ning-Ling; Chen, Yi; Zhang, Bo-Heng; Ye, Sheng-Long

    2015-11-01

    Inflammation plays a critical role in tumor metastasis. However, few inflammation-related biomarkers are currently available to predict the risk of metastasis for advanced hepatocellular carcinoma (HCC). Using huge tumors (diameter >10 cm) as a model, we evaluated the potential risk of pre- and post-treatment inflammatory responses in the development of metastasis of HCC patients undergoing transarterial chemoembolization (TACE). A logistic regression model was used to analyze the risk factors. One hundred and sixty-five patients with huge HCC were enrolled in the study. Metastases were identified in 25.5% (42/165) patients by imaging evaluation post-TACE. Neutrophils increased, whereas lymphocytes decreased significantly post-TACE. Univariate analysis showed that high post-treatment neutrophil-to-lymphocyte ratio (NLR; p = 0.003), low post-treatment lymphocyte count (p = 0.047), and high baseline NLR (p = 0.100) were potential risk factors for metastasis. Further, multivariate analysis showed that high post-treatment NLR, but not pre-treatment NLR, was an independent risk factor for metastasis; this was confirmed by receiver operating characteristic curve analysis. Post-treatment NLR, however, had no correlation to tumor response and overall survival of patients. In conclusion, post-treatment NLR but not pre-treatment NLR independently increases the risk of metastasis in huge HCC. Our findings suggest the potential contribution of treatment-related inflammation to metastasis in advanced HCC.

  2. Totally inverted cervix due to a huge prolapsed cervical myoma simulating chronic non-puerperal uterine inversion.

    Science.gov (United States)

    Turhan, Nilgun; Simavli, Serap; Kaygusuz, Ikbal; Kasap, Burcu

    2014-01-01

    Inversion of the uterus is an extremely rare complication of the non-puerperal period and is commonly caused by benign submucous, especially fundal, leiomyomas. A case of a totally inverted cervix due to a prolapsed huge cervical leiomyoma mimicking chronic non-puerperal uterine inversion in a perimenopausal woman is presented. A 52-year-old perimenopausal woman was admitted to our clinic with an ulcerated, necrotic, infected and swollen prolapsed mass. Gynecologic history revealed that she was advised myomectomy because of her cervical myoma 2 years ago but she refused to have an operation as she believed that her positive thoughts would shrink the myoma. Presumed diagnosis before surgery was chronic non-puerperal uterine inversion. An intraoperative diagnosis was totally inverted cervix due to a huge cervical leiomyoma. Vaginal hysterectomy without adnexectomy, was performed. This is the first case in the literature which a totally inverted cervix due to a prolapsed huge cervical leiomyoma. Cervical fibroids can grow in perimenopausal period and in extremely rare cases can cause total cervical inversion. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. [Analysis of efficacy and prognostic factors of transarterial chemoembolization combined with multimodality therapy for huge hepatocellular carcinoma].

    Science.gov (United States)

    Chang, Zhongfei; Wang, Maoqiang; Liu, Fengyong; Duan, Feng; Wang, Zhijun; Song, Peng

    2014-01-01

    The aim of this study was to evaluate the efficacy, survival and prognosis of transarterial chemoembolization (TACE) alone and TACE in combination with multimodality therapy for huge hepatocellular carcinoma. A retrospective analysis was conducted in 115 patients with huge hepatocellular carcinoma treated in our hospital from August 2008 to January 2012. Among them, 72 patients were treated by TACE alone (TACE group) and 43 patients by TACE plus multimodality therapy (TACE-combined treatment group). Their clinicopathological data and survival were analyzed. The median follow-up of the 115 cases was 24 months (range 1-40 months). The 1-, 2-, and 3-year overall survival (OS) rates for the TACE group were 60.4,% 23.3% and 9.8%, respectively, and 39 months, 78.1%, 43.3% and 36.8%, respectively, for the combined treatment group (P 0.05 for all), while multimodality therapy, Child's grading, ECOG scores, distant metastasis, and portal vein tumor thrombus were significantly related to the overall survival. Moreover, the Cox multivariate survival analysis revealed that therapy and ECOG scores were independent prognostic indicators (P huge hepatocellular carcinoma. Multimodality therapy and ECOG scores are independent prognostic indicators for the patients.

  4. Spectroscopic investigation of the interfaces in new poly(9,9-dihexyl–9H-fluorene-2,7- diyl based electroluminescent devices

    Directory of Open Access Journals (Sweden)

    C. Donitsi

    2014-01-01

    Full Text Available The highest occupied and lowest unoccupied states of the new electroluminescent material poly(9,9-dihexyl–9H- fluorene-2,7-diyl (PPV-D and polyvinylcarbazole (PVK are investigated using ultraviolet photoelectron and inverse photoemission spectroscopies. Hole injection barriers are determined for interfaces between indium-tin oxide covered substrates with work function ranging from 4.4 to 4.7 eV and these two polymers. Vacuum level alignment with flat bands away from the interface is found when the interface hole barrier is 0.6 eV or larger. Band bending away from the Fermi level occurs when the hole barrier is smaller than 0.6 eV. This is due to the accumulation charges at the interface with the polymer when the injection barrier is small. The resulting field bends the polymer levels to limit charge incoming in the bulk of the film. The efficiency of the electroluminescent structures is strongly influenced by the different energy levels alignment at the layer interfaces.

  5. Preparation and characterizations of electroluminescent p-ZnO : N/n-ZnO : Ga/ITO thin films by spray pyrolysis method

    Directory of Open Access Journals (Sweden)

    C. Panatarani

    2016-02-01

    Full Text Available ZnO thin films were fabricated by spray pyrolysis (SP method with p-ZnO : N/n-ZnO:Ga/ITO structure. The X-ray results show that the deposited films have hexagonal wurtzite structure. The EDS results observed that the composition of Ga in ZnO:Ga and N in ZnO:N was 3.73% and 27.73% respectively. The photoluminescence (PL with excitation wave length of 260 nm shows that ZnO:Ga and ZnO:N films emitted UV emission at ∼393 and ∼388 nm, respectively and the films resistivity was 7.12 and 12.80 Ohm-cm respectively. The electroluminescence of the p-ZnO : N/n-ZnO:Ga/ITO structure was obtained by applying forward bias of 5 volt with 30 mA current, resulting in a 3.35 volt threshold bias with the peak electroluminescence in UV-blue range.

  6. Room Temperature Electroluminescence from Tensile-Strained Si0.13Ge0.87/Ge Multiple Quantum Wells on a Ge Virtual Substrate

    Directory of Open Access Journals (Sweden)

    Guangyang Lin

    2016-09-01

    Full Text Available Direct band electroluminescence (EL from tensile-strained Si0.13Ge0.87/Ge multiple quantum wells (MQWs on a Ge virtual substrate (VS at room temperature is reported herein. Due to the competitive result of quantum confinement Stark effect and bandgap narrowing induced by tensile strain in Ge wells, electroluminescence from Γ1-HH1 transition in 12-nm Ge wells was observed at around 1550 nm. As injection current density increases, additional emission shoulders from Γ2-HH2 transition in Ge wells and Ge VS appeared at around 1300–1400 nm and 1600–1700 nm, respectively. The peak energy of EL shifted to the lower energy side superquadratically with an increase of injection current density as a result of the Joule heating effect. During the elevation of environmental temperature, EL intensity increased due to a reduction of energy between L and Γ valleys of Ge. Empirical fitting of the relationship between the integrated intensity of EL (L and injection current density (J with L~Jm shows that the m factor increased with injection current density, suggesting higher light emitting efficiency of the diode at larger injection current densities, which can be attributed to larger carrier occupations in the Γ valley and the heavy hole (HH valance band at higher temperatures.

  7. Photo- and electroluminescent properties of bithiophene disubstituted 1,3,4-thiadiazoles and their application as active components in organic light emitting diodes

    Science.gov (United States)

    Grykien, Remigiusz; Luszczynska, Beata; Glowacki, Ireneusz; Kurach, Ewa; Rybakiewicz, Renata; Kotwica, Kamil; Zagorska, Malgorzata; Pron, Adam; Tassini, Paolo; Maglione, Maria Grazia; Mauro, Anna De Girolamo Del; Fasolino, Tommaso; Rega, Romina; Pandolfi, Giuseppe; Minarini, Carla; Aprano, Salvatore

    2014-11-01

    Photo- and electroluminescence of five bithiophene disubstituted 1,3,4-thiadiazoles, constituting a new class of solution processable materials for organic opto-electronics, were studied. It was found that the introduction of alkyl solubilizing substituents bathochromically shifted the photo- and electroluminescence bands. The most pronounced effect was observed for the substitution at the Cα position which changed the emitting light color from bluish to green. All five derivatives were tested in host/guest type organic light emitting diodes (OLEDs) with either poly(N-vinylcarbazole) (PVK) or poly(N-vinylcarbazole) + 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PVK + PBD) matrices. The latter matrix turned out especially well suited for these guest molecules yielding devices of varying color coordinates. The best luminance (750 cd/m2) was measured for 2,5-bis(5‧-octyl-2,2‧-bithiophene-5-yl)-1,3,4-thiadiazole with the luminous efficiency exceeding 0.4 cd/A.

  8. Electrical and electroluminescent characterization of nanometric multilayers of SiOX/SiOY obtained by LPCVD including non-normal emission

    Science.gov (United States)

    Alarcón-Salazar, J.; Zaldívar-Huerta, I. E.; Aceves-Mijares, M.

    2016-06-01

    This work describes the analysis and fabrication by Low Pressure Chemical Vapor Deposition of two light-emitting capacitors (LECs) constituted by nanometric multilayers of silicon-rich oxide. For both structures, seven layers were used: three light emitting layers with 6% silicon excess and four conductive layers with 12% silicon excess for one LEC and the other with 14% silicon excess. Both LECs were annealed at 1100 °C. Both multilayers demonstrate a substantially improved photoluminescent response compared to single emitting layers. A dielectric constant of 4.1 and a trap density of 1016 cm-3 were obtained from capacitance-voltage curves. Analysis of current-voltage and electroluminescence-voltage (EL-V) characteristics indicates that EL initiates under the space-charge-limited current mechanism, and the required voltage to turn on the emission is 38 V which is the trap-free limit voltage. However, EL increases exponentially under the impact ionization and trap-assisted tunneling conduction mechanisms. The electroluminescence spectra for both multilayers show two emission peaks centered in 450 and 700 nm attributed to oxygen defects. Also, the LEC non-normal emission was measured and it behaves like a Lambertian optical source. Both multilayers obtain the values of efficiency in the order of 10-6 which is in good agreement with the values reported in the literature.

  9. Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

    Energy Technology Data Exchange (ETDEWEB)

    Calciati, Marco; Vallone, Marco; Zhou, Xiangyu; Ghione, Giovanni [Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino (Italy); Goano, Michele, E-mail: michele.goano@polito.it; Bertazzi, Francesco [Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino (Italy); IEIIT-CNR, Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino (Italy); Meneghini, Matteo; Meneghesso, Gaudenzio; Zanoni, Enrico [Dipartimento di Ingegneria dell' Informazione, Università di Padova, Via Gradenigo 6/B, 35131 Padova (Italy); Bellotti, Enrico [Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary' s Street, 02215 Boston, MA (United States); Verzellesi, Giovanni [Dipartimento di Scienze e Metodi dell' Ingegneria, Università di Modena e Reggio Emilia, 42122 Reggio Emilia (Italy); Zhu, Dandan; Humphreys, Colin [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

    2014-06-15

    Electroluminescence (EL) characterization of InGaN/GaN light-emitting diodes (LEDs), coupled with numerical device models of different sophistication, is routinely adopted not only to establish correlations between device efficiency and structural features, but also to make inferences about the loss mechanisms responsible for LED efficiency droop at high driving currents. The limits of this investigative approach are discussed here in a case study based on a comprehensive set of current- and temperature-dependent EL data from blue LEDs with low and high densities of threading dislocations (TDs). First, the effects limiting the applicability of simpler (closed-form and/or one-dimensional) classes of models are addressed, like lateral current crowding, vertical carrier distribution nonuniformity, and interband transition broadening. Then, the major sources of uncertainty affecting state-of-the-art numerical device simulation are reviewed and discussed, including (i) the approximations in the transport description through the multi-quantum-well active region, (ii) the alternative valence band parametrizations proposed to calculate the spontaneous emission rate, (iii) the difficulties in defining the Auger coefficients due to inadequacies in the microscopic quantum well description and the possible presence of extra, non-Auger high-current-density recombination mechanisms and/or Auger-induced leakage. In the case of the present LED structures, the application of three-dimensional numerical-simulation-based analysis to the EL data leads to an explanation of efficiency droop in terms of TD-related and Auger-like nonradiative losses, with a C coefficient in the 10{sup −30} cm{sup 6}/s range at room temperature, close to the larger theoretical calculations reported so far. However, a study of the combined effects of structural and model uncertainties suggests that the C values thus determined could be overestimated by about an order of magnitude. This preliminary

  10. Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

    Science.gov (United States)

    Calciati, Marco; Goano, Michele; Bertazzi, Francesco; Vallone, Marco; Zhou, Xiangyu; Ghione, Giovanni; Meneghini, Matteo; Meneghesso, Gaudenzio; Zanoni, Enrico; Bellotti, Enrico; Verzellesi, Giovanni; Zhu, Dandan; Humphreys, Colin

    2014-06-01

    Electroluminescence (EL) characterization of InGaN/GaN light-emitting diodes (LEDs), coupled with numerical device models of different sophistication, is routinely adopted not only to establish correlations between device efficiency and structural features, but also to make inferences about the loss mechanisms responsible for LED efficiency droop at high driving currents. The limits of this investigative approach are discussed here in a case study based on a comprehensive set of current- and temperature-dependent EL data from blue LEDs with low and high densities of threading dislocations (TDs). First, the effects limiting the applicability of simpler (closed-form and/or one-dimensional) classes of models are addressed, like lateral current crowding, vertical carrier distribution nonuniformity, and interband transition broadening. Then, the major sources of uncertainty affecting state-of-the-art numerical device simulation are reviewed and discussed, including (i) the approximations in the transport description through the multi-quantum-well active region, (ii) the alternative valence band parametrizations proposed to calculate the spontaneous emission rate, (iii) the difficulties in defining the Auger coefficients due to inadequacies in the microscopic quantum well description and the possible presence of extra, non-Auger high-current-density recombination mechanisms and/or Auger-induced leakage. In the case of the present LED structures, the application of three-dimensional numerical-simulation-based analysis to the EL data leads to an explanation of efficiency droop in terms of TD-related and Auger-like nonradiative losses, with a C coefficient in the 10-30 cm6/s range at room temperature, close to the larger theoretical calculations reported so far. However, a study of the combined effects of structural and model uncertainties suggests that the C values thus determined could be overestimated by about an order of magnitude. This preliminary attempt at

  11. Correlating electroluminescence characterization and physics-based models of InGaN/GaN LEDs: Pitfalls and open issues

    Directory of Open Access Journals (Sweden)

    Marco Calciati

    2014-06-01

    Full Text Available Electroluminescence (EL characterization of InGaN/GaN light-emitting diodes (LEDs, coupled with numerical device models of different sophistication, is routinely adopted not only to establish correlations between device efficiency and structural features, but also to make inferences about the loss mechanisms responsible for LED efficiency droop at high driving currents. The limits of this investigative approach are discussed here in a case study based on a comprehensive set of current- and temperature-dependent EL data from blue LEDs with low and high densities of threading dislocations (TDs. First, the effects limiting the applicability of simpler (closed-form and/or one-dimensional classes of models are addressed, like lateral current crowding, vertical carrier distribution nonuniformity, and interband transition broadening. Then, the major sources of uncertainty affecting state-of-the-art numerical device simulation are reviewed and discussed, including (i the approximations in the transport description through the multi-quantum-well active region, (ii the alternative valence band parametrizations proposed to calculate the spontaneous emission rate, (iii the difficulties in defining the Auger coefficients due to inadequacies in the microscopic quantum well description and the possible presence of extra, non-Auger high-current-density recombination mechanisms and/or Auger-induced leakage. In the case of the present LED structures, the application of three-dimensional numerical-simulation-based analysis to the EL data leads to an explanation of efficiency droop in terms of TD-related and Auger-like nonradiative losses, with a C coefficient in the 10−30 cm6/s range at room temperature, close to the larger theoretical calculations reported so far. However, a study of the combined effects of structural and model uncertainties suggests that the C values thus determined could be overestimated by about an order of magnitude. This preliminary

  12. Synthesis, characterization, and photophysical and electroluminescent properties of blue-emitting cationic iridium(III) complexes bearing nonconjugated ligands.

    Science.gov (United States)

    Zhang, Fuli; Ma, Dongxin; Duan, Lian; Qiao, Juan; Dong, Guifang; Wang, Liduo; Qiu, Yong

    2014-07-07

    -type ancillary ligands, where emission originates from the cyclometalated main ligands. Solution-processed organic light-emitting diodes based on complexes 1 and 2 gave blue-green (498 nm) and blue (478 nm) electroluminescence with maximum current efficiencies of 3.8 and 3.4 cd A(-1), respectively. The results indicate that introducing nonconjugated ligands into cationic iridium complexes is an effective means of achieving short-wavelength light-emitting phosphors.

  13. Stereotactic body radiotherapy combined with transarterial chemoembolization for huge (≥10 cm) hepatocellular carcinomas: A clinical study.

    Science.gov (United States)

    Zhong, Nan Bao; Lv, Guang Ming; Chen, Zhong Hua

    2014-09-01

    This study was conducted to evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) combined with transarterial chemoembolization (TACE) for huge (≥10 cm) hepatocellular carcinomas (HCCs). Between May, 2006 and December, 2012, 72 patients with huge HCCs were treated by SBRT following incomplete TACE. The median total dose of 35.6 Gy was delivered over 12-14 days with a fractional dose of 2.6-3.0 Gy and 6 fractions per week. The patients were classified into those with tumor encapsulation (group A, n=33) and those without tumor encapsulation (group B, n=39). The clinical outcomes of tumor response, overall cumulative survival and toxicities/complications were retrospectively analyzed. Among the 72 patients, CR, PR, SD and PD were achieved in 6 (8.3%), 51 (70.8%), 9 (12.5%) and 6 patients (8.3%), respectively, within a median follow-up of 18 months. The objective response rate was 79.1%. The overall cumulative 1-, 3- and 5-year survival rates and the median survival time were 38, 12 and 3% and 12.2 months, respectively. In group A, the overall cumulative 1-, 3- and 5-year survival rates were 56, 21 and 6%, respectively, with a median survival of 19 months; in group B, the overall cumulative 1-, 3- and 5-year survival rates were 23, 4 and 0%, respectively, with a median survival of 10.8 months (P=0.023). The treatment was well tolerated, with no severe radiation-induced liver disease and no reported > grade 3 toxicity. Tumor encapsulation was found to be a significant prognostic factor for survival. In conclusion, the combination of SBRT and TACE was shown to be a safe and effective treatment option for patients with unresectable huge HCC.

  14. Huge ac magnetoresistance of La0.7Sr0.3MnO3 in sub-kilogauss magnetic fields

    Science.gov (United States)

    Mahendiran, Ramanathan; Rebello, Alwyn; Naik, Vinayak B.; Barik, Sujit Kumar

    2010-03-01

    We report radio frequency (f = 0.1 5 MHz) magnetotransport of La0.7Sr0.3MnO3 in sub kilogauss magnetic fields (H = 0-1 kG). We measured ac resistance (R) and reactance (X) simultaneously. In zero field, R decreases smoothly around the Curie temperature TC when f = 100 kHz, but it increases abruptly and shows a peak close to TC for f = 0.5-5 MHz. The peak decreases in amplitude, broadens and shifts downward in temperature as the bias field increases. The peak is completely suppressed under Hdc = 1 kOe when f = 0.5 MHz. A huge low-field ac magnetoresistance (δR/R = 40 %) and magnetoinductance (δX/X = 12 %) are found in a field of Hdc = 700 Oe and f = 2 MHz. We suggest that the observed ac magnetoresistance arises from the suppression of ac permeability and enhanced magnetic skin depth under a magnetic field. The dynamical magnetotransport reported here will be interesting from view points of fundamental physics and applications.

  15. Huge pelvi-abdominal malignant inflammatory myofibroblastic tumor with rapid recurrence in a 14-year-old boy

    Institute of Scientific and Technical Information of China (English)

    Chia-Hsun; Lu; Hsuan-Ying; Huang; Han-Koo; Chen; Jiin-Haur; Chuang; Shu-Hang; Ng; Sheung-Fat; Ko

    2010-01-01

    Inflammatory myofibroblastic tumor(IMT) is an uncommon benign neoplasm with locally aggressive behavior but malignant change is rare.We report an unusual case of pelvic-abdominal inflammatory myofibroblastic tumor with malignant transformation in a 14-year-old boy presenting with abdominal pain and 9 kg body weight loss in one month.Computed tomography revealed a huge pelvi-abdominal mass(30 cm),possibly originating from the pelvic extraperitoneal space,protruding into the abdomen leading to upward displace...

  16. Huge Varicose Inferior Mesenteric Vein: an Unanticipated {sup 99m}Tc-labeled Red Blood Cell Scintigraphy Finding

    Energy Technology Data Exchange (ETDEWEB)

    Hoseinzadeh, Samaneh; Shafiei, Babak; Salehian, Mohamadtaghi; Neshandar Asli, Isa; Ghodoosi, Iraj [Shaheed Beheshti Medical University, Tehran (Iran, Islamic Republic of)

    2010-09-15

    Ectopic varices (EcV) are enlarged portosystemic venous collaterals, which usually develop secondary to portal hypertension (PHT). Mesocaval collateral vessels are unusual pathways to decompress the portal system. Here we report the case of a huge varicose inferior mesenteric vein (IMV) that drained into peri rectal collateral veins, demonstrated by {sup 99m}Tc-labeled red blood cell (RBC) scintigraphy performed for lower gastrointestinal (GI) bleeding in a 14-year-old girl. This case illustrates the crucial role of {sup 99m}Tc-labeled RBC scintigraphy for the diagnosis of rare ectopic lower GI varices.

  17. Reporting of Human Genome Epidemiology (HuGE association studies: An empirical assessment

    Directory of Open Access Journals (Sweden)

    Gwinn Marta

    2008-05-01

    Full Text Available Abstract Background Several thousand human genome epidemiology association studies are published every year investigating the relationship between common genetic variants and diverse phenotypes. Transparent reporting of study methods and results allows readers to better assess the validity of study findings. Here, we document reporting practices of human genome epidemiology studies. Methods Articles were randomly selected from a continuously updated database of human genome epidemiology association studies to be representative of genetic epidemiology literature. The main analysis evaluated 315 articles published in 2001–2003. For a comparative update, we evaluated 28 more recent articles published in 2006, focusing on issues that were poorly reported in 2001–2003. Results During both time periods, most studies comprised relatively small study populations and examined one or more genetic variants within a single gene. Articles were inconsistent in reporting the data needed to assess selection bias and the methods used to minimize misclassification (of the genotype, outcome, and environmental exposure or to identify population stratification. Statistical power, the use of unrelated study participants, and the use of replicate samples were reported more often in articles published during 2006 when compared with the earlier sample. Conclusion We conclude that many items needed to assess error and bias in human genome epidemiology association studies are not consistently reported. Although some improvements were seen over time, reporting guidelines and online supplemental material may help enhance the transparency of this literature.

  18. HUBBLE REVEALS HUGE CRATER ON THE SURFACE OF THE ASTEROID VESTA

    Science.gov (United States)

    2002-01-01

    [left] A NASA Hubble Space Telescope image of the asteroid Vesta, taken in May 1996 when the asteroid was 110 million miles from Earth. The asymmetry of the asteroid and 'nub' and the south pole is suggestive that it suffered a large impact event. The image was digitally restored to yield an effective scale of six miles per pixel (picture element). [center] A color-encoded elevation map of Vesta clearly shows the giant 285- mile diameter impact basin and 'bull's-eye' central peak. The map was constructed from 78 Wide Field Planetary Camera 2 pictures. Surface topography was estimated by noting irregularities along the limb and at the terminator (day/night boundary) where shadows are enhanced by the low Sun angle. [right] A 3-D computer model of the asteroid Vesta synthesized from Hubble topographic data. The crater's 8-mile high central peak can clearly be seen near the pole. The surface texture on the model is artificial, and is not representative of the true brightness variations on the asteroid. Elevation features have not been exaggerated. Photo Credit: Ben Zellner (Georgia Southern University), Peter Thomas (Cornell University), NASA

  19. Light-emitting nanolattices with enhanced brightness

    Science.gov (United States)

    Ng, Ryan C.; Mandal, Rajib; Anthony, Rebecca J.; Greer, Julia R.

    2017-02-01

    Three-dimensional (3D) photonic crystals have potential in solid state lighting applications due to their advantages over conventional planar thin film devices. Periodicity in a photonic crystal structure enables engineering of the density of states to improve spontaneous light emission according to Fermi's golden rule. Unlike planar thin films, which suffer significantly from total internal reflection, a 3D architectured structure is distributed in space with many non-flat interfaces, which facilitates a substantial enhancement in light extraction. We demonstrate the fabrication of 3D nano-architectures with octahedron geometry that utilize luminescing silicon nanocrystals as active media with an aluminum cathode and indium tin oxide anode towards the realization of a 3D light emitting device. The developed fabrication procedure allows charge to pass through the nanolattice between two contacts for electroluminescence. These initial fabrication efforts suggest that 3D nano-architected devices are realizable and can reach greater efficiencies than planar devices.

  20. Genome network medicine: innovation to overcome huge challenges in cancer therapy.

    Science.gov (United States)

    Roukos, Dimitrios H

    2014-01-01

    The post-ENCODE era shapes now a new biomedical research direction for understanding transcriptional and signaling networks driving gene expression and core cellular processes such as cell fate, survival, and apoptosis. Over the past half century, the Francis Crick 'central dogma' of single n gene/protein-phenotype (trait/disease) has defined biology, human physiology, disease, diagnostics, and drugs discovery. However, the ENCODE project and several other genomic studies using high-throughput sequencing technologies, computational strategies, and imaging techniques to visualize regulatory networks, provide evidence that transcriptional process and gene expression are regulated by highly complex dynamic molecular and signaling networks. This Focus article describes the linear experimentation-based limitations of diagnostics and therapeutics to cure advanced cancer and the need to move on from reductionist to network-based approaches. With evident a wide genomic heterogeneity, the power and challenges of next-generation sequencing (NGS) technologies to identify a patient's personal mutational landscape for tailoring the best target drugs in the individual patient are discussed. However, the available drugs are not capable of targeting aberrant signaling networks and research on functional transcriptional heterogeneity and functional genome organization is poorly understood. Therefore, the future clinical genome network medicine aiming at overcoming multiple problems in the new fields of regulatory DNA mapping, noncoding RNA, enhancer RNAs, and dynamic complexity of transcriptional circuitry are also discussed expecting in new innovation technology and strong appreciation of clinical data and evidence-based medicine. The problematic and potential solutions in the discovery of next-generation, molecular, and signaling circuitry-based biomarkers and drugs are explored.

  1. Research on fast Fourier transforms algorithm of huge remote sensing image technology with GPU and partitioning technology.

    Science.gov (United States)

    Yang, Xue; Li, Xue-You; Li, Jia-Guo; Ma, Jun; Zhang, Li; Yang, Jan; Du, Quan-Ye

    2014-02-01

    Fast Fourier transforms (FFT) is a basic approach to remote sensing image processing. With the improvement of capacity of remote sensing image capture with the features of hyperspectrum, high spatial resolution and high temporal resolution, how to use FFT technology to efficiently process huge remote sensing image becomes the critical step and research hot spot of current image processing technology. FFT algorithm, one of the basic algorithms of image processing, can be used for stripe noise removal, image compression, image registration, etc. in processing remote sensing image. CUFFT function library is the FFT algorithm library based on CPU and FFTW. FFTW is a FFT algorithm developed based on CPU in PC platform, and is currently the fastest CPU based FFT algorithm function library. However there is a common problem that once the available memory or memory is less than the capacity of image, there will be out of memory or memory overflow when using the above two methods to realize image FFT arithmetic. To address this problem, a CPU and partitioning technology based Huge Remote Fast Fourier Transform (HRFFT) algorithm is proposed in this paper. By improving the FFT algorithm in CUFFT function library, the problem of out of memory and memory overflow is solved. Moreover, this method is proved rational by experiment combined with the CCD image of HJ-1A satellite. When applied to practical image processing, it improves effect of the image processing, speeds up the processing, which saves the time of computation and achieves sound result.

  2. Free perforating branch flap for primary repairing the huge soft-tissue defects on the scalp and face.

    Science.gov (United States)

    Wang, Hong-Yuan; Wang, Ming-Gang; Yu, Gang; Chu, Yan-Jun; Wang, Kai; Wei, Xiang-Pin; Sun, Jing-Wu

    2016-11-01

    This study aimed to explore the effect of free perforating branch flap on the reconstruction of huge soft-tissue defects on the scalp and face. Sixteen cases of huge soft-tissue defects on the scalp and face were reconstructed by nine latissimus dorsi-free perforator flaps and seven anterolateral thigh-free perforator flaps. The defects area was from 12 cm× 7 cm to 20 cm × 11 cm, while the flaps area was from 14 cm × 8 cm to 23 cm × 12 cm. The survival, planeness, chromatic aberration, radiotherapy toleration of flap and the function, scar of donor site were observed postoperatively. All of the flaps were survived completely, and 15 cases presented for primary reconstruction; one underwent secondary reconstruction. One of the patients died one-year postoperatively due to intracranial tumor recurrence and the others had no recurrence. All of the flaps showed perfect shape and appropriate thickness. No roentgen ulcer was observed except for some extent of chromatic aberration. The donor-site scar was larvaceous and the function was good. This study indicated that the latissimus dorsi-free perforator flap or anterolateral thigh-free perforator flap was an ideal choice for the reconstruction of defects on the scalp and face.

  3. Effect of solution combusted TiO2 nanopowder within commercial BaTiO3 dielectric layer on the photoelectric properties for AC powder electroluminescence devices.

    Science.gov (United States)

    Park, Sung; Choi, Gil Rak; Kim, Youn Cheol; Lee, Jae Chun; Lee, Ju Hyeon

    2013-05-01

    A unique synthesis method was developed, which is called solution combustion method (SCM). TiO2 nanopowder was synthesized by this method. This SCM TiO2 nanopowder (-35 nm) was added to the dielectric layer of AC powder electroluminescence (EL) device. The dielectric layer was made of commercial BaTiO3 powder (-1.2 microm) and binding polymer. 0, 5, 10 and 15 wt% of SCM TiO2 nanopowder was added to the dielectric layer during fabrication of AC powder EL device respectively. Dielectric constant of these four kinds of dielectric layers was measured. The brightness and current density of AC powder EL device were also measured. When 10 wt% of SCM TiO2 nanopowder was added, dielectric constant and brightness were increased by 30% and 101% respectively. Furthermore, the current density was decreased by 71%. This means that the brightness was double and the power consumption was one third.

  4. Reverse-bias-driven dichromatic electroluminescence of n-ZnO wire arrays/p-GaN film heterojunction light-emitting diodes

    Science.gov (United States)

    Jeong, Junseok; Choi, Ji Eun; Kim, Yong-Jin; Hwang, Sunyong; Kim, Sung Kyu; Kim, Jong Kyu; Jeong, Hu Young; Hong, Young Joon

    2016-09-01

    Position-controlled n-ZnO microwire (MW) and nanowire-bundle (NW-B) arrays were fabricated using hydrothermal growth of ZnO on a patterned p-GaN film. Both the wire/film p-n heterojunctions showed electrical rectification features at reverse-bias (rb) voltages, analogous to backward diodes. Dichromatic electroluminescence (EL) emissions with 445- and 560-nm-wavelength peaks displayed whitish-blue and greenish-yellow light from MW- and NW-B-based heterojunctions at rb voltages, respectively. The different dichromatic EL emission colors were studied based on photoluminescence spectra and the dichromatic EL peak intensity ratios as a function of the rb voltage. The different EL colors are discussed with respect to depletion thickness and electron tunneling probability determined by wire/film junction geometry and size.

  5. Electroluminescence from perovskite LEDs with the structure of Ag/Spiro-OMeTAD/CH3NH3PbI3/TiO2/FTO

    Science.gov (United States)

    Wang, Minhuan; Shi, Yantao; Bian, Jiming; Dong, Qingshun; Sun, Hongjun; Liu, Hongzhu; Luo, Yingmin; Zhang, Yuzhi

    2016-10-01

    The perovskite light-emitting diodes (Pe-LEDs) with the structure of Ag/Spiro-OMeTAD/CH3NH3PbI3/TiO2/FTO were synthesized, where the CH3NH3PbI3 perovskite layer was deposited by a two-step spin-coating process. A dominant near-infrared electroluminescence (EL) at 773 nm was detected from the Pe-LEDs under forward bias at room temperature. The origin and mechanism of the EL were discussed in comparison with the photoluminescence (PL) spectra, and it was attributed to the radiative recombination of electrons and holes confined in the CH3NH3PbI3 emissive layer. Moreover, the corresponding energy band diagrams was proposed to illustrate the carrier transport mechanism in the Pe-LED device.

  6. Electroluminescence from a forward-biased Schottky barrier diode on modulation Si {delta}-doped GaAs/InGaAs/AlGaAs heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Babinski, Adam; Witczak, P.; Twardowski, A.; Baranowski, J. M.

    2001-06-18

    Electroluminescence (EL) from a forward-biased Schottky barrier diode on modulation Si {delta}-doped pseudomorphic GaAs/InGaAs/AlGaAs heterostructure with high mobility electron gas is investigated in this work. It has been found that the EL from the InGaAs quantum well can be observed at temperatures up to 90 K. The EL line shape depends on the current density, which reflects the filling of the InGaAs channel with electrons. The total integrated EL intensity depends linearly on the current density. We propose that hole diffusion from an inversion layer at the Schottky barrier is responsible for the observed optical recombination with electrons in the InGaAs quantum well. {copyright} 2001 American Institute of Physics.

  7. Characterization of the InGaN/GaN Multi-Quantum-Wells Light-Emitting Diode Grown on Patterned Sapphire Substrate with Wide Electroluminescence Spectrum

    Science.gov (United States)

    Reum Lee, Ah; Jeon, Hunsoo; Lee, Gang-Seok; Ok, Jin-Eun; Jo, Dong-Wan; Kim, Kyoung Hwa; Yi, Sam Nyung; Yang, Min; Ahn, Hyung Soo; Cho, Chae-Ryong; Kim, Suok-Whan; Lee, Jae-Hak; Ha, Hong-Ju

    2011-01-01

    We report the characterization of the InGaN/GaN multi-quantum-well (MQW) light-emitting diode (LED) grown on a patterned sapphire substrate by metal organic chemical vapor deposition (MOCVD) using the selective area growth (SAG) method. The SAG patterns were designed to be circular and their diameters were 700 and 200 µm. After the growth, the InGaN/GaN MQW LED of 200 µm diameter had various crystal facets and a shape similar to volcanic craters, which were not observed in the 700-µm-diameter sample. We obtained an active layer with compositional nonuniformity and superior optical properties. We found wide electroluminescence (EL) spectral peaks near 470, 570, and 600 nm. The distribution of the EL spectrum of the sample was similar to that of a conventional phosphor-converted white LED.

  8. Mid-infrared electro-luminescence and absorption from AlGaN/GaN-based multi-quantum well inter-subband structures

    Science.gov (United States)

    Hofstetter, Daniel; Bour, David P.; Kirste, Lutz

    2014-06-01

    We present electro-modulated absorption and electro-luminescence measurements on chirped AlGaN/GaN-based multi-quantum well inter-subband structures grown by metal-organic vapour phase epitaxy. The absorption signal is a TM-polarized, 70 meV wide feature centred at 230 meV. At medium injection current, a 58 meV wide luminescence peak corresponding to an inter-subband transition at 1450 cm-1 (180 meV) is observed. Under high injection current, we measured a 4 meV wide structure peaking at 92.5 meV in the luminescence spectrum. The energy location of this peak is exactly at the longitudinal optical phonon of GaN.

  9. Mid-infrared electro-luminescence and absorption from AlGaN/GaN-based multi-quantum well inter-subband structures

    Energy Technology Data Exchange (ETDEWEB)

    Hofstetter, Daniel, E-mail: Daniel.Hofstetter@unine.ch [University of Neuchâtel, Institute of Physics, 51 Avenue de Bellevaux, Neuchâtel, CH–2009 (Switzerland); Bour, David P. [Avogy, Inc., 677 River Oaks Parkway, San Jose, California 95134 (United States); Kirste, Lutz [Fraunhofer Institute for Applied Solid State Physics (IAF), Tullastrasse 72, D-79108 Freiburg i. Brsg. (Germany)

    2014-06-16

    We present electro-modulated absorption and electro-luminescence measurements on chirped AlGaN/GaN-based multi-quantum well inter-subband structures grown by metal-organic vapour phase epitaxy. The absorption signal is a TM-polarized, 70 meV wide feature centred at 230 meV. At medium injection current, a 58 meV wide luminescence peak corresponding to an inter-subband transition at 1450 cm{sup −1} (180 meV) is observed. Under high injection current, we measured a 4 meV wide structure peaking at 92.5 meV in the luminescence spectrum. The energy location of this peak is exactly at the longitudinal optical phonon of GaN.

  10. Thermal resistanse and nonuniform distribution of electroluminescence and temperature in high-power AlGaInN light-emitting diodes

    Directory of Open Access Journals (Sweden)

    A.V. Aladov

    2015-06-01

    Full Text Available The paper studies current spreading, light emission, and heat transfer in high-power flip-chip light-emitting diodes (LEDs and their effect on the chip thermal resistance by experimental and theoretical approaches. The thermal resistance was measured using two methods: by monitoring the transient response of the LED operation voltage to the temperature variation with the Transient Tester T3Ster and by temperature mapping with the use of an infrared thermal-imaging microscope. The near field of the electroluminescence intensity was recorded with an optical microscope and a CCD camera. Three-dimensional numerical simulation of the current spreading and heat transfer in the LED chip was carried out using the SimuLED package in order to interpret the obtained experimental results.

  11. Patch antenna microcavity terahertz sources with enhanced emission

    Science.gov (United States)

    Madéo, J.; Todorov, Y.; Gilman, A.; Frucci, G.; Li, L. H.; Davies, A. G.; Linfield, E. H.; Sirtori, C.; Dani, K. M.

    2016-10-01

    We study the emission properties of an electroluminescent THz frequency quantum cascade structure embedded in an array of patch antenna double-metal microcavities. We show that high photon extraction efficiencies can be obtained by adjusting the active region thickness and array periodicity as well as high Purcell factors (up to 65), leading to an enhanced overall emitted power. Up to a 44-fold increase in power is experimentally observed in comparison with a reference device processed in conventional mesa geometry. Estimation of the Purcell factors using electromagnetic simulations and the theoretical extraction efficiency are in agreement with the observed power enhancement and show that, in these microcavities, the overall enhancement solely depends on the square of the total quality factor.

  12. High-performance alternating current field-induced chromatic-stable white polymer electroluminescent devices employing a down-conversion layer

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yingdong; Chen, Yonghua; Smith, Gregory M. [Center for Nanotechnology and Molecular Materials, Department of Physics, Wake Forest University, Winston-Salem, NC 27105 (United States); Sun, Hengda; Yang, Dezhi [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Nie, Wanyi; Li, Yuan; Huang, Wenxiao [Center for Nanotechnology and Molecular Materials, Department of Physics, Wake Forest University, Winston-Salem, NC 27105 (United States); Ma, Dongge [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Carroll, David L., E-mail: carroldl@wfu.edu [Center for Nanotechnology and Molecular Materials, Department of Physics, Wake Forest University, Winston-Salem, NC 27105 (United States)

    2015-05-15

    In this work, a high-performance alternating current (AC) filed-induced chromatic-stable white polymer electroluminescence (WFIPEL) device was fabricated by combining a fluorophor Poly(9,9-dioctylfluorene) (PFO)-based blue device with a yellow down-conversion layer (YAG:Ce). A maximum luminance of this down-conversion FIPEL device achieves 3230 cd m{sup −2}, which is 1.41 times higher than the device without the down-conversion layer. A maximum current efficiency and power efficiency of the down-conversion WFIPEL device reach 19.7 cd A{sup −1} at 3050 cd m{sup −2} and 5.37 lm W{sup −1} at 2310 cd m{sup −2} respectively. To the best of our knowledge, the power efficiency is one of the highest reports for the WFIPEL up to now. Moreover, Commison Internationale de L’Eclairage (CIE) coordinates of (0.28, 0.30) is obtained by adjusting the thickness of the down-conversion layer to 30 μm and it is kept stable over the entire AC-driven voltage range. We believe that this AC-driven, down-conversion, WFIPEL device may offer an easy way towards future flat and flexible lighting sources. - Highlights: • A high-performance AC filed-induced chromatic-stable white polymer electroluminescence (WFIPEL) device was fabricated. • A maximum luminance, current efficiency, and power efficiency achieves 3230 cd m{sup −2}, 19.7 cd A{sup −1}, and 5.37 lm W{sup −1}, respectively. • The power efficiency is one of the highest reports for the WFIPEL up to now. • The EL spectrum kept very stable over the entire AC-driven voltage range.

  13. The prostatic utricle cyst with huge calculus and hypospadias: A case report and a review of the literature.

    Science.gov (United States)

    Wang, Weigang; Wang, Yuantao; Zhu, Dechun; Yan, Pengfei; Dong, Biao; Zhou, Honglan

    2015-01-01

    Prostatic utricle cysts with calculus and hypospadias are rare. There are a few reported cases. We present a case of a prostatic utricle cyst with huge calculus in a 25-year-old male. He had a history of left cryptorchidism and surgery for penoscrotal hypospadias in his infancy. He was referred for frequent micturition, urgency of urination, urine pain, terminal hematuria, and dysuria. A computed tomography (CT) revealed a retrovesical cystic lesion of low density, showing a 5 × 5-cm calcification. Retrograde urethrocystography showed a 5 × 5-cm high-density shadow in the posterior urethra. The cyst was incised by transperineal approach and the stone was clearly observed and removed. Urethral stricture repair was performed simultaneously. The patient recovered smoothly after surgery.

  14. L-Tree Match: A New Data Extraction Model and Algorithm for Huge Text Stream with Noises

    Institute of Scientific and Technical Information of China (English)

    Xu-Bin Deng; Yang-Yong Zhu

    2005-01-01

    In this paper, a new method, named as L-tree match, is presented for extracting data from complex data sources. Firstly, based on data extraction logic presented in this work, a new data extraction model is constructed in which model components are structurally correlated via a generalized template. Secondly, a database-populating mechanism is built, along with some object-manipulating operations needed for flexible database design, to support data extraction from huge text stream. Thirdly, top-down and bottom-up strategies are combined to design a new extraction algorithm that can extract data from data sources with optional, unordered, nested, and/or noisy components. Lastly, this method is applied to extract accurate data from biological documents amounting to 100GB for the first online integrated biological data warehouse of China.

  15. Playing games with a thrombus: a dangerous match. Paradoxical embolism from a huge central venous cathether thrombus: a case report

    Directory of Open Access Journals (Sweden)

    Mariana Sylvie

    2010-03-01

    Full Text Available Abstract Thromboembolism is a major cause of death in cancer patients. The association between paraneoplastic hypercoagulability of oncological patients and long-term central venous catheters (CVC may result in CVC associated thrombosis. Patent Foramen Ovale (PFO, especially when associated with atrial septal aneurysm (ASA is a risk factor for paradoxical embolism. We report a case of paradoxical embolism with stroke in an oncological patient with a huge CVC thrombus playing "ping-pong" with an hypermobile ASA with a PFO. We review the management of hypercoagulability in oncologic patients and discuss the potential role of routine transthoracic echocardiography before the implantation of long term central venous catheters to identify predisposing conditions to paradoxical embolism and select patients for anticoagulant therapy.

  16. A New Distyrylarylene Derivative Used as Blue Light Emitter in Organic Electroluminescent Device%一种新型联苯乙烯衍生物--蓝色有机电致发光材料

    Institute of Scientific and Technical Information of China (English)

    郑新友; 朱文清; 吴有智; 张步新; 蒋雪茵; 张志林; 许少鸿

    2002-01-01

    A new blue electroluminescent material, distyrylarylene(DSA) derivative, 4,4'-bis[2,2-(1-naphthyl,phenyl)vinyl]-l,l'-biphenyl(NPVBi) is designed and synthesized. The DSA derivative shows better thermal stability because of its high glass transition temperature. A blue organic light emitting diode(OLED) with the structure ITO/TPD/NPVBi/Alq/LiF/A1 is studied. The electroluminescent(EL) spectrum of the OLED exhibits that light emission originates from NPVBi with a peak at 460 nm, its Commission Internationale de l' Eclairage(CIE) color coordinates are x = 0.16, y = 0.15, and showing independence of CIE color coordinates on current density. The new DSA derivative is expectable as a new candidate for blue light emitter in OLEDs.

  17. Huge Investment Needed

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China needs a massive investment to maintain its rampant economic boom-at least a 20 percent annual growth rate, according to Fan Gang, Deputy Director of the National Economic Research Institute and a member of the central bank's Monetary Policy Committee.

  18. Ultraviolet-Visible Electroluminescence of a p-ZnO:As/n-Si Device Formed by the GaAs Interlayer Doping Method

    Institute of Scientific and Technical Information of China (English)

    XIA Xiao-Chuan; DU Guo-Tong; WANG Hui; ZHAO Yang; WANG Jin; ZHAO Jian-Ze; SHI Zhi-Feng; LI Xiang-Ping; LIANG Hong-Wei; ZHANG Bao-Lin

    2011-01-01

    Arsenic doped p-type ZnO films were grown on n-type silicon substrates using the GaAs interlayer doping method.Under our growth conditions the main doping element is arsenic,which was confirmed by x-ray photoelectroscopy.X-ray diffraction measurements revealed that the p-ZnO:As film was still in the (002) preferred orientation.The Hall test showed that the hole concentration of the p-ZnO:As film was 2.6 × 1017 cm-3.The acceptor level was located at 135 meV above the valance band maximum,according to the low-temperature photoluminescence results.We then fabricated a p-ZnO:As/n-Si hetero junction light-emitting device.Its current-voltage curve showed the typical rectifying behavior of a p-n diode.At forward current injections,the electroluminescence peaks,which cover the ultraviolet-to-visible region,could be clearly detected.ZnO is a Ⅱ-Ⅵ compound semiconductor with a wide direct gap (3.37eV) and a high exciton binding energy (60meV).It has been studied as the candidate material for ultraviolet (UV) light emitting devices (LEDs).Many methods have been used to prepare ZnO films.[1,2] Among them,the metal organic chemical vapor deposition (MOCVD) method has its own excellent advantages in industrial applications.Today,the preparation of p-ZnO is still a challenge.%Arsenic doped p-type ZnO films were grown on n-type silicon substrates using the GaAs interlayer doping method. Under our growth conditions the main doping element is arsenic, which was confirmed by x-ray photoelectroscopy. X-ray diffraction measurements revealed that the p-ZnO:As Him was still in the (002) preferred orientation. The Hall test showed that the hole concentration of the p-ZnO:As film was 2.6 × 1017 cm-3. The acceptor level was located at 135 meV above the valance band maximum, according to the low-temperature photoluminescence results. We then fabricated a p-ZnO:As/n-Si heterojunction light-emitting device. Its current-voltage curve showed the typical rectifying behavior of a p-n diode

  19. Submucosal tunnelling endoscopic resection (STER) for the treatment of a case of huge esophageal tumor arising in the muscularis propria: a case report and review of literature.

    Science.gov (United States)

    Liu, Hui; Wei, Li-Li; Zhang, Yu-Zhen; Sha, Qi-Mei; Huang, Ya; Qin, Cheng-Yong; Xu, Hong-Wei

    2015-01-01

    Endoscopic Interventional Treatment is of little trauma and less complications in the treatment of esophageal tumor and leads to faster recovery and fewer days of hospitalization. This study was aimed to investigate the safety and efficacy of endoscopic interventional therapy for huge esophageal tumor arising in the muscularis propria. The patient was treated by submucosal tunneling endoscopic resection (STER). The huge esophageal tumor was resected completely by STER technique, with little trauma and less complications. The size of the resected tumor was 5.5×3.5×3.0 cm. Submucosal tunneling endoscopic resection is a safe and efficient technique for treating Huge Esophageal Tumor originating from muscularis propria layer.

  20. Hypercalcemia and huge splenomegaly presenting in an elderly patient with B-cell non-Hodgkin's lymphoma: a case report

    Directory of Open Access Journals (Sweden)

    Tirgari Farrokh

    2010-10-01

    Full Text Available Abstract Introduction Hypercalcemia is the major electrolyte abnormality in patients with malignant tumors. It can be due to localized osteolytic hypercalcemia or elaboration of humoral substances such as parathyroid hormone-related protein from tumoral cells. In hematological malignancies, a third mechanism of uncontrolled synthesis and secretion of 1-25(OH2D3 from tumoral cells or neighboring macrophages may contribute to the problem. However, hypercalcemia is quite unusual in patients with B-cell non-Hodgkin's lymphoma. Case presentation An 85-year-old Caucasian woman presented with low grade fever, anorexia, abdominal discomfort and fullness in her left abdomen for the last six months. She was mildly anemic and complained of fatigability. She had huge splenomegaly and was hypercalcemic. After correction of her hypercalcemia, she had a splenectomy. Microscopic evaluation revealed a malignant lymphoma. Her immunohistochemistry was positive for leukocyte common antigen, CD20 and parathyroid hormone-related peptide. Conclusion Immunopositivity for parathyroid hormone-related peptide clearly demonstrates that hypersecretion of a parathyroid hormone-like substance from the tumor had led to hypercalcemia in this case. High serum calcium is seen in only seven to eight percent of patients with B-cell non-Hodgkin's lymphoma, apparently due to different mechanisms. Evaluation of serum parathyroid hormone-related protein and 1-25(OH2D3 can be helpful in diagnosis and management. It should be noted that presentation with hypercalcemia has a serious impact on prognosis and survival.